Second Sighting Of Hybrid Coal, Gas, Wind, Solar-Thermal Power Beast

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Image credit:Libra Rising, Centaur, Art and Myth: a pictorial

The last sighting of this beast was during US Congressional testimony, during 2008:- Mythical Hybrid Beast To Battle Climate Change. Recent news indicates a growing interest in co-locating wind turbines and large scale solar thermal plants with fossil-fueled electricity generators. See below for an excerpt from the US Department of Energy announcement about the places hybrid plant projects are being investigated, or actively pursued.

Electric Power Research Institute (EPRI) and a number of utilities are now studying the potential to add solar power to existing power plants in order to help cut their greenhouse gas emissions. EPRI will work with Tri-State Generation & Transmission Association, Inc. and Progress Energy to evaluate the potential to add solar thermal energy systems to the utilities' power plants in Prewitt, New Mexico, and Roxboro, North Carolina. EPRI is also studying the potential to add solar thermal energy systems to natural-gas fired power plants owned by Dynergy Inc. and NV Energy and located in Kingman, Arizona, and Las Vegas, Nevada.
Here are a few relevant excerpts from the earlier Hybrid Mythical Power Beast post .
Coal utilities lack expertise in wind farm or solar thermal facility siting and operation.
There was already strong demand for capacity additions in both wind and central solar capacity... before the banking crisis.
Adding a coal plant to a wind farm proposal makes it a horse of a different environmental color, which certainly would boost opposition to the overall plan. Can you imagine a coal [or even a natural gas power] plant...on the beach as part of Cape Wind. Come on!

Key questions about the beast variations:
about the Coal/Wind Chimera:- Let's suppose that two electrical power sources, one a coal-fired generator and the other a renewable electricity source (a wind farm in this case) are being considered for connection to the same regional grid. What economic or administrative advantages might accrue from co-location on a site owned by a single corporation?

Wind-turbine produced electricity could be used to help heat the coal plant's boiler water; or, perhaps wind power could be used to operate the various electric motors or electrostatic pollution controls. This might be quite handy if the adjacent wind turbines output peaked at the same time that consumer demand did. That said, wouldn't it be easier, more flexible, and less capital intensive for coal plant operators to just purchase wind-generated electricity from wind farms that are optimal for that function? You'd think.

Unless the real purpose was to be able to duck out from under stack emission limits on the coal plant's amended operating permit, or to avoid paying for exceeding carbon caps. See, neither of those potential administrative advantages can be realized if the wind power is generated at a separate site, regardless of whether the owner is the same or it's a JV. Each separate power generating facility has it's own emission permit, with emissions limits per each stack, and its own prospective carbon cap (zero limits or caps for the wind farm, of course.)
about the Natural Gas/Wind Power Chimera:- Ditto here, for all points raised about the Coal/Wind beast.

and finally, about the Coal/Solar-Thermal Power Chimera:-With a coal/solar thermal hybrid, both steam sources (coal and sun, in this example) would presumably share a bank of turbines that generate electricity. As mentioned in the earlier post, 'adding a few daytime steam turbine efficiency points with a thermal solar steam generator bolted onto coal plant turbines', whether with new or existing turbines, poses new challenges and perhaps long term opportunities.

The overall site air operating permit, which will need to be amended, will have limits that don't exist for a plain solar thermal plant, and be contestable.

Working off of existing coal plant power turbines, the hybrid plant can not satisfy demand growth if it is already operating at or near capacity. It can only satisfy existing demand. albeit with "lower" emissions. Conversely, building the two separately, produces more power overall.

If, on the other hand, the goal of the coal/solar-thermal beast is to keep under combined air emission limits and avoid penalties for the site exceeding a carbon cap, until either more nuclear base-load comes on line and/or until carbon sequestration technology becomes available, then maybe, just maybe, you have a climate-fight winning beast, assuming also that the long-range goal of the owner is to get out of coal, entirely.

Am I missing something here? Critiques are welcome.

Otherwise, I sure hope taxpayer dollars are not supporting the work.

Additional hybrid power posts.
Using Solar Roofs To Power Hybrids
Hybrid Solar Thermal-Biomass Power for California
Plug-in Hybrids Might not Need New Power Plants
Flashlight Uses Hybrid Solar and Battery Power
Solar Powered Prius Could Be First Hybrid With Solar

Tags: Coal | Electricity | Wind Power

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