PEORIA, Ill. (WMBD) — Residents in Peoria County can expect to pay more on their energy bills this summer.

Ameren Illinois customers living in the City of Peoria or Peoria County will see their utility bills increase by more than $500 per year, area leaders announced Tuesday. That increase will be felt as early as the June billing period.

Leaders cited “soaring capacity auction prices” from April’s Midwest capacity auction, which helps determine power rates that pay for generators to maintain operations for grid capacity.

Those higher auction prices signaled a shortfall of generation reserves across the entire Midwest region, which impacts Ameren’s default utility rates and aggregation contract prices.

According to the Midcontinent Independent System Operator (MISO), Illinois is one of 11 states where there is not enough owned or contracted capacity by local electricity generators.

As a result, residents are expected to pay increased prices for limited supply.

MISO said the shortfall in energy is due to several factors. One example is the phase-out of fossil fuels, and renewable energy sources are not yet providing enough energy to fill the gap.

Global demand for energy coupled with market turmoil due to the conflict in Ukraine also does not help the situation. Brownouts, or intentional lowering of voltage by a utility for a short period of time, are also possible, according to MISO.

“We realize that the increase in energy costs could pose a financial burden on our community members and the cities and counties engaged in our buying group are working hard to provide the best possible alternative for our residents,” said City of Peoria City Manager Patrick Urich, “As more information becomes available on the pricing and term we will be able to provide our residents, we will make that available to all.”

“We urge both residential and commercial customers to examine their energy usage and plan ahead for these increases,” said Scott Sorrel, Peoria County Administrator. “Ameren’s website and are two great resources for energy and cost-saving advice.”