Most of the projects analysed in the Battery Storage in the United States: An Update on Market Trends July 2020 report combine solar-PV and lithium-ion battery-storage technology.
Declining energy storage costs are driving the increasing trend to pair renewable generation and energy storage.
Between 2016 and 2019, the number of solar and wind generation sites co-located with battery-storage systems more than doubled, from 19 paired sites in 2016 to 53 in 2019.
The EIA’s projections suggest installed operational renewables-plus-storage capacity will increase from just over 2GW in 2020 to about 4.5GW in 2021, to a little over 6GW in 2022 to just over 8GW in 2023.
As of February 2020, more than 90% of the operating capacity from co-located battery and renewable-generation sites is located in nine states, the EIA found (see chart, next page).
Texas had the most operational capacity with 886MW, followed by Illinois, Florida, Hawaii, California and New Mexico.
The chart shows that in terms of energy storage, as a proportion of operational co-located renewables and storage capacity, Texas has the most, followed by Hawaii, Arizona, Illinois and then Florida.
New states to the fore
However, by the end of 2023, based on projected capacity from announced and reported projects due to be installed in the period, that breakdown of states looks very different.
Texas remains in the lead, just ahead of Nevada. Texas is expected to install around 1.2GW of storage-plus-renewables, taking the total installed capacity to just over 2GW by the end of 2023. Most of this projected capacity, amounting to just over 1GW, will be renewables generation, with storage making up the rest.
Nevada, a state with virtually no co-located renewables and storage capacity at present, is set to install just under 2GW of renewables-plus-storage capacity by the end of 2023. A third of the capacity will be storage, the rest will be renewables, almost all of it solar PV.(see box)
California is in third place, with just over a 1GW of installed renewables-plus-storage capacity by the end of 2023. Over the next three years, the ratio of storage capacity in proportion to renewables looks set to increase, so that it will account for around a third of renewables-plus-storage capacity.
Florida will be in fourth place in terms of installed renewables-plus-storage capacity, with just under 700MW. In this case, most of the capacity installed in 2020-23 will be storage.
On average, existing co-located projects have a renewable nameplate capacity to battery power capacity ratio of 6:1, while planned projects have a ratio of 2:1.
While Covid-19 will likely have a short-term impact on the financing and construction of hybrid projects, longer-term demand is expected to remain strong in the US, according to Deloitte’s mid-year update to its 2020 Renewable Energy Industry Outlook.
In March this year, the Public Utilities Commission of Nevada (PUCN) established biennial targets for state power company NV Energy to guide its procurement of energy storage, beginning with 100MW by the end of 2020 and increasing in 200MW increments to reach 1,000MW by the end of 2030.
The targets, in accordance with a state law passed in 2017, are goals rather than mandates. Electric utilities only have to procure energy storage if the benefits outweigh costs for ratepayers. The regulation requires utilities to consider the targets in their integrated resource plans (IRPs), however.
Under its latest plan, NV Energy is developing 816MW of solar-plus-storage capacity, split into 478MW of solar and 338MW of battery capacity.
The capacity is being developed as three projects, all due online by the end of 2023: Dry Lake, comprising 150MW of solar and a 100MW four-hour battery; Boulder Solar III, with 128MW of solar and a 58MW four-hour battery; and Chuckwalla, consisting of a 200MW solar array and a 180MW four-hour battery.