On 12 August, most of the United States registered a daily high temperature above 90°F. The Energy Information Administration’s Hourly Electric Grid Monitor shows that electricity demand in the Lower 48 states reached 720 GWh for the hour ending 5:00 pm eastern daylight time on that day, which is the highest reported value for a single hour since balancing authorities began reporting hourly electricity demand to EIA in July 2015. The previous high was 718 GWh reported for the hour ending 6:00 pm EDT on July 20, 2017.
On hot summer days, electricity demand typically peaks later in the day. Late afternoon and early evening hours are typically the warmest times of the day, which results in increased use of air conditioners, dehumidifiers, fans, and other cooling equipment.
EIA’s Hourly Electric Grid Monitor is a centralised and comprehensive source for operating data about the high-voltage bulk electric power grid in the Lower 48 states. It provides data on hourly electricity use for the 64 BAs that operate the electric grid in the Lower 48 states.
The Hourly Electric Grid Monitor provides operating data for use by balancing authorities for much of the United States with a minimal reporting lag. However, because the data are published as reported, EIA consider them to be less definitive than the data gathered in its monthly and annual surveys. Information from those surveys is compiled in the Electric Power Monthly and Electric Power Annual reports. According to those more definitive series, US net electricity generation reached a monthly record high in August 2007 and an annual record high in 2018. Forecasts in EIA’s latest Short Term Energy Outlook show that it does not expect the United States to exceed those monthly or annual records at any point in 2021 or 2022.