Power station harnesses Sun's rays

There is a scene in one of the Austin Powers films where Dr Evil unleashes a giant "tractor beam" of energy at Earth in order to extract a massive payment.

Well, the memory of it kept me chuckling as I toured the extraordinary scene of the new solar thermal power plant outside Seville in southern Spain.

From a distance, as we rounded a bend and first caught sight of it, I couldn't believe the strange structure ahead of me was actually real.

A concrete tower - 40 storeys high - stood bathed in intense white light, a totally bizarre image in the depths of the Andalusian countryside.

The tower looked like it was being hosed with giant sprays of water or was somehow being squirted with jets of pale gas. I had trouble working it out.

In fact, as we found out when we got closer, the rays of sunlight reflected by a field of 600 huge mirrors are so intense they illuminate the water vapour and dust hanging in the air.

The effect is to give the whole place a glow - even an aura - and if you're concerned about climate change that may well be deserved.

Read More . . .

Top Ten List: New Year's Resolutions to Protect the Earth

We are all creatures of habit. Whether you vow to stop bad habits or start good ones, now is the time to make New Year’s resolutions you can keep. These ten simple tips for creating a healthier Earth are sure to last through 2007 and beyond:

	1) Replace your incandescent light bulbs with compact florescent lights (CFLs). Look closely at labels when buying light bulbs. Those marked as CFLs last 10 times longer and use 66 percent less energy than incandescent bulbs. As a result, CFLs save an average of $30 in energy costs over their lifetimes – as much as 10,000 hours, though turning CFLs on and off too frequently will shorten their lives. CFLs also reduce the release of greenhouse gas emissions and are safer because they burn at a lower temperature (100° F) than incandescent and halogen lights, which can burn at temperatures up to 1000° F.
	2) Inflate your car tires. When walking or biking isn't feasible, you can do something to better protect the Earth while driving. Take a step in the right direction by inflating your car tires. Pumping them up can improve your gas mileage by about 3.3 percent – a savings of about 7 cents per gallon. It‘s the right thing to do for your wallet and the right thing to do for the Earth.
	3) Weigh your ecological impact. It’s far easier than stepping on a scale. Take CI's short eco-footprint quiz to find out if you need to tread more lightly on Earth’s biodiversity. Measure how last year’s habits stack up, and you’ll be well on your way to becoming a full-fledged eco-warrior in the year ahead.
	4) Turn down the hot water heater. Set your water heater to 130° F. While you’re at it, throw on a sweater and lower your thermostat for the winter by just three degrees. These simple actions can have enormous positive consequences, preventing the emission of nearly 1,100 pounds of carbon dioxide over the course of 2007. And that’s just from you! Get your friends on board, and the benefits will multiply.
	5) Choose your seafood wisely. We can’t afford to wait until 2008. The world’s seafood will be entirely depleted by 2048, according to an early November report in the journal Science. That means the moment to shape up is now. By buying and eating certain types of seafood, you can discourage harmful fishing practices and avoid the more depleted or threatened species. Take a look at Seafood Choices Alliance or Seafood Watch to make smart choices.
	6) Plant a tree. It’s not nearly as labor-intensive as it sounds, and it’s a small price to pay for a healthy Earth. Trees soak up carbon and absorb harmful greenhouse gases, but they are disappearing at a shocking rate. The United Nations Food and Agriculture Organization estimates that an average of 32 million acres of forests are destroyed each year. Not if we can help it. Order your tree online at a website like this one: Tree In A Box.
	7) Offset your carbon footprint. Carbon footprints are soooo last year. Luckily, CI's new carbon calculator guarantees you’ll be on the cutting edge in 2007. It empowers you to offset your personal impact on Earth’s rising climate. Donate $10 to offset your cross-country road trip, $20 for the upcoming family reunion, or $7 for a domestic roundtrip flight. Your money will help protect the roughly 832,000-acre Makira Forest in northeast Madagascar and prevent millions of tons of CO2 from entering the atmosphere.
	8) Buy locally produced meats and produce. Sounds like a good idea, but you don’t know where to start? Just type in your zip code on Local Harvest's website to see a list of farms and farmers’ markets close to home, as well as nearby restaurants committed to supporting their neighbors. Buying locally produced food cuts out the middlemen and the vast amounts of energy required to get your products onto store shelves. Most produce in U.S. supermarkets travels an average 1,500 miles before it is sold!
	9) Drink more water from reusable glassware. It’s great for your bank account, your health, and your planet. The average American consumed more than 400 beverage bottles and cans in 2006, leaving behind wasted glass, plastic, steel, and aluminum. That adds up to excessive amounts of fossil fuels and hydropower for mining, processing, refining, shaping, shipping, storing, refrigerating, and disposing of those materials. Of course, changing your drinking habits both at home and at work is applicable to just about every other habit, as well. You’ve heard it before and you’ll hear it again: Reduce, reuse, and recycle.
	10) Get an early start. Make a year-end gift to support conservation efforts in 2007. It will be money well-spent. CI has received a 4-star rating from Charity Navigator, America’s largest independent evaluator of charities. More than 85 percent of our expenses go directly to conservation programs and only 4 percent to fundraising. And if you donate before the ball drops at midnight on Dec. 31, you can double your impact on conservation in our Chairman’s Council Challenge Fund.

How To Build a Solar Generator

Affordable solar power using auto parts could make this electricity source far more available.

A set of prototype solar concentrators installed in Lesotho. (Courtesy of Amy Mueller.)

Demand for solar power is rapidly heating up (see "New Solar Technologies Fueled by Hot Markets"). But constructing and deploying large photovoltaic panels to generate electricity remains expensive. Now two groups at MIT are working on alternative approaches to solar-based electricity that could significantly cut costs -- and put the ability to harvest electricity from the sun into the hands of villagers in poor countries and backyard tinkerers alike.

During a stint in the Peace Corps in Lesotho in southern Africa, Matthew Orosz, an MIT graduate student advised by Harold Hemond, professor of civil and environmental engineering, learned that reflective parabolic troughs can bake bread. Now he plans to use these same contraptions to bring power to parts of Africa baked in sun but starved for electricity. His solar generators, cobbled together from auto parts and plumbing supplies, can easily be built in a backyard.

The basic design of Orosz's solar generator system is simple: a parabolic trough (taking up 15 square meters in this case) focuses light on a pipe containing motor oil. The oil circulates through a heat exchanger, turning a refrigerant into steam, which drives a turbine that, in turn, drives a generator.

The refrigerant is then cooled in two stages. The first stage recovers heat to make hot water or, in one design, to power an absorption process chiller, like the propane-powered refrigerators in RVs. The solar-generated heat would replace or augment the propane flame used in these devices. The second stage cools the refrigerant further, which improves the efficiency of the system, Orosz says. This stage will probably use cool groundwater pumped to the surface using power from the generator. The water can then be stored in a reservoir for drinking water.

The design uses readily available parts and tools. For example, both the feed pump and steam turbine are actually power-steering pumps used in cars and trucks. To generate electricity, the team uses an alternator, which is not as efficient as an ordinary generator, but comes already designed to charge a battery, which reduces some of the complexity of the system. And, like power-steering pumps, alternators, including less-expensive reconditioned ones, are easy to come by.

As a result, the complete system for generating one kilowatt of electricity and 10 kilowatts of heat, including a battery for storing the power generated, can be built for a couple thousand dollars, Orosz says, which is less than half the cost of one kilowatt of photovoltaic panels.

"You can't afford something that's designed for solar. You have to buy something that's mass-produced for something else -- that way the cost is reasonable," says Duane Johnson, owner of Red Rock Energy, in White Bear Lake, MN, who developed and sells thousands of the inexpensive LED-based sun-tracking devices Orosz uses to orient the solar concentrators. Most of the devices are used to position photovoltaic panels, he says, but some people are using them with old satellite dishes to concentrate heat and make steam. Sales of his devices have been growing 25 percent a year, a rate similar to that of the solar photovoltaics industry.

more > > >