A month of triple-digit temperatures isn’t all that will contribute to eye-popping Southern California Edison bills – the utility will raise rates Aug. 1 by up to 55 percent. And the increase is retroactive to January, though Edison, which serves the Santa Clarita and Antelope valleys, will spread that pain over a year rather than billing a lump sum, spokesman Gil Alexander said Friday. The rate increase, the third this year, was approved Thursday by the state Public Utilities Commission, the third hike this year. The revenue is needed to expand and renovate California’s power system, Alexander said. “Southern California’s power infrastructure is aging and we told the commission we believe it’s prudent now to spend money and invest in upgrading it,” Alexander said. “The commission agreed.” At the urging of the PUC, Edison has created a tiered pricing system that means lower rates for residential customers who conserve power. In January, Edison increased rates by an average 9 percent, and 5.5 percent in February. The PUC approved those hikes to cover the increasing costs of energy contracts and the rising cost of natural gas, used to run the system. The gross increase is the result of a three-year review of Edison’s operations and maintenance costs. The PUC agreed to the rate increases but the process was delayed, making it necessary to raise rates retroactively. [email protected] (661) 257-5251160Want local news?Sign up for the Localist and stay informed Something went wrong. Please try again.subscribeCongratulations! You’re all set! AD Quality Auto 360p 720p 1080p Top articles1/5READ MOREPhotos: At LA County Jail, Archbishop José H. Gomez celebrates Christmas Mass with inmatesThe latest increase applies to medium and heavy energy users. For the average customer – including residential, business and agricultural users – the three increases will amount to an additional 17 percent a year, Alexander said. In the High Desert, where energy-gobbling air conditioning is a necessity rather than a luxury, the Antelope Valley Union High School District already is paying $4 million a year for electricity. The district has been hard hit by unannounced increases in one segment of its bill – the peak load rate – and has pleaded with Edison to give officials advance warnings of increases so they can budget. “Edison will charge what they have to charge, but we need to plan. We need to budget for it, and we can’t seem to get that across,” said Larry Freise, coordinator of consolidated projects for the district. “Last year, we overran our power budget by a couple hundred thousand dollars because rates changed and we weren’t notified in advance.” Private business looks at the increase as just another hurdle in doing business in California. “It just increases your costs, it makes it tougher to compete with your competition in Asia,” said Doug Sink, chief financial of Remo Inc., a drum manufacturer in Valencia.