Cheap, Abundant Materials Could Exist for PV California Energy Markets
March 2, 2009
Thin-film solar may not be the only cheap game in town.A UC Berkeley report released this month emphasized the potential
for cheaper materials to cut the cost of solar photovoltaics and
bolster large-scale deployment. The study, from researchers at
Lawrence Berkeley National Laboratory, UC Berkeley's Energy and
Resources Group, and the university's chemistry department, noted the
abundance of various materials that could be used in PV applications.
It found 12 out of 23 semiconducting materials abundant enough to meet
annual worldwide energy demand-and found nine out of the 12 cheaper
than crystalline silicon, an often-used PV material. Silicon remains
hard to mine, process and mass-produce.
"To be a viable alternative to fossil fuels, PV must expand
dramatically and form a new, far larger industrial sector," the study
stated.
Such non-silicon-based options-including materials already being
used for thin-film PV technology, such as cadmium telluride and the
compound semiconductor material copper indium gallium selenide, or
CIGS-can help cut expenses.
"Quantifying material cost and the availability of these and other
emerging material systems provides a critical metric to guide future
research and development decisions toward a greatly expanded solar
cell industry of the future," said the report.
However, according to the report, natural resources could be
depleted if the production of thin-film materials is greatly scaled
up. Other materials-including iron pyrite, copper sulfide and copper
oxide-can offer more abundant supply and cheaper extraction costs.
"Our analysis highlights a photovoltaic future that may not be
dependent on either silicon technologies or currently popular thin
films,"
the study stated.
The study also pointed out the chance for new manufacturing
techniques to increase the total output of more expensive materials by
sacrificing efficiency. For instance, some materials may not perform
as efficiently as thin films, but can require less material or
lower-cost processing.
"Our analysis demonstrates a major opportunity for fruitful new
research and development based on low-cost and commonly available
materials," the study stated.
Jeffrey Grossman, executive director of the Center of Integrated
Nanomechanical Systems and group leader of the Computational
Nanoscience Group at UC Berkeley, cited the study at a conference this
week.
"The periodic table seems to be opening up before our eyes,"
Grossman said during a talk on PV and concentrating solar technology at the UC
Berkeley Energy Symposium on Monday. But research needs to continue
into the materials, as well as into thin-film materials and issues
such as safe disposal of cadmium.
"We need to understand the basic science to understand these
materials," Grossman said.
Sunpower Corp. Senior Manager of Utility Sales Ed Smeloff noted
the cost of installing PV is now at about $5.50 a watt, down from
about $20 a watt 20 years ago.
"PV will succeed," Smeloff said. "It can be built anywhere, it is
scalable, and it can be rapidly deployed."
But while PV will continue to contribute to the overall energy
solution, Charles Ricker, senior vice president of marketing and
business development at BrightSource Energy Inc., expects solar
thermal to advance.
"For the planning horizon I see the scale at which we can develop
solar thermal is much faster," Ricker said, adding that solar thermal
"is where utilities are making their bets."
Earlier this month, BrightSource signed the world's largest solar
power deal with Southern California Edison, a series of contracts for
1.3 GW of solar thermal energy.
But cost information for concentrated solar power remains less
transparent, University of California Energy Institute Director
Severin Borenstein said during the symposium. Referring to a big
contract PG&E signed with BrightSource for 900 MW of concentrated
solar power, "we actually don't know how much it costs," Borenstein
said.
On a totally unsubsidized basis, residential solar PV is the most
expensive form of energy, at about 40 cents/kWh, according to
Borenstein.
Utility-scale solar PV comes in at a range of 20 cents to 30 cents/
kWh, followed by concentrated solar or solar thermal power, at about
18 cents/kWh. Wind power is at 9 to 13 cents/kWh; natural gas
generation costs about 8 cents; and coal-fired generation runs about 5
to 6 cents/kWh [Hilary Corrigan and Mavis Scanlon].
Thin-film solar may not be the only cheap game in town.A UC Berkeley report released this month emphasized the potential
for cheaper materials to cut the cost of solar photovoltaics and
bolster large-scale deployment. The study, from researchers at
Lawrence Berkeley National Laboratory, UC Berkeley's Energy and
Resources Group, and the university's chemistry department, noted the
abundance of various materials that could be used in PV applications.
It found 12 out of 23 semiconducting materials abundant enough to meet
annual worldwide energy demand-and found nine out of the 12 cheaper
than crystalline silicon, an often-used PV material. Silicon remains
hard to mine, process and mass-produce.
"To be a viable alternative to fossil fuels, PV must expand
dramatically and form a new, far larger industrial sector," the study
stated.
Such non-silicon-based options-including materials already being
used for thin-film PV technology, such as cadmium telluride and the
compound semiconductor material copper indium gallium selenide, or
CIGS-can help cut expenses.
"Quantifying material cost and the availability of these and other
emerging material systems provides a critical metric to guide future
research and development decisions toward a greatly expanded solar
cell industry of the future," said the report.
However, according to the report, natural resources could be
depleted if the production of thin-film materials is greatly scaled
up. Other materials-including iron pyrite, copper sulfide and copper
oxide-can offer more abundant supply and cheaper extraction costs.
"Our analysis highlights a photovoltaic future that may not be
dependent on either silicon technologies or currently popular thin
films,"
the study stated.
The study also pointed out the chance for new manufacturing
techniques to increase the total output of more expensive materials by
sacrificing efficiency. For instance, some materials may not perform
as efficiently as thin films, but can require less material or
lower-cost processing.
"Our analysis demonstrates a major opportunity for fruitful new
research and development based on low-cost and commonly available
materials," the study stated.
Jeffrey Grossman, executive director of the Center of Integrated
Nanomechanical Systems and group leader of the Computational
Nanoscience Group at UC Berkeley, cited the study at a conference this
week.
"The periodic table seems to be opening up before our eyes,"
Grossman said during a talk on PV and concentrating solar technology at the UC
Berkeley Energy Symposium on Monday. But research needs to continue
into the materials, as well as into thin-film materials and issues
such as safe disposal of cadmium.
"We need to understand the basic science to understand these
materials," Grossman said.
Sunpower Corp. Senior Manager of Utility Sales Ed Smeloff noted
the cost of installing PV is now at about $5.50 a watt, down from
about $20 a watt 20 years ago.
"PV will succeed," Smeloff said. "It can be built anywhere, it is
scalable, and it can be rapidly deployed."
But while PV will continue to contribute to the overall energy
solution, Charles Ricker, senior vice president of marketing and
business development at BrightSource Energy Inc., expects solar
thermal to advance.
"For the planning horizon I see the scale at which we can develop
solar thermal is much faster," Ricker said, adding that solar thermal
"is where utilities are making their bets."
Earlier this month, BrightSource signed the world's largest solar
power deal with Southern California Edison, a series of contracts for
1.3 GW of solar thermal energy.
But cost information for concentrated solar power remains less
transparent, University of California Energy Institute Director
Severin Borenstein said during the symposium. Referring to a big
contract PG&E signed with BrightSource for 900 MW of concentrated
solar power, "we actually don't know how much it costs," Borenstein
said.
On a totally unsubsidized basis, residential solar PV is the most
expensive form of energy, at about 40 cents/kWh, according to
Borenstein.
Utility-scale solar PV comes in at a range of 20 cents to 30 cents/
kWh, followed by concentrated solar or solar thermal power, at about
18 cents/kWh. Wind power is at 9 to 13 cents/kWh; natural gas
generation costs about 8 cents; and coal-fired generation runs about 5
to 6 cents/kWh [Hilary Corrigan and Mavis Scanlon].