Customers in Illinois purchasing power from Commonwealth Edison can expect their electricity rates to fall 2 percent, or roughly $1.70 per month, in June after a recent ruling by the Illinois Commerce Commission.

According to the Chicago Tribune, the decline in prices will follow a lower rate of return for the company, spurred by a new formula it uses to set electricity rates. The new formula also calls for $2.6 billion in investments the utility plans to make to not be included on customers' energy bills.

The rate decreases could be the last Illinois energy users see for some time, as rates are expected to rise again in January 2013 during ComEd's 10-year plan to install smart grid devices across its grid network. However, with energy deregulation laws passed in Illinois, the state's electricity users now have the option to shop around for their electricity rates, the media outlet stated.

New pricing schemes can be highly confusing at times, but several resources have been made available to help customers understand electricity rates and payment options for electricity. In short, customers can receive a monthly bill with a fixed energy price, protecting them from sharp spikes in rates.