Benefits, Challenges of Two Microgrid Case Studies (Summary of CEATI Report: Integration and Coordination of Energy Storage Within Microgrids—Part 2 of 3)

Business & Technology Surveillance

Microgrids with Energy Storage: Benefits, Challenges of Two Microgrid Case Studies (Summary of CEATI report: Integration and Coordination of Energy Storage within Microgrids—Part 2 of 3)

By Alice Clamp

SEPTEMBER 2020 Business & Technology Surveillance Microgrids with Energy Storage: Benefits, Challenges of Two Microgrid Case Studies (Summary of CEATI report: Integration and Coordination of Energy Storage within Microgrids—Part 2 of 3)

By Alice Clamp

SEPTEMBER 2020

SUBJECT MATTER EXPERT ON THIS TOPIC Dan Walsh Senior Power Supply & Generation Director [email protected]

Jan Ahlen Director, Energy Solutions [email protected]

This article is a product of the Generation, Environment, and Carbon Work Group

ARTICLE SNAPSHOT WHAT HAS CHANGED IN THE INDUSTRY? Microgrids have the potential to help utilities and their customers by mitigating long-term outages from extreme weather events, providing grid services, and improving reliability. Improved performance and decreasing costs for distributed energy technologies have resulted in increased microgrid deployments, many of which are beginning to incorporate energy storage.

WHAT IS THE IMPACT ON ELECTRIC COOPERATIVES? The processes and considerations for enabling resilient microgrids lack a list of best practices that can guide their practical implementation, particularly in reference to developing energy storage technologies.

WHAT DO COOPERATIVES NEED TO KNOW/DO ABOUT IT? Rural electric cooperatives, as well as end-users and developers, need to understand how microgrids with energy storage are currently being used and how they may be most effectively used in the future. By learning how energy storage can be used in different microgrid applications, cooperatives can better plan current and future uses. They will also understand how communication between the battery management system and the power conversion system is critical in efficient operation of the battery, and in turn, overall microgrid operation. Cooperatives should also learn about best practices that can be applied to all microgrids that incorporate energy storage. Microgrids with Energy Storage: Benefits, Challenges of Two Microgrid Case Studies | 3

Introduction Task 3: Case Studies for Microgrids have the potential to help utilities Microgrids with Energy Storage and their customers by mitigating long-du- For this task, different microgrids with energy ration outages from extreme weather events, storage were analyzed in order to: providing grid services and improving reli- • Summarize how energy storage technol- ability. Improved performance and decreasing ogies had been implemented within each costs for distributed energy technologies have microgrid resulted in increased microgrid deployments, many of which are beginning to incorporate • Review the primary drivers and motiva- energy storage. tions for developing the microgrid and incorporating energy storage However, the processes and considerations for enabling resilient microgrids lack a list of best • Highlight key design and operational fea- practices that can guide their practical imple- tures, including energy storage integration mentation, particularly in reference to devel- • Review microgrid ownership structures oping energy storage technologies. and financing details

This series of three Surveillance articles eval- • Summarize the project benefits, challenges uates how energy storage is currently being and potential best practices for incorporat- used in microgrids and develops best practices ing energy storage in each microgrid. for integrating energy storage technologies. CASE STUDY 1: UNIVERSITY OF The articles are based on a report—Integra- CALIFORNIA, SAN DIEGO tion and Coordination of Energy Storage within Background Microgrids—that is the result of a collaboration The University of California, San Diego (UCSD) between utilities, CEATI’s Strategic Options is a public research institution and campus for Integrating Emerging Technologies and community of more than 45,000 people. The Distribution Energy Interest Group, and ICF (a UCSD microgrid serves students, faculty and consulting and technology services firm). guests with resilient on-site power across 1,200 acres and 16 million square feet of building The work—and the findings—are divided into space, producing approximately 47 MW of four tasks: peak capacity on an annual basis. • Task 1: Research and analyze current energy storage and microgrid operational Project Drivers and Motivations structures There are several key factors that prompted the original formation of the UCSD microgrid, • Task 2: Conduct surveys of stakeholders as well as its many additions in recent years. involved in integrating energy storage The primary drivers and motivations for the systems with microgrids UCSD microgrid include: • Task 3: Develop case studies based on • Improving power quality and reliability stakeholder experiences with energy for all campus operations and, in turn, storage and microgrid integration increasing the survivability and safety of • Task 4: Identify best practices for the all critical operations integration and coordination of energy • Providing a means of self-sufficiency storage with microgrids. through on-site generation, and balancing The first article discussed Tasks 1 and 2. This campus energy supply and demand more efficiently by incorporating a variety of article, the second in the series, discusses two energy and storage resources of the four use cases from Task 3. The third article will discuss the other two use cases, • Providing time-based energy cost savings and provide best practices for implementing for the UCSD campus compared with grid energy storage within microgrids. power

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• Reducing the overall greenhouse gas emis- to minimize the potential effects of power sions of the campus through renewable disruptions. energy integration and use of a biogas- • Resistive load bank on fuel cell: The fuel fueled fuel cell generator cell requires roughly eight hours to restart • Promoting campus research and collabora- if it goes offline. In the event of a power tion through the ongoing integration and outage, the resistive load bank helps the testing of new technologies. fuel cell restart quickly by apportioning electrical output from the fuel cell and Microgrid Equipment and Technologies allowing a quick transition once grid The UCSD microgrid currently produces 92% power is restored. of the entire campus’ energy needs, with the • Automatic substation control system: remaining 8% coming from the California An automatic substation control system Independent System Operator (ISO), delivered through a San Diego Gas and Electric sub- allows the campus cogeneration plant to station. The energy generation technologies, operate independently during an interrup- controls systems, and other resources included tion or loss of San Diego Gas and Electric in the microgrid—together with a simple grid-supplied power. schematic of the UCSD microgrid—are • Paralleling emergency automatic trans- shown in Appendix A. fer switches: If the campus experiences an interruption of power, the paralleling Microgrid Design and Operation automatic transfer switches enable select Key Operational Features campus emergency generators to work The UCSD microgrid is a complex and evolv- in parallel with either the utility grid or ing mix of resources and technologies that microgrid. provide a number of services to the UCSD Energy Storage Integration and campus. These resources and technologies have Deployment specific design features and characteristics that allow them to function within the microgrid. The energy storage systems that provide A number of key features for resources and the direct service to the campus microgrid are microgrid as a whole include: the thermal energy storage system and the advanced energy storage system (92.5 MW • Utility grid connection: The campus is battery). The most important function of these connected to the California ISO by a single systems is to control and constantly balance 69 kV substation. campus supply and demand. They act as a • Microgrid control: The Central Utilities shock-absorber to provide flexibility to the Plant control room manages the campus’ UCSD microgrid, allowing UCSD to charge evolving microgrid, with real-time energy the systems off-peak with onsite generation, monitoring that ensures that the energy and use the stored energy on-peak when systems work in tandem with the utility utility prices are the highest. grid and efficiently integrate all distributed energy resources. In addition to the battery storage system, the thermal energy storage system (39,000 • Bypass stacks at the cogeneration plant: ton-hours of chilled water) is cooled at night steam bypass stacks enable rapid starting during off-peak hours when electricity rates of the central utility plant turbines, if a are lower, providing arbitrage opportunities power interruption occurs. for UCSD and also minimizing the use of • PMU monitoring system: Phasor Mea- electric-driven chillers. These key functions surement Units (PMU) or synchrophasors of the storage systems are made possible with monitor the utility grid feed and notify the advanced control systems and microgrid the central utilities plant of potential platform. The energy storage systems are power interruptions, giving the campus also a key factor in demand response market an opportunity to reduce or transfer loads participation.

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Controls and Communication Systems system costs, including: power purchase The UCSD microgrid incorporates a high-end agreements (PPAs); clean renewable energy master controller, which provides optimiza- bonds; and grants. tion setpoints and constraints for all genera- • Power Purchase Agreements (PPAs): tion, storage and loads with hourly computing UCSD has a PPA with Solar Power Part- to optimize operating conditions. The control- ners for the 1.2 MW solar PV system. This ler receives hundreds of thousands of inputs has allowed UCSD to take advantage and per second, and is supported by software incorporate solar PV without any upfront that processes market price signals, weather cash. The estimate average cost of the forecasts and the availability of microgrid UCSD solar PPA is currently $0.185/kWh. resources. The UCSD campus has installed The 2.8 MW fuel cell project also uses a power meters throughout the main electrical similar PPA arrangement. The molten lines and at the buildings’ main circuit break- carbonate fuel cell runs on waste meth- ers to provide data inputs to the system. ane that is supplied from the Point Loma wastewater treatment plant. BioFuels In addition to microgrid optimization, SEL’s Energy supplied the upfront capital for the POWERMAX utility microgrid control plat- system and supplies biogas to SDG&E. form has been integrated with UCSD’s on-site The project used California’s self-gener- power generation, load balancing and energy ation incentive program funds and takes storage systems. The platform uses more than advantage of a 30% federal investment 100 SEL devices, such as protective relays, tax credit. automation control equipment and commu- nications equipment in order to assist with • Clean Renewable Energy Bonds (CREBs): continuous load balancing, distributed energy UCSD will receive a total of $15 million for resource integration and unstable load detec- 15 projects from Clean Renewable Energy tion and protection schemes. Bonds, which have interest rates lower than the market, through the Internal The control system is used to detect, respond Revenue Service, which has allocated to and mitigate potential microgrid blackouts $154 million for financing renewable through synchrophasor-based monitoring that energy projects for public facilities. initiates a primary load shedding scheme and enables microgrid islanding. • Grants: For details on grants, see Section 4.1.3.3 in CEATI’s Coordination of Energy Johnson Controls provides all building control Storage within Microgrids. systems through an energy management system that helps reduce energy consumption Key Takeaways from Interviews based on building occupancy. The system Interviews were conducted with several uses smart meters placed throughout campus, individuals involved in the design and opera- and assists in coordinating demand-response tion of the UCSD microgrid, including Byron efforts. UCSD is the largest participant in the Washom, director of strategic energy initiatives San Diego Gas and Electric demand response at UCSD. Washom emphasized the impor- market, at times shedding between 6 MW and tance of an advanced, robust and dependable 10 MW when called upon. controller system, which can yield significant operational and economic efficiencies. Microgrid Ownership Structure and Financing With an advanced control system and smart The ownership of microgrid assets and grid design, less storage is required for load operations is split between UCSD and San balancing. The thermal storage and lithium ion Diego Gas and Electric. Given the diverse set battery system at UCSD represent a small frac- of resources deployed to the microgrid, there tion of the total microgrid loads, but have been are a number of financing structures and ini- effective at continuously balancing energy tiatives that have been used to reduce overall supply and demand in daily operations.

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Washom attributed the UCSD microgrid suc- A summary of the benefits includes: cess to significant planning efforts in identi- • The microgrid has also improved energy fying and pursuing various energy financing security on campus through the advanced options, tax credits and funding options. microgrid controls and load shedding UCSD employs financial mechanisms like schemes, which allow for autonomous PPAs for commercially established technol- islanding, increasing the reliability and ogies, like CHP, while using funding oppor- resiliency for critical loads, such as univer- tunities for demonstration projects involving sity hospitals, student housing and fire/ prototype technologies. police stations. Washom also discussed the multiple mea- • The microgrid has promoted forward sures that UCSD has undertaken to ensure thinking technology deployment, col- the technologies used within the campus laboration and innovation to students, met sustainability goals of the organization, researchers and other universities, and has including aspects related to after-life disposal positioned UCSD as a facilitator of innova- and electronic waste. Washom also stressed tive technology testing. that with the advancement in monitoring and controlling systems, cybersecurity will pose • The arbitrage opportunities from energy a critical challenge, especially as these are storage systems have provided economic billions of dollars of research and assets benefits to the campus and allowed connected to the UCSD microgrid system. researchers to identify individual technology use cases (solar + storage) and the key Key staff from Schweitzer Engineering Lab- considerations that make these cases most oratories were also interviewed to provide effective. detail on control systems and control plat- • The microgrid has allowed UCSD to sig- forms. One takeaway from these interviews nificantly reduce peak demand and energy included precautions around programming costs for the university; campus energy microgrid and energy storage controllers costs have been reduced by more than $8 for different use cases without considering million per year. the life cycle effects of changing operational characteristics. • The advanced controls and communication systems allow for real-time modeling and Energy storage can strengthen the short-term optimization in order to maximize value proposition of a microgrid, but signif- efficiency for all included technologies icant attention also needs to be paid to the and resources. long-term value of energy storage, including the effects of different cycling patterns on Project Challenges equipment degradation. At lower operational While the UCSD microgrid has provided efficiencies, energy storage may not provide many benefits to the campus and UCSD as a the same value proposition. The cost and whole, there have been a number of challenges frequency of battery replacements also need to in incorporating the many different resources be considered when evaluating use cases that and new technologies. They are: could shorten a battery’s life span. • Originally integrating and optimizing the Project Benefits, Challenges and diverse set of energy assets, and continu- Best Practices ally integrating new technologies, control Project benefits and communication systems, and demand response energy savings measures on cam- The UCSD microgrid has provided significant pus. In addition to the ongoing integration benefits to the campus community and UCSD’s and optimization of resources, understand- energy system as a whole. The use of multiple ing how to coordinate new resources with energy resources and technologies at UCSD existing infrastructure and the systems has demonstrated the viability of advanced already in place. microgrids integrating energy storage and multiple distributed energy resources with • Capturing, storing and understanding how advanced controls and optimization strategies. to use the vast amount of energy monitoring

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data, given the variety of data protocols and • When evaluating the economic benefits output formats associated with the complex of different use cases for energy storage, microgrid system. Roughly 200 power degradation and cycle life for batteries— meters have been installed on campus and their associated effects on long-term power lines and at circuit breakers. OSIsoft’s project economics—should be considered PI system has been used to capture, trans- and thoroughly analyzed. late and store data from the meters and • Identify and select the appropriate financ- sensors to monitor data outputs and ing method (or combination of methods) coordinate energy asset operations. UCSD continues to work with SDG&E and other for a new technology based on its market stakeholders to understand the potential of viability and available funding/incentives this data and its use within the microgrid at the federal, state and local level. optimization framework. • It is important to take appropriate phys- • Planning for further renewables integra- ical safety measures while deploying tion, because rooftop space for solar PV energy storage technologies. For instance, is limited and parking lots are temporary fire safety and prevention measures are deployment locations and may not serve as extremely important when using large permanent locations well into the future. battery systems with varying chemical combinations. • There have been a number of environmental safety and health inspection permis- • Identifying vulnerabilities and taking sions given for fire and chemical hazards measures to prevent cybersecurity threats, with various energy storage technologies. ranging from data and privacy issues to major operational failures of the microgrid • Cybersecurity risks are increasingly monitoring and controller system, is of important for a university with a number critical importance, and will only become of tangible and intangible resources and more important as technologies advance. research assets, and understanding the concerns in the context of the microgrid • UCSD has realized the importance of will be an important factor in future deci- employing novel methods to develop sion making. interest and encourage participation in programs that can support microgrid oper- Best practices ations. For example, UCSD promotes “EV The UCSD microgrid has been successful Happy Hours” (periods with low-cost EV in employing various distributed energy charging) during periods of highly forecast resource technologies by overcoming multi- solar output, to help balance the microgrid ple challenges on the technical, operational, energy system. financial and environmental fronts. Some of the essential practices that have contributed to CASE STUDY 2: KODIAK ISLAND, its success are: ALASKA • When selecting and engineering advanced Background microgrid controller systems, it is critical to Kodiak Electric Association (KEA), a rural thoroughly assess the robustness, oper- cooperative utility, operates an isolated ational warranty and commercial field- electrical grid system serving roughly 5,800 tested results of the controller technologies. individual members on Kodiak Island, Alaska. • The operational purpose and functionality In 2004, the KEA board voted to pursue an of a microgrid should inform the energy ambitious plan to generate 95% of its electric- storage requirements. For instance, the size ity from wind and hydroelectric resources by and type of storage system will vary based 2020. By 2014, the utility microgrid—which on whether the microgrid is being used to has peak demand of approximately 28 MW— provide grid-support services (wholesale had already surpassed that goal, producing power market participation, ancillary ser- more than 99% of its power from wind and vices) or being used internally for balanc- hydropower, with support from flywheel and ing energy system services in island mode. battery energy storage systems.

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The Kodiak Island microgrid offers an excel- been added in recent years. All equipment and lent example of how different types of energy technologies deployed within the microgrid storage technologies can function within an are detailed below and the energy generation islanded microgrid that supports a variety of technologies, controls systems, and other loads and generation sources. resources included in the microgrid are shown in Appendix B. Project Drivers and Motivations KEA has operated an islanded electric grid Microgrid Design and Operation system or island microgrid since 1941. How- Key Operational Features ever, given the need to upgrade port infra- The Kodiak Island microgrid has undergone structure and move away from costly diesel a significant number of changes in recent generation, the integration of new energy years. The integration of new resources and resources and storage technologies has played technologies has led to the need to continu- a key role in developing the microgrid as it ously balance the overall system and respond exists today. The main drives for pursuing to frequency fluctuations. The characteristics these upgrades were: detailed below highlight some of the key • Wind turbines were installed in 2009 operational features and considerations for *correction: diesel fuel (4.5 MW) and 2012 (4.5 MW) in order to the newly incorporated technologies: estimated savings of almost decrease the reliance on costly diesel fuel • Terror Lake is the largest form of energy 2,000,000 gallons per year. (estimated to save 20,000* gallons per year). storage that is deployed within the micro- • In 2012, the City of Kodiak was planning grid, generating roughly 124,400 MWh to install a 2 MW electric crane at its Pier of electricity annually, and providing III to replace the older, less efficient die- long-term storage of excess wind energy sel-powered crane. The new electric crane as opposed to responding to intermittent would create destabilizing power fluctu- loads on a second-to-minute (BESS) or ations and undesirable battery cycling, microsecond basis (FESS). so a new flywheel energy storage system (FESS) was installed to effectively integrate • The BESS stabilizes variable wind genera- the crane load onto the KEA grid and pro- tion on a second-to-minute basis and also vide frequency and voltage regulation. provides frequency regulation. Both the BESS and FESS are able to inject both real • The wind and FESS projects would play and reactive power to the microgrid and a key role in decreasing the dependency provide spinning reserves for the large on diesel fuel that had been previously load fluctuations while the newly installed used to power the crane, and operated electric crane is in use. inefficiently as a spinning reserve on an as-needed basis. • Large frequency changes or disturbances were the main driver when originally inte- • The project would also allow for the integrating the BESS with the wind and hydro gration of a greater number of renewable generation, although the primary activity of resources (hydro and wind) and provide the BESS has been in response to microsec- grid stabilization services given the vari- ond frequency fluctuations on the system. ability of renewable energy generation. The integration of the FESS reduces stress • These technological upgrades and addi- and increases cycle life on the BESS by tions would also serve as a model for being able to respond to microsecond fre- remote communities looking to integrate quency changes on the system. This allows variable loads, renewables and /or energy the BESS to function as originally designed. storage onto their system. Energy Storage Integration and Microgrid Equipment and Technologies Deployment The Kodiak Island microgrid has historically The Terror Lake hydro project has long served relied on diesel and hydroelectric power gen- as the main source of energy storage within eration, but new hydroelectric turbines, wind the microgrid. Water is stored in the form of turbines and energy storage technologies have potential energy and is released for hydroelec-

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tric power generation as needed. Terror Lake Controls and Communication Systems provides long-term storage for the excess wind The Kodiak Island microgrid uses a net- energy on an annual basis. The Terror Lake worked ABB Microgrid Plus control system system is also able to respond to over- to manage the various energy resources. ABB frequency disturbances caused by high pene- MGC600 Decentralized Microgrid Control tration of wind energy onto the microgrid system is also used, consisting of distributed through an internal governor system that control modules for all resources coordinated can rapidly limit hydro power output. on a peer-to-peer basis, allowing communication among and between resources. However, given the requirements for responding to over-frequency disturbances and the For details on these systems, see Section 4.2.2.3 short-term storage required with variable of CEATI’s Coordination of Energy Storage wind power, the incorporation of the BESS within Microgrids was needed in order to stabilize the highly variable wind generation and provide addi- Microgrid Ownership Structure tional services for under-frequency distur- and Financing bances when wind output suddenly drops. Kodiak Electrical Association (KEA) owns and operates the microgrid, which has been The incorporation of the BESS into the Kodiak funded through a number of sources, includ- Island microgrid has allowed all storage ing grant money created by the Alaska Energy resources to operate more efficiently and Authority fund, Alaska Legislature, KEA and effectively. The FESS stores short-term energy Clean Renewable Energy Bonds (CREBs), and responds to frequency fluctuations on which were provided through Co-Bank, a a microsecond basis that are caused by the cooperative bank that funds rural utilities. electric crane. The recent FESS project was coordinated and funded through a public-private partnership, The FESS is also critical in responding to other with KEA contributing a total of $3.5 million over-frequency disturbances produced by the to the project, and Matson (crane equipment sudden increase in wind output that the Terror provider) and the City of Kodiak contributing Lake system cannot address. It is designed to $400,000 each. respond first to these microsecond frequency variations, and is also able to inject both Key Takeaways from Interviews real and reactive power onto the microgrid ICF interviewed Nathan Adams, director of through the ABB inverters within the individ- microgrids and renewable automation at ABB ual Power Store flywheel units. and discussed his experience in using energy storage within microgrids, with a focus on the This allows the BESS to serve its original pur- Kodiak Island microgrid. Adams emphasized pose in essentially bridging the gap between the importance of correctly identifying the intermittent wind generation and a ramp up specific need for energy storage in the microg- of hydro generation. The PowerStore system rid under consideration and selecting the most operates under two different control modes appropriate storage technology for meeting discussed in the next section, Controls and that need. Communication Systems. Until about 5 years ago, when the cost of energy Although the different storage systems within storage was high, the primary role of storage the Kodiak Island system essentially operate in microgrids was to support the intermittent on different time scales, the combination of renewable power. However, with the decrease the Terror Lake storage, BESS and FESS is able in the cost of energy storage, energy shifting to fulfill the technical needs of the microgrid, and peak shaving applications of storage within while also limiting stress on certain compo- microgrids are becoming more cost effective. nents. This combination of storage resources makes the microgrid more robust in its opera- A range of storage technologies are now tional capabilities and more responsive when available, but are generally not well under- reacting to grid disturbances. stood by the market that may be buying them.

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Given the nascent nature of the energy storage • The BESS works to smooth renewable market, there have been many cases in which generation from wind output, and also those who have invested in deploying storage provides under-frequency responses technology have not been able to achieve the when wind output decreases, allowing desired results. In one of these instances, the the renewable resources to operate most storage system was not sized correctly for efficiently and cost-effectively. the application, while in another, the storage • The FESS has helped the BESS operate as system did not meet the charging/discharging originally designed and protected it from speed requirement for the applications. unintended operational processes that The Kodiak Island microgrid took these caused degradation of the BESS before concerns into consideration when ABB was the FESS was implemented. approached to install a storage system to sup- • The FESS was instrumental in providing a port the new crane. ABB’s flywheel technol- variety of services for the integration of a ogy and MGC controller appropriately meet new electric crane, which increases effi- the site application, which requires the storage ciency for the fish processing industry in to maintain system frequency while support- Kodiak and does not use costly diesel for ing the crane’s operation. operation.

Adams also noted that financing for microgrid • The FESS is essential in protecting the projects is challenging because they do not existing BESS from providing rapid typically present the scale of investment that response to frequency fluctuations, and is attractive for large lending organizations. will allow the BESS to operate as originally Therefore, capital grants and incentives are designed. important for such deployments. • The FESS also provides a number of services to the microgrid, including backup Project Benefits, Challenges and power, excess energy storage (from the Best Practices intermittent resources), frequency regu- Project benefits lation in grid support mode and voltage The incorporation of renewable energy regulation in crane support mode. resources and multiple energy storage systems Project challenges into the Kodiak Island microgrid has not only provided multiple benefits to the technical A number of challenges arose throughout operation of the Kodiak electrical system, but the commissioning and initial operation of also to the surrounding community, including the Kodiak Island microgrid, many of which residential, commercial and industrial custom- were due to the remote location and climate, ers. These benefits are: and unique configuration of the isolated grid that KEA operates. These challenges were: • The increased use and integration of cleaner generation sources like hydro • KEA had limited knowledge on how to and wind energy has allowed KEA to manage grid frequency and voltage issues decrease its reliance on diesel fuel to inherent to intermittent wind resources due generate power, providing benefits to the to the limited examples at the time. Thus, environment and also decreasing prices the integration of the electric crane with the for end-use electric customers. new and existing energy storage systems was a primary engineering challenge. • The integration of a variety of forms of energy storage has allowed the microgrid • There were issues related to the timeline to operate more efficiently, and made it of funding, system design and turbine possible to respond to different disturbance construction. events produced by resources or loads.

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• Kodiak’s remote location made wind tur- ious system configurations and use cases, bine transport and installation difficult. Due which could validate a microgrid design to extreme weather variations, the installa- and significantly increase the success rate tion had to take place in the summer. of physical deployments. • KEA faces additional and ongoing opera- • The Kodiak Island microgrid demonstrates tional challenges because of Kodiak’s wet how incorporating various kinds of energy and windy climate, which can cause excess storage to provide different types of func- water to collect inside the turbine hubs. tionality can improve the overall flexibility • There were additional challenges with the of a microgrid. Ensuring that the various regulatory system related to how different energy storage technologies accurately agencies viewed the integration of dif- meet the site characteristics and resources ferent distributed energy resources and is key to a successful deployment. energy storage resources, and the potential • Remote island communities with similar functions that they could provide. technical capabilities can use Kodiak Island as an example of how communities can Best Practices decrease their reliance on costly fossil fuels The Kodiak Island microgrid represents a (e.g., diesel) in order to achieve environ- unique situation where different forms of mental and economic goals. The upfront energy storage can be used to meet a variety costs of microgrid applications can be sig- of technical challenges and foster the incor- nificant, but the savings over time should poration of renewable energy within a remote not be overlooked. microgrid. Some best practices that led to the successful deployment of this project are: • A variety of funding options and resources can be used when pursuing this type of • The BESS was originally designed to community microgrid project. Interested provide storage and other services on a parties seeking financial assistance should second-to-minute basis, but was largely consider state renewable energy funds, used to respond to microsecond frequency Clean Renewable Energy Bonds (CREBs), fluctuations on the microgrid. This caused local programs and local financial institu- significant stress on the battery and tions, among other options. significantly impacted its projected life- time, which was determined by detailed performance data obtained for the BESS. Conclusion Therefore, it is critical to identify both the This article will give cooperatives insights— current and future technical requirements through the case studies—into how energy for an energy storage system in the micro- storage can be used in various configurations grid and select an appropriate energy and for different types of microgrids. Cooper- storage system (or combination of systems) atives also will benefit from the best practices accordingly. One method would be to gen- developed for incorporating energy storage in erate a simulation model to evaluate var- microgrids. n

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APPENDIX A: UCSD MICROGRID ENERGY TECHNOLOGIES

The energy generation technologies, control systems and other resources included in the microgrid are shown below:

EXCERPT A-1: Microgrid Energy Generation Technologies, Control Systems and Other Resources (Source: CEATI report: Integration and Coordination of Energy Storage within Microgrids, pp 30)

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APPENDIX A: UCSD MICROGRID ENERGY TECHNOLOGIES (CONT.)

The figure below shows a simple schematic of the UCSD microgrid and how the energy storage and distributed energy resources components interact with the site loads.

Electrical Energy Storage Non-Renewable Generation

Lithium-ion batteries 100kW/300kWh 28kW Ultra 200kW/800kWh — 2.5MW/5MWh Advanced Zinc/Bromine Capacitors Compressed Air 30 Nat Gas CHP Diesel Backup Energy Storage System Flow Battery — 2x 13.5 MW NG turbines — 2x <35kW/35kWh Systems — 1x 3 MW steam Turbines — 2x PV Integrated Systems

Renewable Generation

UCSD Substation Power Management System 2.8 MW Directed Biogas Fuel Cell To Utility

2.9 MW Solar PV Network SEL Powermax Microgrid Controller Paladin Master Controller OSIsoft Pi Sensor System Off Peak PMU Utility Monitoring System

Thermal Energy Storage Peak Demand 47 MW Electricity Consumers

4000 Controlled Theromostats

56 EV Charging Stations Chilled Water Thermal Storage Cooling 39,000 ton-hours Residential & Institutional

FIGURE A-1: UCSD Microgrid Shematic Showing Energy Storage and Distributed Energy Resources Interaction with Site Loads (Source: CEATI report: Integration and Coordination of Energy Storage within Microgrids—pp 31, Figure 4-2)

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APPENDIX B: KODIAK ISLAND MICROGRID ENERGY TECHNOLOGIES

All equipment and technologies deployed within the Kodiak Island microgrid are show below:

EXCERPT B-1: Kodiak Island Microgrid’s Equipment and Technologies (Source: CEATI report: Integration and Coordination of Energy Storage within Microgrids—pp 37-38, Section 4.2.1.3)

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APPENDIX B: KODIAK ISLAND MICROGRID ENERGY TECHNOLOGIES (CONT.)

The figure below shows a simple schematic of the Kodiak Island microgrid.

Renewable Generation Energy Storage Energy Storage

Terror Lake Hydro Pillar Mountain Wind Younicos Lithium-Ion Batteries 2x ABB PowerStore Flywheel 31 MW Turbines 3 MW 2 MW total 9 MW

Power Management System Kodiak Island Substation

ABB Microgrid Plus Non external grid ABB MGC600 Decentalized Microgrid Control connection Peak Demand Non-Renewable 26 MW Electricity Consumers Generation

Diesel Generators Commercial & Residential Fisheries Industry

FIGURE B-1: Kodiak Island Microgrid Schematic (Source: CEATI report: Integration and Coordination of Energy Storage within Microgrids—pp 38, Figure 4-4)

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ABOUT THE AUTHOR

Alice Clamp is a technology writer for the Virginia-based National Rural Electric Cooperative Association. With more than two decades of experience in the energy field, she has researched and written articles on renewable energy, nuclear energy, fossil fuels, grid reliability, environmental issues, energy efficiency, demand response, and emerging technologies.

QUESTIONS OR COMMENTS

• Daniel Walsh, Senior Power Supply & Generation Director: [email protected] • Jan Ahlen, Director—Energy Solutions: [email protected] • To find more resources on business and technology issues for cooperatives, visit our website.

GENERATION, ENVIRONMENT, AND CARBON WORK GROUP

The Business and Technologies Strategies—Generation, Environment, and Carbon Work Group is focused on identifying the opportunities and challenges associated with electricity generation. Surveillance research relevant to this work group looks at the various aspects of electricity generation technology, including market status, related policies and regulations, and business models to assist cooperatives in making operational and investment decisions. For more information about technology and business resources available to members through the Generation, Environment, and Carbon Work Group, please visit www.cooperative.com, and for the current work by the Business and Technology Strategies department of NRECA, please see our Portfolio.

LEGAL NOTICE This work contains findings that are general in nature. Readers are reminded to perform due diligence in applying these findings to their specific needs, as it is not possible for NRECA to have sufficient understanding of any specific situation to ensure applicability of the findings in all cases. The information in this work is not a recommendation, model, or standard for all electric cooperatives. Electric cooperatives are: (1) independent entities; (2) governed by independent boards of directors; and (3) affected by different member, financial, legal, political, policy, operational, and other considerations. For these reasons, electric cooperatives make independent decisions and investments based upon their individual needs, desires, and constraints. Neither the authors nor NRECA assume liability for how readers may use, interpret, or apply the information, analysis, templates, and guidance herein or with respect to the use of, or damages resulting from the use of, any information, apparatus, method, or process contained herein. In addition, the authors and NRECA make no warranty or representation that the use of these contents does not infringe on privately held rights. This work product constitutes the intellectual property of NRECA and its suppliers, and as such, it must be used in accordance with the NRECA copyright policy. Copyright © 2020 by the National Rural Electric Cooperative Association.

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