The new hybrid solar-natural gas system from Pacific Northwest National Laboratory (PNNL) works through concentrating solar power, which uses a reflecting surface to concentrate the sun's rays like a magnifying glass. In the case of the new system from PNNL, a mirrored parabolic dish directs sunbeams to a central point, where a device absorbs the solar heat to make syngas.| Photo courtesy of PNNL.
The race to transition to cleaner, greener natural gas power plants is getting a boost from an unlikely source -- solar energy. A new system developed by the Energy Department's Pacific Northwest National Laboratory (PNNL) converts natural gas and sunlight into a more energy-rich fuel called syngas, which will allow hybrid solar-gas power plants to use about 20 percent less natural gas to produce the same amount of electricity while also lowering the plant's greenhouse gas emissions.
The system works through concentrating solar power, which uses a reflecting surface to concentrate the sun's rays like a magnifying glass. In the case of the new system from PNNL, a mirrored parabolic dish directs sunbeams to a central point, where a device absorbs the solar heat to make syngas.
The 4-foot long, 2-foot wide device contains a chemical reactor and several heat exchangers. The concentrated sunlight heats up the natural gas flowing through the reactor's channels, where a catalyst helps turn the natural gas into syngas. The heat exchangers recycle leftover heat from the chemical reaction gas -- increasing the efficiency of the system. In fact, tests on an early prototype of the device demonstrated that more than 60 percent of the sunlight hitting the parabolic dish was converted into chemical energy contained in the syngas.
The system is adaptable to the size of a given natural gas power plant -- the number of devices needed changes based upon the size of the power plant -- and can be bypassed to burn natural gas directly in the event of cloud cover.
The team's goal is to keep the system's overall cost low enough to ensure that hybrid solar-gas power plants are cost competitive with conventional, fossil fuel-burning power plants by 2020. PNNL is refining that early prototype to increase its efficiency and cost competitiveness, while developing more cost effective manufacturing techniques for mass production.
The current project at Pacific Northwest National Laboratory is funded by a combined $4.3 million from the Energy Department's Sunshot Initiative and industrial partner SolarThermoChemical LLC -- an agreement with SolarThermoChemical allows the company to manufacture and sell the system after the project ends.