Terawatt Solar Farms By 2050?

Government policies should shift incentives in solar energy away from rooftop deployment in residences toward utility-scale use because this is the most cost-effective way to deploy solar in order to reduce greenhouse gas emissions, researchers at MIT say.

By the same token, government sponsored research and development in solar should concentrate on thin-film technologies, based on naturally abundant materials rather than on reducing costs of the crystalline silicon technology that is currently dominant in photovoltaic panels.

These are some of the conclusions in a 332-page report, “The Future of Solar Energy,” released in early May by the cross-disciplinary MIT Energy Initiative.

“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 Robert Armstrong, director of the initiative, which involves four of MIT’s schools and some 300 faculty members.

Economics professor Richard Schmalensee, who chaired the solar study, added: “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.”

Solar electricity is “one of very few low-carbon energy technologies with the potential to grow to very large scale,” the study said. “As a consequence, massive expansion of global solar-generating capacity to multi-terawatt scale is a very likely and essential component of a workable strategy to mitigate climate change risk.” A terawatt is equivalent to 1,000 gigawatts, or about the capacity of 1,000 large power plants.

Current tax subsidies based on the cost of residential investment and not on the amount of energy produced are about two and a half times higher than they would be if the subsidy supported utility-scale photovoltaic (PV) production, the study said.

The wafer-based crystalline silicon (c-Si) predominant in most PV panels represents 85% of the cost in the average residential rooftop unit, and 65% of the cost for utility-scale installations.

Instead of finding ways to reduce this cost, the MIT report says, government funds should be used to develop new thin-film technologies that rely on earth-abundant materials instead of the scarce elements currently used.

“The recent shift of federal dollars for solar R&D away from fundamental research of this sort to focus on near-term cost reductions in c-Si technology should be reversed,” the MIT experts said.

The study found that even with today's crystalline silicon (PV) technologies, the industry could achieve terawatt-scale deployment of solar power by 2050 without major technological advances.

In other recommendations, the MIT study also urged more government research into concentrated solar power (CSP), an alternative form of solar energy that focuses the sun’s heat to power turbines that generate electricity.

This technology is less mature than PV technology and remains high-risk for commercial-scale projects. Federal R&D should focus on pilot-scale facilities to develop and test new materials and system designs in CSP, the MIT report said.

The report also emphasized the need for more research into low-cost, large-scale electricity storage technologies to facilitate use of PV energy by utilities, which must meet base load requirements even if the sun is not shining.

The MIT study does not dismiss residential rooftop installations altogether and calls for more states to allow third-party ownership that spares homeowners the upfront costs of installation.

Even so, the study adds, the “inherent inefficiency in the current, investment-based federal subsidy system will remain.”

In a separate report this month, the Paris-based International Energy Agency also called for more government spending on renewable R&D.

The agency cited progress in clean-energy technology in “Energy Technology Perspectives 2015,” but said current efforts fall short of goals in combating climate change.

“We are setting ourselves environmental and energy access targets that rely on better technologies,” IEA executive director Maria van der Hoeven said in a statement releasing the report. “Today’s annual government spending on energy research and development is estimated to be USD 17 billion. Tripling this level, as we recommend, requires governments and the private sector to work closely together and shift their focus to low-carbon technologies.”

By Darrell Delamaide

sourche: http://oilprice.com/Alternative-Energy/Solar-Energy/Terawatt-Solar-Farms-By-2050.html