A "massive" global expansion of solar power — possibly enough to
supply about a third or more of the world's electricity — may be
necessary by 2050 to reduce the impacts of fossil fuels on the climate,
according to a report published by MIT this week.
Solar's efficiency and abundance make it the clean energy source best
suited to cut greenhouse gas emissions. But for it to make a big enough
climate difference, the amount of solar power generation capacity on
U.S. soil would have to increase from today's 20 gigawatts to up to 400
gigawatts, or enough to provide power to 80 million homes, Robert
Stoner, deputy director of the MIT Energy Initiative and a co-author of
the report, said.
The study says that may not happen in the U.S.
unless solar industry-supported funding and incentives are almost
completely re-imagined. The solar industry currently supports keeping
those incentives in place.
Those changes would include scrapping state renewable power
generation standards for utilities and directly subsidizing solar power
generation in lieu of tax credits, according to the report,
"The Future of Solar Energy." As new ways of funding solar power are
being worked out, new technology needs to be developed for solar energy
storage, smarter power grid management and new kinds of solar panels
that use more abundant raw materials that would help keep solar panel
prices low, the study suggests.
Today, the solar industry is booming. The cost of a utility scale solar photovoltaic installation has fallen about 55% since 2010. Employment in the solar industry rose 22%
in 2014 after the number of solar projects in the U.S. jumped 140% the
year before. But the solar industry fears its expansion could slow if
Congress does not renew a federal solar subsidy, the Solar Investment Tax Credit, after it expires in 2016.
John Rogers,
senior energy analyst for the Union of Concerned Scientists, said the
study gets a lot of things right and talks about building the foundation
for a massive scale-up in solar power in the U.S.
"It says drastic cuts in government support are a bad idea, and I think that many of us would agree with that," he said.
Government support for solar should be redefined, eschewing tax
credits for a direct subsidy for solar power generation, creating a
direct incentive to generate as much solar power as possible, the study
suggests.
A tax credit rewards building solar farms — adding capacity, in
industry parlance — more than the actual generation of electricity,
Stoner said.
"It never really finds its way to solar panels on roofs," he said.
"To get the most bang for your buck in terms of climate with solar
assets, you should provide a benefit to production instead of capacity
creation."
MIT also downplays the cost effectiveness of residential rooftop
solar, saying its current cost per watt is about 80% greater than for a
utility-scale solar power plant. It doesn't dismiss rooftop solar
entirely, however. The report recommends that more states allow
companies such as Solar City to own and operate solar panels on homeowners' roofs.
Though Stoner said the goal of the study is to show that solar power
needs all the help it can get from Washington, the solar industry itself
disagrees with the tactics the study suggests.
Solar Energy Industry Association Vice President Ken Johnson said the
report "offers an incomplete and flawed picture of solar economics,"
especially regarding rooftop solar and tax credits, which have proved to
be an incentive to build nearly all the solar installations operating
today.
On a larger scale, scrapping state renewable portfolio standards
would make more efficient use of utility-scale solar energy
developments, even though the standards are effective in many states,
Stoner said.
Renewable portfolio standards
are requirements that states impose upon major utilities often
mandating that a certain percentage of their power generation come from
renewables. They vary from state to state, and many have none at all,
especially Southern states.
The standards go far to boost solar in some states. For example,
solar installations are being built all across North Carolina, partly
because its renewable portfolio standard requires utilities to get a
certain percentage of their renewable power from solar.
Stoner said those mandates restrict utilities from building solar farms where it may be sunniest.
"Artificially confining it within the borders of a state makes solar power more expensive," Stoner said.
But that may be based on an outdated assumption about the ability of solar panels to generate electricity, Rogers said.
It was previously thought that fairly cloudy regions such as New
England could not produce as much solar power as Southern states, but recent research
suggests that solar power generation capabilities of New England and
Florida aren't very different if solar panels are oriented optimally to
take the most advantage of seasonal sunlight and temperatures, he said.
"Turns out we have a resource a whole lot more widespread than (the
study) would lead one to believe," Rogers said. "You want to be setting
the record straight, not perpetuating myths."
