Day of the Week

Hourly, market-based electricity prices typically change as the demand for electricity changes; prices tend to increase as demand rises. As a result, average prices tend to be higher on weekdays and lower on weekends and holidays, when some businesses and factories shut down.

Maintenance, Technical Problems, and Fuel Costs

Prices can sometimes increase in the spring or fall if a heat wave occurs during a time when some power plants are shut down for maintenance.

During the winter, electricity prices can also spike when sudden and significant temperature drops, or extended cold snaps push up natural gas prices, increasing the cost of operating gas-burning power plants.

There can also be unexpected and brief price spikes if multiple power plants have technical or mechanical problems at the same time, or if there are problems in parts of the regional transmission network that is used to transport electricity from the power plant to Ameren’s distribution system.

Natural gas and coal prices also impact the market price of electricity, so when the costs of these and other fuels increase, those changes can be reflected in hourly electricity prices.