The latest news on wind and solar storage

Accelerating energy transition towards renewables is central to net-zero emissions. However, building a global power system dominated by solar and wind energy presents immense challenges. Here, we demonstrate the potential of a globally interconnected solar-wind system to meet future electricity demands.

Energy Dome and Alliant Energy's 200MWh long-duration energy storage (LDES) project in Wisconsin, US, has been approved by state regulators. The Ministers of Energy and the Environment in Lithuania have approved an additional €37 million (US$43 million) for an energy storage capex grant scheme, while Trina Storage has secured orders in the country.

High penetration of solar-wind generation is invariably associated with increased curtailments and system-wide costs, with pronounced marginal cost effects. For instance, the cost increase required to raise penetration from 78% to 80% is more than four times that of raising it from 72% to 75%.

One of the biggest solar and storage projects underway in the U.S. is Longroad Energy's Sun Streams Complex in Arizona, totaling 973 MW of solar and 600 MW/2.4 GWh of battery storage capacity. After the first two phases began operations in 2021 and 2024, the fourth and largest project is underway with 377 MW of solar and 300 MW/1.2 GWh of storage.

When solar-wind generation within a grid exceeds its net power demand (i.e., total demand minus baseload), surplus power is first transferred to interconnected grids experiencing shortages, with the remaining surplus stored until capacity is reached. Any surplus beyond storage capacity is curtailed.

Under the S-G scenario, the decline in solar-wind electricity supply caused by the complete outage of a single regional grid averages only 2.6% (ranging from 0.7% to 11.7%), compared to declines of 5.8%, 15.1%, and 26.4% under the S-C, S-A, and S-I scenarios, respectively (Fig. 4b).