ARPA-E Supports 12 Unique Solar Projects With $30 Million

High-Temperature Topping Cells from LED Materials

Arizona State University will develop a solar cell that can
operate efficiently at temperatures above 450°C, unlike
today’s solar cells, which lose efficiency rapidly above 100°C.
The team will adapt semiconducting materials used in today’s
light-emitting diode (LED) industry to enable high-temperature
operation. These solar cells will extract as much energy as
possible from the highest-energy portion of the solar spectrum
when used in the next generation of hybrid solar converters.

Solar-Concentrating Photovoltaic Mirrors

Arizona State University will develop a curved mirror made of
solar cells to collect both direct and diffuse sunlight for
conversion to electricity and heat. While today’s concentrating
solar systems cannot use diffuse sunlight that has been
scattered by the atmosphere, this system will simultaneously
convert diffuse sunlight and some direct sunlight into
electricity in solar cells while reflecting the unused portion of
the direct sunlight for conversion to heat. This design can
provide a low-cost way to utilize the di

Solar-Concentrating Photovoltaic Mirrors

Arizona State University will develop a curved mirror made of
solar cells to collect both direct and diffuse sunlight for
conversion to electricity and heat. While today’s concentrating
solar systems cannot use diffuse sunlight that has been
scattered by the atmosphere, this system will simultaneously
convert diffuse sunlight and some direct sunlight into
electricity in solar cells while reflecting the unused portion of
the direct sunlight for conversion to heat. This design can
provide a low-cost way to utilize the di

Solar-Concentrating Photovoltaic Mirrors

Arizona State University will develop a curved mirror made of
solar cells to collect both direct and diffuse sunlight for
conversion to electricity and heat. While today’s concentrating
solar systems cannot use diffuse sunlight that has been
scattered by the atmosphere, this system will simultaneously
convert diffuse sunlight and some direct sunlight into
electricity in solar cells while reflecting the unused portion of
the direct sunlight for conversion to heat. This design can
provide a low-cost way to utilize the di

Electrothermal Energy Storage with a Supercritical CO2 Cycle

GE will design and test components of a unique gas turbine
that is driven by high-temperature, high-pressure carbon
dioxide. The carbon dioxide expands to low pressure and
extremely cold temperatures to generate electricity
from stored electrical and heat energy. The dramatic change in
temperature and pressure is necessitated by an innovative
design that prevents thermal losses across the turbine. This
grid-scale energy storage system could be coupled to a hybrid
solar converter to deliver solar electricity on demand.

Full-Spectrum Stacked Solar-Thermal and PV Receiver

The Massachusetts Institute of Technology will develop a
hybrid solar converter that integrates a thermal absorber and a
solar cell into a layered stack. The design allows focused
sunlight to heat fluid piped through layers of optically
transparent thermal insulation. The part of the spectrum most
easily converted to electricity filters through to the solar cells.
This unique stack design would enable low-cost solar energy
conversion systems that can flexibly dispatch electricity when
most needed.

Full-Spectrum Stacked Solar-Thermal and PV Receiver

The Massachusetts Institute of Technology will develop a
hybrid solar converter that integrates a thermal absorber and a
solar cell into a layered stack. The design allows focused
sunlight to heat fluid piped through layers of optically
transparent thermal insulation. The part of the spectrum most
easily converted to electricity filters through to the solar cells.
This unique stack design would enable low-cost solar energy
conversion systems that can flexibly dispatch electricity when
most needed.

Full-Spectrum Stacked Solar-Thermal and PV Receiver

The Massachusetts Institute of Technology will develop a
hybrid solar converter that integrates a thermal absorber and a
solar cell into a layered stack. The design allows focused
sunlight to heat fluid piped through layers of optically
transparent thermal insulation. The part of the spectrum most
easily converted to electricity filters through to the solar cells.
This unique stack design would enable low-cost solar energy
conversion systems that can flexibly dispatch electricity when
most needed.

Full-Spectrum Stacked Solar-Thermal and PV Receiver

The Massachusetts Institute of Technology will develop a
hybrid solar converter that integrates a thermal absorber and a
solar cell into a layered stack. The design allows focused
sunlight to heat fluid piped through layers of optically
transparent thermal insulation. The part of the spectrum most
easily converted to electricity filters through to the solar cells.
This unique stack design would enable low-cost solar energy
conversion systems that can flexibly dispatch electricity when
most needed.

Hybrid Solar Converter with Solar Pond Receiver

Otherlab will develop an integrated system that splits the solar
spectrum, converting the most suitable wavelengths of
sunlight into electricity via high-efficiency solar cells and using
the rest of the spectrum to directly heat a pool of molten salt.
The system will collect sunlight using an array of small,
pneumatically driven mirrors that track the sun’s movement,
allowing the molten salt pool to cost-effectively store solar
heat for generation of dispatchable electricity. This technology
could enable a low-cost solar system that would fit easily
inside a football field, in contrast to today’s solar fields that
can cover several square miles.

High-Concentration Full-Spectrum Solar Energy System

Sharp Labs of America will develop a hybrid solar converter
that incorporates a partially transmitting mirror to reflect
visible wavelengths of light to extremely high-efficiency solar
cells while passing ultraviolet and most infrared light to heat a
thermal fluid. The extremely high concentration of visible
wavelengths of light would allow expensive solar cells to be used in an inexpensive converter. The converter could enable utilities to provide dispatchable, on-demand, solar electricity at low cost.

Liquid Filter with Plasmonic Nanoparticles

The University of Tulsa will develop a hybrid solar converter
that captures non-visible wavelengths of light to heat a fluid
containing light-absorbing nanoparticles that are far too small
to be seen with the naked eye. The fluid would also transmit
the part of the spectrum most easily converted to electricity to
a solar cell and passes waste heat back to the fluid. This heat
in the fluid can be stored to provide low-cost solar energy
beyond the time when the sun is shining.