Cloud cover cuts solar generation, and on calm days wind turbines won’t spin. When cloudy and windless conditions coincide for hours or days, the result is called a compound energy drought. Pacific Northwest National Laboratory recently found that these energy droughts can last nearly a week in some parts of the country and that they overlap with periods of peak grid demand more often than would be expected by chance.

Australia’s two large lithium-ion storage batteries are getting attention for all the wrong reasons. Hornsdale Power Reserve, a 150-MW battery collocated with a wind farm in South Australia, is being charged in federal court with failing to deliver on promises to respond to grid demands, and of being technically unable to deliver under the terms it was being paid to meet. Proceedings were filed September 22, just before the testing of a second Tesla-manufactured “Big Battery” resumed after a two-month delay following a fire in July.

Coal-fired plants fed the most power to Germany's electricity grid in the first half of 2021, while wind power dropped to its lowest level since 2018. As a September 13 article published on the German news site DW.com explained, the situation was blamed in part on a wind energy shortfall that is causing power price spikes across Europe.