A new report from The Massachusetts Institute of Technology says solar is an important source of renewable energy as the consequences of climate change become more urgent.
But solar technology can be expensive and it's not being utilized as widely as it could be. How can Minnesota leverage the potential of solar?
Two guests joined MPR News' Kerri Miller and MPR Meteorologist Paul Huttner for an hour-long Climate Cast.
Solar energy: What you need to know
What the new study says
The MIT study looked at three broad areas that will determine the growth of solar energy: technology, economics of the sector, and the policies in place to support solar development, Francis O'Sullivan, director of research and analysis at the MIT Energy Initiative, said.
From the report:
While costs have declined substantially in recent years and market penetration has grown, major scale-up in the decades ahead will depend on the solar industry's ability to overcome several major hurdles with respect to cost, the availability of technology and materials to support very large-scale expansion, and successful integration at large scale into existing electric systems. Without government policies to help overcome these challenges, it is likely that solar energy will continue to supply only a small percentage of world electricity needs and that the cost of reducing carbon emissions will be higher than it could be.
It's not just about panels on your roof
"When we speak about solar, we could be speaking about an enormous utility scale solar farm, the type of ground-mounted systems that people often see when they see pictures of the desert and the southwest," O'Sullivan said. "That's one bookend and right at the other end is a unit sitting on your roof... Those paradigms have very different economics. It's significantly cheaper to develop those utility-scale facilities per watt of generating capacity than it is to put a system on the roof... In some settings in the United States today, it's true that the cost of putting your own system on the roof remains very high relative to the benefits you get, particularly in regions where the solar resources aren't very good."
Ellen Anderson, executive director of the Energy Transition Lab at the University of Minnesota, said community solar gardens are a way for citizens to get involved, even if they don't have a good south-facing roof.
"The concept of a solar garden is that it's a shared solar project," Anderson said. "Under the law they can be up to 1 megawatt... The idea is that you put the project together, you build it and you have to have one anchor tenant that owns up to 40 percent of the solar capacity and the solar panels in the project. You can sell shares to other subscribers, so you can buy as little as one solar panel out of a larger project... When you buy a subscription you get a bill credit for the amount of electricity that's produced by your share. So on your monthly bill you'll see the benefits of being a solar owner."
For scale, a one megawatt community solar garden would provide electricity for about 150 to 160 homes, she said.
Minnesota has good solar potential
"What you're looking for is regions with a lot of sunshine—it doesn't necessarily have to be very hot—in order to have a good solar resource," he said. "So here in the United States, for example, across the Midwest can be very cold during the winter, [but] you have a lot of sunshine. That contrast, for example, with northern Europe where it may not be as cold at all due to the moderating effects of the Gulf Stream, but you have a lot more cloud cover. Their solar resource is significantly worse than ours."
The future of solar
Using today's technology and typical efficiencies, the United States could generate the entire electricity demand using half the area we currently dedicate to growing corn-ethanol, O'Sullivan said. That would be about the size of Rhode Island.
"That resource is really enormous and we can tap into a huge amount of solar energy without necessarily having a ubiquitous plastering of solar panels all over the country," he said.
Up-front costs are still a barrier
If you want solar panels on your residential property, you still need a lot of money up front for installation, but those prices are dropping, O'Sullivan said.