Electricity demand varies throughout the day and seasonally (U.S. Department of Energy (DOE) 2016). Generally, daily demand peaks in the late afternoon and early evening. Over the course of a year, energy demand in MO peaks in summer and again in winter (Energy Information Administration (EIA) 2026, Lawson 2019). These peaks correspond to highest cooling and heating demands.
Baseload power refers to sources that have constant operation to meet constant demand (DOE 2016). To meet daily peak demand, the grid needs power sources that can quickly increase or decrease their output, known as ramping. Variable sources of generation, like solar and wind, can lower the amount of ramping required to meet peak demand. When demand is low, these variable sources can charge storage systems to save energy for later use (Lawson 2019).
Nuclear energy, coal, and hydropower deliver baseload power (U.S. Environmental Protection Agency n.d.). Natural gas, oil-based fuels, and stored solar and wind power help meet daily peak demand. Solar and wind are used as they are generated to either lower peak demand on other sources or charge storage systems.
In Missouri, the largest sources of electricity generation are: (EIA 2026)
Between 2020 and 2025, monthly electricity generation in MO peaked around 7,300 gigawatthours (GWh) in July and August (EIA 2026, Figure 1). Average monthly generation was lowest in April, around 4,900 GWh, or about two-thirds of the summer peak. Nationally, electricity generation followed a similar pattern over the same period. On average, 423,000 GWh were generated in July, compared to 301,000 GWh in April.
Coal and natural gas generation increased in the summer and winter when electricity demand increased (EIA 2026, Figure 1). Wind generation was highest in spring and autumn, while nuclear production stayed relatively steady throughout the year.
For more information on the benefits and limitations of different sources of electricity, see our Science Note on Grid Reliability.
Figure 1. Average MO electricity generation by source, 2020-2025. Energy generation amounts are in gigawatthours (GWh). Electricity generation peaks in the winter and summer when heating and cooling demands are greatest. Nuclear power typically provides steady generation when operating. Wind generation is highest in the spring and autumn. Coal and natural gas generation increase to meet peak electricity demand. Data from EIA 2026.
References
Energy Information Administration (EIA) (2026) Electricity Data Browser. Link.
Lawson AJ (2019) Variable Renewable Energy: An Introduction. Congressional Research Service. IF11257. https://www.congress.gov/crs-product/IF11257
U.S. Department of Energy (DOE) (2016) Maintaining Reliability in the Modern Power System. https://www.energy.gov/sites/prod/files/2017/01/f34/Maintaining%20Reliability%20in%20the%20Modern%20Power%20System.pdf
U.S. Environmental Protection Agency (n.d.) Electric Power Sector Basics. https://www.epa.gov/power-sector/electric-power-sector-basics
