We’ve been underestimating the solar industry’s momentum. That could be a big problem.
Analysts have been underestimating the expansion of solar energy for nearly two decades, scientists report in a new study released Friday. And that could be a serious problem for the industry and, maybe, the planet.
If policymakers believe solar is growing more slowly than it actually is, they may be less likely to prioritize the kinds of research and development that will help better integrate renewables onto the grid, such as improving battery storage technology. This could lead us to continue relying on more carbon-intensive energy sources.
“I think the most important risk is that the regulatory environment does not adapt in time to a rising share in solar energy,” said lead study author Felix Creutzig, a professor at the Mercator Research Institute on Global Commons and Climate Change, based in Germany.
The paper comes just a day after the release of a much-anticipated study on the electric grid, ordered by Energy Secretary Rick Perry back in April. At the time the study was launched, environmentalists feared the report might be used to bash renewables and were quick to point out that multiple previous studies have concluded that wind and solar can continue to expand significantly without posing a threat to the grid’s reliability. (The final report is somewhat more moderate than some renewable energy advocates had feared, although still favorable to coal and nuclear power.)
The new paper, published Friday in the journal Nature Energy, points out that the deployment of solar energy has consistently outperformed the predictions made by so-called “integrated assessment models,” which are commonly used to evaluate the ways different social, economic and technological factors might mitigate climate change, since at least 1998. For instance, the authors point out, the International Energy Agency has repeatedly predicted growth rates for solar deployment that are anywhere from 16 to 30 percent lower than their actual rates end up being.
The researchers outline a number of reasons for the discrepancy. For one thing, models have often failed to account for the policies different nations have put in place to speed the expansion of renewable energy. In the United States, an investment tax credit supports new solar installations, while other nations around the world have enacted feed-in tariffs, which compensate consumers for any renewable energy they generate (for instance, through their own rooftop solar panels) and provide to the grid.
Additionally, the study notes, the costs of solar panels have been falling faster than expected. And the models may have also been overly optimistic in their assumptions about the expansion of other low-carbon technologies, such as nuclear power or carbon capture and storage technology. These low-carbon alternatives have actually been slower to develop, but modeling studies frequently assume they will be widely deployed in the future, creating less space for solar to fill.
David Victor, an energy policy expert at the University of California who was not involved with the new research, suggested that solar’s relatively small share of the global electricity market also plays a significant role.
“When market share is small, big shifts in policy or technology can have a huge effect on growth,” he pointed out in an email to The Post. These types of sudden changes, and their aftermath, may be difficult for models to account for.
Victor also expressed caution about some of the researchers’ concerns.
For instance, he noted that the plummeting costs of solar equipment are all well and good — but other industry costs, such as the price of installing and maintaining solar systems, are not falling as rapidly. This is important to keep in mind when considering the industry’s overall performance.
In general, though, the paper “strikes me as basically right,” Victor noted.