Increased pairing of Battery Energy Storage Systems (BESS) with renewable resources – solar and wind – will provide for stabilizing of the U.S. Grid by leveling loads, while also providing a full range of energy management services.  Pairing is driven by the need to store excess energy for later times when intermittent renewable energy resources, such as sunlight and wind are not available.  BESS paired with renewables improves the system’s overall capacity factor from the point of interconnection.

Figure 1.0 illustrates load leveling resultant from charging in the early hours and discharging during peak demand (Center for Sustainable Systems).

Figure 1.0 – Load Leveling

Declining battery costs combined with increases in state renewable energy targets will support adoption of utility scale BESS that enable integration of intermittent renewable resources on the grid, as well as replacing traditional generation sources (Gibson). 

Some of the notable projects include:

• The Gemini Project BESS is an early stage, pre-construction, energy storage project located in Las Vegas, Nevada. The 690 MW solar project (Gemini Solar) being planned for 25 miles northeast of Las Vegas may include a 531 MW battery component to allow power delivery, even when the sun has set. The Owner, Developer, and EPC Arevia Power began construction in the 3^rd Quarter of 2019 with plans to be operational by 2023 (Zimmerman).
• The FPL Manatee Energy Storage Center project is an early stage, pre-construction energy storage project located in Manatee County, Florida. The 409 MW Manatee Energy Storage Center is scheduled to be operational by 2021. In connection with the 74.50 MW FPL Manatee Solar Energy Center (Solar PV), this energy storage project is being built to help phase out two units of its gas-fired Manatee Clean Energy Center (Zimmerman).
• The Hawaii Public Utilities Commission approved six solar-plus-storage projects for the Hawaiian Electric Companies; totaling 253 MW of solar, and 1 GWh of energy storage (Hawaiian Electric).

Leveling the playing field for market participation, FERC Order 841 requires each RTO/ISO to revise its tariff to establish a participation model consisting of market rules that recognizes the physical and operational characteristics of electric storage resources and facilitates their participation in the RTO/ISO markets (Electric Storage).

Protection engineers will continue to be challenged to design invertor-based BESS with safety and reliability considerations at the fore front.  Specifically, low fault current characteristics of invertor-based BESS make detecting and responding to faults difficult.  The article, Impact of the Penetration of Inverter-Based Systems on Grid Protection, by L. R. Tuladhar and K. Banerjee identifies how protective relays may lose the ability to sense fault conditions because the available fault current is drastically reduced.  Furthermore, traditional analysis software lacks adequate modeling of invertor-based BESS (Tuladhar and Banerjee). 

NFPA unveils its new 2020 edition of NFPA 855, Standard for the installation of Stationary Energy Storage Systems, which was created to address the rise in use of new technologies in modern energy storage systems and the fire and life safety hazards associated with them.  The Standard specifies the requirements for the installation of energy storage systems including locations, size and separation, and fire suppression and control.

Look for safety and protection engineering concerns to require considerable effort in 2020 and beyond.

REFERENCES

Center for Sustainable Systems. "U.S. GRID ENERGY STORAGE FACTSHEET." University of Michigan, css.umich.edu/factsheets/us-grid-energy-storage-factsheet. Accessed 20 Jan. 2020.

"Electric Storage Participation in Markets Operated by Regional Transmission Organizations and Independent System Operators." FERC Order No. 841. www.ferc.gov, www.ferc.gov/whats-new/comm-meet/2018/021518/E-1.pdf. Accessed 22 Jan. 2020.

Gibson, Trevor. "Lithium-Ion Battery Prices are Declining, Powering Growth and Opportunity in the U.S. Energy Storage Market." Smart Electric Power Alliance, 15 Aug. 2019, sepapower.org/knowledge/lithium-ion-battery-prices-are-declining-powering-growth-and-opportunity-in-the-u-s-energy-storage-market/. Accessed 20 Jan. 2020.

Hawaiian Electric. "Six Low-Priced Solar-Plus-Storage Projects Approved for Oahu, Maui, and Hawaii Islands." Hawaiian Electric, 27 Mar. 2019, www.hawaiianelectric.com/six-low-priced-solar-plus-storage-projects-appr.... Accessed 22 Jan. 2020.

Maiello, Michael. "The Battery Energy Storage System (BESS) Primer." Energy CIO Insights, battery-technology.energycioinsights.com/cxo-insights/the-battery-energy-storage-system-bess-primer-nwid-336.html.

rmi.org. rmi.org/wp-content/uploads/2017/03/RMI-TheEconomicsOfBatteryEnergyStorage-FullReport-FINAL.pdf.

Tuladhar, L. R., and K. Banerjee. "Impact of the Penetration of Inverter-Based Systems on Grid Protection." CIGRE US National Committee, 2019 Grid of the Future Symposium.

Zimmerman, Greg. "2019 Top 10 Energy Storage Battery Projects." Energy Acuity, 22 July 2019, energyacuity.com/blog/2019-top-10-energy-storage-battery-projects/. Accessed 20 Jan. 2020.