The city of Tucson and Tucson Electric Power Co. have signed a letter of intent to work toward powering 100% of city operations with renewable energy, even as Tucson voters are being asked to help fund future city climate initiatives.

The agreement stems from a commitment TEP made in January amid discussions about a new franchise agreement between the city and TEP, which is up for approval by city voters as Proposition 412 in a May 16 special election, the company said.