The board of directors at Arizona utility Salt River Project recently approved a 3.9 percent electricity rate hike after three months of reviewing the proposal, the East Valley Tribune reports.

According to the news source, the utility stated that monthly residential electricity bills for those enrolled in the Basic Price Plan will rise by about $6.17. The company announced that the board also gave the nod to a plan that would raise rates annually by $24, which would create funds that will be used to provide low-income customers with discounts on their rates.

The company's Economy Price Plan, as it is called, will give customers a discount of $21 per month, and a $17-per-month discount in the winter months.

The rates will also help fund a $400,000 contribution to the Arizona Community Action Association Home Energy Assistance program.

Salt River Project's incentives and discount programs reflect the state's deregulated energy market, which has attracted dozens of retail energy providers to the area, driving up competition, and in turn, forcing both utilities and electricity suppliers to offer such rewards and savings programs.