After Gutenberg

This is just another post about utility-scale, solar thermoelectric power providing base load. The most recent post on the topic was an expression of hope that the World Bank was investing in solar thermal electric power plants across North Africa and the Middle East that could easily meet the regions electric power demands with excess sold to Europe.

That was during the first week of COP15 when there was still some hope about its outcome. But, this is not a time to be crying into our egg nog. ‘Tis the season to turn our gaze toward Hawaii, where, Toronto Treehugger Lloyd Alter tells us, “Keahole Solar Power has installed an array of Sopogy Micro-scale Concentrating Solar Power Concentrators.”

A Parabolic Trough Organic Rankine Cycle Solar Power Plant with waste heat generators that improve efficiency is one model of small power station running on renewable energy.

At the Holaniku Solar Farm on Hawaii’s Big Island- a thousand solar collectors covers 3.8 acres with a thermal energy of 2 megawatts, which they use to heat 8,000 gallons of water. The result: according to Keahole, “firm, fixed power which has been deemed as the holy grail for renewable energy.”

The hot water runs through organic rankine cycle waste heat generators. Treehugger has shown these previously; those Electratherm waste heat generators were part of geothermal electric power generation. An advocate of solar thermal electric power, this blog also has mentioned combining geothermal and solar thermal power.

The ElectraTherm units are called Waste Heat Generators and run on a temperature difference of only 20 degrees, while the output of the Sopogy array is anything but waste heat- it is hot enough to run turbines, absorption air conditioners and even make steam.

The absorption cooling gas turbine system has a decided advantage over traditional turbines in that it maintains its efficiency whether operated at peak or partial power. “The addition of ElectraTherm units squeezes a lot more energy out of it and improve system efficiencies,” writes Alter; and, Robert Hoover of ElectraTherm tells us that “ElectraTherm’s generation of electricity consumes only a small portion of the Btu generated by the concentrators.”

“But if all the waste heat left over after using the high grade stuff is used to heat water, there is more than enough to run the Green Machines day and night, cloudy or sunny. ‘Holy Grail’ may be overstating the case, but it is certainly a big step forward. Utility-scale solar thermal electric power combined with thermal storage can address demand for base and peak load.

How The ElectraTherm Generator works:

“ElectraTherm power systems use a closed-loop organic Rankine cycle (ORC) to create pressure by boiling EPA-approved chemical working fluids into gas. The gas expands in a one way system and turns a patented Twin Screw Expander, which drives a generator to ultimately put out electricity.”

Promotional videos prepared by Sopogy on how their system works:

There is more info at ElectraTherm about how the Sopogy system works, to include info about rooftop solar thermal systems, see “Sopogy SolarFlare Brings Solar Thermal Power to Commercial Rooftops.”

How Solar Powered Air Conditioning Works

More Treehugger posts on the topic of Solar Powered Air Conditioning

• Small-Scale Solar Powered Air Conditioning Is Here (in Spain, Anyways)
• Challenge: Build the Solar Powered Air Conditioner
• Solar-Powered Air Conditioner About To Be Released
• Solar Powered Air Conditioning Just Makes Sense

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