The oil giant Chevron has transformed an old refinery site in California into a test bed for seven advanced photovoltaic solar technologies, which the company is evaluating for use at its facilities worldwide. Chevron is unveiling 7,700 solar panels installed on 18 acres in Bakersfield, the capital of California's oil patch. Called Project Brightfield, the plant will generate 740 kilowatts of electricity to power nearby oil operations. Any excess electricity will be fed to the power grid. Chevron will test the technologies for three years and decide which might merit use at the company's facilities, or by Chevron Energy Solutions, which builds solar power plants and installs solar arrays for commercial customers.