Sustainable business practices and environmental impact via engineering renewable energy are keys to naming 10 of the greenest states in America, according to Olivet Nazarene University’s engineering department. Using data showing renewable energy production, Maine came in as the No. 1 greenest state, which is able to produce more wind energy than the rest of New England combined.

Solar energy was a hot topic for Rhode Island and Idaho, coming in at No. 2 and 3, respectively. Solar energy jobs in Rhode Island soared by 62 percent in 2013, while Idaho thrives on geothermal energy resources to produce electricity. In fact, in 2013, 78 percent of Idaho’s net generated electricity came from renewable sources of energy, primarily via geothermal energy sources. Rounding out the top five are Delaware and Hawaii. Delaware’s renewable portfolio standard requires retail electricity suppliers to generate 25 percent of the electricity sold in the state from renewable energy resources, with at least 3.5 percent from photovoltaics, by the compliance year June 2025 to May 2026. The Aloha State also generated electricity from renewable sources, about 18 percent, ahead of its goal of 40 percent by 2030.

No. 6, Oregon, gave an even deeper meaning to green, using hydroelectric plants as a means to generate almost 73 percent of the state’s net generated electricity. Despite No. 7 Nevada’s high amount of imported energy, about 90 percent, the state is ranked second in the nation for geothermal energy potential. South Dakota, coming in at No. 8, has 88 percent of land well-suited for the development of wind power resources, according to the National Renewable Energy Laboratory.

Rounding out the top 10 are Washington and Iowa. Washington was the nation’s leading producer of hydroelectric power in 2014. Much of it is produced from the Grand Coulee Dam on the Columbia River, the largest single producer of hydroelectric power in the country. More than a quarter of No. 10 Iowa’s energy was produced by wind power, and the state was ranked third in the production of non-hydroelectric renewable energy.