#1 cleantech news, reviews, & analysis site in the world. Subscribe today. The future is now.

Clean Power no image

Published on June 12th, 2014 | by Tina Casey


LNG Exports Bump Up Against Exportable Concentrating Solar Power

June 12th, 2014 by  

You knew we could not let another day go by without yet another article about concentrating solar power, right? This one has a bit of a twist. The Colorado-based company Cool Energy has just jumped into the global concentrating solar power market by hooking up its proprietary Stirling engine, which converts heat to electricity, with the concentrating solar power company Edisun Heliostats.

Since the Department of Energy has just come out with a new report estimating the methane leakage involved in exporting liquid natural gas from the US, now would be a good time to underscore the difference between exporting solar technology from the US, rather than incurring the risk, waste, local impacts, and greenhouse gas emissions from increasing our fossil fuel exports.

concentrating solar power meets Stirling Engine

Waste heat conversion courtesy of Cool Energy, Inc.

Cool Energy And Concentrating Solar Power

Cool Energy came across our radar in 2009 when it introduced its SolarHeart® Engine system. At the time, Cool Energy was marketing a home renewable energy package that combines solar input with waste heat capture.

The Stirling engine angle comes in right there. As a Stirling-type engine, SolarHeart operates by expansion and compression of air. The change in compression corresponds to different levels of temperatures, and the result is to convert heat energy to mechanical energy. A built-in generator converts the mechanical work to electricity and Bob’s your uncle (for more details, Ohio U. has a good backgrounder on Stirling engines.

Cool Energy has been expanding its market since 2009, one development being a $1 million Energy Department grant last year to develop a “GeoHeart” version to capture geothermal waste heat from oil and gas wells.

We’re not particularly thrilled about that application, but this new thing looks pretty neat.

Earlier this week, Cool Energy announced that it had signed on with Pasadena-based Edisun Heliostats to license its concentrating solar power system, which adds a lot more solar punch to the SolarHeart concept.

Edisun has designed its system around cost efficiencies, which nips away at the argument that CSP can’t compete with photovoltaic cells on price.

The company’s heliostats balance wind loading with an economical design, and Edisun claims that its “passive” particle-bed thermal energy storage system is more economical than other CSP alternatives such as molten salt.

Edisun also points out that its partnership with Cool Energy represents an additional efficiency, since Cool Energy’s Stirling engine is designed to run within a moderate temperature range.

Exporting Concentrating Solar Power

But, that’s not what we’re really interested in. Of special interest to us is that Edisun’s concentrating solar power (CSP) system is specifically designed to be trucked around in standard shipping containers.

Transportability is a huge issue for both solar and wind tech (for more on wind angle, see GE’s retro-styled, shippable “space frame” wind turbine towers), and breaking the system down into easily shippable components represents a huge cost savings.

In terms of this big push that’s on to increase natural gas exports from the US for the sake of energy security in Europe (think: bad Russia, bad!) perhaps it would make more sense to ship CSP systems and other renewable energy harvesting equipment around the world rather than continuing to increase the transportation impacts of fossil fuel pipelines as well as maritime, rail, and road transporation.


Here in the US we’ve had a string of high-profile environmental disasters related to fossil fuel transportation, and to that you can add the growing list of local impacts from natural gas fracking.

Follow me on Twitter and Google+.


Tags: , ,

About the Author

specializes in military and corporate sustainability, advanced technology, emerging materials, biofuels, and water and wastewater issues. Tina’s articles are reposted frequently on Reuters, Scientific American, and many other sites. Views expressed are her own. Follow her on Twitter @TinaMCasey and Google+.

Back to Top ↑