Solar energy has grown faster than most analysts expected, and improvements in solar panels could make it a much bigger part of the world’s electrical power systems in the future.
More than 100 gigawatts of solar — the equivalent of 100 mid-sized power plants — are now in operation worldwide, according to a new study by German researchers. While that’s still a fraction of a percent of global output, the numbers have come in higher than government agencies, private firms, or even the environmental group Greenpeace projected, said Felix Creutzig, a physicist and energy analyst at Berlin’s Mercator Research Institute on Global Commons and Climate Change.
In Germany and other parts of Europe, Creutzig said consumers were willing to pay slightly higher prices for renewable energy compared to fossil fuels. That helped investments in utility-scale solar power, as opposed to rooftop solar panels. In the United States, tax credits also boosted the growth of large-scale solar projects.
“Because of this initial high deployment, the costs decreased faster than they thought before,” he said. “Each doubling of capacity saw a 22.5 percent decrease in prices.”
But most observers’ assumptions were “really, really conservative,” said Creutzig, the lead author of the new study and a contributor to the UN Intergovernmental Panel on Climate Change 2014 assessment. Previous estimates of solar growth didn’t reflect the effects of falling prices and underestimated costs of nuclear energy and coal plants equipped to capture and store carbon emissions — a technology that has struggled to succeed economically.
“Those low prices didn’t materialize, so in the end solar and wind took up the market share,” he said.
RELATED: Here’s How Nearly All Nations Could Run on Renewable Power by 2050
Solar energy still provides less than 1 percent of power in the United States and around the world. But solar panels, which convert energy from sunlight into electricity, have been sprouting on buildings and in fields at a rapid clip. Nearly 30 percent of new American electrical capacity in 2016 came from solar power, according to the US Energy Information Administration.
The numbers are higher in Europe, where solar provides more than 7 percent of electricity in Germany, Italy, and Greece. And China is building and installing solar panels rapidly as it tries to meet its climate goals and curb the notorious pollution that has accompanied its rise as an industrial power. The costs of solar are likely to keep falling with more investment in technology and as more production comes online, producing economies of scale, Creutzig said.
That rapid growth holds out hope that solar could provide between 30 and 50 percent of the world’s electricity by 2050. That would be an important step toward meeting the world’s goal of reducing carbon emissions enough to head off the worst effects of climate change.
“It looks quite optimistic in a certain way,” Creutzig said. However, hitting that target will require some improvements in technology and access to the capital needed to fund solar energy projects, particularly in the developing world. Better battery systems are needed to store the electricity produced during the day for use at night.
RELATED: Next-Gen Geothermal Could Unlock Vast Energy Supplies Just Below Earth’s Surface
And there’s another issue that will need to be tackled: The typical solar panel turns less than a quarter of the energy that strikes it into electricity. Only the most advanced top 30 percent. But the more efficient a panel gets, the cheaper a solar system becomes, said Adele Tamboli, a materials scientist at the National Renewable Energy Laboratory in Colorado.
“If you have a higher efficiency, you’re getting more electricity out of your device, which means you can install a smaller array of solar panels for the same output,” Tamboli said.
Tamboli was part of a team of scientists at NREL and two institutions in Switzerland, the Center for Electronics and Microtechnology and Lausanne’s École Polytechnique Fédérale de Lausanne, that got efficiencies reaching just under 36 percent by using cells made of semi-conductive elements like gallium and indium. Those metals are better at capturing more energy from higher wavelengths of the spectrum than conventional silicon-based photovoltaic cells, which are more receptive to lower wavelengths.
The materials are more expensive by themselves — but when used to boost a solar panel’s efficiency, they can bring down the cost of the electricity produced and likely speed up the adoption of solar energy, she said.
“We’re already installing a lot of solar in utility-scale applications where you have large solar arrays in the desert. There’s good illumination conditions, and land is cheap,” Tamboli said. “As we move into increased penetration of solar into the grid, I think we’ll see an increasing need for dense solar arrays in or near cities and where we have to make better use of land area. I think in that case, efficiency becomes a lot more important.”
RELATED: Here’s Why the US Nuclear Industry Is in Jeopardy
Both studies were published recently in the research journal Nature Energy, along with a commentary by former Obama administration adviser Jason Bordoff on the consequences of the Trump administration’s planned withdrawal from the Paris climate agreement. Bordoff warned the decision and the administration’s proposed cuts to energy research means the United States “risks being left behind in the race to develop the energy technologies of tomorrow.”
Though the American pledges under the Paris accord were non-binding and withdrawal won’t be final until late 2020, Bordoff said the effects of the announcement will likely result in a diminished US role around the world.
“In the diplomatic realm, withdrawal from the Paris Agreement was the proverbial own goal, a historic blunder that upsets key diplomatic partnerships, cedes leadership in tomorrow’s energy technologies to other nations, and stymies the ability to ratchet up the ambition of international action on climate change as time to address this threat runs ever shorter,” he wrote.
WATCH: Storing the Sun's Energy in Liquid Could Change Solar Forever