Clean energy like solar and wind have grown in popularity over the past 15 years, but detailed analysis of how and why this has happened or failed to happen has largely been a matter of conjecture.

To illuminate the issue, nonprofit Clean Energy States Alliance (CESA) released a report on June 22 that examines 31 clean energy case studies across 22 states. The report – Clean Energy Champions: The Importance of State Programs and Policies – shows the central role that state incentivization programs have played in building the clean energy movement, along with suggestions for how states might further encourage growth in one of the most influential industries in the world economy.

The report is intended for officials in state government, the federal government and state legislatures, so that those officials might understand the impact their contributions have had to clean energy and encourage them to continue facilitating that growth, said Warren Leon, executive director of CESA.

“The lesson is the great variety of ways in which the states have innovated,” Leon said. “By producing this comprehensive report that goes soup to nuts conveying all the different ways states have advanced clean energy is to show the great range of experimentation and great range of innovation and the great range of motivations that states have had. We aren’t necessarily expecting everybody to read this report from cover to cover, but it’s the type of thing you could flip through and find a topic you’re interested in and focus on that.”

The 130-page report identifies lessons in clean energy that have been demonstrated in recent history, which relate to the roles of state and federal governments, policy approaches, the importance of addressing clean energy issues outside the influence of partisan politics, tax incentives, developing new legislation that supports existing programs, and consumer protection.

The report also identifies methods that states have used in recent years to overcome market barriers, including the adoption of minimum renewable energy mandates placed on electricity suppliers, supporting infrastructure investment by streamlining administrative processes and establishing new financial infrastructure, encouraging new institutions like research labs, university groups and clean energy startups to form and work on clean energy problems, and the creation of new standards for consumer protection that ensure buyers are equipped with the information needed to make sound purchasing decisions and that workers are qualified to install and maintain the equipment.

In 1999, the U.S. Energy Information Administration estimated that without new incentives, the energy generated by solar and wind power would increase over the next 15 years, but at relatively modest rates. The actual increases in power over the past 15 years were 15 and nine times greater than what the EIA had projected for wind and solar, respectively – enough energy to power 16.7 million homes from wind and 1.7 million from solar.

“I think the report indicates that the future can be bright if the states continue to innovate and if the federal government continues to be supportive,” Leon said. “Now, neither of those things are definite and in the report we make suggestions for how the states can innovate and how the federal government can continue to be supportive. The future is uncertain, but it can and should be bright, because clean energy is important, it’s popular on a bi-partisan basis, and it’s necessary for our country.”

The full report is available free in PDF form on the CESA website.