(CN) — Lower costs and improved technology in wind and solar energy have helped the United States produce almost five times more electricity from renewable sources than it did a decade ago, according to a new analysis from an environmental advocacy group.
The Thursday report from the Environment Texas Research and Policy Center found the gains have been strongest in California, which has led the nation in solar energy production and in the industry’s growth over the past decade, and Texas, which dominates in wind energy.
Nationwide, wind power deployment has tripled since 2009, according to the report, “Renewables on the Rise — A Decade of Progress Toward a Clean Energy Future,” and the United States now produces more than 40 times as much solar power as it did a decade ago.
“I think the numbers show that thanks to a combination of good policy, good public investments, as well as just good market design, renewables and clean energy are no longer just a niche energy supply, but are part of the mainstream now,” Luke Metzger, head of the group behind the report, said in an interview.
The analysis cited strong policy support for solar energy in California as key to the industry’s success there, including the state’s Million Solar Roofs program launched in the mid-2000s with the help of $16 million in federal funding.
In Texas, a $7 billion electric transmission line upgrade completed in 2013 helped bring huge amounts of new wind power onto the state’s electric grid.
While the nation has seen impressive gains in renewable energy over the past decade, those sources still make up a small portion of the nation’s overall energy mix. The growth in electric generation from natural gas unleashed by the fracking boom in West Texas and elsewhere has dwarfed the addition of new wind and solar farms.
An electricity emergency in Texas just last week illuminated one of the tricky aspects of electric grids depending more on renewable energy. Extreme heat swept the state just as wind speeds slowed and the grid experienced unplanned power outages, prompting a call for conservation from the grid operator for most of the state.
“The Texas power market is designed to play chicken with blackouts, but the real question moving forward is if the model is sustainable in a high-renewables power system,” Matt Daprato, with the energy analyst firm Wood Mackenzie, wrote a few days later.
Metzger said that despite the strains, new wind, solar and natural gas projects in the works for Texas over the next few years should ease the challenges.
“You know, we had a little less wind than what was projected, but there was also less fossil fuel generation than projected, there were some natural gas plants that were down,” he said. “So I think overall, the system is working.”
While wind and solar power is expected to grow in Texas and across the country, the pace of growth could slow as renewables become more commonplace, according to Kenneth Medlock, senior director of the Center for Energy Studies at Rice University’s Baker Institute.
“The capital requirement for a target growth rate increases with deployment,” Medlock said in an email. “It is more realistic to expect growth to be robust but ultimately slow. This becomes even more salient when one considers setting. As the best areas for capacity deployment are used, the next places to deploy are inevitably sub-optimal, which reduces the value proposition.”