Could Mixing Solar + Gas Speed Utility-Scale Solar Deployment?

A Florida Power and Light hybrid of solar and gas at the Martin Next Generation Solar Energy Center in Florida could provide a road map for helping shepherd utility-scale solar past regulatory roadblocks. Perhaps by combining solar with fossil energy plants (that are always somehow on the fast-track ) we can finally ease utility-scale solar into the marketplace.
At the hybrid gas/solar plant in Martin, a relatively modest 70 MW heliostat solar thermal power plant – but which is nevertheless second in size only to its much larger US heliostat solar thermal prototype that totals 354 MW – SEGS, that has operated since the ’80’s in California’s Mojave – is to be grafted onto an existing natural gas plant; one that is itself the largest in the US.
The capacity of the natural gas plant has been gradually built up over the years. It comprises three 800 MW steam-generating units, two 450 MW combined-cycle units and two 160 MW combustion turbine peaking units, and now totals 3,800 MW.
However, the solar portion is large enough so that because of the size of each source, this pilot project will definitively answer the question: “But is this doable at full-scale?” Small solar projects already sometimes use a small gas turbine for cloudy days backup, but this is a first at this scale.
Larger similar heliostat-based solar thermal projects Brightsource (440 MW) Solar Reserve (150 MW) and Abengoa (250 MW) are currently bogged down in the regulatory review pipeline in California. The difference? Theirs are not married to natural gas plants.
Using the same heliostat solar thermal technology as is used at the 354 MW SEGS, the $476 million solar installation comprises mirrors that will rotate with the sun to concentrate the sun’s rays into a vacuum-sealed tube that contains a synthetic oil, which heats up to 748 degrees Fahrenheit. The boiling oil is then used to produce steam that is fed into an existing turbine at the gas plant to produce electricity.
The full-scale pilot test will show natural gas producers how solar could be added cheaply, reducing their greenhouse gas emissions. Because the new solar thermal project does not need to build a new steam turbine or new high-power transmission lines, (since the natural gas plant already is so equipped) these extra solar electrons are 20% cheaper than if they were built as a stand alone project.
The traditional natural gas business is dominated by fossil energy companies who find it easier to move projects expeditiously through the environmental review process because these are old established companies that know how to grease the skids. More shotgun marriages between a fossil fuel and solar might make that process speed up for utility-scale solar too.
Currently, not mere MW, but tens of GW-worth of solar projects are backed up in the approval pipeline in California alone, and many of these employ similar heliostat solar thermal mirror technology as both the SEGS original and this project. Because, like fossil electricity, they ultimately use steam to generate electricity, heliostat-based solar thermal projects are a natural marriage partner for a fossil electricity plant.
Solar, while it now supplies close to 2.5% of the California grid from rooftop PV, has made little dent in utility-scale power on the grid. This project in Florida could help change that.
And then, once natural gas peaks, the solar will still be there; pumping out juice.
Image: Martin Next Generation Solar Energy Center
Source: New York Times
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March 8th, 2010 at 10:02 pm
Like what there doing there. Everyone thinks they’ll change the world overnight, to me this is a very positive step forward.
March 9th, 2010 at 12:26 pm
What’s with silly enviro and nimbyism causing RE roadblocks? “They” say to reduce CO2, then they say “Oh no, we can’t have massive solar”!
I say “Let’s ditch solar troughs for the better, solar power tower”. No enviro/nimby problems because heliostats are post mounted (little or no grading. Molten salts storage is simply the best form of energy storage, especially since the tower concept heats it sufficiently to power a Brayton cycle (unlike troughs). Molten salt heat storage is like twenty times cheaper than batteries.
Now is the time to focus the sun (and our research) into the “best” solar. Heliostats should be robotically mass produced and they can power ten times global demand on about 10% of the deserts alone… (This is because all the heat wasted to FF generation does not have to be accounted for).
March 9th, 2010 at 12:41 pm
I think a lot of the “environmentalism” roadblock is actually orchestrated by the very effective fossil industry via The Heartland Institute, rather the way the Tea Party opposition to “don’t let gummint mess with my medicare” opposition was orchestrated by that Dick Armey DC lobbying firm DLAPiper that owns Freedomworks (Rachel Maddow last night)
March 9th, 2010 at 1:18 pm
Thanks, I just bitched them out big time (the heartland Institute)! They complain about how solar is “bad” for the environment…
March 9th, 2010 at 2:42 pm
Yes, they got a lot of traction with their drumming up fears about solar’s supposed water usage. The NYT, really all the media followed their story with endless more of the same, with no exposure that the Heartland Institue was behind it. Yet natural gas, (which is what we’ll get more of without solar – uses more water and endangers clean water supplies with contaminants.
March 11th, 2010 at 5:42 pm
Gas & Solar combined cycle should be developed where possible. Landfills should produce syngas via pyrolysis and develop solar tower fields on the then largely unused landfill site to generate combined cycle power.
March 12th, 2010 at 10:43 am
Landfill gas and solar – you are right – wow!
Great combo – the solar could be embedded right into those huge plastic sheets that cover the landfill to trap the methane for energy. Would need to be thinfilm, of course – flexible solar, like Konarka makes for the military. Even though thin-film needs more space… that s just what the landfill capture has!
Tom, you should patent this quick!
March 12th, 2010 at 2:04 pm
“The full-scale pilot test will show natural gas producers how solar could be added cheaply, reducing their greenhouse gas emissions.”
What part of this is cheap? $476 million to produce an average of 18 MW means about 40¢/kW·h.
March 12th, 2010 at 8:25 pm
@Bill, Your math may be wrong. Solar is down to about 15 cents a kwh at retail (on residential roofs) here in California – I doubt that 40 cents kwh for utility scale could be remotely correct.
March 13th, 2010 at 12:34 am
$476 million / 155,000 MW·h x 0.13 [Capital Recovery Factor] = 0.40 $/kW·h
CRF is a shortcut to Levelized Cost of Energy; obviously the value depends on the interest rate and length of the loan.
Sanity check: FPL’s new reactors at Turkey Point are estimated to cost about $18 billion (including financing and all the trimmings) and produce 2 GW on average.
If $476 million / 18 MW = 26 $/W is cheap,
then $18 billion / 2 GW = 9 $/W is dirt cheap.
As for retail solar, is that after federal and state tax credits, and with net metering?