Arizona's largest utility, Arizona Public Service (APS), proposes to exceed the current Renewable Energy Standard (RES), which requires the company to generate 15 percent of its energy from renewables by 2025.

In its resource plan filed with the Arizona Corporation Commission, the utility shared that it proposes to exceed the current Renewable Energy Standard (RES), which requires the company to generate 15 percent of its energy from renewables by 2025.

APS expects to add approximately 1,600 megawatts (MW) of renewable resources, or enough energy for about 400,000 homes. Renewables should satisfy about 45 percent of the projected growth in energy consumption. This could include the construction of up to 1,000 MW of solar power plants, similar to Solana Generating Station, a 280 MW facility planned for 2012. APS also plans continued expansion of distributed energy resources as well as other renewable energy purchases. The company will continue to engage and evaluate the market for renewable power projects.

Developed over the past 18 months, the APS Resource Plan incorporates input from more than 100 public meetings held statewide.

"This plan reflects the highly productive discussions we've had with the public about the right resources for Arizona's specific strengths and challenges," said APS president and COO, Don Robinson.

Overall, the plan could require a total investment of $18 billion over the next two decades. APS may fund these investments directly, or, like Solana, allow other entities to construct plants and then sell power to the company.