A Solar Booster Shot for Natural
Gas Power Plants
4/11/2013 - Pacific Northwest National Laboratory - PNNLís
concentrating solar power system reduces greenhouse emissions - at a
price thatís competitive with fossil fuel power
ó RICHLAND, Wash. Ė Natural gas power plants can use about 20
percent less fuel when the sun is shining by injecting solar energy
into natural gas with a new system being developed by the Department
of Energyís Pacific Northwest National Laboratory.
converts natural gas and sunlight into a more energy-rich fuel
called syngas, which power plants can burn to make electricity.
ďOur system will enable power plants to use less natural gas to
produce the same amount of electricity they already make,Ē said PNNL
engineer Bob Wegeng, who is leading the project.
ďAt the same time,
the system lowers a power plantís greenhouse gas emissions at a cost
thatís competitive with traditional fossil fuel power.Ē
will conduct field tests of the system at its sunny campus in
Richland, Wash., this summer.
With the U.S. increasingly relying on inexpensive natural gas for
energy, this system can reduce the carbon footprint of power
DOEís Energy Information Administration estimates
natural gas will make up 27 percent of the nationís electricity by
2020. Wegeng noted PNNLís system is best suited for power plants
located in sunshine-drenched areas such as the American Southwest.
Installing PNNLís system in front of natural gas power plants turns
them into hybrid solar-gas power plants. The system uses solar heat
to convert natural gas into syngas, a fuel containing hydrogen and
Because syngas has a higher energy content, a power
plant equipped with the system can consume about 20 percent less
natural gas while producing the same amount of electricity.
This decreased fuel usage is made possible with concentrating solar
power, which uses a reflecting surface to concentrate the sunís rays
like a magnifying glass. PNNLís system uses a mirrored parabolic
dish to direct sunbeams to a central point, where a PNNL-developed
device absorbs the solar heat to make syngas.
Macro savings, micro technology
About four feet long and two feet wide, the device contains a
chemical reactor and several heat exchangers.
The reactor has narrow
channels that are as wide as six dimes stacked on top of each other.
Concentrated sunlight heats up the natural gas flowing through the
reactorís channels, which hold a catalyst that helps turn natural
gas into syngas.
The heat exchanger features narrower channels that are a couple
times thicker than a strand of human hair.
The exchangerís channels
help recycle heat left over from the chemical reaction gas.
reusing the heat, solar energy is used more efficiently to convert
natural gas into syngas. Tests on an earlier prototype of the device
showed more than 60 percent of the solar energy that hit the
systemís mirrored dish was converted into chemical energy contained
in the syngas.
Lower-carbon cousin to traditional power plants
PNNL is refining the earlier prototype to increase its efficiency
while creating a design that can be made at a reasonable price.
project includes developing cost-effective manufacturing techniques
that could be used for the mass production.
methods will be developed by PNNL staff at the Microproducts
Breakthrough Institute, a research and development facility in
Corvallis, Ore., that is jointly managed by PNNL and Oregon State
Wegengís team aims to keep the systemís overall cost low enough so
that the electricity produced by a natural gas power plant equipped
with the system would cost no more than 6 cents per kilowatt-hour by
Such a price tag would make hybrid solar-gas power plants
competitive with conventional, fossil fuel-burning power plants
while also reducing greenhouse gas emissions.
The system is adaptable to a large range of natural gas power plant
sizes. The number of PNNL devices needed depends on a particular
power plantís size.
For example, a 500 MW plant would need roughly
3,000 dishes equipped with PNNLís device.
Unlike many other solar technologies, PNNLís system doesnít require
power plants to cease operations when the sun sets or clouds cover
Power plants can bypass the system and burn natural gas
Though outside the scope of the current project, Wegeng also
envisions a day when PNNLís solar-driven system could be used to
create transportation fuels. Syngas can also be used to make
synthetic crude oil, which can be refined into diesel and gasoline
than runs our cars.
The current project is receiving about $4.3 million combined from
DOEís SunShot Initiative, which aims to advance American-made solar
technologies, and industrial partner SolarThermoChemical LLC of
Santa Maria, California
SolarThermoChemcial has a Cooperative Research
and Development Agreement for the project and plans to manufacture
and sell the system after the project ends.
More information about PNNLís
concentrating solar power system for natural gas power plants.
REFERENCE: RS Wegeng, DR Palo, RA Dagle, PH Humble, JA
Lizarazo-Adarme, SK, SD Leith, CJ Pestak, S Qiu, B Boler, J Modrell,
G McFadden, ďDevelopment and Demonstration of a Prototype Solar
Methane Reforming System for Thermochemical Energy Storage --
Including Preliminary Shakedown Testing Results,Ē
9th Annual International Energy Conversion Engineering Conference,
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