Last month, we predicted that summer temperatures might drive high demand — high enough to cause a peak day! Indeed, despite the depressive effect of the COVID-19 pandemic on regional electricity demand, weeks that saw 90+ degree days across New England were enough for us to call peaks on July 20th, 27th, and 28th. A peak electricity demand day is a day on which extreme weather (usually hot temperatures) leads to a spike in electricity demand; these spikes are associated with more expensive and polluting electricity than usual.

Last month, we covered some of the impacts that COVID-19 and the resulting stay-at-home orders have had on our electric grid. This month, the pandemic has continued to drive low electricity demand and record low electricity prices. Even better, low demand and higher than ever solar production has led to a greener grid. But as temperatures rise and stay-at-home orders relax this summer, can we expect low demand, prices, and emissions to continue?

Over the past two months, the world’s daily patterns have changed drastically. As we know from Shave the Peak, even small changes to routines, especially during peak hours, can have an outsize impact on the emissions, costs, and fuel mix of our electricity system. So it’s no surprise to see that the pandemic and the subsequent stay-at-home orders have shifted many aspects of the electricity mix, here in New England and beyond. In fact, the average cost of electricity during March was the lowest in market history, in large part because of the pandemic.

So what’s going on in our electricity mix, and why? And perhaps most importantly, what lessons from the pandemic’s impact on the electric system should we be taking into the future?