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NRG Energy Testing GreenFuel Algae Emissions-to-Fuel System at Coal Power Plant

NRG Energy has begun field testing GreenFuel Technologies’ proprietary Emissions-to-Biofuels bioreactor technology (earlier post) at NRG’s Big Cajun II—a 1,489 net MW coal-fueled power plant in New Roads, Louisiana.

GreenFuel’s Emissions-to-Biofuels process uses naturally occurring algae to capture and reduce flue gas carbon dioxide emissions into the atmosphere. The algae are harvested daily and can be converted into a broad range of biofuels or high-value animal feed supplements.

Power generators can choose to dry and store the carbon-rich algae biomass for use as renewable fuel for the power plant or convert it to transportation fuels such as biodiesel or ethanol. The process requires no re-engineering of the power plant.

In the initial field testing, which will last approximately four months, algae species will be selected to optimize biofuel production based on the site’s flue gas composition, local climate and geography toward an ultimate goal of construction of a commercial-scale facility. A full scale commercial deployment could recycle enough CO2 to yield as much as 8,000 gallons of biodiesel per acre annually under optimum conditions.

NRG owns a diverse portfolio of power-generating facilities, primarily in Texas and the Northeast, South Central and West regions of the United States. Its operations include baseload, intermediate, peaking, and cogeneration and thermal energy production facilities. NRG also has ownership interests in generating facilities in Australia, Brazil and Germany.



Great. A very important step in addressing the problems of coal fired power generation. Let's hope there are more utilities ready to examine the benefits of algal CO2 sequestration and ancillary green products. And in Louisiana - home of big oil.


I really don't have much more to say but:

Faster, please.

Johnny B Good

Somehow I like the idea of buying my biodiesel from the power company. Perhaps I might get this fuel at a discount if I could get my electric meter to run backward (via the PV panels on my roof).


Is it here yet?, is it here yet?, is it here yet?, is it here yet?, When is it going to be here? Will we still be here when
it gets here? Maybe, if we keep leveling off mountains,
filling in valleys, destroying watersheds and natural
ecosystems, we will have it here, when, here has dissappeared.
Whew, just in time. I was worried there for a second.


8000 gallons/acre/year... hmmm.  An acre is just over 44,000 square feet.  If you covered the roof of a 2200 ft^2 ranch house with algae systems, you'd expect about 400 gallons/year out of it.  A one-liter-per-square-meter house would use less than 50 gallons of this for heating, leaving the other 350 gallons for other purposes.  Diesel PHEV fuel?

Looks like a house with an algae-growing roof could power both its occupants' heating and transportation needs.


E-P: Now we just have to breath a lot harder to provide the CO2 the process needs ... Brace yourself wife I want to drive to the store. ;) I suppose I could burn the algae in an in home generator to get the CO2. Would you happen to have numbers for the energy return per ft^2 compared to PV?


I wouldn't want all that water up on my roof, E-P.


Wouldn't the point be to bury (or otherwise permanently lock away) the algae once it has resequestered the coals Carbon. Seems to me converting back to fuel would once again release the CO2 that we don't want in the atmosphere. Maybe they can have an algae farm capture the algae's released CO2... hmmm.

If you grow algae directly from atmospheric C02 and then burn it... at least you're CO2 neutral.


Using industrial photosynthesis to convert CO2 emissions into biofuel seems like a great idea, but there are hurdles that aren't likely to be overcome. Krassen Dimitrov has taken the time to study the science, and economics behind this type of approach and concluded that basically this has hasn't got a snowball's chance in hell of working. There just isn't enough energy available from sunlight per meter of land surface to do the job, especially when the theoretical efficiency limit for conversion of sunlight into carbohydrate is 27%. See www.nanostring.net/Algae/CaseStudy.pdf

Photovoltaic cells are being made today that are significantly more efficient than photosynthesis and produce energy in a form that can be efficiently used and transported. Fortunately, the sun's radiation also creates massive amounts of wind energy that can be captured day or night. Li-ion batteries for cars seem to be the best answer because electric motors are so much more efficient, simpler, and cleaner than any kind of combustion engine can be.


Yes it does stink that this seems to put a spot of light on coal plants but I will take what I can get for now. It still reduces the CO2 foot print and that is a plus.


We aren't likely to stop using coal for power anytime soon, Dirk. Recycling the CO2 emissions via algae biofuel displaces oil that would otherwise come out of the ground and used as diesel. This creates a net reduction in emissions, which is a good step forward.

And Mark... I suspect that the MIT scientists who started GreenFuel Tech know at least as much as Dimitrov. Additionally, the biodiesel and ethanol produced this way can be used in millions of vehicles presently on the road, not in EVs that don't even exist.


I'd happily rebuild my roof to carry that much water (not much more than a heavy wet snowfall, if you arrange it in short stair-steps) if it let me produce more fuel than I used.

Cervus, one problem with adding CO2-recovery systems onto coal plants is that this creates an expectation of a long service life.  Powerplants have a lifespan of 50 years or more, while light-duty vehicles are under 20 years.  We can change our vehicle fleet much faster, and combining our coal-fired electric systems with motor-fuel production creates more pressure to keep the unified system going.  I'm not sure the climate can afford this.


E-P: Okay, so you're willing to put one of those systems on you roof. But someone still has to run it and come collect the raw algae for processing. Much simpler and cost effective and efficient to put such systems in large-scale production plants rather than a few million rooftops. We're not talking about PVs that can automatically feed into the grid, after all.

As for vehicle fleet changover time, I'm not holding my breath on EVs becoming affordable for a middle class person like me anytime soon (is there even enough lithium?). So I'm looking at this system to make the best use of the domestic energy resources we have (a few billion tons of coal). I'm trying to balance our energy security with climate issues, and this is an acceptable compromise for me.


E-P: in all seriousness, If you have this system on your roof, where are you getting the CO2 from? Are you thinking of recycling it somehow?

Cervus: there's more lithium in the ocean than you can spit at.

I can see LDVs moving to electric fairly quickly but we still need fuel for trucks and airplanes.


Neil, if it was on my roof it would be getting the CO2 from the atmosphere.  I have no expectation of storing CO2 from winter heating to feed the summer growth.

As for PHEV's, the VentureOne's designers are currently talking about a prototype this year and deliveries next year.  Price tag is in the $20,000 range (more for the pure EV).  I'll have about 6 years to go on my usual 10-year car lifespan, but I plan to buy one anyway.

Once vehicles are PHEV's, anything that generates electricity makes "motor fuel".  This is everything from a wind turbine or PV panel to the biogas engines at the landfill to your Climate Energy cogenerating furnace to the nuclear plant in the next county.


E-P: since the greenfuel reactors are designed to run off of CO2 rich emissions from a coal plant ... do you think they can get enough from the air?

P.S. I WANT one of those VentureOne machines! They look like a blast to drive.


I don't expect Greenfuel's algae strains to work in such a regime (they are thermophiles and probably need the exhaust heat), but the work done with wild algae strains growing on wastewater might show how to do the job and remediate the wastewater too.


If the Venture One can actually price out at $20k US, they will sell 100,000. easy. Lookout Harley D... This thing is FUN.

Peter Malkin

Great idea and it seems like they have more of them. I just saw how many awards they have won in the last year. Then my eyes went towards what seems like an even bigger project than this at the Redhawk facility out in Arizona. Have you guys seen the greenfuel video they have, a bit long but not a bad summary:


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