GREENHOUSE PROTECTION: By shielding equipment in a greenhouse, a new project aims to prove that solar thermal is as cheap as burning natural gas.
Image: Courtesy of GlassPoint
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How do you make mirror-concentrated sunlight cheaper than burning natural gas? Put it in a greenhouse, argues new solar start-up GlassPoint, which unveiled its first such solar hot water greenhouse on February 24—in a dusty, old oil field in California's Central Valley. Why? Because cheap steam means more oil.
Ensconced amidst the derricks of Berry Petroleum Company's oil field in McKittrick, Calif., the 650-square-meter demonstration of a greenhouse-based solar thermal steam plant will help pre-heat water to 88 degrees Celsius. That hot water will then be boiled to steam with natural gas and used to heat the rock in old oil fields to pump out more petroleum.
"Steam is the largest cost associated with producing oil in these thermal projects," says GlassPoint vice president John O'Donnell. "Now you can run them longer because the steam is cheaper. You can get 10 to 20 percent more oil production out of the same well."
View a slide show of the new greenhouse-based solar thermal plant
The goal is to provide a cleaner and cheaper way to heat up the steam used to melt the field's thicker oils and scour out more of the black gold. Essentially, the technology heats cubic volumes of rock to roughly 175 degrees Celsius to melt heavy oils and get them flowing. Roughly 40 percent of the oil produced from California's century-old fields relies on the steam technique—and it is the largest industrial use of natural gas in that state.
As it stands, the two rows of mirrors in this initial solar thermal greenhouse can generate some 1 million British thermal units of heat an hour. The company claims its technology can produce steam at a cost of $3 per million BTUs, based on U.S. National Renewable Laboratory calculations; natural gas currently costs some $4 per million BTUs, though that price may continue to fall as natural gas freed up by fracking floods the market.
Here's how the technology works: GlassPoint builds a fairly conventional greenhouse with a crenellated roof to maximize the amount of sunshine inside year-round. Below, the seven-meters-across mirrors to concentrate the sun's rays—along with the tube carrying the water to be heated—are suspended from the greenhouse itself. Since the greenhouse blocks the wind, the mirrors and tubing in this plant are roughly 10 percent of the weight of a traditional solar thermal mirror installation, which requires steel supports. As O'Donnell notes, what makes solar thermal power plant technology expensive "is the cost of the hydraulics and steel and concrete associated with maintaining a half-degree of pointing accuracy in a 20 mile-per-hour breeze."
Another advantage is speed: the glass house and solar thermal mirrors took six weeks to build, compared to a solar thermal power tower project under construction since 2009 by BrightSource Energy for Chevron in California's Coalinga oil field near Fresno. "The project is still under construction," says Chevron spokesman Morgan Crinklaw, adding "we expect to have it completed this year…. This is a demonstration project to determine the viability of the technology."
That viability will come down to cost, as projects in previous decades foundered in the face of cheap natural gas. There is only one other solar thermal project delivering heat to an industrial process—a SunChips plant in Modesto, Calif., produces snack chips with the sun's heat—and this marks the only one in the world currently working in an oil field. The company estimates that a full-scale field could deliver as much as 80 percent of the heat energy required for such projects, displacing natural gas in the process.
It is also one that is not confined to California. "There is reasonably good solar radiation in places where steam floods are going," O'Donnell says, such as Kuwait, Oman and other Persian Gulf oil-producing states. "There are resources both over your head and under your feet."
But the greenhouse also offers another key advantage: keeping the mirrors clean of the dust, dirt, sand and humidity that plague oil fields (and deserts generally) around the world. And automated washing equipment borrowed from the agricultural greenhouse industry—essentially automated water sprayers with brushes like those in a car wash—scan clean the glass house that shields the solar thermal equipment from the wind and dust.
"With 100 years of optimization the greenhouse industry has gotten really good at lower shading and lower cost. After all, 1 percent more light is 1 percent more tomatoes," O'Donnell notes. "These reflectors are in a dry, dust-free, non-condensing environment, which means we can use materials that couldn't survive outdoors."
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16 Comments
Add CommentInstead of wasting that technology and hot steam on fossil fuels like oil, couldn't they put turbines at the end of each of those greenhouses and create electricity for the grid or for a storage battery like the molten metal or even the liquid medal and liquid salt batteries?
Reply | Report Abuse | Link to thisThey could:
Reply | Report Abuse | Link to thishttp://www.scientificamerican.com/blog/post.cfm?id=worlds-first-solar-power-plant-that-2010-08-04
http://www.scientificamerican.com/article.cfm?id=how-to-use-solar-energy-at-night
But this is a way to get more money for the solar steam, much as the carbon capture and storage folks are all chasing "enhanced oil recovery":
http://www.scientificamerican.com/article.cfm?id=enhanced-oil-recovery
JamesDavis: "Instead of wasting that technology and hot steam on fossil fuels like oil, couldn't they put turbines at the end of each of those greenhouses and create electricity for the grid or for a storage battery like the molten metal or even the liquid medal and liquid salt batteries?"
Reply | Report Abuse | Link to thisAndrew: No.
Subsequent delivery and its infrastructure costs would make energy production at the source very inefficient.
If it was feasible, what would make you think the scientists and engineers involved with the project would miss such an obvious design?
The issue would be DELIVERY of the produced energy. Note that this project uses the energy on site. Not only that but what they want is heat, thus there is neither a conversion efficiency to worry about, nor a transmission infrastructure and associated efficiency consideration. Note too that the NG that would be otherwise used has to be piped in. This kind of setup is ideal for passive solar, best case really. Domestic hot water is another scenario with similar considerations and not surprisingly is quite cost effective.
Reply | Report Abuse | Link to thisOTOH generating electricity this way is less ideal. It still DOES make sense, but you have to actually generate electricity, transmit it, etc, which is all pretty expensive. NG plants can OTOH be built in locations where there is already transmission infrastructure and where piping it in is cheapest. In those situations solar generally loses with current technology. PV will eventually get there.
What we really need to do is deal with internalizing the costs of fossil fuels, at which point NG won't look so good and people will be a lot less interested in pumping oil too.
tharter: Thank you for your clarifications to Vendicar Decarian. You are correct, I was talking about the practicality of delivery (since, pretty much by definition, oil extraction is done in areas remote to energy use areas, i.e. population centers)
Reply | Report Abuse | Link to thisVendicar Decarian's response was the usual knee-jerk, fanatical, 'go-green in all cases' response you get when any suggestion is made that solar or wind power not be used (even if it is, in practice, an overwhelming energy and environmental loss).
This particular application, solar water pre-heating, is a great use of green energy. I wish I could do it at my house.
The article states the solar greenhouse is only used to pre-heat the water to 88°C. Water requires 60 calories per gram to heat from 28°C to 88°C. From that point to having steam at 175°C requires another 627 calories per gram, 540° calories per gram just to vaporize from liquid water to steam.
Reply | Report Abuse | Link to thisIt doesn't sound like the 10% contribution of the solar greenhouse is more than "window dressing" on a dirty oil project.
In what way is this not simply fracking with solar powered steam hydraulics? Wouldn't the same issues of water contamination apply?
Reply | Report Abuse | Link to thisSee: http://www.scientificamerican.com/search/?q=fracking+and+oil&x=0&y=0
My invention of Gravity Control can be used to generate Gigas. It depends on the size of the building used.
Reply | Report Abuse | Link to thisThe expensive part would be the generator.
For 1 Billion dollar California can have all the power it needs.
Looks like a lot of unneccessary bother and expense. Use the same amount of dollars to put solar panels on the average citizens rooftop. This will further the economy over the long haul. No voltage drops or transmission costs as the energy created is used directly. The extra $4-$500 a month saved by each consumer will go a long ways towards strenthening our future.
Reply | Report Abuse | Link to thisThe cost of oil will also drop as the need for it (and the inherent problems including pollution and health risk) goes away.
The article advocating getting the US completely off oil makes the same tired old claims that oil caused the recession and the Iraq war was about oil. It was not, it was, even mistakenly, about weapons of mass destruction.
Reply | Report Abuse | Link to thisCertainly we can run some vehicles on domestic natural gas, if the enviros will get off the backs of the folks drilling for it. We can heat a lot of homes and offices and generate electricity with it, too.
I live where I can't use a 40 mile range vehicle, or wait 8 hours for a re-charge (using coal-produced power.) Like it or not, we will be using gasoline another 50 years. We should prospect everywhere we can, on and offshore of the US for domestic supplies. Ethanol, for the US, is counterproductive. Even Al Gore knows that.
Yeah,I agree with you.And I am really willing to expect that the green techs.We nodoubtedly should support this issue.
Reply | Report Abuse | Link to thisThey say the temperature of their collector isn't high enough to make dry steam.
Reply | Report Abuse | Link to this"Another advantage, according to Mr. MacGregor, is that the well is not fussy about steam quality, in contrast to a steam turbine that makes electricity, which demands constant temperature and pressure. “If there are hot water droplets in the steam stream, the rock won’t care, but a turbine certainly would,’’ he said."
http://green.blogs.nytimes.com/2011/02/24/using-solar-power-to-extract-oil/?partner=rss&emc=rss
What's always entertaining about reading articles pertaining to industrial uses of green energy on news sites like this are the inevitable comments from hardcore greens who become noticeably angry that industrial companies are daring to employ green energy in ways that the greens do not approve of or did not envision in their utopian daydreams. They then proceed to lecture all of us living in the real world that we are lazy or stupid or simply not quite as good as they are, because we are not willing to spare no cost to reduce our carbon footprint.
Reply | Report Abuse | Link to thisGreat stuff, always good for a chuckle.
Working for an electrical utility I have been monitoring the "green energy" situation avidly for a long time. So far nothing has come close to our big 3 sources; hydro, coal and nuclear. I have yet to find a solar panel that can produce enough electricity in its lifespan to produce another solar panel of the same capacity from start to finish. Wind is even worse. Power storage is expensive and tends to involve deadly chemicals.
Reply | Report Abuse | Link to thisThere have been a number of breakthroughs that show promise but until they are competitive with the big three you won't see any meaningful change in energy generation. That just leaves consumption changes.
The best way to reduce consumption is to have 2 or less children or better yet, kick over dead and reduce consumption immediately. Personally I went for the 2 or less children route.
10% is infinitely better than 0%.
Reply | Report Abuse | Link to thisWhat not making enough doe all ready? So they have to save and use solar. Why not use solar so we don't have to use crude oil? B4WeRu2L8
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