The future of solar is large-scale grid deployment

A report by the Massachusetts Institute of Technology Energy Initiative (MITEI) looked at the future of solar, and found that to further solar’s progress, there would need to be an added emphasis on developing lower-cost technologies as well as more effective deployment policy.

Massachussetts Institute of Technology. Credit: Aavindraa/Wikimedia Commons

The report, “The Future of Solar Energy,” studied technical, commercial, and policy dimensions of solar energy, and made recommendations for the support of research and development, technology demonstration, and solar deployment.

“Our objective has been to assess solar energy’s current and potential competitive position and to identify changes in US government policies that could more efficiently and effectively support its massive deployment over the long-term, which we view as necessary,” said MITEI Director Robert Armstrong in a statement.

The report also showed the need to prepare electricity systems for large-scale deployment of solar generation. Although solar energy accounts for only 1 percent of electricity generation in the United States, the researchers said “we believe a focus on solar technologies is nonetheless warranted because… the use of solar energy to generate electricity at very large scale is likely to be an essential component of any serious strategy to mitigate global climate change.”

“Fortunately,” the report continued, “the solar resource dwarfs current and projected future electricity demand. In recent years, solar costs have fallen substantially and installed capacity has grown very rapidly.”

The report found that the main goal of the United States should be a solar policy that builds a foundation for massive solar infrastructure within the next two decades. The researchers believe this can be done through three goals: developing new solar technologies; integrating solar generation at large scale into existing electric systems; and designing efficient policies to support solar technology deployment — but development of new technologies should take priority over current policies. According to MITEI, the trend in recent years has been near-term reductions in the costs of solar, but the focus should instead shift to developing new technologies.

The study looked at both solar generation from both photovoltaic (PV) and concentrated solar (or solar thermal) power (CSP) systems.

“A CSP plant is a single largescale installation, typically with a generating capacity of 100 megawatts (MW) or more, that can be designed to store thermal energy and use it to generate power in hours with little or no sunshine,” the report explained. “PV systems, by contrast, can be installed at many scales — from utility plants with capacity in excess of 1 MW to residential rooftop installations with capacities under 10 kilowatts (kW) — and their output responds rapidly to changes in solar radiation. In addition, PV can use all incident solar radiation while CSP uses only direct irradiance and is therefore more sensitive to the scattering effects of clouds, haze, and dust.”

Further development of CSP could be beneficial due to its characteristics, including that the technology involves solar-to-heat conversion that allows it to incorporate high efficiency thermal energy storage into a CSP plant — which would allow the plant to provide “dispatchable” renewable electricity. CSP can also be “hybridized” with other sources of energy generation — even fossil fuels.

But large-scale deployments won’t only be through CSP. The study found that research and development focused on low-cost, scalable energy storage technologies will also be important for the future of PV development on a large scale — and “drastic cuts in federal support for solar technology deployment would be unwise.”

“What the study shows is that our focus needs to shift toward new technologies and policies that have the potential to make solar a compelling economic option,” said study chair Richard Schmalensee in a statement.

The study found a need for both federal and state subsidy programs and increased research to support the advancement of low-cost, large-scale electricity storage technologies.

The group will be presenting their findings to lawmakers and administration officials in Washington, D.C. this week.

For more:
– read the full report

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