The U.S. is seeing growth of energy storage capacity, particularly storage technologies colocated at power plants, to integrate a growing amount of renewable energy resources into the grid.
About 1,400 MW of energy storage capacity currently operates in the U.S., according to S&P Global Market Intelligence data. Of that, 849 MW comes from standalone projects and 563 MW is located at existing power plants though not necessarily integrated with those plants. The data is limited to projects at least 1 MW in size and excludes hydro projects and thermal energy storage technologies such as molten energy storage.
Colocated projects include specific hybrid technologies such as AES Corp.'s Lawai Solar and Energy Storage Project (Kauai Hybrid Solar & Energy Storage Project), which combines 28 MW of solar photovoltaics with 100 MWh of storage capacity.
About 2,765 MW of colocated storage capacity is in development, at both existing and planned power plants, with about 63% paired with solar facilities.
Some of the larger solar-plus-storage projects in development include 250 MW of storage capacity at NextEra Energy Inc.'s proposed 250-MW Yellow Pine Solar facility in Nevada and a 110-MW storage facility NextEra proposed at its 131-MW Riverside County Solar Project in Riverside County, Calif.
In California, three batteries, totaling 300 MW/1,200 MWh, are in development at the AES Alamitos Energy Battery Storage Array, sited along with more than 1,000 MW of new gas capacity scheduled at AES' Alamitos Repowering and Alamitos Repowering CT projects. Also in California, Vistra Energy Corp. is planning the 300-MW/1,200-MWh Vistra Moss Landing Energy Storage project at its mothballed Moss Landing plant, operated by subsidiary Dynegy Inc.
PPL Corp. subsidiaries Kentucky Utilities Co. and Louisville Gas and Electric Co. are testing 1 MW of operating storage capacity and 2 MW of planned capacity at a site in Mercer County, Ky., that includes their 688-MW E.W. Brown coal plant, 10-MW E.W. Brown Solar Project (Universal Solar Facility) and 1,004-MW gas-fired E.W. Brown CT plant.
Economics of combining storage with renewables
Felix Maire, a senior analyst for policy and technology analytics at S&P Global Platts Analytics, expects over 7,000 MW of energy storage to be deployed by 2022, particularly from batteries, as outlined in the U.S. Power Storage Outlook published Jan. 17. California is one large market, Maire said in a separate interview, as are several areas outside of organized wholesale power markets. For instance, he sees almost 1,000 MW of storage being proposed with solar in Nevada.
For the outlook and his modeling, Maire found that "when you combine storage with solar PV in these types of states with very high solar resources, these resources start to compete with natural gas peakers. That's why you see more and more announcements in the southwest for solar-plus-storage assets."
The federal investment tax credit also improves the economics of combined solar-and-storage facilities. "It really depends on federal policy because the primary driver for solar-plus-storage is the federal [investment] tax credit," he said. "Because if you build solar-plus-storage, you can basically get the share of the solar investment tax credit."
The type of storage seeing the most growth depends on how wholesale power markets update their rules to comply with the Federal Energy Regulatory Commission's Order 841, Maire added.
Looking at battery storage technologies on their own, Platts Analytics sees more than 21,000 MW in development across the seven U.S. wholesale power markets. In the California ISO, for example, there were 9,226 MW of standalone storage in the queue, three times the capacity in June 2018. The Southwest Power Pool Inc. had 4,373 MW in its queue.
In the Electric Reliability Council of Texas, standalone storage capacity in the queue hit 2,847 MW in February, nearly 14 times the amount since June 2018.
In the PJM Interconnection, there is about 1,000 MW of standalone storage capacity requesting to interconnect and nearly 2,000 MW from hybrid storage projects, mostly solar-plus-storage, Andrew Levitt, a senior business solutions architect at the grid operator, said Feb. 13 at the Energy Storage Association's policy forum in Washington, D.C.
S&P Global Market Intelligence and S&P Global Platts Analytics are owned by S&P Global Inc.
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