Armstrong is one of 30 authors of “The Future of Solar Energy,” the latest of seven interdisciplinary reports from MITEI exploring major energy technologies that might play significant roles as the world looks to address climate change over the coming decades. “We face a dual challenge with respect to energy and climate,” Armstrong says. “Energy demand is expected to double globally by 2050. But it’s clear that because of global warming we also need to decarbonize the energy system,” or replace today’s energy systems with alternatives that don’t emit carbon dioxide and other greenhouse gases.
Richard Schmalensee, the study chair, agrees. “If we are going to seriously decarbonize the economy, it is hard to see how we can do that globally without a lot more solar generation. The question is, how will we make solar power useable at large scale by mid century?” Schmalensee, who is the Howard W. Johnson Professor of Economics and Management Emeritus, notes that the solar study identifies key technologies and policies to that end.
Another author of the 332-page report, Francis O’Sullivan, cites three main takeaways of the study, whose principal audience is industry participants and policymakers in Washington.
“Solar as a technology has rapidly transitioned through its nascency to a point today where it is increasingly competitive as a source of electricity,” says O’Sullivan, director of research and analysis at MITEI, adding that since 2008, prices for electricity generated from solar panels on residential homes have dropped by 50%, while prices from utility-scale plants have dropped by 70%.
Nevertheless, he says, “much work remains for a solar-heavy future to be realized.” For example, “we must maintain a focus on the development of technologies that have the potential to lower costs even more drastically than the gains achieved over the past five years. And that means government funding of long-term research that’s too risky for industry to tackle.”
Armstrong, who is the Chevron Professor of Chemical Engineering, adds: “There’s no doubt that a lot more can be done to assure that solar meets long-term energy needs by shifting federal solar R&D focus from market penetration of existing systems to generation of new ideas for the long-term.”
Another critical point is that we need to prepare both technically and from a regulatory perspective for a much greater use of solar. On the technical side, that means the development of technologies to store the electricity generated by solar for use when the sun doesn’t shine. “The success of photovoltaics in particular at very high penetration is heavily dependent on the vailability of cost-effective storage,” O’Sullivan says. From a regulatory perspective, “solar is introducing a lot of new dynamics that will require regulators to be more nimble.”
The study further recommends changing the subsidy paradigm for solar in the United States. Currently, subsidies are based on the investment associated with a solar installation. Although that’s helpful, “we believe the government can do much more” to encourage solar, O’Sullivan says. For example, “we ought to transition to a subsidy based on solar energy production. That will give asset owners much more of an incentive to maximize the amount of solar generation.”
Armstrong is optimistic about solar and MIT’s continuing contributions to the field.
“There are many new technologies we are working on that could make a big difference to our solar future,” he says. “I think one of MIT’s jobs is to shake up the world of technology on a regular basis.”