K-Project Final Evaluation Core Document

K-Project

Final Evaluation Core Document

Part A: Project Content Total max. 50 pages

Full Title K-Project: GreenStorageGrid

Short Title K-Project: GSG

eCall ID: 2947528

FFG Project Number: 836636

Funding & Reporting Period: from: 01.06.2013 to: 31.05.2017

Date: 29.09.2017

Final Evaluation Report

K-Project >Short Title<

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Table of Contents Please update the table of contents after completing all parts of the form.

1 Executive Summary ........................................................................................ 1

2 Intention and Goal Achievement ................................................................... 2

2.1 Initial Vision, Mission and Goals of the K-Project ..................................................... 2

2.2 Development and Goal Achievement ....................................................................... 2

2.3 Contribution of the K-Project to the Programme Goals of COMET ........................... 2

2.4 Future Perspectives ................................................................................................. 3

3 Fulfilment of Requirements & Implementation of Recommendations ....... 3

3.1 Requirements & Recommendations of the ex-ante Evaluation ................................ 3

3.2 Requirements & Recommendations of the Mid-Term Review .................................. 8

4 Research Programme ................................................................................... 11

4.1 Overall Research Programme ............................................................................... 11

4.2 Areas ..................................................................................................................... 11

4.3 Work Plan and Time Schedule of the Research Programme ................................. 13

5 Research Results & Outputs ....................................................................... 14

5.1 Publications ........................................................................................................... 14

5.2 Patents & Licences ................................................................................................ 14

5.3 Research Results & Technical Achievements ........................................................ 15

5.4 Success Stories ..................................................................................................... 49

5.5 List of Deliverables of the K-Project ....................................................................... 50

6 Cooperation between Science & Industry .................................................. 52

6.1 Partner Structure ................................................................................................... 52

6.2 Industrial Involvement & Interaction (Company Partners) ...................................... 52

6.3 Scientific Involvement & Interaction (Scientific Partners)........................................ 52

7 Organisation & Management ....................................................................... 52



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7.1 Organigram & Management Structure ................................................................... 52

8 Achievement of Target Values ..................................................................... 54

8.1 Research Programme ............................................................................................ 54

8.2 Research Results .................................................................................................. 54

8.3 Added Value .......................................................................................................... 54

8.4 Human Resources ................................................................................................. 54

9 Annex ............................................................................................................. 54



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1 Executive Summary Overview of research topics, key figures (budget, partners and staff in FTE)

Research topics:

Hydraulic energy storage

Grids and overall optimization

Thermal and chemical storage

Key figures:

Budget: ≈2.500.000 €

Partners:

TU Wien, Institute for Energy Systems and Thermodynamics1

TU Wien, Institute for Energy Systems and electrical Drives2

TU Wien, Institute of Chemical Engineering3

ANDRITZ HYDRO GmbH

ENRAG GmbH

EVN AG

Zementwerk Hatschek GmbH

ZT Hirtenlehner

Österreichs E-Wirtschaft

Siemens VAI Metals Technologies GmbH

STRABAG Energy Technologies GmbH

VERBUND Hydro Power AG

Voith Hydro GmbH & CO. KG

Valmet GesmbH

TIWAG - Tiroler Wasserkraft AG

Vorarlberger Illwerke AG

Employees: ≈50, equivalent to ≈8 FTE

Further information: www.greenstoragegrid.at

1 Institut für Energietechnik und Thermodynamik

2 Institut für Energiesysteme und Elektrische Antriebe -

3 Institut für Verfahrenstechnik, Umwelttechnik und Techn. Biowissenschaften

http://www.greenstoragegrid.at/



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2 Intention and Goal Achievement

2.1 Initial Vision, Mission and Goals of the K-Project

Please outline briefly the initial vision, mission and goals of the K-Project (max. ½ page)

The holistic project approach of GSG - GreenStorageGrid faces the new challenges related

to the rising shares of renewable energy in the European energy systems. In detail the

project deals with grid and storage technologies.

The storage and distribution of energy is one of the dominant topics of international energy

research. The main objective of the project GSG is the combination of regional optimisation

of the energy storage, the power grid and the power plants themselves. It is absolutely

necessary to optimise the interaction between consumption and increasingly renewable

energy. Especially the thermal, chemical and hydraulic storages with a direct connection to

the grid-requirements are looked at more closely. The relevant technologies are analysed

and applied with several optimization strategies as well as progressive simulation methods.

The numerical simulation will be validated with field measurements in power plants.

2.2 Development and Goal Achievement

Including major changes compared to the K-Project application/ project plan and reasons for

adaptations

No remarkable changes did occur, regarding the overall project GSG or its specific Areas.

One company partner had to leave the project from internal reasons (change in the area of

business) and was substituted by another company regarding both monetary and scientific

issues. Apart from this change of partners, two additional companies could be included into

the consortium as associated members.

2.3 Contribution of the K-Project to the Programme Goals of COMET

COMET Goals: Strengthening the new culture of cooperation between science and industry

to achieve joint high-quality research; Aligning strategic interests between industry and

science, thus enabling joint research expertise, initiating new scientific and technological

developments and preparing implementation; Bundling of players by using thematic

synergies; Strengthening Austria as a research location

As already mentioned in the project application, an all-embracing access to storage

technology and its connection to the grid was one of the core elements of GSG-project. This

provided favourable conditions for the TU Wien’s intensive collaboration in the national

“storage Initiative” of the Climate and Energy Fund of the Austrian Federal Government

(“Speicherinitiative” - http://speicherinitiative.at ).

http://speicherinitiative.at/



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Additionally, the project made an important contribution to both inter-faculty cooperation as

well as cooperation between industry and science. It was one of the main tasks of the project

management to maintain the common “spirit” of GSG. In practical operation it became

evident that both the Scientific Advisory Board and the Strategy Advisory Board were able to

strengthen the necessary, steady interchange. Acting as an independent, international

steering committee, these boards also provided positive contribution for deepening the

cooperative character of the project.

2.4 Future Perspectives

What are the plans to continue the research programme/ network/ partnerships? Are there

any plans to sustain the project outcomes after the funding period?

Several efforts have been made to pursue the target of further cooperation projects.

Numerous funding applications have been made since the end of project GSG, which are

available in the funding agency.

It is also being examined deeply and steadily if cooperation with other universities and

industrial partners in the thematic framework of water protection, water technology as well as

hydro power under the framework of a COMET-Centre would be possible. In this context, the

energy market situation, especially the sector of hydraulic energy, represents a major

challenge unfortunately at present.

3 Fulfilment of Requirements & Implementation of Recommendations

3.1 Requirements & Recommendations of the ex-ante Evaluation

Please copy and paste the requirements & recommendations of the jury and explain in how

far these requirements/ recommendations were fulfilled/ implemented.

Requirements:

(1) “The Consortium must present a detailed work plan providing the context for the

proposed work, showing how this project is distinct from other current initiatives,

both within the Consortium and elsewhere.”



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Related Funded Research Projects:

Project

Title

Description in

key words

Funding

by

Cooperation

Partners involved in

the Project

Duration

from - to

distinction from GSG

SEES Sublake Elektrical

Energy Storage

FFG ENRAG GmbH,

STRABAG Energy

Technologies,

Vienna University

of Technology

2012-

2013

SEES focuses on the development and improvement of an isobaric

compressed air storage system. SEES pursues the strategy of

realizing this concept at the bottom of deep lakes. So the alignment

of SEES is fundamentally different from GSG. SEES has only a

cross-connection to the GSG-sub-project 3.1 SeLaTES: Storage of

the heat of air-compression could be an application for SeLaTES

(especially sand based active fluidisation thermal energy storage).

SYMBIOSE Cross-System optimum

hybrid energy storage

FFG ENRAG GmbH,

Vienna University

of Technology,

VKW

2012-

2014

The development of new potentials for distributed energy storages by

decentralized coupling of existing parallel infrastructures (electrical

power system, gas and thermal networks) is the basic idea of the

SYMBIOSE project. In GSG, we are aiming to achieve such coupling

on all system levels and the implications for an optimal grid structure.

ECOCEM Integration of a

gasification concept in

the cement production

process

FFG Vienna University

of Technology,

Hatschek

Zementwerke

2008-

2009

The ECOCEM project focussed on process simulation of different

cases of heat recovery from a cement plant. Seven cases have been

compared, one of this cases concerned the implementation of a

fluidized bed gasifier in combination to the cement kiln. ECOCEM-

project has no overlapping with the present comet proposal

Solid Heat

0

District heat by

thermochemical energy

storage in solids


of Technology,

Wien Energie

Fernwärme Wien

2012-

2013

Project Solid Heat is a 1-year exploration project with the target to

evaluate possibilities for thermochemical energy storage especially

at low temperature applications. The project concerns an overview

about materials, reactor design and modelling as well as economic

aspects. The exploration project has been done to generate a

profound basis for further research activities (development of

materials and reactor design) in the field of TCS. So Solid Heat 0 is a

basis for subproject SolidHeat of GSG without any overlaps.

GECO Green Energy

Conversion and

Storage

FFG Agrana Bioethanol,

EVN,

Technologies,

Vienna University

of Technology

2011 –

2012

GECO focuses on hydrogen (in contrast to GSG); conversion of

surplus electric power into to hydrogen (electrolysis) which is then

processed with CO2 to methane or ethanol.

Super-4-

Micro-Grid

100% renewable

energy supply in Austria

KLIEN VUT - ESEA

Zentralanstalt für

Meteorologie und

Geodynamik

VUT - Institut für

Ingenieurhydrologie

und

Wasserwirtschaft

TIWAG

VERBUND Hydro

Power AG

Illwerke-VKW AG

2009-

2011

In the Super 4 Micro-Grid project, requirements for grid and storage

capacities under the assumption of 100% renewable supply with

electrical energy were assessed. In GSG, among other project

contents, we also consider thermal storage capacities and take a

look into the coupling of hydraulic and electric components in the

system also under transient conditions.

Ecovar Development of a

variable speed

generating unit

consisting of turbine,

permanent magnet

generator, converter


of Technology

2010 –

2013

Contribution of grid stabilization is a common intention of GSG and

ECOVAR. On the other hand, the focus of EcoVar is different: The

project deals with the problem of covering a wide range of height of

fall, the development of a innovative control method for inverters etc..

DAMSE Europäische

Methodologie zur

Sicherheitsbewertung

von Dämmen

Verbund Hydro

Power

2006 –

2010

other topic



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Recycling von

Tunnelausbruchmaterial

Verbund Hydro

Power

2010 -

open

other issue

Relevant research assignments of other groups

Hydraulic Systems:

Planned R&D-initiatives regarding hydraulic systems are shown in the “Hydro Equipment

Technology Roadmap” published by the Hydro Equipment Association [Brussels, 2013,

report may be downloaded from: www.thehea.org]. A comparison between the priorities

outlined in this document (see figure below) and the planned R&D-issues in GSG clearly

show that the GSG’s consortium's access to the issues is on the one hand in accordance

with EU’s energy policy objective and on the other hand is GSG ahead of other initiatives: In

the “Technology Roadmap” the starting time of similar research projects is scheduled by

2015 and the projects will last up to 2020 or 2030 respectively while GSG will already start

on 1st of June 2013.

Grids:

As example, two ongoing European research projects are shortly described below. EcoGrid

EU (FP7): The key idea of EcoGrid EU is to introduce market-based mechanisms close to

the operation of the power system that will release balancing capacity, particularly from

flexible consumption. In total 2000 households on the Danish island Bornholm will by means

of more flexible consumption show how Europe can manage over 50 % wind power and

other fluctuating and less predictable renewable sources.

UMBRELLA (FP7): The UMBRELLA research and demonstration project is designed for

coping with growing share of electricity generation from intermittent renewable energy

sources as well as increasing market-based cross border flows and related physical flows.

The toolbox to be developed will enable TSOs to ensure secure grid operation also in future

http://www.thehea.org/



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electricity networks with high penetration of intermittent renewables. It enables TSOs to act in

a coordinated European target system where regional strategies converge to ensure the best

possible use of the European electricity infrastructure.

The GSG project differentiates itself from the current ongoing research as it, in the area of

grids, especially tackles transient phenomena and the resulting requirements and

implications for coupled hybrid energy networks.

Thermal systems:

IEA SHC Task 42: Thermochemical Storage: This is a joint task with the IEA Energy

Conservation through Energy Storage (ECES). Within this task especially the possibilities for

TCS in connection to solar systems are investigated.

DLR: Solid heat storage, Latent heat storage, Chemical heat storage, Hydrogen storage:

The research of the DLR focuses on a wide range of storage technologies. Some alignment

of the DLR research has the same aim as parts of the GSG-sub-project 3.1. The consortium

of GSG has made efforts to enter into cooperation, but DLR has contracts with companies

which do not permit further cooperation.

Institut für Energie- und Systemverfahrenstechnik, TU-Braunschweig; KBB Underground

Technologies GmbH, SIEMENS AG, E.ON: Isobaric Adiabatic Compressed Air Energy: The

project deals with the storage of compressed air in cavern under isobaric conditions. The

compressed air displaces the brine at the bottom of the caver through pipes to a brine shuttle

bond arranged outside of the cavern (country side brine lake). For storage of heat they use a

spiral formed multilayer solid material heat storage (sand) as well as a system consisting of 3

different storage materials (water, thermal oil and molten salt). The alignment of the project is

fundamentally different from GSG and has only a cross-connection to the GSG-sub-project

3.1; e.g. the latent heat of the molten salt will not be used in the project. The sand in the

spiral formed storage equipment is not fluidized.

(2) “The work plan should demonstrate that the institute heading the Consortium has

access to the resources necessary to undertake all projects with which it is involved.”

The institute leading the consortium has years of experience in handling of research projects

in various, different sizes.

The institutions responsible for the individual areas, including the IET, are equipped with

appropriate technical capacities such as laboratory equipment, scientific literature, powerful

computers, licenses, etc.. Additionally the Vienna University of Technology, as the Austria’s

largest scientific-technical research and educational institution, has a legal department, a

central event management, facilities and an accounting department. A target/actual

comparison was shown in the interim reports annually.

javascript:mainp('0')



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Requirements:

(1) “The Consortium should undertake a cost-benefit analysis of the expected results

to assess their suitability for commercialization.”

Due to the nature of the research project, at least for its parts of fundamental research, it is

not easy to give an estimation for cost-benefit relation at the moment. The fundamental

benefit of the research project can be derived from the expected results. A better adaptation

of the whole energy system on volatile, renewable energy supply is in the center of

considerations. A detailed quantification would currently contain a very large proportion of

guesswork, since individual, yet unforeseeable developments can have very far-reaching

effects in the complex energy system.

Regarding the fact that GSG will on one hand deal with hydraulic storage and appropriate

operation of hydraulic machines, one could, for the hydraulic area, give a possible scenario.

It is probable that situations in which the marginal cost of electrical energy production are

close to zero and also times when energy prices rise sharply will increase in the future. The

integral over the amount of the difference between a probable future price without GSGs

measures and the average electricity price represents the monetary potential of the project.

Similar considerations can be made for thermal systems. The problem of time-mismatch, the

problem of spatial- and exergy- difference between supply and demand of energy can be

seen in analogy here.

The considerations shown above should just give an impression of the planned basic line of

the planned cost-benefit-analysis of GSG, which will be developed parallel to the technical

parts of the project.

(2) “The proportion of strategic projects should be re-evaluated in line with the FFG’s

guidelines.”

As mentioned in the consortium’s original COMET-applications for GSG, especially sub-

project “2.2 StrukDRESS” was considered to “foster the synergies of the new technologies

developed in the other projects, in order to create a sustainable structure and strategies for

operation of a truly universal energy system, including increased storage facilities on all

levels.“ So this sub-project was conceived to be the core strategic part of the whole

GreenStorageGrid project. For this reason the table shown below contains a value of 100%

for strategic share for the case of StrukDRESS.

The remaining projects do also have a strong interconnection among each other. All of them

have a strategic share in line with the FFG’s guidelines as estimated below. The reason for

the specific values is given in the last column.

As a target value, the consortium has defined strategic projects’ cost-share of total costs of

one-third. As can be seen in “TablesOfApplication/3.ListOfProjects” the calculation shows an

weighted average of 32,56%.



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It is important to underline that none of the six projects are conceived as a single-firm project.

They exclusively have multi-firm and mainly interfaculty schemes. This can also be regarded

as the consortium’s attempt to establish an integrated project in line with the FFG’s

guidelines.

Project

single

firm

project

Strategic

share

[%]

reason for strategic share (in keywords)

1.1 - PSP-Grid-H

NO 30 transient behaviour of pumped storage in context

with increasing, volatile renewable energies;

relevant contribution to long-term-goals;

involvement of ANDRITZ and VOITH and use of

common simulation tool

1.2 - PSP-

LowLoad

NO 30 measurement of (very) low-load conditions is a

particular feature also on an international scale

2.1 - PSP-Grid-N

NO 40 special focus on coupling of electrical and

mechanical/hydraulic transients in pump turbines

contains scientific innovation

2.2 - StrukDRESS NO 100 as mentioned above

3.1 - SeLaTES

NO 30 storage is an important topic for a well-integrated

solution for the energy system’s challenges;

relatively far away from commercial application; 5

company partners

3.2 - SolidHeat NO 30 5 company partners

3.2 Requirements & Recommendations of the Mid-Term Review

Please copy and paste the requirements & recommendations of the mid-term review and

explain in how far these requirements/ recommendations were fulfilled/ implemented.

Requirements

(1) “The added value concerning the achieved benefits for the company partners was

not completed in the present written review report (chapter 9) and must be reported in

details in the final report.”

Assuming that the expansion of renewable, volatile energy will proceed, new control systems

will have to be found to ensure the stability of the European grid. The established power



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plant operators together with their suppliers will have to consider greater flexibility of their

existing production facilities. Hence, the energy balance in electric grids could be achieved in

the next years until new storage technologies can be applied in a reasonable economic way.

Regarding Area H, the additional value for the companies involved in GSG is based on

sophisticated measurements, accompanied by numerical simulations. Especially in the

operational region of very low load the occurring flow pattern and characteristic lead to a

higher damage of the hydraulic machine. Combining measurements with numerical

simulations gave a better understanding of the machine behaviour under these flexible

operation and subsequent a basis for new maintenance strategies. In terms of condition

monitoring the residual lifetime of hydraulic parts plays a vital role and the research project

focused to this point. The findings will contribute to the improvement of machine lifetime

analysis and diagnostics thus helping operators to better understand the fatigue of their

machines and a better utilization of the hydropower plants. In the future, cooperation

between operators and suppliers will focus more and more on flexible hydropower stations to

meet the grid demand and further instalment of renewable energy sources. On the one hand

the research results will help to build more comprehensive hydraulic machines and on the

other hand it will assist operators by running their machines in a better way. As operators,

suppliers and academia joined hands within this project and shared their knowledge, the

approved results are of common interest and have an added value for each partner.

The fact that TIWAG and Illwerke, two well-known operators of pumped storage plants,

joined the consortium is a clear indication that the project has a positive added value for

companies from the industry.

With regard to electric grid, various possibilities of energy supply, connection requirements,

decentralized electricity generation will be enhanced by the various findings of GSG.

The industrial partners in the thermal sector got a benefit in the field of latent and sensible

heat storage, as described in the success-stories and as shown in the report of the mid-term

review.

Together with company partners, scientific publications in journals and conferences have

been prepared and published. The most significant added value of GreenStorageGrid

resulted from the cooperation of companies working in totally different markets and

producing different products, associated with inter-faculty cooperation with and between

scientific partners.

Recommendations

(1) “Area 1 and 2: The variable speed pump-storage and generation with “full

conversion” allows fast dynamics at the electric power level, both for active and

reactive power. Additionally the use of some kinetic energy from the rotating

machinery could be investigated.“



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Currently, the subject of providing necessary inertia to the system is discussed within

ENTSO-E. Currently no market or products are defined for inertia in ENTSO-E Regional

Group Central Europe. However, the important role of synthetic and real inertia was identified

during execution of the project, and some joint publications within the project partners on this

matter have been placed.

Corresponding publications:

R. Schürhuber, A. Lechner, W. Gawlik: "Bereitstellung synthetischer Schwungmasse durch

Wasserkraftwerke"; E&I Elektrotechnik und Informationstechnik, 133 (2016), 8; S. 388 - 394.

W. Gawlik, A. Lechner, R. Schürhuber: "Inertia Certificates - Bedeutung und Wert von

Momentanreserve für den Verbundnetzbetrieb"; Vortrag: IEWT Internationale

Energiewirtschaftstagung TU Wien, Wien; 15.02.2017 - 17.02.2017; in: "Klimaziele 2050:

Chance für einen Paradigmenwechsel?", (2017), S. 1 - 8.

(2) “Additional activities in the direction of using the future hydro power facilities for

the stabilisation of the grid (also for short term phenomena) could enhance the global

output and visibility of the K-Project GSG.“

Findings on the potential of large scale hydro storage has been used for investigating the

interaction of long term and short term storage potentials, combining knowledge found in

GSG and previous projects.

Corresponding publications:

Ch. Groiss, W. Schaffer, W. Gawlik: "Interaction between short-term and seasonal storages

in a renewable power system"; Poster: Congrès International des Réseaux Electriques de

Distribution (CIRED), Glasgow, Scotland; 12.06.2017 - 15.06.2017; in: "CIRED 2017",

(2017), Paper-Nr. 0169, 1 S.

(3) “In the 1st and 2nd Area a potential for successful commercial utilization exists,

but efforts must be undertaken to develop new functionalities to be offered for the

users. Especially in the domain of thermal and thermochemical storage, the possible

fields of use as future energy systems, in houses, in mobility and in solar thermal

generation should be integrated in the project results and documents.“

Some findings, especially in context with latent storage, should and hopefully will be used for

the development of decentralised, thermal storage systems on household level – depending

on the willingness of funding agencies to provide projects to the scientific partners in the

future. On the other hand, downscaling of the SandTES-System would be unrealistic

because of complex construction principle. Its application only makes sense in an industrial

scale from the consortium’s point of view.



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(4) “Consideration of external initiatives should belong to the actual local project. The

aspect of the positioning of the actual programme in comparison to other current

initiatives especially elsewhere should be treated with more emphasis.”

This was ensured by steady exchange between industry and scientific partners in numerous

meetings, conferences etc.

(5) “Efforts within the consortium should be increased in order to reach the target

values of publications in reviewed journals and of patents.“

In fact, practical experience in the GSG-project showed that papers in reviewed journals do

not necessarily have higher scientific quality than papers in conference proceedings –

especially in the context of industry-oriented research, which was in the focus of GSG.

(6) “Other research fields, which could not be covered by the present K-Project GSG,

could become interesting topics for follow-up projects, such as battery storages,

flywheel storages, fuel cells, power-to-gas.”

Several project partners of GSG already work in these research areas in different projects.

Exchange between industry and science as well as exchange between scientific institutions

regarding the topic of battery storage is ongoing (see comment in chapter 2.3). These

research topics are also addressed in several project applications as mentioned in chapter

2.4.

4 Research Programme

4.1 Overall Research Programme

Main Challenges, development, achievement of milestones & goals, main adaptations/

changes compared to the application/ project plan.

Please refer to the work plan in Part A: 4.3 if applicable.

As already mentioned in chapter 2.2, no significant changes have occurred on the level of

the overall project.

4.2 Areas

Main challenges, development, achievement of milestones & goals, main adaptations/

changes compared to the application/ project plan.

Please refer to the work plan in Part A: 4.3 if applicable.

Project 1.1 PSP-Grid-H: The Projects 1.1 and 2.1 are closely related. The models are

successfully developed and have been connected to one overall system. All defined

mile stones were reached in time.



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Project 1.2 PSP-LowLoad: In this project the research focus are in the development

of a method to determine the stochastically appearing flow conondition and to predict

the mechanical impact on affected components. Additional to the numerical

investigation site measurements on a power plant of an industrial partner have been

done in purpose for the validation of the numerical simulation results. All the define

mile stones were reached in time.

Project 2.1 PSP-Grid-N: It was decided to add a model of synchronous machine with

full converter as a third option for including hydro power in the grid. All the defined

mile stones are reached in time.

Project 2.2 StrukDRESS: According to the initial planning, this project could be

finished in time.

Project 3.1 SeLaTES: Because of construction delays in the provision of laboratory

infrastructure (laboratory building) the installation, commissioning and measurement

campaigns on the latent and sensible heat storage (sandTES plant), as explained in

the Mid-Term Review. In total, the goals set at the application of the project were

reached as explained in chapter 0

Project 3.2 SolidHeat: Project start of partner VT was 3 month delayed due to

unavailability of free staff. Nevertheless, the milestones were reached in time due to a

synergy with the FFG-project SolidHeatBasic (FFG-project number: 315679) in the

search for thermochemical energy storage materials. Further details are explained in

chapter 0 and in the Mid-Term report.



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4.3 Work Plan and Time Schedule of the Research Programme

Work plan of planned (approved) & actual status of the research projects including milestones.

Please highlight the most significant milestones (M1, M2, etc.) and the period of finalisation (F) of the research projects.

Year 1 Year 2 Year 3 Year 4

Area 1 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4

Project 1.1 PSP-Grid-H (as approved) S M1 M2 M3 M4 M5 E, M6

Project 1.1 PSP-Grid-H (actual status) M2 M1 M3

Project 1.2 PSP-LowLoad (as approved) S M1 M2 M3 E, M4

Project 1.2 PSP-LowLoad (actual status) M1 M2

Area 2

Project 2.1 PSP-Grid-N (as approved) S M1 M2 M3 M4 M5 E, M6

Project 2.1 PSP-Grid-N (actual status) S M1 M2 M3

Project 2.2 StrukDRESS (as approved) S M1 M2 M3 E, M4

Project 2.2 StrukDRESS (actual status)

Area 3

Project 3.1 SeLaTES (as approved) S M1 M2 M3 M4 E, M5

Project 3.1 SeLaTES (actual status) M1 M2

Project 3.2 SolidHeat (as approved) S M3 M1 M4 E,

M2/M5

Project 3.2 SolidHeat (actual status) M3 M1 M4

Project 1.1 PSP-Grid-H (as approved) S M1 M2 M3 M4 M5 E, M6



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5 Research Results & Outputs

5.1 Publications

See Part B1: Tables “3. Publications” and “6. PhD & Master Theses”

Highlight 5-10 Key Publications

Rules and strategy concerning publications

In the first year, the consortium had a focus on making progress in content-related and

organisational issues. The aim was to get reliable results before publishing as it is common

in science. Therefore, the number of publication steadily increased hand in hand with the

timely progress of the project.

A compilation of key publications can be found on the GSG-Website:

www.greenstoragegrid.at > Inhalte > Publikationen

5.2 Patents & Licences

See Part B1: Table “2. Patents”

Rules and Strategy concerning Intellectual Property Rights (IPR)

Patents/ Licences (resulting from the K-Project) held by the consortium leader, by Company

Partners and by Scientific Partners

See Excel Sheet: 150918_CB_2240_review_k-project_PartB.xls, Table “2. Patents”

Rules and Strategies concerning Intellectual Property Rights have become contractual with

the help of the legal departments of both the university and the companies in the consortial

agreement. Patents /Licences are shown in the monitoring part.

http://www.greenstoragegrid.at/



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5.3 Research Results & Technical Achievements

Outcomes of the research projects

Project 1.1: PSP-Grid-H

In this sub-project different types of pumped-storage plants have been investigated and

compared against one another. The different pumped-storage plant schemes are:

Fixed speed PSP with pump-turbine (FSPT): This is the most common scheme, used

e.g. in Limberg 2 plant, Austria. A single hydraulic machine is used both for turbining

and pumping. The unit is connected to the power system via a synchronous motor-

generator.

Fixed speed ternary set PSP (FSTS): A scheme comprising two separate hydraulic

machines for pumping and turbining. The grid connection is the same as with the

FSPT scheme.

Variable speed doubly-fed motor-generator (VSDFG). A single hydraulic machine

operates either as a pump or turbine, speed variation is enabled by means of the

electric system, which consists of a doubly-fed asynchronous machine with a

converter in its rotor circuit. An example for this scheme is the PSP Goldisthal in

Germany.

Variable speed full size converter (VSFSC): The hydraulic machine is used as pump

as well as turbine and the synchronous motor-generator converting the mechanical to

electric energy is coupled to the grid via a full power frequency converter. In case of

one hydraulic machine this option offers the greatest possible flexibility in operation. It

is used in the PSP Grimsel 2 in Switzerland. Note that contrary to the configuration

investigated in this study at Grimsel 2 plant two separate hydraulic machines are in

operation.

Fixed speed ternary set PSP with continuous operating range (FSTS0): Same

scheme like the FSTS with the difference that both hydraulic units are able to operate

simultaneously in a so called hydraulic short circuit operation. This scheme allows for

regulating the power output from 100 % pump to 100 % turbine power e.g. in the PSP

Kops 2, Austria.

The three main points investigated are losses, the economic behaviour and the transient

performance. Each point is modelled separately in order to investigate one specific part of

the plant, but all three models can be connected to one overall model in order to investigate

the entire plant. The discussed structure is presented in figure 1 and all appearing blocks are

explained in the following sections.



- 16 -

Figure 1: FSPT scheme structure in turbine mode

Automaton: This block enables the automatically investigation of several cases. The three

inner blocks can be executed one after another, parameters can be changed automatically or

a list of cases to be examined can be processed automatically.

Transient Block: The investigation of the transient behaviour is realized in the simulation

software SIMSEN. In this software all transient behaviour effecting components can be

modelled. These systems include the hydraulic, the electrical, the mechanical and the

controlling part of the plant. The development of the electrical part has been carried out in

close collaboration with the PSP-Grid-N sub-project. The models are designed in such a way

that they just need a power reference signal and predefined values of speed and guide vane

opening regarding on specific power output and gross head value, respectively, in order to

allow for feed-forward controlling. The power reference signal and the related guide vane and

speed values, respectively, are determined in the BEL and Power Reference Signal Block

and are described further on in this report. The investigation of the compensation of a fault in

the power system is one studied example case. Figure 2 shows the most significant

parameters of the plants (net head (Hnet), speed (n), guide vane opening (y), efficiency (η),

mechanical power (PMe) and power output (PEL,TF)) while compensating faults in the power

system. Pictured are faults on the generation side (Outage) and on the consumption side

(Surplus) for the FSPT, VSDFG and VSFSC schemes. These faults are compensated by

changing the operating points of the pumped-storage plants taking into account their physical

limits.



- 17 -

Outage Surplus

Figure 2: Main parameters while switching from one operating point to another

The related frequency trends are presented in figure 3 for the FSPT, VSDFG and

VSFSC schemes in the Outage and Surplus case.

Figure 3: Frequency deviations caused by faults on the generation and consumption

side



- 18 -

BEL Block: In this block the highest possible efficiency values are determined depending on

power output, and gross head values. Additional, the operating ranges are predefined. For

all schemes a minimum hydraulic efficiency of 80% is predefined with the exception of the

FSTS0 scheme, which is allowed to operate continuously between maximum absolute pump

and maximum turbine power. The determination of the operating parameters within this block

predefines the guide vane opening (and speed) for the feed-forward control. The highest

possible efficiency according to one specific head (Hgross) and power output value,

respectively, is presented in figure 5.

Figure 5: Efficiency depending on power output and gross head

Power Reference Signal Block: In this block, the offered power on the day-ahead market

as well as the offered power on the balancing energy market is determined by an

optimization task. The optimization task takes into account the current gross head and the

efficiency depending on gross head and power output. Subsequently, the actual gross head

trend and the actual income can be determined by the actual retrieved balancing energy.

Figure 6 shows the head trend and the quarter-hourly discretised power output for the

investigated schemes.



- 19 -

Figure 6: Gross head value and operating points for the five investigated schemes

Work packages:

In this section the conduction of the work packages is explained.

1. Definition of requirements: The principal stated four-block model structure has

been developed, investigated types of plants have been chosen and the required

characteristics have been organized.

2. Setup of model components and required model expansions: Fixed speed and

variable speed schemes have been modelled in SIMSEN and GAMS as well as

binary and ternary set pumped-storage plants.

3. Integration into overall system model and validation: The principal stated four

blocks have been connected to one entire model and the models of the PSP-Grid-H

and PSP-Grid-N sub-project have been merged. Furthermore, for one binary and one

ternary set model validations have been executed by comparing the accuracy of the

models with the accuracy of real plants.

4. Simulation of defined cases: Detailed studies/comparisons of the different plants

have been executed on the economical side as well as on the technical side.



- 20 -

5. Optimization of controller parameters: For the controlling of the guide vane

opening a sophisticated feed-forward control has been applied while the generator

controlling is realized by a multi-variable controller.

Conclusion:

Concluding may be said, that within this project detailed models of common pumped-storage

plants have been developed. The economic model can be used to investigate if planned

plants are profitable or not. Furthermore, operators may verify their bidding strategy on day-

ahead and balancing energy markets. The transient models have shown the technical limits

of the flexibility of common pumped-storage plants and their impact on the power system

frequency. These models can in further be used by operators for parameter studies and

optimization of their control strategy. By combining all four blocks, a virtual power plant is

generated, which enables a parallel simulation to a real plant or the simulation of a planned

plant in order to check its feasibility.

References:

[1] L. Ruppert, K. Käfer, C. Bauer: "Steady Efficiency Optimization of several hydraulic

generating unit systems"; Vortrag: 18th International Seminar on Hydropower Plants,

Laxenburg; 26.11.2014 - 28.11.2014; in: "18. International Seminar on Hydropower

Plants - Innovations and Development Needs for Sustainable Growth of Hydropower",

(2014), ISBN: 978-3-9501937-9-4; S. 477 - 486.

[2] L. Ruppert, K. Käfer, C. Bauer: "Optimizing Steady Operating Points of Several

Generating unit Systems for Transient Applications"; Wasserwirtschaft, 105 (2015), 1;

S. 63 - 67.

[3] L. Ruppert, Ch. Maier, C. Bauer: "Service of Different Pumped-Storage Schemes for an

Electrical Grid with increased Renewable Energy Generation"; Vortrag: 19th

International Seminar on Hydropower Plants, Laxenburg; 09.11.2016 - 11.11.2016; in:

"19th International Seminar on Hydropower Plants - Flexible Operation of Hydropower

Plants in the Energy System", (2016), ISBN: 978-3-9504338-0-7; S. 707 - 717.

[4] L. Ruppert, R. Schürhuber, C. Bauer: "Technisch-wirtschaftliche Untersuchung

verschiedener Großspeicherlösungen";

Poster: 10. Internationale Energiewirtschaftstagung an der TU Wien, Wien; 15.02.2017

- 17.02.2017; in: "IEWT 2017", (2017), S. 444 - 445.

[5] L. Ruppert, R. Schürhuber, B. List, A. Lechner, C. Bauer: " An analysis of different

pumped storage schemes from a technological and economic perspective"; Energy;

under review



- 21 -

Project 1.2: PSP-LowLoad

Overview

In the context of the COMET K-Project GreenStorageGrid the modern challenges of the

pumped storage technology due to an increasing energy demand and high-stressed power

grids are determined in the sub-project PSP-LowLoad. To provide or use energy from power

grids as quick as possible Francis and pump turbines are operated more frequent and over

longer periods of time in lower part load. This leads to more turbulent operating conditions

and to higher requirements of the strength of stressed components (e.g. runner, guide or

stay vanes) due to unfavourable flow conditions.

The research focuses on the development of an approach to determine the mechanical

impact of different operating conditions on the fatigue of prototype Francis runners.

Therefore, numerical CFD and FEM simulations are performed on a medium and a high

head Francis turbine. The achieved results are compared with measured data from the

corresponding hydraulic machines to verify the accuracy of the applied models and methods.

The whole approach is displayed in Figure 1.

Numerical Investigations

To predict the lifetime of the medium and the high head Francis runner, numerical

investigations using CFD and FEM simulations are performed. The focus of the project is

related to the usage of open-source tools. Commercial software like ANSYS is used in

addition to validate the accuracy and applicability.

Figure 1: Approach for the lifetime analysis of Francis turbines.



- 22 -

The flow and the unsteady pressure field in the hydraulic machine are computed with

OpenFOAM. Therefore, the components of the turbine, like the spiral casing, the distributor,

the runner and the draft tube, are modelled and discretized (see Figure 2). A mesh

convergence study is performed to evaluate the discretization error. The CFD simulations are

done in the appropriate operating points according to the site measurements. The results are

compared with the operating parameters, to validate the simulations.

Figure 2: Model (left) and discretization (right) of the high head Francis turbine.

To evaluate the static displacements and stresses on the turbine, the unsteady pressure

distribution from the CFD simulations is averaged over several runner rotations and then

applied to the structure using Code_Aster. A cyclic sector model is therefore used for the

FEM simulations (see Figure 3 left). To assess the dynamic behaviour of the structure the

natural mode shapes and the appropriate eigenfrequencies of the Francis turbines are

determined by a modal analysis. This is important to evaluate eventually appearing

resonances. The effect of the added water masses around the Francis runner is further

evaluated (see Figure 3 middle). The interaction of the rotating runner blades with the static

guide vanes (rotor-stator-interaction - RSI) produces an oscillating pressure field, which

harmonically excites the structure at the certain RSI frequency. This is more significant for

high head Francis turbines due to the smaller gap between the runner and the stator. Hence,

the impact of the RSI on the structure of the high head runner is obtained using a harmonic

response analysis (HRA). Therefore, the unsteady pressure field obtained by the CFD

simulations is transformed from the time domain to the frequency domain using a Fourier

transformation. The dynamic stress amplitudes are then obtained at the RSI frequency to

assess the mechanical impact.



- 23 -

Figure 3: Cyclic sector model for the static FEM simulations (left); Model for the modal

analysis and HRA including the water volume (middle); Model for the transient FEM

simulations (right).

In part and low-load operation more stochastic flow phenomena are appearing in the

hydraulic machines (e.g. draft tube vortex ropes, interblade vortices) at uncertain or

broadband frequencies. Hence, a harmonic response analysis is not sufficient to determine

their influence on the fatigue of the runner. Therefore, transient FEM simulations are

performed using the full runner model (see Figure 3 right). The pressure distribution from the

CFD computations is applied to the runner surfaces at the according time steps of the FEM

analysis. The resulting stress signals are then used to assess the fatigue by the rainflow

counting algorithm together with the S-N curves of the turbine material.

Prototype Site Measurements

In March 2014 prototype site measurements at a high head Francis turbine have been

performed to evaluate the stresses on the runner during turbine operation. Therefore, eight

strain gauges have been attached to the suction side (SS) and pressure side (PS) of one

turbine blade (see Figure 4 left).



- 24 -

Figure 4: Position of the strain gauges on the runner blade (left) and resulting stresses

during operation (right) of the high head Francis turbine.

The measurements were performed in different operating points from the start-up in steps of

10 MW respectively 20 MW to the maximum output power of 180 MW and back again. The

results of the strain gauge measurements on the suction side are displayed in Figure 4

(right). To validate the measurements and the numerical computations, the water was

drained from the machine during the last operating point (Rotation), to evaluate the strains on

the runner due to the centrifugal forces without any hydraulic pressure force. Additionally, to

validate the CFD simulations, the operating parameters, such as head, output power, guide

vane opening, pressure in the spiral casing and draft tube, have been recorded during the

measurements.

The same procedure has been done by the associated project partner Vorarlberger Illwerke

AG on a medium head Francis turbine with a maximum output power of 20 MW. The results

of the measurements have been provided to the project partners for further numerical

investigations on the according machine.

Achieved Results

The comparison of the numerical investigations with the prototype site measurements

reveals an appropriate agreement of both Francis turbines. In Figure 5 (left) the static mean

stresses σm obtained from the strain gauge measurements (EXP) and the FEM simulations of

the high head runner are displayed. The results are normalized by the yield strength of the

runner material σy. The load spectra of the stress amplitudes σa obtained by the application

of the rainflow counting algorithm to the measured and computed stress signals of the high

head runner are displayed in Figure 5 (right). The results at the strain gauge SS4 shows a

good agreement between the site measurements and the numerical simulations. The load



- 25 -

spectra at the critical notches at the leading egde (LE) and trailing edge (TE) of the runner

obtained from the FEM computations are below the fatigue limit of the runner material.

Figure 5: Comparison of the measured and computed mean stresses σm (left) and

load spectra with the stress amplitude σa (right) of the high head Francis turbine.

For more detailed information about the applied methods and achieved results of the

numerical and experimental investigations in the course of the project PSP-LowLoad it is

referred to the related literature (see [1] - [12]).

Project Implementation

The implementation of the subproject PSP-LowLoad has been successfully fulfilled according

to the planned work packages. The overall output is more than initially expected, especially

due to the effective cooperation with the industrial partners. The project expansion by the two

associated partners Tiroler Wasserkraft AG and Vorarlberger Illwerke AG involved an added

value for the whole project.



- 26 -

References:

[1] E. Doujak and M. Eichhorn: An Approach to Evaluate the Lifetime of a High Head

Francis runner. In: 16th International Symposium on Transport Phenomena and

Dynamics of Rotating Machinery, 2016.

[2] M. Eichhorn, E. Doujak and L. Waldner: Investigation of the fluid-structure interaction of

a high head Francis turbine using OpenFOAM and Code_Aster. In: IOP Conf. Ser.:

Earth Environ. Sci. 49, 72005, 2016.

[3] E. Doujak and M. Eichhorn: Impact of volatile electricity generation to the partial load

behaviour of hydraulic machines. In: Proceedings of the HydroVision International

Conference 2016.

[4] M. Eichhorn and E. Doujak: Impact of Different Operating Conditions on the Dynamic

Excitation of a High Head Francis Turbine. In: Proceedings of the ASME 2016

International Mechanical Engineering Congress & Exposition, IMECE 2016.

[5] A. Maly, M. Eichhorn and C. Bauer: Experimental investigation of transient pressure

effects in the side chambers of a reversible pump turbine model. In: Proceedings of the

19th International Seminar on Hydropower Plants, 2016.

[6] J. Unterluggauer, M. Eichhorn and E. Doujak: Fatigue analysis of Francis turbines with

different specific speeds using site measurements. In: Proceedings of the 19th

International Seminar on Hydropower Plants, 2016.

[7] M. Eichhorn, L. Waldner and C. Bauer, C: Fatigue Analysis of a Medium Head Francis

Runner at Low-Load Operation Using Numerical Investigations. In: Proceedings of the

19th International Seminar on Hydropower Plants, 2016.

[8] M. Wachauer. Numerische Lebensdauerberechnung einer Francis Turbine im

Auslegungspunkt. Diploma Thesis, TU Wien, 2016.

[9] C. Fischer. CFD Berechnung der Muschelkurve einer Francis Turbine. Diploma Thesis,

TU Wien, 2016.

[10] J. Unterluggauer. Lebensdauerberechnung einer Francis Turbine aus Daten einer

Anlagenmessung. Diploma Thesis, TU Wien, 2016.

[11] M. Eichhorn, A. Taruffi and C. Bauer: Expected load spectra of prototype Francis

turbines in low-load operation using numerical simulations and site measurements. In:

Journal of Physics: Conference Series, 813/1, 012052, 2017.

[12] M. Eichhorn. Fatigue Analysis of Prototype Francis Turbines Using Numerical

Simulations and Site Measurements. PhD Thesis, TU Wien, 2017.



- 27 -

Projekt 2.1: PSP-Grid-N:

Motivation and Goals of Project PSP-Grid-N

The net generating capacity of wind and solar plants in the ENTSO-E area has been

continuously rising during the last decade [1]. The massive integration of renewable

generation causes an increase of of electrical power and grid frequency fluctuations [2]. The

frequency fluctuations are compensated by rotating masses of directly coupled rotating

machines such as generators, motors and synchronous condensers, while short-term power

fluctuations are compensated mainly by the utilization of energy storage systems and flexible

conventional power plants. Large-scale electrical energy storage has been accomplished

mainly by pumped-storage power plants (PSP), but during the last years more and more high

capacity battery storage systems come into operation in pilot projects (e.g. [3]). To adapt to a

more flexible operation scheme in terms of quick power supply, new technologies for PSPs

emerged during the last years, such as the hydraulic short circuit scheme and the variable

speed machines The two main technologies for variable-speed pump-turbines are the

variable speed doubly-fed generator (VSDFG) and the variable-speed full-size converter

(VSFSC) scheme. These technologies allow to participate in energy balancing markets in a

wide operating range, generating additional revenues for such pumped-storage projects [4].

However, capacities for pumped storages are limited and projects often are hindered not only

by economical, but also ecological considerations. So there will still be a need for flexible

thermal power plants that can operate efficiently and economically with high power gradients

in a wide operation range.

Hydroelectric power plants utilizing variable speed technology and their dynamic behavior

were studied in e.g. in [5, 6] recently. Investigations of thermal power plants and PSPs in a

single hydroelectric model was considered in [7–12].

To explore the behavior of different pumped storage power plant schemes in combination

with a combined cycle gas turbine plant (CCGT) also taking into account electrical and

hydraulic effects, , a new combined electrical and hydraulic model is introduced in this project

using the simulation tool SIMSEN [13].

Models and Network Configuration

The proposed model can be used for a variety of simulation scenarios e. g.

Load-frequency control, interaction of primary, secondary control and tertiary control

Storage management of water reservoirs

Market based dynamic simulations

Activation and changeover of operation modes of different pumped hydro schemes

(turbine mode, pump mode, synchronous condenser mode)

Figure 6 shows the SIMSEN model of the investigated network configuration consisting of a

grid, residual load, CCGT and PSP (VSDFG or VSFSC) model. The CCGT and the PSP are

connected to the grid by 100 km radial transmission lines. The residual load integrates the

power consumption as well as renewable generation such as photovoltaics and wind energy



- 28 -

generation.

Modelling of the electric system

The electrical grid and the power generation modules aremodelled in SIMSEN and consist of

a pumped storage plant, a combined cycle plant, a lumped residual load and a grid

connection. For the PSP different schemes can be applied (fixed speed, variable speed,

ternary set). It is also possible to investigate this configuration in islanding mode, with

frequency deviation strictly depending on the power imbalance between load and generation.

Another option is to investigate the control capabilities of the generators in a wide area grid

(like the Continental European Power System). In this case, the control mechanisms of all

connected generators and loads in the network have to be taken into account. These

generators as well as the loads are summarized as part of the residual load.

In the following scenario, the frequency response of the ENTSO-E Continental Europe grid is

calculated based on [14]. Its static frequency limits are defined by a 50.2 Hz upper and a

49.8 Hz lower boundary. Dynamically these limits can be exceeded for a short time, but

deviations must not be greater than 800 mHz.

Figure 7 shows the frequency curves in a simulated case of the complete European grid with

control mechanisms for a 150 GW network with , and . The time

constant TA is a measure of total connected inertia of the system and thus an indicator of the

systems dynamical response (the higher Ta, the more inert the system reacts). A sudden

power imbalance of 3000 MW is considered, .In addition, the so-called trumpet curves [14],

which define a range of acceptable boundaries for the system frequency, are depictured.

Note, that the secondary control will relief the primary control after 30 seconds and has to

restore the frequency within 900 seconds (15 minutes). We see the large impact of the

system inertia on the grid frequency: The less inertia present, the higher the frequency

deviations from the nominal values in case of power imbalances.

Figure 6: SIMSEN model of the investigated grid configuration



- 29 -

Modelling of the combined cycle gas turbine (CCGT) and selected results

Modern CCGT plants are characterized by high operational flexibility. In order to investigate

the dynamic behavior of a combined cycle power plant connected, the plant and the electrical

grid connection are modelled based on [15]. The implemented model represents a CCGT

with 266 MW electrical power output and consists of the thermomechanical subsystem based

on IEEE CCGT model [16] and the electrical subsystem connecting the plant to the power

grid. The gas turbine model includes the power frequency control, the gradient control, the

fuel control, the temperature control, the air control and the gas turbine model. The gradient

controller emulates the flexibility of power output of a modern combined cycle power plant.

Depending on the operation point, two power gradients are defined. Between 90 % and 100

% of the rated power output, the CCGT uses a gradient of 2 % per second to enable fast

response for primary control. For operation point changes between 50 % and 90 % of the

rated power, the gradient is limited to 0.2 % per second, with 50 % being the lower limit of

the steady-state operation range of the plant. A droop controller implements a 2 % droop for

primary control. Droop is the percentage change in speed required for 100% governor action

for primary control. The validation of the model based on typical parameters can be found in

Figure 7: Frequency responses to a sudden loss and surplus in generating capacity of

3000 MW (network size 150 GW) with trumpet curves for different TA

Figure 8: Frequency containment (left figure) and frequency restoration reserve (right

figure) control response of the CCGT to an outage after 10 seconds with TA = 10 s



- 30 -

[15]. Two cases for load-frequency control responses of the CCGT are displayed in Figure 8.

It can be seen that while the primary response reacts to the frequency changes rather

quickly, the secondary response time is limited by the power gradient limits, which are

inherently induced by the plant technology.

Modelling of pumped storage plants (PSP) and selected results

The simulation tool SIMSEN offers a variety of electrical machine models and hydraulic

components. To enable combined electrical and hydraulic investigations of the dynamic

behavior of PSPs some simplifications are necessary. Especially the investigation of variable

speed PSPs needs short simulation time steps in order to model the behavior of the power

electronic devices used in such plants. In order to avoid very long simulation durations with

large memory requirements, the model used in this projects implements variable speed

machines (doubly-fed induction generators and full-size converter scheme) as controlled

power sources. This kind of modelling yields sufficient accuracy for the cases under

consideration, especially since the hydraulically induced transients usually are in the range of

hundreds of milliseconds to seconds and so can be fully considered in the simulations. To

investigate the control capabilities of variable speed pumped storages, different turbine hill

charts as well as limits for machine speed and operation mode changeover times are used

for different PSP schemes.

Figure 10a: Frequency containment control (primary control) response of the VSDFG

with limited rise time of 30 s to an outage after 10 seconds with TA = 10 s in turbine

mode.

Figure 10b: Frequency containment control (primary control) response of the VSDFG

with limited rise time of 30 s to an outage after 10 seconds with TA = 10 s in pump

mode.



- 31 -

Different load-frequency control scenarios for the VSDFG and the VSFSC in pump and

turbine mode were investigated. The frequency containment control response considering

different active power gradients were calculated. A 30 s case study is displayed in Figure 10

(VSDFG, turbine mode), Figure 10 (VSDFG, pump mode), Figure 12 (VSFSC, turbine mode)

and Figure 12 (VSFSC, pump mode).

Compared to plants with a directly connected motor-generator, the fast response to the

power requests can clearly be seen. The figures show the limitation in the gradient of the

power output due to speed limit restrictions for the VSDFG, especially in turbine mode.

These restrictions are a consequence of technical limits of the power converter, which allow

only operation within a limited voltage, which transmits to a speed range in the VSDFG

connection [17]. As a result, the electrical power output of the VSDFG has to be limited to

avoid a violation of the lower speed limit of 0.9 pu. The VSFSC has a wider speed

operational range and therefore the capability to change power output in turbine mode faster

in a wide operation range.

Pooling of PSP, CCGT and Battery Storage

Finally, the combined operation of VSFSC and VSDFG with the CCGT and optionally a

large-scale battery was investigated. The goal was to show synergies between these plants

Figure 12: Frequency containment control response of the VSFSC with limited rise

time of 30 s to an outage after 10 seconds with TA = 10 s in turbine mode.

Figure 12b: Frequency containment control response of the VSFSC with limited rise

time of 30 s to an outage after 10 seconds with TA = 10 s in pump mode.



- 32 -

for load-frequency purposes to achieve a wider operational range for the VSFSC, VSDFG

and the CCGT. For different frequency containment control scenarios with varying network

sizes, the necessary battery storage was calculated as well to accomplish todays and future

load-frequency demands with these power plant types.

Conclusion

The developed model enables investigation of the dynamic behavior of electrical and

hydraulic components of (variable-speed) pumped storages in combination with a combined

cycle gas turbine in a single common simulation framework. Simulations covering time spans

up to several hours usually exceed the simulation horizons when small time steps are

needed for the simulation. However, with the developed model different generator types for

pumped storages can be investigated for the load-frequency control capabilities and their

performance over such long time frames. The project has been performed in close

cooperation with parallel project PSP-Grid H. The approaches and models have been

successfully used also in the parallel project to allow long term investigation of pumped

storage power plants while considering hydraulic constraints and machine dynamics.

References

[1] ENTSO-E, “ELECTRICITY IN EUROPE 2015: Synthetic overview of electric system

consumption, generation and exchanges in the ENTSO-E Area,” 2016.

[2] R. Yan, et al, “The combined effects of high penetration of wind and PV on power

system frequency response,” Applied Energy, vol. 145, pp. 320–330, 2015.

[3] D. Colin, et al, “The VENTEEA 2 MW / 1.3 MWh battery system: an industrial pilot to

demonstrate multi-service operation of storage in distribution grids,” The 23rd

International Conference and Exhibition on Electricity Distribution - CIRED 2015, 2015.

[4] FfE - Forschungstelle für Energiewirtschaft e.V, “Gutachten zur Rentabilität von

Pumpspeicherkraftwerken,” 2014.

[5] Y. Pannatier, et al, “Transient Behavior of Variable Speed Pump-Turbine Units,”

Proceedings of the 24th IAHR Symposium on Hydraulic Machinery and Systems, Foz

do Iguassu, Brazil, October 27 -31, 2008.

[6] Y. Pannatier, B. Kawkabani, C. Nicolet, A. Schwery, and J.J. Simond, Eds, Start-up

and synchronization of a variable speed pump-turbine unit in pumping mode. Electrical

Machines (ICEM), 2010 XIX International Conference on, 2010.

[7] C. Nicolet, et al, “Pumped Storage Units to Stabilize Mixed Islanded Power Network: a

Transient Analysis,” Proceedings of HYDRO 2008, 2008.

[8] C. Nicolet, et al, “Benefits of Variable Speed Pumped Storage Units in Mixed Islanded

Power Network during Transient Operation,” Proceedings of HYDRO 2009, Lyon,

France, October 26-28, 2009.



- 33 -

[9] C. Nicolet, B. Greiveldinger, J. J. Herou, P. Allenbach, J. J. Simond, and F. Avellan,

Eds, On the hydroelectric stability of an islanded power network. 2006 IEEE Power

Engineering Society General Meeting, 2006.

[10] C. Nicolet, et al, “Variable Speed and Ternary Units to Mitigate Wind and Solar

Intermittent Production,” Proceedings of Hydrovision Conference 2014, Nashville, TN,

USA, July 22-25, 2014.

[11] C. Nicolet, et al, “Contribution of Pumped Storage Units to Mixed Islanded Power

Network Stability,” Proceedings of HYDRO 2012 in Bilbao, Spain, October 29-31, 2012.

[12] A. Béguin, C. Nicolet, B. Kawkabani, and F. Avellan, Eds, Virtual power plant with

pumped storage power plant for renewable energy integration, 2014.

[13] C. Nicolet, et al, “A new tool for the simulation of dynamic behaviour of hydroelectric

power plants,” Proceedings of the 10th International Meeting of the work group on the

behaviour of hydraulic machinery under steady oscillatory conditions, IAHR, Norway,

June 26-28, 2001.

[14] ENTSO-E, P1 – Policy 1: Load-Frequency Control and Performance [C]. Available:

https://www.entsoe.eu/fileadmin/user_upload/_library/publications/ce/oh/Policy1_final.p

df (2016, Aug. 22).

[15] I. Grabovickic, “Modelling of a combined cycle power plant using SIMSEN,” Diploma

Theses, TU Wien, 2014.

[16] F. P. De Mello, et al, “Dynamic models for combined cycle plants in power system

studies,” IEEE Transactions on Power Systems (Institute of Electrical and Electronics

Engineers);(United States), vol. 9, no. 3, 1994.

[17] R. Schürhuber, et al, “Stationary behaviour of different variable speed pumped storage

concepts,” Vienna, 2015´4.



- 34 -

Projekt 2.2: StrukDRESS

WP1: Coordination with technology projects within GreenStorageGrid

To achieve this work package, between StrukDRESS and the other GSG projects data and

information were individual exchanged. This ensured the consideration of characteristics of

the new developed technology approaches in the other GSG projects. To complete the

exchange and verify the used data after the data collection process (WP2), a workshop was

held.

WP2: Collect capabilities and capacities of green storage technologies

Table 1 lists the most imported collected and researched characteristics of storage

technologies.

Table 1: Overview of the capabilities of storage technologies ([1], [3], [4], [5], [6], [7],

[8], [9]). The green technologies were researched in this project

WP3: Analyze and map with existing technologies

The following figures (Figure 13 to Figure 15) show storage technologies for the different

energy mediums electricity, heat and gas. Each storage technology uses up a certain area.

The height of this area is defined by the minimum and maximum power of the technology,

whilst the width is defined by the minimal response time (left boundary) and the discharge

time at rated power (right boundary). These points span a quadrangular area for the usage of

storage technology energy density power density energy Power loading time dynamic discharge time efficiency

Capacitor (EDLC) 0.1 - 10 Wh/kg 0.1 - 10 kW/kg < 10 kWh 1 kW - 1 MW 5 - 60 s 1 - 10 ms < 10 s 0.9 - 0.95

Coil (SMES) 1 Wh/kg 1 - 10 kW/kg 0.1 - 100 kWh < 10 MW < few min 1 - 10 ms 1 - 20 s 0.92

Fly wheel (FES) 5-90 Wh/kg 10 kWh/l 0.1 - 5 MWh 1 kW - 20 MW 1 - 15 min. ~ 10 ms 8 s - 15 min 0.83 - 0.93

Pump storage (PHES) 0.3 - 1.4 Wh/kg n.s. 10 MWh- 70 GWh 60 MW - 3 GW 10 min - 24 d 60 - 180 s 12 min - 24 d 0.7 - 0.82

Compressed air (CAES) 1.8 - 4.9 kWh/m³ 0.2 - 1 kW/m³ 10 - 2640 MWh 10 - 330 MW 8 h - 38 h 6 - 15 min 2 - 26 h 0.42 - 0.54

Lead-Acid Battery 25 - 40 Wh/kg 100 W/kg < 300 MWh < 50 MW 0,25 - 16 h 3 - 5 ms 0,25 - 16 h 0.74 - 0.89

Li-Ion Battery 110 - 190 Wh/kg 0.3 - 3 kW/kg < 120 MWh < 90 MW 2 - 4 h 3 - 5 ms < 80 min 0.9 - 0.97

Redox Flow Battery 15 - 50 Wh/kg n.s. 0.1 - 6 MWh 0,03 - 4 MW 20 min - 10 h < 5 ms 20 min - 10 h 0.7 - 0.8

Pore storage 9.4 - 11 kWh/m³ n.s. 0.13 - 188 TWh 0.18 - 108 GW 590 h - 9230 h 1 s 0.9 - 1.8 a ~1

Cavern storage 9.4 - 11 kWh/m³ n.s. 0.11 - 10 TWh 0.48 - 18 GW 20 h - 6520 h 1 s 0.8 - 62,5 d ~1

Gas cylinder 9.4 - 11 kWh/m³ n.s. 65 - 420 kWh 2.6 - 7.7 kW n.s. 1 s 25 - 55 h ~1

Pipe storage 9.4 - 11 kWh/m³ n.s. 6.1 TWh 950 MW 6.5 h 1 s 6.5 h ~1

solid matter storage LT < 500°C 0.6 - 0.75 kWh/m² n.s. 37.5 - 937.5 kWh 10 - 250 kW n.s. ~ 5 min 3,75 h n.s.

solid matter storage HT > 500°C n.s. n.s. 0.1 - 200 GWh 0.05 - 100 MW n.s. 10 - 60 min 83 d 0.7 - 0.8

deep geothermic 15 - 50 kWh/m³ n.s. 7.5 - 300 GWh 10 - 400 kW n.s. ~ 10 min 85 a > 0.6

small water storage n.s. 0.14 - 1.4 kW/kg 3,5 - 17,5 MWh 5 - 25 kW n.s. 0,5 - 1 min 29 d 0.75 - 0.85

large water storage < 2GWh 40 - 60 kWh/m³ n.s. 2 - 20 GWh 1 - 10 MW n.s. ~ 5 min 83 d n.s.

large water storage < 200GWh 40 - 60 kWh/m³ n.s. 200 - 1000 GWh 100 - 500 MW n.s. ~ 5 min 83 d > 0.95

PCM, anorg. salt hydrates n.s. n.s. 1,5 - 42 MWh 0.1 - 2.8 MW n.s. ~ 30 min 15 h 0.9 - 1

PCM, org. MT/HT 80 kWh/m³ n.s. 2 - 20 kWh 1 - 10 kW n.s. ~ 10 min 2 h > 0.99

PCM H2O (ice) n.s. 80 - 100 kW/kg 2 - 150 MWh 1 - 75 MW n.s. ~ 30 min 2 h 0.7 - 0.8

adsorption storage n.s. n.s. 2 - 40 MWh 1 - 20 kW n.s. 10 - 15 min 83 d 0.35 - 0.8

thermochem. storage n.s. 20 - 40 kW/kg < 2.5 TWh 0.0001 - 5 MW n.s. 5 - 60 min 57 a 0.35 - 0.8

mobile storage n.s. 10 - 25 kW/kg 1 - 1000 MWh 0.1 - 100 kW n.s. ~ 5 min 1.14 a 0.7 - 0.8

storage supported power plant n.s. n.s. 2 - 2000 GWh 0,05 - 50 MW n.s. ~ 10 min 4.5 a 0.6 - 0.8

sensible water storage n.s. n.s. 0.1 - 4 TWh 10 - 400 MW n.s. ~ 5 min 1.14 a 0.7 - 0.8

electric

gas

therm

al



- 35 -

that storage technology. Some of the technologies have different response times for different

power levels, which results in non-square shapes of the spanned areas. If no general

assumption is possible, the areas are assumed to be square. The used data for the storage

technologies are taken from already installed units, from predictions in studies and from other

GSG projects. Both axes of the plots are scaled logarithmically due to the wide range of time

and power of the technologies.

Figure 13 shows storage technologies for the electrical grid. Non-electrical energy mediums

are also included (e.g. compressed air), as long as they are solely used for storing electrical

energy. Heat storages for example do not fall in this category, because they can also be

used in a heat grid and therefore will be mentioned separately. The figure shows the

existence of many fast electrical storages for short time periods, which can be used for grid

stabilization, like flywheel energy storage (FES), superconducting magnetic energy storage,

storage with electric double layer capacitors (EDLC) or several electrochemical battery

storages. Those technologies are faster than the lower boundary of the time axis of 20ms.

However, 20ms is the period of the fundamental 50 Hz wave of the electrical power grid and

therefore it is not necessary to observe smaller time ranges. For long term storage like day

and seasonal storage compressed air energy storage (CAES) or pump hydro electrical

storages (PHES) can be used. The colours of the technologies specify the kind of storage:

green for mechanical storage, blue for electrical storage and pink for electrochemical

storage.

Figure 13: map of electrical storage technologies. The colour mapping specifies:

green for mechanical storage, blue for electrical storage and pink for electrochemical

storage



- 36 -

The heat storage technologies are taken from results of Area T of this project and existing

installed units. They are mapped in Figure 14. The majority of the heat storages have a

response time between one and ten minutes, whilst the discharge time at rated power

spreads beyond a year. For better comparison with the storage technologies of the other

energy mediums, only one year is pictured in the figure. All technologies with a higher

discharge time have an open border on the right side (no bold border line). The best use for

heat storages is, as expected, for long-term storage or day storage. The colour of the storage

technologies shows the Carnot efficiency of that technology.

Figure 14: map of heat storage technologies. The colour mapping shows the Carnot

efficiency

Several technologies for storing gas are shown in Figure 15. Gas can be stored in natural

underground pore storages with huge capacities. These technologies provide long discharge

times for long-term storage. Generally, Gas storages are scalable and can be produced for

many sizes. In Figure 15 only existing storages are mapped. The response time of gas

storages are generally short because of the gas is immediately usable after opening the

valve. If gas storages should be used to feed in to other energy grids, a coupling technology

has between the energy mediums has to be used that may reduce the response time (e.g.

gas turbine from the gas to the electrical grid).



- 37 -

Figure 15: map of gas storage technologies

WP4: Adapt structures and operation of future grids

Figure 17 shows the mapping of conversion and storage technologies. The storage

technologies as shown in Figure 13 to Figure 15 are mapped in layers based on their energy

medium and coloured as follows: yellow for thermal storage, blue for electrical storage and

black for gas storage. The conversion technologies are mapped in each linked medium and a

coloured accordingly: green for conversion technologies between power and gas, pink for

power and heat and brown for gas and heat.

Figure 17 shows a detailed map of storage and conversion technologies of the electrical grid

along with the electrical network levels. If the same conversion technology is considered in

different energy systems the difference between the power values is caused by the

efficiency, e.g., the electrolysis process has an electric power range of 0.4 MW to 6 MW and

in the gas system the power is 0.24 MW to 3.6 MW. No conversion technologies have right

boundaries, since they usually have a lifespan of several years to several decades.

If gas power plants are stopped, their start process is usually not fast enough to fulfil fast

control mechanism like primary control since the start up time is too long. To be able to take

place in the primary control mechanism at least 1 MW of control power has to be provided

[1]. As shown in Figure 17, with a combination of battery storages and gas power plants fast

power responses would be possible. With a maximum discharge time at rated power up to

several hours and a cold start-up time of the power to gas power plant of 3h - 4h [2] even a

cold start-up would be possible. Apart from the requirement for provision of enough short-

circuit current; gas power plants could be stopped if not needed and started-up, if the power



- 38 -

demand rises. Right now, some of the gas power plants operate in idle state to be fast

enough for the control required, which causes unnecessary greenhouse gas emissions.

The electrolysis and fuel cell is counted as one single system, since for some electrolysis/fuel

cell types the technological approach is related and therefore the limits (power and response

time) are similar. Fuel cells have comparable response times as gas power plants.

Therefore, the combination of battery storages and fuel cells could be alternatives to the

battery/gas power plants combination.

In an energy system dominated by renewable production, seasonal energy shifts due to

production fluctuations are necessary. This results in shifting huge amounts of energy and

therefor in rather few full load cycles. In the electric system, so far, from cost perspectives

only compressed air energy storages (CAES) and pumped hydro storages (PHES) are

suitable to fulfil these requirements. The gas and thermal storage system are capable in

storing big amounts of energy for long times. For future electric grid operation with dominated

renewable energy production, bidirectional couplings between the electric and gas or the

electric and thermal system are necessary. It can be concluded, that storage systems

located directly in the electric system (battery, capacitor, coil) are ideal for fast system

requirements from sub seconds to several hours or up to several days. Those technologies

are perfect for control and stabilization of the grid. For long time shifts, it is better to use other

energy systems, ideally the gas system and convert the gas back to electricity when needed.

The heat system can also be used for long time shifts, but the energy cannot be transformed

back to electrical energy. However, there are heat storage technologies for every time frame,

which means, that renewable overproduction in summer can be used to generate and store

heat for higher heat demand in winter.

Figure 16: map of all storage and conversion technologies. The colour specifies:

yellow: heat storage technologies; blue: electric storage technologies; black: gas

storage technologies; green: conversion of gas and electricity; pink: conversion of

electricity and heat; brown: conversion of gas and heat



- 39 -

Figure 17: map of electrical storage and conversion technologies

References:

[1] S. Erben, “Wirtschaftlicher, energetischer und ökologischer Vergleich von Technologien

zur Speicherung elektrischer Energie.,” 2008.

[2] O. Freund, B. Ernst and J. Seume, “Anforderungen an konventionelle Kraftwerke für die

Transformation des Energiesystems,” Leibnitz Universität Hannover, Hannover, 2012.

[3] G. Fuchs, B. Lunz, M. Leuthold and D. U. Sauer, “Technologischer Überblick zur

Speicherung von Elektrizität,” 2012.

[4] ETG Task Force Energiespeicher, “Energiespeicher in Stromversorgungssystemen mit

hohem Anteil erneuerbarer Energieträger,” 2009.

[5] Mitsubishi Electric, “Mitsubishi Electric beliefert das Umspannwerk von Kyushu Electric

Power in Buzen mit Energiespeichersystem mit hoher Kapazität,” 03 03 2016. [Online].

Available: http://emea.mitsubishielectric.com/de/news-events/releases/2016/0303-

b/index.page. [Accessed 27 04 2017].

[6] D. Oertel, “Energiespeicher - Stand und Perspektiven,” 2008.

[7] STEAG, “STEAG Großbatterie Systeme,” [Online]. Available: http://www.steag-



- 40 -

grossbatterie-system.com/. [Accessed 27 04 2017].

[8] D. U. Sauer, “Optionen zur Speicherung elektrischer Energie in

Energieversorgungssystemen”.

[9] M. Sterner and I. Stadler, “Energiespeicher - Bedarf, Technologie, Integration,” Springer

Verlag, 2014.

[10] Austrian Power Grid, “Ausschreibungsdetails Der Austrian Power Grid AG Für die

Beschaffung der benötigten Primärregelreserve in Österreich,” APG, Vienna, 2015.



- 41 -

Projekt 3.1: SeLaTES

The subproject SeLaTES covered a large range of activities going from fundamental

research to numerical analysis, test rig design, erection and operation as well as techno-

economic analysis. The subproject suffered from construction delays in laboratory

infrastructure (new buildings), which are not within the sphere of influence by the beneficiary.

Nevertheless the project team succeeded to erect and operate during the project all planned

test rigs - the semi industrial laboratory SandTES test rig (see Figure 18), the fluidized

regenerator test rig, the fixed bed test rig (see Figure 19) and the test rig for the phase

change material (LaTES) (see Figure 20). Furthermore the conception of the measurement

and control system for the different pilot plants was also designed and implemented. The

control system includes also the control and regulation of a thermal oil plant which is used as

heat source and -sink for all storage test rigs. All test rigs can be operated in parallel from a

control room.

Figure 18: SandTES test rig with boiler

house which contains the thermal oil

plant and the phase change material

test rigs

Figure 19: 15 kWth fixed

bed-regenerator

Figure 20:

Single tube test

rig for PCM

SandTES

The SandTES sub-subproject deals with the core technology of SeLaTES; a novel sensible

thermal energy storage system (SandTES, see Figure 18) based on a combination of

fluidized bed technology and counter current heat exchanger characteristic. The project work

encompassed both research and engineering work and had one essential objective in the

successful commissioning of the semi industrial laboratory test rig. Different measurement

campaigns were carried out with the test rig under cold conditions. During these

investigations e.g. the back pressure at different heat exchanger height and mass fluxes (see

Figure 22) was analysed. The number of active wind boxes was varied in order to find

operational limits. Further experimental investigations had the objective of testing the

dynamic behaviour of the sandTES storage device. In these investigations e.g. the start-up

and shut-down behaviour, the reversing time of the storage material in the heat exchanger

(see Figure 21), the influence of the fluidization grade on the sand mass flux, the required



- 42 -

degree on uniformity of the fluidization air distribution over the heat exchanger (HEX) length

and of the fluidization air distribution on the system stability has been analysed.

Beside these investigations also basic analysis was done to get a better understanding of the

viscosity of the storage material inside the fluidized bed heat exchanger as well as the

bubbling behaviour in the fluidized bed.

Figure 21: Measurement of the reversing

time of the storage material in the

SandTES heat exchanger

Figure 22 Back pressure through the

SandTES heat exchanger

Parallel to the experimental work a design program for the sandTES technology, which has

been written in the software package Matlab, was been developed. With the help of this in-

house design software it is possible to perform design calculations for SandTES heat

exchangers (sandTES HEX). The software allows in a first step a rough design of the HEX

followed by an accurate analysis which includes the calculation of all governing effects. The

software provides sketches of the sandTES HEX-design and all major components and

generates automated process flow sheets.

In addition to the development work for the design program also 3-dimensional numerical

investigations were performed for the sandTES HEX. These 3-dimensional numerical

simulations were realized with the software Barracuda which allows the simulation of

multiphase particle-gas flows based on the multiphase Particle-in-Cell (MP-PIC) method.

This method allows a description of the particle phase based on a particle probability

function. With these computations detailed issues for the test rig design of the sandTES HEX

e.g. the mixing behaviour of the storage material or the air mass flow density distribution of

the suspension within the sandTES HEX could be clarified.

LaTES

Within the sub-subproject LaTES, experimental and numerical investigations on the melting

and solidification behaviour of phase change materials (PCM) were performed. As PCM

sodium nitrate was used. Three dimensional numerical investigations on a first fin design



- 43 -

(see Figure 23) as well as on basic geometries of finned tube designs for enhancing the heat

transport from the heat transfer fluid (HTF) to the PCM have been conducted (see Figure

24). Based on this fundamental work a second tube geometry was selected for further

investigations. All numerical work was successfully completed within the project period.

For the numerical simulation the enthalpy porosity model implemented in ANSYS Fluent was

used. Within this model the mushy zone constant is an important factor. This factor depends

on the PCM and must be specified by the user. This mushy zone constant is available

however only for a minor number of materials – especially for materials with low phase

change temperature. Therefore experimental investigations were performed to get this factor

for sodium nitrate. These experimental analyses are finished within the project.

Figure 23: Contours of the

temperature in pipe, fin and solid

PCM 330s after simulation start

(expansion considered)

Figure 24: Sketch of some of the investigated

finned tubes and corresponding chronological

sequence of the averaged charged power per

volume

As a consequence of the fire in the laboratory and the additional construction delays at the

new laboratory location, which are not within the sphere of influence by the beneficiary, the

planned experiments with our latent heat storage test rigs (single pipe and multiple pipe TES)

are only partly finished. For the first fin design the experiments are finished (for example see

Figure 26). For the second fin design the storage unit is under construction and the

experimental investigation will be done in june/july 2017.



- 44 -

Stainless

steel

Steel

Aluminium

Cooper

Figure 25: Different analysed materials after

corrosion test and mass change of the single

probe during corrosion test

Figure 26: Temperature evolution

during charging and discharging

by using the first fin design.

Based on the low thermal conductivity of the PCM and the high operation conditions of the

heat transfer fluid (HTF, e.g. water or water vapour in industrial or power cycles), the heat

exchanger tube should be designed as a bimetallic tube. The fins are made of a material with

high thermal conductivity like e.g. aluminium or copper and the material of the tube has to be

steel due to creep strength requirements). It is well known that sodium nitrate in contact with

other materials can lead to corrosion. Corrosion tests with selected materials have been

undertaken (see Figure 25) and successfully completed.

Flexibility of industry and power plant processes

In addition to the development work the suitability of the different storage devices for

enhancing the flexibility of industry and power plant processes (e.g. batch operation) was

analyzed (as example see Figure 27). Different storage integration scenarios were calculated

and compared. The work on increasing of the process flexibility includes also a techno-

economic estimation of the additional costs for the storage integration.



- 45 -

Figure 27: Flow chart of a power cycle with integrated sandTES technology to increase

the plant flexibility.

One result of this work was the receiving of a patent for a novel power plant set-up with an

integrated thermal energy storage device.

The tecno-economic analysis is scheduled to be finished by june/july 2017.

Analysis of other storage technologies

Beside the development of the two core technologies sandTES and LaTES within the GSG-

project other storage technologies were also analysed theoretically and experimentally.

During the project the scientific literature in the area of storage technology was continuously

screened. For the storage technologies fixed bed regenerator and fluidized bed regenerator

experimental and numerical investigations have been done. Laboratory test rigs for both

technologies were erected and extensive experimental work has been undertaken to

understand e.g. the transient charging and discharging behaviour of the regenerators under

different operation conditions (for example see Figure 28 and Figure 29).

Figure 28: Comparison of the temperature

distribution between measurement and

simulation during discharging process

within the fixed bed regenerator

Figure 29: Heat flux between storage

medium and heat exchanger tube in the

fluidized bed regenerator



- 46 -

One and three dimensional simulations for the charging and discharging process have been

done for the fixed bed regenerator. For the one dimensional simulation of the fixed bed

regenerator a numerical model was developed while for the three dimensional model the

software package ANSYS Fluent was used. The one dimensional model was written with the

help of the programming language C and therefore it can be implemented in different other

software packages as subroutine. The numerical and the experimental results are compared

- an example for the results of the three dimensional simulations can be seen in Figure 28.

For the fluidised bed regenerator also a numerical model for quasi-stationary processes

which works by cell method has been written. This model is implemented in the software

package Ebsilon as a separate subroutine and therefore it is available for all process

calculations done with Ebsilon.



- 47 -

Projekt 3.2: SolidHeat

Subproject SolidHeat has been defined as a basic oriented research project. The project

itself initiated the extension of research work to three succeeding projects: SolidHeatBasic,

Tes4Set and SolidHeatKinetics, where cooperation with other disciplines of science

(chemists and external partners) could be initiated. Valuable results returned back to GSG-

SolidHeat e. g. from SolidHeatBasics where a systematic search algorithm for TCS-Materials

helped to select and evaluate materials.

With the goal of finding suitable storage materials in work package 1 it was necessary to find

possible storage systems and then test them for their applicability first of all. To find possible

storage system, a wide systematic computer driven database search was performed in

cooperation with the FFG project “Solid Heat Basic”.

This synergy led to a search algorithm which found possible storage systems based a

thermodynamical database (HSC Chemistry 7). It paired the solid materials within the

database with various technical gases (H2O, CO2, O2, SO2). This method resulted in over

2000 possible reactions which were evaluated based on their energy content (>1MJ/kg),

useable temperature range (100-300°C), toxicicy and price (<10US$/kg).

The reactions were screened using an STA (simultaneous thermal analysis) to check their

reversibility. To test the most promising candidates under operating conditions a test rig

similar to an STA at a 100g scale was build, which is capable to online measure both, weight

and temperature signals (Figure 12). Additionally a test rig to test the substances with up to

10 bar pressure of the reactive gas was designed.

The most promising reactions are



- 48 -

reaction energy

content

usable

temperature range price

2166 kJ/kg

RT-75°C

100-160 °C

250-315 °C

100 US$/t

963,4 kJ/kg 145 – 200°C 100 US$/kg

2300 kJ/kg 110 – 225°C 500 US$/t

2015 kJ/kg 320 – 400°C 100 US$/t

The reaction kinetics of the reaction of Mg(OH)2 is already described in the literature but or

the other three reactions only insufficient information is found. To identify the reaction

kinetics for the reactions the so called NPK method has been chosen and implemented.

Figure 13 shows the result of a simulation with the identified reaction kinetic of the last

dehydration step of FeSO4*H2O for different heating rates.

Additionally to the search for new storage materials, a special reactor designs capable of

handling gas/solid reactions is needed to implement such system on a large scale. Therefor

a cold model of a screw reactor was build to test the transport of cohesive bulk materials at

different tilts of the screw (0°, 30°, 60° ,90°). (Fehler! Verweisquelle konnte nicht

gefunden werden.Fehler! Verweisquelle konnte nicht gefunden werden.)

Furthermore the inflow of the reactive gas and the mixing of the bulk materal was

investigated. To do so, a numerical calculation, utilizing the software environment

“Baraccuda” (CPFD) was performed (Figure 33). This showed the importance of how the

Figure 31b: screw reactor in

45° position

Figure 31a: Simulation of the

dehydration of FeSO4*H2O with different

heating rates



- 49 -

reactive gas is introduced into the reaction zone in the reactor. The calculated nozzle

positions were implemented in small cold model to experimentally validate the simulation

(Figure 16). It showed similar tendencies but some deviations, which must be considered

when building a reactor.

Parallel to the work mentioned above a process integration study for 3 industrial sectors and

an economic analysis have been performed.

The three industrial sectors are a steel plant, a power plant and a cement production site. All

sectors where analysed for the potential applicability of thermochemical energy storage.

Therefore contact points for a thermochemical energy storage system where identified. It has

been found that it is possible to utilize thermochemical energy storage to enhance the

flexibility of the process (power plant), and to use thermal energy more efficiently (e.g. to

connect a cement production site to distant heating grid).

The economic analysis showed the dependencies of various parameters (e.g. energy

density, cycle stability, transport distance) to the expected energy price for energy stored

thermochemically. It can be concluded that the cycle stability of the storage materials have

the highest impact on the energy price and the energy density of the material is less

important than expected.

5.4 Success Stories

List app. 5 Success Stories including Topic and Area (max. ½ page per Success Story)

See Annexes.

Figure 32: experimental investigation of

the mixing

Figure 33: Baraccuda simulation of

the mixing



- 50 -

5.5 List of Deliverables of the K-Project

Deliverable Name Project Number - Name Delivery Date

Pilot plant performance, design of 150MW system, design of an EAF-

system 3.1 SeLaTES 30.4.2013

Model components (compiled files) 1.1 PSP-Grid-H 16.09.2013

Model components (compiled files) 1.1 PSP-Grid-H 31.10.2013

Model components (compiled files) 2.1 PSP-Grid-N 31.10.2013

Classification of storage materials 3.2 SolidHeat 30.12.2013

Model components (compiled files) 2.1 PSP-Grid-N 28.02.2014

Methodology for the lifetime description of hydraulic components

1.2 PSP-LowLoad 28.2.2014

Simulation results, fabrication demo, experimental results 3.1 SeLaTES 30.4.2014

State of chemical equilibrium 3.2 SolidHeat 31.5.2014

Classification of storage materials 3.2 SolidHeat 30.06.2014

Model description and complete model files 1.1 PSP-Grid-H 31.8.2014

Model description and complete model files 2.1 PSP-Grid-N 31.8.2014

Model description and complete model files 1.1 PSP-Grid-H 10.02.2015

Methodology for the lifetime description of hydraulic components 1.2 PSP-LowLoad 28.2.2015

Comparison and validation of the method with existing machines

1.2 PSP-LowLoad 28.2.2015

Report 3.1 SeLaTES 28.2.2015

Rector concepts and design concepts 3.2 SolidHeat 30.4.2015

Rector concepts and design concepts 3.2 SolidHeat 30.05.2015

System design report, cost analysis 3.1 SeLaTES 31.1.2016

Concepts for process integration 3.2 SolidHeat 31.1.2016

Overview of capabilities and cap. of GS-techn. 2.2 StrukDRESS 31.3.2016

First operation experience 3.2 SolidHeat 31.12.2016



- 51 -

Comparison and validation of the method with existing machines 1.2 PSP-LowLoad 31.5.2017

Model description and complete model files 2.1 PSP-Grid-N 31.5.2017

Pilot plant performance, design of 150MW system, design of an EAF-

system

3.1 SeLaTES 31.5.2017

Simulation results, fabrication demo, experimental results 3.1 SeLaTES 31.5.2017

Report 3.1 SeLaTES 31.5.2017



State of chemical equilibrium 3.2 SolidHeat 31.5.2017

Concepts for process integration 3.2 SolidHeat 31.5.2017

First operation experience 3.2 SolidHeat 31.5.2017

Final report of results 1.1 PSP-Grid-H 31.05.2017

Final report on results

1.2 PSP-LowLoad 31.05.2017

Final report of results 2.1 PSP-Grid-N 31.05.2017

Final report 2.2 StrukDRESS 31.05.2017




- 52 -

6 Cooperation between Science & Industry

6.1 Partner Structure

See Part B1:Table “4.1 List of Scientific Partners” and “4.2 List of Company Partners”

Describe the development of the partner structure including changes & adaptations and the

impacts on the K-Project.

Describe changes, adaptations and impacts on the K-Project etc.

See the explanations in the Mid-Term Review. Apart from the changes explained there, two

additional companies (TIWAG - Tiroler Wasserkraft AG and Vorarlberger Illwerke AG) could

be included in the consortium as associated members successfully.

6.2 Industrial Involvement & Interaction (Company Partners)

Cooperation policies, company partner contributions to the K-Project

See consortial agreement, and Mid-Term Review

6.3 Scientific Involvement & Interaction (Scientific Partners)

Cooperation Policies, scientific partner contributions to the K-Project

See consortial agreement, and Mid-Term Review

7 Organisation & Management

7.1 Organigram & Management Structure

Please provide the organigram of the K- project and describe adaptations/ changes in the

course of the K-Project compared to the application/ project plan.



- 53 -

There were no essential changes in the structure of GSG-project. The following staff

changes occurred, compared to the original application:

Project 2.2 was project was started in 11/2015.Up to now, preparatory scientific and

organisational work was implemented by Wolfgang Gawlik instead of Michael Chochole.

Rainer Schlager left the project and was substituted by Christoph Maier. Alexander Winter

was working in Area N since 1st of October 2016.



- 54 -

8 Achievement of Target Values See Part B1: Table “7. Target Values”

Describe the development and the achievement of target values and explain deviations from

the planned figures in the project plan where applicable.

Not applicable

8.1 Research Programme

Share of strategic research projects in the entire research programme

The stated goal of strategic shares of the individual sub-projects could be reached.

8.2 Research Results

Publications in relevant journals/ Patents/ Licensing

See part B

8.3 Added Value

Initiated Products and Processes:

Explain the achieved benefits for the company partners. Describe the achieved and potential

process- and product innovations initiated by the K-Project, the development into marketable

products or new processes. A quantitative as well as qualitative description is expected.

See the explanations in chapter 3.2. as well as the information included in the success

stories.

8.4 Human Resources

Number of Key Researchers (female/ male)/ Dissertations (PhD)/ Diploma & Master Theses

in the scope of the research programme

See part B

9 Annex Annex 1: References (aktuelle, gesamte Literaturliste)

Annex 2: Additional CVs (new key individuals only)

Annex 3: Success Stories

K-Project Final Evaluation Core Document

Documents

Transcript of K-Project Final Evaluation Core Document