Category Archives: Energy

Cost Efficient Solar Dish by Students

Solar Energy Dish

Low-cost system could revolutionize global energy production

A team led by MIT students this week successfully tested a prototype of what may be the most cost-efficient solar power system in the world – one team members believe has the potential to revolutionize global energy production.

The system consists of a 12-foot-wide mirrored dish that team members have spent the last several weeks assembling. The dish, made from a lightweight frame of thin, inexpensive aluminum tubing and strips of mirror, concentrates sunlight by a factor of 1,000 – creating heat so intense it could melt a bar of steel.

To demonstrate the system’s power, Spencer Ahrens, who just received his master’s in mechanical engineering from MIT, stood in a grassy field on the edge of the campus this week holding a long plank. Slowly, he eased it into position in front of the dish. Almost instantly there was a big puff of smoke, and flames erupted from the wood. Success!

Burning sticks is not what this dish is really for, of course. Attached to the end of a 12-foot-long aluminum tube rising from the center of the dish is a black-painted coil of tubing that has water running through it. When the dish is pointing directly at the sun, the water in the coil flashes immediately into steam.

Someday soon, Ahrens hopes, the company he and his teammates have founded, called RawSolar, will produce such dishes by the thousands. They could be set up in huge arrays to provide steam for industrial processing, or for heating or cooling buildings, as well as to hook up to steam turbines and generate electricity. Once in mass production, such arrays should pay for themselves within a couple of years with the energy they produce.

“This is actually the most efficient solar collector in existence, and it was just completed,” says Doug Wood, an inventor based in Washington state who patented key parts of the dish’s design–the rights to which he has signed over to the student team.

Great job students. Good luck with RawSolar. Photo (by David Chandler): Matt Ritter shows steam coming from the return hose after passing through the coil above the solar dish.

Kudzu Biofuel Potential

Kudzu Gets Kudos as a Potential Biofuel

The kudzu vine, also known as “the plant that ate the South,” was brought from eastern Asia in 1876 and can grow more than 6.5 feet a week. Its starchy roots plunge deep into the soil, and just a fragment of the plant remaining in the ground is enough to allow it to come back next season.

“Kudzu is just a large amount of carbohydrate sitting below ground waiting for anyone to come along and dig it up,” Sage said. “The question is, is it worthwhile to dig it up?”
…
The roots were by far the largest source of carbohydrate in the plant: up to 68 percent carbohydrate by dry weight, compared to a few percent in leaves and vines.

The researchers estimate that kudzu could produce 2.2 to 5.3 tons of carbohydrate per acre in much of the South, or about 270 gallons per acre of ethanol, which is comparable to the yield for corn of 210 to 320 gallons per acre. They recently published their findings in Biomass and Bioenergy.

Crucial to making the plan work would be figuring out whether kudzu could be economically harvested, especially the roots, which can be thick and grow more than six feet deep. To balance this expense, Sage said, the plant requires zero planting, fertilizer or irrigation costs.

Data Center Energy Needs

It’s Too Darn Hot

The tech industry is facing an energy crisis. The cost of power consumption by data centers doubled between 2000 and 2006, to $4.5 billion, and could double again by 2011, according to the U.S. government. With energy prices spiking, the challenge of powering and cooling these SUVs of the tech world has become a major issue for corporations and utilities.
…
The modern data center is like a vast refrigerator with hundreds or thousands of ovens blazing away inside. Six-foot-tall metal racks stacked with pizza box-size computers, storage devices, and network-routing machines are lined up in rows. Chilled air blows through the equipment from vents in the floors of “cold aisles.” Hot air blows out of the back ends into “hot aisles” and is drawn off and vented out of the building. Inside the centers, there’s a dull roar as large quantities of air shoot through ducts, vents, and computers.

So intense is the competition among tech companies to lower their costs of processing data that some treat information about their energy use like state secrets.
…
The $4.5 billion spent in the U.S. in 2006 is the equivalent of the electric bills for 5.8 million U.S. households.

When you realize the huge cooling needs (in addition to the need for electricity to run the computers) you can see the huge advantage of a cold climate where you can take advantage of cool air for cooling.

Solar Thermal in Desert, to Beat Coal by 2020

Google, Chevron Build Mirrors in Desert to Beat Coal With Solar

Along a dusty two-lane highway in California’s Mojave Desert, 550,000 mirrors point skyward to make steam for electricity. Google Inc., Chevron Corp. and Goldman Sachs Group Inc. are betting this energy will become cheaper than coal.

The 1,000-acre plant uses concentrated sunlight to generate power for as many as 112,500 homes in Southern California. Rising natural gas prices and emissions limits may make solar thermal the fastest-growing energy source in the next decade, say backers including Vinod Khosla, the founder of computer maker Sun Microsystems Inc. Costs for the technology will fall below coal as soon as 2020, the U.S. government estimates.
…
“Solar thermal can provide a substantial amount of our power, more than 50 percent,” says Khosla
…
Nine solar thermal plants built in the California desert from 1985 to 1991 still operate, with Juno Beach, Florida-based FPL Group Inc. running seven. They have combined capacity of 354 megawatts, enough to power 230,000 Southern California homes. Development slowed when Congress eliminated tax credits for alternative energy in the early 1990s. Laws put in place in 2005 give solar investors a 30 percent tax credit.

Great progress is being made adding wind and solar capacity. And the increasing oil prices are encouraging much faster adoption of these technologies. The promise of widespread adoption is rapidly becoming a reality.

Wind Power Potential to Produce 20% of Electricity Supply by 2030

Wind energy has been growing tremendously. In 2000 there were 2,500 megawatts (MW) of installed wind capacity in the United States. By the end of 2007, the U.S. installed capacity exceeded 16,000. A recent Department of Energy report sees the potential to provide up to 20% of our nation’s electrical supply via wind power by 2030.

Inspirational Engineer

One of the topics I care about is engineers making a real difference in the world. I lived in Singapore and Nigeria while I was growing up and traveled widely. My father was a professor of engineering (chemical, industrial), statistics and business. He was very interested in applying technology and human knowledge to help people have better lives, and I share that interest.

People like William Kamkwamba are the people that are worthy of respect. I wish the USA was more focused on people that are worthy of attention, instead of who the news media choose to show and people choose to read about. At least a few of you seem to like reading about those I do, based on the traffic this blog receives (well actually that would be a pretty poor metric, let say the attention popular science sites, magazines, podcasts, TV shows… receive).

Another video with William at TED. I posted about William previously: Make the World Better and Home Engineering: Windmill for Electricity.

More Efficient Water Heaters

GE’s New Water Heater Could Kill 30 Coal Plants

until today, Energy Star didn’t regulate water heaters at all. They’re the most energy-hungry single appliance in the home, and are responsible for about 17% of residential energy use. But because of a lack of consensus on how they should be regulated, and resistance from industry, their efficiency went completely unregulated. Well, that all changed today.
…
The water heater first uses a heat pump to bring the water up to the temperature of the ambient air. Then the electric water heater takes over, bringing the water up to 140 degrees F.

This new design is more than 50% more efficient than previous water heaters. If every home in America had one right now, we would need 30 fewer coal-fired power plants! Every home that installs one will see their yearly power bills drop up to $250. Because the new device uses a heat exchanger, it will actually make your furnace work harder during the winter. But in the summer, and in warm climates, it will actually help cool your house!

The new water heater will be available in 2009. A great deal of savings are available from simple actions like using compact fluorescent light bulbs, better insulation and when buying new appliances buying energy efficient appliances. Tankless water heaters, for example, are available now: Bosch AquaStar Natural Gas Tankless Water Heater.

Ethanol Scam

The Clean Energy Scam

The Amazon was the chic eco-cause of the 1990s, revered as an incomparable storehouse of biodiversity. It’s been overshadowed lately by global warming, but the Amazon rain forest happens also to be an incomparable storehouse of carbon, the very carbon that heats up the planet when it’s released into the atmosphere. Brazil now ranks fourth in the world in carbon emissions, and most of its emissions come from deforestation.
…
Meanwhile, by diverting grain and oilseed crops from dinner plates to fuel tanks, biofuels are jacking up world food prices and endangering the hungry. The grain it takes to fill an SUV tank with ethanol could feed a person for a year. Harvests are being plucked to fuel our cars instead of ourselves. The U.N.’s World Food Program says it needs $500 million in additional funding and supplies, calling the rising costs for food nothing less than a global emergency. Soaring corn prices have sparked tortilla riots in Mexico City, and skyrocketing flour prices have destabilized Pakistan, which wasn’t exactly tranquil when flour was affordable.
…
One groundbreaking new study in Science concluded that when this deforestation effect is taken into account, corn ethanol and soy biodiesel produce about twice the emissions of gasoline. Sugarcane ethanol is much cleaner, and biofuels created from waste products that don’t gobble up land have real potential, but even cellulosic ethanol increases overall emissions when its plant source is grown on good cropland. “People don’t want to believe renewable fuels could be bad,” says the lead author, Tim Searchinger, a Princeton scholar and former Environmental Defense attorney. “But when you realize we’re tearing down rain forests that store loads of carbon to grow crops that store much less carbon, it becomes obvious.”

Solar Energy: Economics, Government and Technology

An American Solar Opportunity Gets Shipped Abroad

The project will pour $1 billion into utility-scale photovoltaic solar farms that will directly feed power into a country’s electrical grid. The installations will range from fewer than 2 MW to up to 50 MW, while a single farm could cover hundreds and hundreds of acres.

They’ll be installed in Europe. In Asia. And maybe even in America too, one day. Why not now? Because AES wants to sow its solar seeds in only those countries that offer the most “attractive tariffs.” That eliminates the US from the list of potentials, immediately. And it gives countries like Germany, Spain, Italy and South Korea the clear advantage. They all have can’t-beat national incentives for solar developers.

It’s one of the sad facts of Washington’s incoherent clean energy policy these days. How can a country lure in clean energy projects when there are far more appealing offers elsewhere?

Government actions impact economic decisions. It will likely take more than 10 years to have good data on what government investments pay off in the energy sector. But I would say it is a pretty good bet to invest in technology such as: solar, geothermal, wind… Countries that create global centers of excellence in these areas are likely to benefit greatly. The only question I think is that many countries are smart enough to see the benefits and so likely many countries will try.

Any time many actors pursue the same economic strategy there is the risk that the payoff is diluted with so many others having done the same thing. Still the reason so many countries have adopted the strategy of developing centers of excellence in science, engineering and technology is that it is such a good idea. The USA has a problem in that we are spending more than we produce on luxuries today so there is much less available to invest compared to other countries (and compared to 40 years ago).

$10 Million X Prize for 100 MPG Car

Progressive Automotive X PRIZE

The window for applications will be open until mid 2008, when a thorough qualification process will assess safety, cost, features and business plans to ensure that only production-capable, consumer-friendly cars compete. Those that qualify will race their vehicles in rigorous cross-country stage races in 2009 and 2010 that combine speed, distance, urban driving and overall performance. The winners will be the vehicles that exceed 100 MPG, meet strict emissions standards and finish in the fastest time. Host cities involved in the competition route are to be announced shortly.