Colorado's largest combination utility Xcel Energy on Tuesday asked the Colorado Public Utilities Commission (PUC) for limits on its efficiency and renewable energy programs in Boulder, whose elected leaders are pushing to municipalize the electric portion of the utility’s operations.The university town has nearly 100,000 residents.

Xcel's PUC filing expressed concerns that utility customers that don’t live in Boulder would subsidize the town’s municipal utility. Xcel alleges that Boulder leaders thus far have been unwilling to enter any agreements to protect other utility customers if a municipal utility were to operate.

"We don't think it is appropriate for our customers outside of Boulder to subsidize any newly formed municipal utility," said Regional Vice President Jerome Davis. "While costs are paid for by Xcel Energy customers, the benefits would go to the new municipal utility once it is formed."

Xcel's filing called out energy efficiency programs and renewable energy contracts that it wants to limit benefits to Boulder customers if they switch to another utility. The filing specifically addresses a new statewide "solar rewards" program, for which contracts  are already outstanding.

"These programs are paid for by all Xcel Energy customers through the renewable Energy Standard Adjustment and the Demand Side Management Cost Adjustment on their bills," said a spokesperson. "Boulder customers have historically participated in those programs."

In 2012, Xcel filed a similar request to the PUC, but the regulatory panel at that time decided that based on the limited steps Boulder had taken that it was premature to make a decision.

However, earlier this month Boulder officials gave Xcel a notice of intent to acquire its electrical utility business. Given the recent moves, Davis said it is appropriate for the PUC to readdress the issue.