Approaches to Energy Storage in Midwest Utilities

1. How Midwest utilities are approaching different energy storage market segments  Midwest Solar Expo, Minneapolis May 1 2019 Laura Caspari Director of Origination Laura.Caspari@ENGIE.com PRESENTATION TITLE ( FOOTER CAN BE PERSONALIZED AS FOLLOW: INSERT / HEADER AND FOOTER")

2. ENGIE: A Global Snapshot ENGIE purchased SoCore Energy in April 2018. 155,000 employees worldwide Operations in more than70countries 70 billion USD revenues 11 billion USD EBITDA 17 billion USD investments over 2016-2018 including 1.2 billion USD in innovation and digital • * as of December 31, 2016

3. An Energy Revolution Is Ongoing The new energy world is characterized by decarbonization, decentralization and digitalization. DECARBONIZATION Worldwide renewable energies: annual additional capacity to grow by +70% in 2030 vs 2015 DECENTRALIZATION Decentralized solutions to more than double by 2030 DIGITALIZATION Digital changes energy systems and improves customer offers

4. Energy Storage – Why Now? Source: BNEF Source: Greentech Media BESS – GDS Associates Partners Meeting 2018

5. Case Studies Case Study: Connexus Energy, Ramsey MN | Solar + Storage Scope: • 10MWac solar, 15MW / 30MWh storage (charged from PV) to shift generation to peak time and offset peak demand • Allowed under wholesale contract with Generation and Transmission Cooperative, Great River Energy • AC coupled, 100% charging from solar to take advantage of ITC Challenges: • Original sites had development challenges and locations shifted • AHJs new to both solar and storage (permitting) Unique Attributes: • All ground cover to be native vegetation supporting pollinators and incorporating beehives

6. Case Studies Case Study: Wisconsin, Illinois, Iowa & Minnesota Electric Cooperatives | Residential VPP Pilot Some Rural Electric Cooperatives see a missed opportunity in residential solar. Their members are installing BTM solar with various installers to various specifications, leading to loss of load, etc. - Potential for a similar future trend with residential storage; want to be the provider for this service to their members. - Use the residential batteries as DERs in a VPP. Primary initial service reducing demand charges. Other values may be assessed in future. Four co-ops are participating with a total of 10 sonnen 8kW and 16 kWh batteries. Deliveries and training is complete, site installation is underway. Economies of scale driven by ENGIE’s cooperative partner, NRTC, bringing four co-ops together in this effort rather than going it alone. Initially utilizing a manual set up of discharge windows and other parameters. Dynamic VP with automatic discharge based on certain signals in progress.

7. Case Studies Case Study: Iowa Electric Cooperative, IA | Storage for T & D Deferral Scope: • 2MW / 8MWh storage Rationale: • Need for a new substation. A battery could delay this need, and improve the voltage of the feeder by reducing the peak demand of the feeder loading. • Reduce voltage fluctuations caused by the variable output of the DG due to cloud movement. • Defer need for additional new transmission to serve the area • Offset demand / transmission charges

8. Case Studies Case Study: United Power Cooperative, Brighton CO | “Community Battery” Value Proposition: • Analysis shows 25 MW (on a 450 MW peak utility) could be shaved over each of the 12 months with a duration of 4 hrs. Chose a 4 MW / 4 hr. BESS • Dispatch ~100 times per year to mitigate peak demand charges • 100% capacity guarantee for 10 years, 15-year overall wrapped warranty • Community Battery: • United’s members cannot reduce their peak (kW) charges very effectively, especially those with high load factor • United structured the community battery program like community solar: members can purchase a “share” of kW reduction from the BESS which will turn into a reduction on their retail kW charges • Allows United to partner with members for BESS savings without restructuring tariffs or waiting for significant BTM “peak shaving” penetration against their tariffs – overall, a more economic and effective approach.

9. Case Studies Case Study: Holyoke Gas and Electric , Holyoke, MA | Solar + Storage • Mt. Tom Solar Project (MA): In February 2017, ENGIE built and commissioned the 5MW Mt. Tom solar array at its decommissioned coal-fired Mt. Tom Generating Station in Holyoke, MA. The solar project provides 100% of its energy output to the Holyoke Gas and Electric distribution system. • In 2018, ENGIE added 3MW/6MWh of battery storage to the solar project. • The former coal and oil-fired generation facility, 90 miles west of Boston, operated for more than 50 years and ceased operation in 2014. • The energy storage system will enhance HG&E’s electricity system and help keep electric rates stable by reducing rising capacity charges for the utility and its customers. • GridSynergy will provide grid stability by responding quickly to electricity demand fluctuations; allow for the increased use of clean energy; and reduce peak load burden on the existing electrical distribution system.

10. Case Studies Case Study: Central Rural Electric Co-op, Stillwater OK | Microgrid • This project was awarded a Greentech Media “Grid Edge” award in 2017. It is part of a functioning “microgrid” pilot along with PV & other distributed resources. • Central’s Progressive Resource Energy Park (PREP) consists of: • A grid-tied photovoltaic (PV) system connected directly to the distribution grid. The PV system provides power for the campus and excess power is provided to the distribution grid. The system is rated at 504 kW AC with a 1.366 DC-to-AC ratio. • A battery energy storage system (BESS) is used in the PREP to mitigate the impact of solar intermittency. The BESS is a Tesla Powerpack system, rated at 250 kW/475 kWh and consists of five battery packs. Each battery pack is rated 100 kW and includes a DC combiner panel, bidirectional inverter and a site master controller. • A diesel generator rated at 750 kW was installed at the PREP for backup generation. The generator was sized to pick up all loads in one step, with the ability to satisfy the campus demand peaks, even in the absence of solar power and a fully discharged BESS.