Every day, somewhere in the world, up to 100 megawatts of new solar power goes online. The global capacity to transform sunrays into clean, carbon-free electricity topped 150 gigawatts of this year, according to the International Energy Agency (IEA), with the U.S. accounting for about a tenth of that.
These are impressive numbers, supporting a bullish scenario laid out by the Paris-based IEA — raising the prospect of solar becoming the world’s largest source of electricity by 2050. That’s quite a turnaround for this abundant resource, which until a few years ago was an afterthought burdened by high costs and unreliability.
At the heart of this transformation is price. Over the past four years, the average cost of silicon-based solar panels in the U.S. has declined by 64 percent, according to the Washington-based Solar Energy Industries Association. Globally, solar panel prices have fallen by 80 percent since 2008. The decline is so steep that solar power in Italy and even sun-challenged Germany is competing subsidy-free with conventional power.
An abundance of Chinese-made silicon photovoltaic (PV) solar panels has helped discount the price of solar, with China supplying more than a third of all U.S. installations. Yet solely attributing this decline to Chinese PVs overlooks the ambitious ecosystem of researchers and startups developing game-changing materials that are setting solar prices on a downward trajectory, says Kannan Ramanathan of the Department of Energy’s National Renewable Energy Lab (NREL).
Tech Innovation Fuels Growth
Advances in thin-film panels made from copper indium gallium selenide (CIGS) are helping to drive solar innovation. The cells are notably cheaper to produce, because they don’t rely on silicon wafers, which require very high temperatures to make. Advances in thin-film technology have helped bring down production cost targets. One Silicon Valley startup, Silva Power, has announced plans to make CIGS modules for 28 cents a watt, nearly half the U.S. Energy Department’s 2020 target of achieving 50 cents a watt for its SunShot Initiative.
In addition to driving down costs, “thin-film crystals are more malleable,” explains Ramanathan, who leads CIGS research at NREL. Thus, thin-film modules can be deployed across more areas than rigid silicon PVs, such as curvy residential rooftops or smartphones. Windows could be into electricity generators, as well, by coating them with a layer of thin-film solar cells.
Yet while CIGS cells have the potential to become truly disruptive, the technology is still held back by low efficiency rates. Indeed, while cheaper to make, silicon PVs better convert the sunlight they capture into electricity. Today, silicon cells convert about 20 percent of the light they capture into electricity, compared to just 11 percent for CIGS cells.
However, recent lab tests show CIGS technology is rapidly catching up. In Germany, the ZSW Center has created a cell with a 20.8 percent efficiency rate, a record that slightly exceeds the 20.4 percent rate of a CIGS cell developed by NREL. These achievements embolden Ramanathan, who is confident that in the not too distant future CIGS solar cells “will be able to compete with silicon-based PVs.”
Solar Ecosystem Starting Up
A number of other innovations are also helping to bring down the cost solar, targeting savings in areas from wafer manufacturing to financing. Meanwhile, a growing universe of startups is developing solutions to support the sector’s expansion. These innovators provide the marketing or operational services that, among other things, connect solar power generators to customers.
“We’ve reached an interesting point where the cost of solar is on its way to becoming the cheapest source of energy,” says Emily Kirsch, CEO and co-founder of SfunCube. GE is a corporate sponsor of the San Francisco-based solar incubator, which is helping these startups grow. “We want to be part of that trajectory,” she says.
Taking a page from the playbook of traditional tech incubators, SfunCube invests $10,000 in solar-focused startups in exchange for a 5 percent equity stake. In addition to the investment, entrepreneurs get nine months of rent-free office space as well access to a network of engineers, cleantech entrepreneurs and investors. “Because of the deep programing knowledge that exists throughout the Bay Area, we’re able to find entrepreneurs who can develop solutions that respond to the operational needs of solar companies,” Kirsch explains.
BrightCurrent is one such company. The startup, which launched in 2011, connects property owners seeking to power up their homes with solar panels with PV installers. When it joined SFunCube a little more than nine months ago, BrightCurrent was already generating revenue and had 20 employees. But the incubator was a real catalyst for the Oakland-based startup, which graduated from the incubator program with a little more than a 100 employees and a larger market reach. “What we did is connect them to our network of investors,” says Kirsch. “They also got to spend nine months gathering ideas and insight from other solar entrepreneurs.”
Has solar’s moment arrived? The future is certainly looking bright. Propelled by an ambitious community of techies, innovators and solar power companies, the sector could be poised to become a dominant source of clean, cheap and reliable power.
Top GIF: Video courtesy of GE Aviation