On the eve of Independence Day, Massachusetts Gov. Deval Patrick signed legislation dealing with energy that may increase work for electrical contractors. The Green Communities Act, a comprehensive energy reform bill, offers a combination of heightened standards and incentives to help the state achieve a more diverse energy economy based on efficiency and alternative energy sources.

The new law doubles the rate of increase in the state’s existing Renewable Portfolio Standard from 0.5 percent per year to 1 percent per year with no cap. As a result, utilities and other electricity suppliers will be required to obtain renewable power equal to 4 percent of sales in 2009, rising to 15 percent in 2020, 25 percent in 2030 and more thereafter.

Toward that goal, the law requires utility companies to enter into 10- to 15-year contracts with renewable energy developers to help developers of clean energy technology obtain financing to build their projects. The agreements will target Massachusetts-based projects. The measure also authorizes utility companies to own solar electric installations they put on their customers’ roofs—a practice that was previously prohibited—up to 50 MW apiece after two years.

The act also makes it possible for people who own wind turbines and solar-generated power to sell their excess electricity into the grid (net metering) at favorable rates for installations of up to 2 MW (up from 60 kW).

Finally, the new law will make energy-efficiency programs compete in the market with traditional energy supply. Utility companies will be required to purchase all available energy-efficiency improvements that cost less than it does to generate power. Utility companies will offer rebates and other incentives for customers to upgrade lighting, air conditioning and industrial equipment to more efficient models, whenever those incentives cost less than generating the electricity it would take to power their older, less-efficient equipment.