Public Service Co. of Colorado on May 20 requested that Colorado regulators authorize a net increase to retail electric base rate revenue of $158.3 million.

The Xcel Energy Inc. subsidiary filed with the Colorado Public Utilities Commission for a 5.7% overall increase in retail electric revenue with a 10.35% return on equity. The rate increase is based on a historic test year ended Dec. 31, 2018, the company said in a Form 8-K filing.

The rate increase request would help the company to support its investments in distribution infrastructure to meet growing demand for electricity, wildfire mitigation improvements and updating outdated software.

On an annualized basis, a typical residential customer would see a monthly increase of $4.46, or 6.49%, from $68.66 to $73.12, while a commercial customer would see a $6.79 increase, or 6.67%, per month on their bills, from $101.76 to $108.55. The company, which operates under the Xcel Energy name, charges different summer and winter rates, and the percentage increase of the summer rates would be higher than the winter rates.

According to the commission filing, the rate impacts are based on an assumed effective date of the proposed rate increase of June 20. In case the commission sets the proposal for hearing, the company is requesting an effective date of Jan. 1, 2020.

Overall, Xcel Energy is seeking an increase of $407.7 million, but $249.4 million in increases have previously been approved and are being recovered through separate riders and are to be folded into base rates. That leaves a net base rate increase request of $158.3 million.