Updated at 2:30 p.m. PST with additional information on PG&E deal.
SolarReserve said on Tuesday it has signed a deal to build a utility-scale solar plant in Nevada with a molten salt storage system that will let it supply power when the sun isn't shining.
The Santa Monica, Calif.-based company has a 25-year power purchase agreement with utility NV Energy to supply about 480,000 megawatt-hours of electricity a year, enough to power about 75,000 homes during peak times. The capacity of the concentrating solar system will be 100 megawatts and be located near the town of Tonopah in Nye County, Nev.
The plant will use a field of heliostats--large mirrors that track the movement of the sun--to heat molten salt held in a tower. That liquid salt is heated to over 1,000 degrees Fahrenheit and transferred to storage tanks. It is then fed into a loop where it creates steam that turns a turbine to generate electricity. The colder molten salt is recaptured and fed back into tanks to be heated again.
Click for larger image.
(Credit: SolarReserve)The company did not indicate how many hours of storage it intends to have at the Tonapah plant but said that the solar field will be able to deliver energy at peak times even when the sun isn't shining.
Construction of the project is expected by the end of 2010, but it still needs approval from the Nevada Public Utilities Commission.
The southwest U.S. is prime land for concentrated solar thermal technology, which needs the right sun angle and a lot of sunlight. Utilities in California and other states are pursuing large-scale solar projects to meet state mandates for renewable energy generation.
The addition of a storage system adds to the overall cost per kilowatt-hour of solar. But it allows the power producer to deliver electricity during peak times when the cost of electricity is highest.
Also on Tuesday, California utility Pacific Gas & Electric said that it has signed a contract to purchase electricity from a SolarReserve-developed project at the Rice Airfield in San Bernardino County, Calif.
The proposed Rice Solar Energy project, which has not yet been approved by state regulators, would produce 150 megawatts of electricity, or enough to power 60,000 average homes, starting in 2013, according to PG&E.
In a company blog, PG&E said that the molten salt storage technology was successfully demonstrated in the 1990s at the Solar Two power plant in California, and plants in Spain have also used the technique. "Best of all, a well-insulated storage tank for molten salt can be 99 percent efficient, so it loses heat only very gradually," company representative Jonathan Marshall wrote.
(Credit:
Prepara)
It's hard to ignore the incessant messages to buy local, plant a garden, check for organic labels, and lead a sustainable lifestyle, yet most of us dismiss these suggestions as practices that require too much money, time, and effort.
And it's true--they really do.
Last summer I went through a green phase, heading to the plant store to purchase soil, seeds, shovels, pots, and everything else that Martha Stewart suggests I buy. Well, $120 and two weeks later, I had forgotten I'd even planted a garden and deemed my project a failure.
Thankfully, there is hope for busy and forgetful people like me. The Prepara Power Plant doesn't require any soil, planting, or high maintenance. Herbs, small vegetables, fruits, and salad greens grow quickly, as the container provides the seeds with the right amount of nutrients and water.
It's not completely care-free, though--you must water the container and place it in sunlight (such as a window sill). But unlike outdoor gardens, the Power Plant Mini is always visible, so don't bother with excuses for neglecting your innocent plant.
Fresh food without bugs, dirt, digging, and worrying sounds like the perfect package. (Plus I can tell all my friends how green and sustainable I am.) Prepara lists the product for $39.99, but it can be purchased on Amazon for $29.99.
A sampling of green-tech news with quick commentary.
- Goals for Ethanol Production Are in Peril - The New York Times
"The ethanol industry is on its back despite the billions of dollars they have gotten in taxpayer assistance, and a guaranteed market," according to one analyst. And the industry is unlikely to meet government production mandates. - Saudi Oil Min: Renewables Push Could Create Energy Havoc - Dow Jones
Saudi oil minister warns of a "nightmare scenario of diminishing energy supplies" if renewable energy is adopted too quickly. - How Better Place plans to revive the electric car - CNET Australia
Australia will be one of the first places to have Better Place's automated battery-swapping stations for electric cars. CNET Australia's Car Tech blog gets the lowdown. - Sequoia Backs Stealthy C12 To Capture Carbon - VentureWire
Boston-area start-up wants to make underground storage of carbon dioxide--of great interest to utilities--less expensive. Commercialization is years away, though. - Wind turbine 'broke due to mechanical failure not collision with flying object' - The Daily Telegraph
So much for the UFO theory. - Hybrids Powered by Air - Technology Review
Researchers look for a more efficient way to use stored compressed air to help power a (smaller) motor. - When Oil Rig Met Wind Turbine - Greentech Media
To do offshore wind, talk to people who know a bit about offshore oil. - Does a Big Economy Need Big Power Plants? - The New York Times
Guest post by energy maven Amory Lovins, who says that gigantic power plants no longer make sense and that distributed "micropower" is the way to grow. - Dell Announces Major Expansion of Free Computer Recycling Program - press release
You can recycle your Dell PC at 1,000 locations in the U.S. now.
SunPower on Thursday announced two deals with Florida Power & Light to build 35 megawatts worth of electricity, including an installation at the Kennedy Space Station.
The deals are the largest to date for SunPower, which makes and installs solar photovoltaic panels.
The Florida power plants will use a sun-tracking system like this one used in the Serpa plant in Spain.
(Credit: SunPower)A 25-megawatt plant will be installed by DeSoto County by 2009 and the Kennedy Space Center will have its 10 megawatt plant done by 2010. Florida Power &Light will own and operate the plants.
The largest solar photovoltaic plant in the U.S. is at the Nellis Air Force base in Nevada, which generates 14 megawatts.
Earlier this week, General Motors said that it intends to build a 10-megawatt installation at an assembly plant in Spain.
Large corporations build these huge installations to get a fixed electricity rate over several years, typically 20 or 25 years.
Utilities are purchasing wind and solar power because of high fossil fuel prices and state-level renewable energy mandates.
Most Americans live and work in buildings awash in chemicals blamed for asthma, lung cancer, and a host of other maladies.
The best way to clean the air could be with a green thumb, according to Bill Wolverton, a former NASA environmental scientist who has spent more than 30 years studying how plants purify the air. The results of his research could come to market this fall as a household air filter that looks like a potted plant.
A U.S. version of the EcoPlanter, sold in Japan, is being produced. It's supposed to provide the air-purifying power of more than 100 potted plants.
(Credit: Bill Wolverton)"Every chemical we tested, plants could take them out," said Wolverton, who originally worked on life support systems for the moon and Mars.
Plants absorb and convert airborne poisons to energy and food. At the roots, ever-adapting microbes munch on toxicants.
Wolverton worked to enhance those processes and has licensed his technology to Phytofilter Technologies, an upstate New York state startup. It's creating potted plant air filters to sell for several hundred dollars each later this year.
The device has a fan at the base of a plant pot, drawing and trapping toxins near the roots, where hungry microorganisms dwell. A version has been sold in Japan for seven years as the EcoPlanter, which includes a mold-killing ultraviolet light.
The self-cleaning filter is supposed to pack the purifying power of more than 100 plants and destroy poisons that are only trapped by carbon, zeolite, and high-efficiency particulate air, or HEPA, filters.
Phytofilter founder Martin Mittelmark also developed a plant-based filtration system for a building at Syracuse University this spring, backed by funding from the Environmental Protection Agency.
In recent years, air quality tests by the University of Technology in Sydney, Australia, found that levels of toxins in offices shrank by 75 percent with the presence of only six plants per room.
Wolverton thinks his technology on a larger scale could clean the exhaust from power plants by trapping air pollution in water, then feeding it through a closed system of marshes. A similar tactic taken by small towns in Mississippi turns sewage into fertilizer by diverting it through marshes. But Wolverton sees more interest coming from developing nations including China and India.
"Universities in the U.S. are geared up to use mechanical means to clean up the environment, and when you mention plants to some of these engineers, that's sissy to them," he said.
For now, Wolverton plans to give away plant filters to residents of formaldehyde-polluted trailers in areas still recovering from Hurricane Katrina. The technology cut formaldehyde levels by one-sixth in trailers from the Federal Emergency Management Agency, in tests he explored with the Sierra Club.
Common building products and furniture are also laced with formaldehyde and toxins including flame retardants. And scientists increasingly link chemicals in consumer electronics to myriad health woes.
Plants can offset indoor air pollution from industrial chemicals in consumer electronics, buildings and furniture. Could they clean up coal power plants too?
(Credit: Good Magazine)Emissions from laser printers can be worse for the lungs than cigarette smoke, according to an Australian study released in August. Toxic flame retardants float from TV sets and desktop PCs within household dust.
The World Health Organization blames bad indoor air for nearly 3 percent of diseases. Americans spend 90 percent of their time indoors, where air is more polluted than outside and can contain more than 900 volatile organic compounds, or VOCs, according to the EPA.
"The newer, more energy efficient buildings are sealed tighter and create more of a problem because chemicals offgas from practically everything in them," Wolverton said.
"Green" buildings might use paints and varnishes without VOCs, which don't release headache-inducing fumes. But standards for green buildings too often overlook the use of plants, Wolverton said. "You need plants to act as lungs in buildings."
Several plants in a 200-square-foot space will improve the air in most rooms, according to Wolverton, who recommends potting in inert pebbles or clay mix rather than soil, in which mold can grow.
A well-drawn guide to household plants that absorb formaldehyde, benzene, and trichloroethylene comes from graphic artists at Good Magazine, who used Wolverton's research.
Based upon chemicals in common consumer products, for instance, a peace lily might be ideal for a laundry room, and a new couch could be flanked by bamboo palms. Among the plants researchers found to have potent air-purifying qualities are the Eureka palm, lady palm, peace lily, and rubber plant.
However, people with curious cats or dogs might beware of lilies, poinsettas, and other plants that may poison them. The Pet Friendly House lists plants that won't hurt pets who chew on their leaves.
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