Renewable energy power plants are more often being built with energy storage systems, especially batteries, as the cost of energy storage continues to fall, according to the U.S. Energy Information Administration (EIA). And Todayâ€™s Power Inc., a subsidiary of Arkansas Electric Cooperatives Inc., is in the final stage of completing another solar array with battery storage.
The number of solar and wind generation sites that include battery storage has risen from 19 in 2016 to 53 in 2019, according to the EIA. The trend is expected to continue, based on planned installations. Another 56 renewable energy plants with battery storage are expected to be completed by the end of 2023.
Some of the benefits of combining renewable energy plants with energy storage include the ability to store energy as itâ€™s generated and redistribute it when itâ€™s needed as opposed to when itâ€™s produced. This reduces the need to limit renewable generation and allows the energy to be used amid high electricity demand.
The most common use for battery storage at renewable energy plants is storing excess energy, but the batteries also help to maintain the gridâ€™s electric frequency. The storage also provides transmission and distribution support and helps to smooth out energy flows. Some of the factors contributing to the rise in the storage systems at renewable energy plants include the ability to support the integration of renewables into the gridâ€™s existing infrastructure and other ancillary services such as frequency regulation.
More than 90% of the total operating capacity of the plants with energy storage is in nine states. Texas has 46% of the existing total, and 10 plants account for more than half of the total. However, only 1% of total wind capacity and 2% of total solar capacity include energy storage.
The average generating capacity and energy storage at U.S. renewable energy plants are projected to increase, and by the end of 2023, average renewable capacity at proposed U.S. facilities will more than double from 34 megawatts to 75 megawatts, and the average battery capacity will increase from 5 megawatts to 36 megawatts.
In northeast Arkansas, Todayâ€™s Power Inc. (TPI) recently completed the test energy phase for a solar plant with battery storage. The project has moved to its final phase, the commissioning stage, said Jennah Denney, marketing and public relations coordinator for TPI. The solar energy company is working with Southland Gin, Delta Farms and Craighead Electric Cooperative to develop a 2-megawatt system with 6 megawatts of battery storage in Bay. Construction started in late November.
In 2019, TPI completed a 10-megawatt solar plant in Fayetteville that includes 24-megawatt-hours of battery storage. Earlier this month, TPI completed a 1-megawatt solar array for C&L Electric Cooperative in Star City.
Also, Entergy Arkansas recently received regulatory approval to build a 100-megawatt solar power plant with 30-megawatt-hours of battery storage in White County near Searcy as the largest utility-owned solar project in the state. It is expected to be completed in 2021 as Entergy Arkansasâ€™ third solar array, expanding the utilityâ€™s solar energy capacity to 281 megawatts. A 100-megawatt array near Lake Village is expected to be completed later this year, and the 81-megawatt Stuttgart Solar Energy Center has been operating since 2018.