OpenAI CEO Sam Altman. Bloomberg/Getty Images DTE Energy is betting on revenue from a new data center project to lower customer bills. The utility expects Oracle and OpenAI's Michigan site to create $300 million in savings. Customers could see future power rate freezes — if the data center uses enough electricity. OpenAI and Oracle are building a massive data center in Michigan — and residents' power bills are hinging on it. The data center is part of OpenAI's  Stargate project , originally a joint venture between Oracle, SoftBank, and OpenAI. If it performs as expected, the Michigan electric utility DTE Energy says it will freeze rates for its entire customer base. Driven largely by Big Tech's sweeping AI data center buildout , electricity bills are rising nationwide. DTE is one of many local utilities that have sought to raise customer rates across the board as it builds new power plants and transmission lines to keep up with unprecedented demand.…