The merits of integrating renewables with smarter grid carimet
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Transcript of The merits of integrating renewables with smarter grid carimet
The Merits of Integrating Renewables with
Smarter Grid SystemsCARIMET Regional Workshop on
Metrology and Technology Challenges of Climate Science and Renewable Energy
April 15, 2015
Rick Case PMP, P.E.SCADA/EMS Manager
JAMAICA PUBLIC SERVICE CO. [email protected]
Jamaican Context - About JPS• Est. 1923• Ownership: EWP (Korea) 40% Marubeni
(Japan) 40%, GOJ ~ 20%• Vertically Integrated Utility - Sole Transmission
and Distribution, Liberalized Generation• Installed Capacity: ~ 900 MW (JPS + IPP),
Fossil, Hydro, Wind• Peak Demand: ~ 644 MW, September 2009• Approximately 16,000 km of T&D, 138kV and
69kV, 55 Substations, 28 Generating Plants • Customer base: ~ 604,000• Staff: ~ 1600
Context• Globally, significant investments are being done in
renewable energy technologies driven by efforts to decarbonize the planet
• The variable nature of their generation poses integration challenges, renewable energy by itself, will not keep the lights on!
• Grid modernization has to take place in concert with the rapid deployment of these variable renewable resources (VRR)
• Balancing resources – integrating large-scale and small distributed energy resources (DER)
• Smarter Grids enable higher penetrations of VRR on T&D networks
Jamaican Context – Energy Policy 2009-2030• Reduce the over-dependence on imported oil for
electricity production – JPS at 90% oil fired• Requires a diversified energy base with focus on “green”
and “clean” technologies• Requires reduction of our carbon footprint and
protection of the environment• Promotion of energy efficiency and energy conservation
and grid modernization to accommodate these goals• Requires that by 2030, renewables (solar, hydro, wind,
biofuel) will be 20% of the energy mix.• No objection for renewable plants < 15 MW (base operating
cost and negotiable premium cap)• Competitive basis for renewable plants >= 15 MW through
the OUR process
Jamaican Context – Energy Policy 2009-2030
RE penetration will be 12.5% in 2015
• If energy demand levels 2013 to 2015 remain flat, renewables will provide over 17% of the required energy by 2015
The Jamaican Context – Renewable Energy Capacity Penetration• Total MCR = 900 MW• Existing RE capacity = 7.5%
• VRR (Wind) = 4.5%
• Projected RE Capacity = 16%• VRR (Wind + Solar) = 13%
Research indicates that in most large scale grid systems, VRR < 10% of peak capacity has little impact on system operation. Larger Shares will present challenges for System Operators. Wind Energy and Power Systems Operations: A review of Wind Integration Studies to Date” The Electricity Journal, Vol 22, Issue 10, 34-43.
Peak Min
Demand (MW) 600.0 400.0
Wind Capacity % 16.5% 24.8%
Solar Capacity % 3.3% 5.0%
TOTAL 19.8% 29.8%P e a k M i n
16.5% 24.8%
3.3% 5.0%
19.8% 29.8%
RE Capacity Penetration at On-Peak and Off-Peak
Wind Capacity % Solar Capacity % TOTAL
The Jamaican Context – Renewable Energy Penetration• Total Projected Energy =
4113 GWh• Projected RE Energy = 17.3%
• VRR (Wind + Solar) = 7.5%
Technology GWh Capacity (MW) CapFact
Existing - Hydro 148.44 25.82 66%
Existing - Wind 109.71 41.00 31%
RFP Firm 212.08 37.00 65%
RFP Energy only 204.87 78.00 30%
Maggotty Exp. (est) 34.69 6.00 66%
TOTAL 709.80 187.82 43%% E n e r g y S h a r e
3.61
2.67
5.16
4.98
0.84
17.26
re penetration - projected energyExisting - Hydro Existing - Wind RFP FirmRFP Energy only Maggotty Exp. (est) TOTAL
Jamaica Load Profile and Capacity • Evening Peak, Highest energy
demand is in Day• Demand met by load-
following dispatchable base-load plant - ELD
• Quick-Start CT’s brought online for short term capacity shortfall or peaking
• High Spinning Reserves during low loads
• Most dispatched capacity is fixed/flexible mix – MR, FD
• Current demand intermittency is absorbed by spinning reserves – 29 MW
Committed Capacity vs System Demand
200
300
400
500
600
12:30 AM 5:30 AM 10:30 AM 3:30 PM 8:30 PMTime
Loa
d / C
apac
ity (M
W)
Capacity Demand
Integrating Intermittent Renewable Resources – Illustration “Duck Curve”Impact upon Net Thermal Output
Growing Need for Flexibility as Renewables Increase
Demand Curve w/Solar & Wind Generation
Source: CAISO, “2020 Flexible Capacity Needs”
Note Three key take-aways:
1. Ramping demands2. Over-Generation3. Declining Marginal
Value
Overview of presentation• A brief look at Integrating Variable Renewable Resources (VRR)• The main challenges posed by VRR integration and applicable SMART
GRID Systems that contribute to overcoming these challenges• Integration and Activation of various SMART GRID solutions• Alignment of SMART GRID development with Renewable Energy
Development• Conclusion• Recommendation
Smart Grid and VRR’s• What share of VRR is possible with more effective use of existing flexible resources?
No one size fits all, careful studies and simulations are necessary. • Integrated Resource Planning using, for example, the Flexibility Assessment (FAST)
method developed by the IEA’s Grid Integration of Variable Renewables (GIVAR) project.
• IEA identifies four technical flexibility resources that can aid in the integration challenge:
• Dispatchable plants: Load-Following Generators with ramp-up/ramp-down and short start-up/shut-down times
• Storage: batteries, pumped hydro, compressed air, flywheels• Interconnection: to neighbouring utilities/systems• Demand-Side measures: Customer participation in power system operation – load shifting, load
shedding etc., SMART-GRID Technologies are integral components
Flexibility needs and Flexible resources – IEA Framework
• Smart Grid Systems and Technologies play a role in:
• Demand Side Management & Response• Energy Storage Facilities• Power Market• System Operations• Grid hardware
• Other Smart Grid Technologies• PHEV’s charging• Modernizing grid Operations through
Advanced SCADA/EMS• Inclusive power markets, storage and demand
side resources for balancing• Establishment of micro-grids during outages
on the main grid
VRR Integration Challenges and Smart Grid Solutions• “A Smart Grid is an electricity
network that can intelligently integrate the actions of all users connected to it – generators, consumers and those that do both – in order to efficiently deliver sustainable, economic and secure electricity supplies” – European Technology Platform Smart Grid (ETPSG)
NIST Conceptual Reference Model
Flexibility is the Answer!• Flexibility expresses the
extent to which a power system can modify electricity production or consumption in response to variability, expected or otherwise
• Curtailing the VRR output when necessary to prevent surplus
NIST Conceptual Reference Model
Key VRR Integration Challenges and Smart Grid Solutions• Integration Challenges
• Transmission• General Ramping Requirements• Near Instantaneous Production Ramps• Over-Generation
• Proposed Response to VRR Integration Challenges:• Smart Grid Tools• Markets Tools• System Operations Tools• Other
Transmission• Siting of VRR are often times located at a
significant distances from load centres. Cost of new transmission or limits on existing lines may pose challenges to additional VRR generation.
• Smart grid technologies, especially advanced transmission and substation technologies, can aid in this challenge by increasing transmission line capacity, reducing system losses, and improving voltage and frequency control
NIST Conceptual Reference Model
Dynamic Line Rating systems provide real-time ratings of transmission circuit capacity through monitoring of transmission line sags.
Wide-Area Situational Awareness and Phasor Measurement Units increase the visibility of grid system health and the power quality impacts of renewable energy generation.Voltage Source Converter-based High-Voltage DC transmission systems increase the effi ciency of large-scale onshore and offshore VRR electricity delivery.Flexible AC Transmission systems (FACTS) enable the full use of circuit capacity while maintaining system stability and providing voltage support
Market ToolsPricing systems that incorporate the cost of congestion (nodal pricing, Locational Marginal Pricing) can send price signals that incentivize adequate investment in transmission expansion.
Advanced simulation systems, including probabilistic tools for improved load forecasting, assist in optimizing power flow over the grid.Larger balancing areas, cross-border interconnections, and better balancing-area coordination can ease transmission constraints.Transitioning from day-ahead unit commitment and hourly dispatch down to five minute dispatch intervals removes constraints on generation flexibility and reduces demand for regulation service.
“Reconductoring” with new low-sag conductors can increase line capacities without need for replacing a line with a higher voltage design.New transmission lines can be constructed, using either conventional AC or High-Voltage DC at current or higher voltages.
Smart Grid Tools
System Operation Tools
Other Tools
Transmission Solutions
General Ramping Requirements• System operators “ramp” the output of generators in response to the
demand for electricity, a vital grid function known as “load-following.” • Conventional ramping is normally due to fluctuations in electricity
demand, high penetration of VRR adds a new variability to this convention and the unique patterns present different ramping challenges.
• High Penetration Solar requires daily (morning and evening) ramping as well as cloud cover changes.
• Wind Power generally increases during the day and dies down in the evening, but has less predictable up-and-down-ramping requirements
Solutions for General Ramping Challenges
Market ToolsIntroduction of imbalance energy markets or competitive load-following services aim to increasing compensation for ancillary services, such as ramping capacity.Market mechanisms can provide incentives for fast-start and fast ramping capabilities
Expanded balancing areas and coordination with neighboring balancing authorities can play a key role in reducing the volatility of overall net ramping requirements.Better wind and solar forecasting allow for better scheduling in the day-ahead and hourly markets.Improved Energy Management Systems, including load forecasting, load dispatch with Advanced EMS, and virtual power plants, can provide more responsive system operation
Conventional solutions for meeting load-following needs include large hydro and cycling thermal generators (e.g. natural gas and coal).Retrofits and procurement of new generation such as large hydro or pumped-storage plants can provide greater flexibility and performance
Smart Grid Tools
System Operation Tools
Other Tools
In conjunction with appropriate market design and utility programs, demand response and demand-side storage capabilities -- e.g. thermal mass, process mass, water heaters, chilled water storage, and dimmable ballast lighting -- can provide load-following services.
Near-Instantaneous Production Ramps• High-Penetrations of Solar present integration challenges, the passage
of clouds over PV panels can result in output changes of +/- 50% in 60 seconds and +/- 70% in 10 minutes.
• Rooftop or utility-scale PV connected directly to the distribution system can introduce voltage challenges. Quick variations from inverter-based generation can impact the voltage to customers if adequate voltage regulation is absent.
• Siting of a single large solar installation at the end of a distribution feeder can strain the entire voltage regulation scheme.
• Generally, the Response-Time for Voltage Regulation is critical.
Solutions for Near-Instantaneous production ramps
Volt & var optimization systems facilitate voltage regulation in areas of high penetration of distributed generation, and also enable PV installations to contribute to voltage regulation.Fault Detection Identification and Restoration (FDIR) technologies are used to quickly detect outages and restore service.Transfer trip schemes allow for proper disconnection and reconnection of distributed generation when an outage is detected.Automation of reclosers and switches allows distributed generation and/or utility-scale battery storage to island load during outage.Active power electronics in conjunction with smart meters can also mitigate rapid production ramps.Coupling new PV inverters and power quality monitoring systems can minimize feeder voltage fluctuations.Short term load management from the distribution system operator may help reducing the impact of voltage fluctuations.
Market Tools No Market tools are available for distribution-level ancillary services such as voltage regulation.
Smart Grid Tools
System Operation Tools
Other Tools
Distribution Management Systems (DMS) integrate grid-monitoring applications to support operation of the grid, allowing improved visualization of the distribution network state, and facilitating fault detection, isolation, restoration and voltage regulation with strong simulation capabilities
Upgrading distribution feeders to a higher voltage or conductor replacement are standard tools, as is the modification of relays and transformers in distribution substations to limit the impact of reverse power flow or to improve voltage regulation
Over-Generation• Over-generation typically occurs when VRR generation is high, loads
are relatively low, and there is a significant share of non-dispatchable
and baseload conventional generation on the grid• The challenge is more common with wind generation in low-load
situations
Solutions for over-generationIn conjunction with high-quality forecasting, demand response can serve as a load-shifting resource to absorb excess generation. For example, PHEVs can be pre-charged during excess wind generation; ice can be made for building HVAC, and industrial refrigerators can be pre-cooled.In the residential sector, electric thermal storage systems (e.g. electric water heaters) have been used to absorb excess generation, and new devices on the market offer improved two-way communication capabilities. The use of heat pumps, smart thermostats, and Home Energy Management Systems for pre-heating and pre-cooling of homes is also envisioned in the mid-term to absorb excess wind energy.Large industrial loads such as aluminum smelting can also be varied to match VRR excess energy and other system needs
Market ToolsMarket design that allows greater customer participation in the energy market can minimize lost revenues due to curtailment
Expanded balancing areas and coordination with neighboring balancing authorities can play a key role in reducing net over-generation.Improved energy management systems with load forecast, load dispatch with Advanced EMS, and virtual power plants, can help mitigate over-generation impacts
Other Tools
Curtailment of VRR generators is a standard method for dealing with over-generation. Ramping thermal units down is another standard method. Using large hydro or pumped storage may provide long term storage for excess wind generation, as well as for sustained periods of under-generation
Smart Grid Tools
System Operation Tools
Integrating Solutions• The design of smart grid systems to enable greater VRR generation should be
driven by analysis of the types, timing, and magnitude of grid challenges posed by the portfolio of VRR sources on each individual grid, as well as the relative cost of the potential solutions – IEA FAST method
• The key challenge for decision-makers (i.e. system or market operators) is to prioritize and implement the appropriate mix of integration solutions detailed above given the specific grid topology, current and future VRR mix, and market structure
• The economics of flexible resources are unique to each electricity market and regulatory landscape, and conducting resource assessments and simulations will be critical to estimating the most cost-effective path to integrating large penetration of VRRs
Flexibility “Merit Order”
Activating demand-side intelligence• Smart grids can enable greater customer
participation in power system operations. • By sending real-time information on cost of
electricity, or offering information about real-time incentive payments, engaged customers and grid-networked housing and commercial buildings can participate in reducing stress on the network caused by system events, such as increasing peak demand or VRR integration events
• Enabling demand to actively respond to load and price conditions can have a dramatic impact on the integration of VRRs.
NIST Conceptual Reference Model
Primary Characteristics of Traditional vs. Smart Grid Demand Response
Conventional DR Smart-Grid DR
ParticipationTargeted, Limited to large C/I &
residentialAll Customers
Who Controls Utility Customers
What is Controlled
Interruptible Rates, Residential HVAC, Water Heating
All Loads Available
Control Equipment
Utility provided, Few SuppliersCustomer Provided, many market
suppliers
IncentivesFixed/Participation Payments,
Baseline MetricsRetail Dynamic Prices, Reservation
Payments, Pay-for performance
DR products Generally limited to ReliabilityCapacity, Energy, Ancillary Services:
Congestion Management
DR, EE, Renewable Integration
NO YES
Activating delivery-side intelligence• Dynamic Line Rating: lines are given a static thermal
capacity rating that limits how much current can be delivered across the line formulated from ambient temp and current flow.
• Sag in transmission lines affect the amount of current flow as well as ambient weather.
• A cloud shadowing can increase line capacity by 3% and wind speed and direction can impact capacity by up to 10%
• “Dynamic line rating” systems consist of tension and/or temperature sensors deployed on high-voltage transmission lines to provide grid operators real time insights into thermal capacity. Such intelligence can allow for greater amounts of electricity to be delivered, which at times can reduce the level of curtailment of VRRs
Activating Markets• Market Design and Structure is critical to integration
and economics and ensures Supply and Demand are balanced on a scale of minutes, not hours.
• What market system exists? Is the electricity generation deregulated? Who owns the T&D? How do you incentivize participation?
• IT improves the ability of markets to accommodate complex power flows and economic dispatch and real time price/cost communication
• Smart Grid technology brings the customers, storage facilities, DER’s together for greater market participation, especially in the near-term.
• Flexible DER are required in sub-hourly dispatch, day-ahead and long term capacity
NIST Conceptual Reference Model
Enabling Distributed Generation & Microgrids• Planned islanding can now be introduced and
integrated with system protection• Microgrids are defined as electrical systems that
include multiple loads and distributed energy resources that may be operated either interconnected with the grid or as an electrical island
• Applicable to rural areas or large residential subdivisions, corporate campuses, hotel zones
• Microgrid Controller takes over the job of the system controller to maintain power quality (voltage, frequency etc.,), balance of generation and load
Integrated System Control Room• Full operational view of Transmission and
Distribution systems• Integrated EMS and DMS• DMS function now critical as DER’s are deployed,
active control of the distribution is essential with storage, generation and load. Advanced Applications and Simulation will be necessary to improve visibility and control over the resources.
• At the transmission level, EMS are managing both conventional and VRR, active demand response, storage devices and safety. The EMS will have to control the DMS and DER’s directly in daily operations
Transmission Control Room Improvements• High resolution visualization of grid
status and health• Automated Demand Management• Algorithms that identify
intermittency events• Integrated forecasting software that
allows for more accurate dispatch• Ability to manage the connection or
disconnection of micro-grids• Work force demographics and skills
Conclusion• What is the regionally-appropriate sequence
and priority of smart grid applications needed to facilitate the development of high-penetration VRR power systems?
• What types of policy frameworks best engage customers in participatory energy markets?
• What is the regionally-appropriate model for renewable energy development (e.g. what share of VRR resources should be distributed?)
• What smart-grid VRR integration solutions are most strongly affected by institutional barriers? Market barriers? What policy changes would mitigate these barriers?
Recommendation• Ensure alignment between smart grid roadmaps and scenarios for future
renewable energy supply • Evaluate smart grid VRR integration solutions in the context of the full
range of integration solutions • Integrated Resource Planning to:
• Establish the existing flexibility of the grid to integrate new resources• Determine the optimal size and sites for renewable energy projects (resources)• Ensure grid sustainability through generation units with appropriate ramp and
frequency stability capabilities• Facilitate better collaboration with customers in Distributive Generation, who are
producing electricity and selling back to the grid
Thank You!Rick Case
References:
ISGAN White paper: “Smart Grid Contribution to Variable Renewable Resource Integration”, 25 April 2012
Ministry of Energy and Mining, “National Renewable Energy Policy 2009-2030”, August 2010
IEA, “Harnessing Variable Renewables, A guide to the Balancing Challenge”, January 2011
US DOE, “Strategies and Decision Support Systems for Integrating Variable Energy Resources in Control Centres for Reliable Grid Operations, Global Best Practices, Examples of Excellence and Lessons Learned”, Lawrence Jones
NIST, “Framework and Roadmap for Smart Grid Interoperability Standards”, 1.0. January 2010
Energy Institute at HAAS, “Renewable Integration Challenges create Demand Response Opportunity,” Meredith Fowlie, Sept 2, 2014