Solar and Storage Orchestration to defer Distribution Augmentation · 13.06.19 Solar and Storage...

Solar and Storage Orchestration to defer Distribution Augmentation

13 June 2019

Australian Solar Storage Conference and Exhibition

Acknowledge

13.06.19 Solar and Storage Orchestration to defer Distribution Augmentation

United Energy acknowledges funding support for this Project from the Australian Renewable Energy Agency (ARENA) as part of ARENA's Advancing Renewables Programme.

13.06.19

United Energy


United Energy


United Energy is a regulated Victorian electricity distribution business that supplies electricity to approximately 680,000 customers across Melbourne’s eastern suburbs, south eastern suburbs and the Mornington Peninsula. United Energy delivers electricity to homes and businesses in a 1,472 square kilometre area, or around 450 customers per square kilometre.

A CK Infrastructure-led consortium owns 66 per cent of United Energy with the balance owned by SGSP (Australia) Assets Pty Ltd.

United Energy Service Area


Item Value

Peak coincident demand (summer 2016/17) 1,858 MW

Record peak coincident demand (summer 2008/09) 2,084 MW

Poles 215,500

Overhead lines 10,043 km

Underground cables 2,834 km

Sub-transmission lines 78

Zone substation 47

Zone substation transformers 112

Distribution feeders 445

Distribution transformers 13,500

13.06.19

Residential Solar Storage Programme


Content


• Objectives

• Key Milestones

• Approach

• Customer Engagement Strategy and Principles

• Typical Customer Installation

• Control Strategy

• Dispatch Results (2018 and 2019)

• Innovation, Benefits and Lessons Learnt

• Conclusions

Objectives


• Deployment and testing of Solar and Storage systems across United Energy’s

selected constrained substations to demonstrate their capability to be used as

an alternative to traditional augmentation.

• United Energy and other Utility Benefits

Increase efficiency and reduce network costs at constrained substations.

Deferral of augmentation.

Confidence in replicating similar solutions.

• Customer benefits

Reduce peak demand and network costs.

Energy arbitrage offered by the systems.

Key Milestones (2017 – 2019)


• Customer engagement strategy – May 2017.

• Customer marketing – June 2017, October 2017 and February 2018.

• Customer registration – June 2017 to March 2018.

• Site assessments and customer engagement (Q&A) – July 2017 to March 2018.

• Customer Contract execution – July 2017 to March 2018.

• Installation – July 2017 to May 2018.

• Development of operational protocols – July 2017 to March 2018.

• Systems dispatched during summer – December 2017 to March 2018, December 2018

to March 2019.

• Final Report – 30 June 2019.

Approach


• United Energy completed an analysis of the 2016/2017 summer data to

identify substations which are overloaded.

• Customers located in constrained substations targeted to reduce demand and

manage outages and equipment life over the coming summers.

• Customer engagement strategy prepared and executed.

• 1500 customers targeted across constrained substations. 150 customers

registered. 85 proposals prepared and submitted to customers.

• Comprehensive investigation into system specifications completed – selected

solar PV system with optimisers (15 Jinko Solar Panels X 270 W = 4 kW,

LGChem RESU10 battery (9.8 kWh), Sungrow SH5k (5 kW) inverter and

Reposit Power equipment as the least-cost lifecycle option for the Program.

• Reviewed a number of technology providers for the installation work selecting

a preferred installer.

Customer Engagement Strategy


Personalised Letters to customers via mail.

Dedicated Registration Website and email for correspondence.

Dedicated phone line to discuss questions/queries on any aspect of the

Program.

Submission of a customer personalised proposal containing roof space

analysis, details on the Solar Storage system, description of how the system

would work, estimated energy mix for the customer property, environmental

benefits, customer savings, cost of the proposed system to be borne by the

customer and contract agreement for consideration. This ensured the

customer received a clear and transparent proposal facilitating a valued

decision to proceed or not.

Selection of a preferred installer for installation of the Solar Storage systems.

Customer Engagement Principles


Consistency (in communication channels deployed).

Continuity (seamless interaction with communication channels).

Customisation (personalised proposals).

Transparency – Marketing was undertaken to all residential customers residing within a

chosen constrained distribution substation.

Commitment – UE ensured customer questions/queries were addressed fully to enable them

to make their decision.

Timely and Meaningful – UE articulated clearly the purpose of the Program and were flexible

with engagement methods (website, phone conversation, personal meetings) to provide two

way communication.

Accountable – Customers were provided with an easy to read and understand contract. The

engagement methods provided, enabled customers to have their queries answered.

Measurable – The customer engagement approach was refined during the Project to

address feedback being received from initial customer engagement.

Typical Customer Installations


Control Strategy


• For days when temperature is less than 35°C, the offset demand control strategy as below will be implemented across the selected constrained substations.

• For days when temperature is greater than 35°C, the network support control strategy below will be implemented across the selected constrained substations.

Time Control Comment

All day Offset Demand

Offset demand control is the typical customer mode which

seeks to limit exports to the network and maximise self-

consumption of solar PV generation. The batteries and

solar PV systems will be used to firstly offset customer

usage. The batteries will only charge from excess solar PV

generation which is not used by the customer.

Time Control Comment

All day Network Support

Ensure battery is charged prior to the weather event

condition. On the weather event condition day, ensure

battery is discharged between a selected duration (e.g. 5pm

and 8pm; or 4pm to 7pm) with due consideration to limits on

battery State of Charge (SOC). For Solar PV, limit export to

network and maximise self-consumption.

Average Dispatch Performance – 23 Jan 2019


Maximum Temperature: 25°C

Average Dispatch Performance – 24 Jan 2019


Maximum Temperature: 37°C

Average BESS State of Charge – 24 Jan 2019


Dispatch Results 3 Jan 2019 – 16°C to 29°C (Normal Day)


On a normal day (03

January 2019), a maximum

reduction in demand of up to

6.6% was achieved (52.16

kW down to 48.73 kW).

When in Offset Demand

mode, the solar PV

generation is used to first

meet household

consumption, with excess

generation used to charge

the battery, with any

additional excess generation

exported to the grid.

Dispatch Results 6 Jan 2018 (42°C)


6 Jan 2018 (42°C)

Dispatch on 6 Jan 2018 achieved a 7% reduction

in demand which in effect will defer augmentation

by 7 years.

Advantage of Solar and Storage system is the

ability to incrementally add to the network to

continue achieving deferral of augmentation.

For Network support mode, battery pre-charges

overnight to allow solar energy to support

network during the day.

Battery exports full capacity in the early evening

during peak demand when solar output reduces.

Test on 6 Jan 2018 demonstrated that solar

storage can address network constraints.

Dispatch Results 7 Jan 2018 (22°C)


7 Jan 2018 (22°C)

The impact of Solar PV should be noted during

the middle of the day.

When Solar PV generation is high, demand is

reduced and excess solar generation is used to

charge the battery.

When demand increases in the evening, battery

commences discharging to support the increased

demand maximising customer benefits.

For energy arbitrage mode, battery charges from

solar energy during the middle of the day.

Innovation & Benefits


United Energy owner with customer approval for deployment during peak

demand days.

Customers benefit with lower electricity bills with exposure to Solar and

Storage systems.

Solar and Storage systems can be an economic network augmentation

alternative, in certain instances. Networks can potentially procure such a

solution to achieve prudency of investment and reduce network costs for

customers.

Improved quality of Supply.

This Program highlights the value of renewable energy and storage

systems to regulators and policy makers, to enable them to establish

appropriate frameworks to encourage increased customer take-up.

Lessons Learnt


Batteries are discharging as expected but require accurate forecasting to

shave peak demand.

Insufficient roof space and shading are the two most common criteria

resulting in elimination of ineligible sites. (To streamline process assessments

are done using google maps data).

Need to assess types of roof tiling and the need to source spare roof tiles

(roof tiles being cracked as part of the installation is common). (Installers

prearrange supply of tiles prior to commencing installation).

Wi-Fi connectivity at some sites has posed issues. (During site visits, details

on Wi-Fi connections are being gathered to ensure installation proceeds

smoothly).

Initial installations took 2 days to complete with subsequent installations

undertaken in a day as the installers became more familiar with equipment

and installation requirements. (Plan is to utilise existing installers to complete

additional installations).

Lessons Learnt – Continued


Some installations required installation of concrete slabs which increased the

installation time. (Installers are now advised of this immediately after the site

visit to fast track installation).

Ideal sites are those with a west or north facing roof with no shading from

surrounding trees. Ensure the roof is clear of flu pipes, antennas or satellite

dishes on the face where panels are to be installed. (This is assessed during

the site visit).

The batteries should be installed close to the switchboard and solar panels to

minimise the length of the AC and DC cable runs. (This is assessed during

the site visit).

Ensure switchboard has sufficient spare terminals to accommodate the critical

load and VT/CT reference MCCBs. (This is assessed during the site visit).

It is essential to engage a reliable installer to ensure installations are

completed in a timely manner and any issues identified are rectified quickly.

Lessons Learnt – Continued


Reliability of components (i.e., inverter as power conversion equipment

typically has a high rate of failures at the beginning - 2 installations had to

have their inverters replaced due to failure).

Extensive monitoring of the battery systems such as voltage, temperature,

current as well as redundant monitoring and control in terms of a fail-safe

battery management system is crucial for a safe operation of the System to

minimise the risk of a thermal run-away.

A control challenge in most applications is the accuracy of the State of Charge

(SoC) value. The uncertainty in SoC estimation therefore needs to be

considered in all control strategies which aim at managing SoC. The typical

limited Storage capacity needs careful management of SoC levels.

It is necessary to implement a Life Cycle Strategy to address the operations

and maintenance of the Solar Storage systems over the contract period.

Conclusions


• This Program has involved recruiting a large base of customers across a

number of constrained sub-stations to reduce constraints on the selected

constrained sub-stations. This has allowed United Energy to halt growth and

defer network augmentation across the selected constrained substations.

• Customer Lessons:

Duration of Contract.

Ownership of the system.

Unfamiliarity with technology.

Upfront payment.

Questions


Solar and Storage Orchestration to defer Distribution Augmentation · 13.06.19 Solar and Storage...

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