1. SOLAR POWER: Sun fuels adventurers' race around the Earth (Greenwire, 10/31/2008)

Michael Burnham, Greenwire senior reporter

LAUSANNE, Switzerland -- A trip around the world is no big deal for the frostbitten and sunburned adventurers of this Alpine nation.

Doing it without a drop of fuel is.

Swiss physics professor, Auguste Piccard, set a pace for adventure travel 77 years ago when he took a balloon into the stratosphere and became the first human to see the Earth's curvature. A quarter-century later, his son, Jacques, took a bathyscaphe to the deepest part of the ocean. Now, his grandson, Betrand Piccard, aims to outdo his forefathers by circling the globe in an airplane with no gas tank and a jumbo-jet wingspan.

The Solar Impulse airplane, known by its tail number, HB-SIA, would sport 200 square meters of photovoltaic cells on its wings to convert sunlight into fuel for four propellers. Piccard and co-pilot André Borschberg hope to complete the flight in less than a week, including brief stops to swap out aviators.

The biggest technical challenge -- no trivial feat -- is capturing and storing enough energy in batteries to keep the 1,500-kilogram airplane high in the night sky with only the moon to light the way.

The Solar Impulse airplane under construction in Switzerland will have a massive wingspan covered with 200 square meters of solar photovoltaic panels. Sunlight captured and stored in on-board batteries will power four propellers day and night. The ultra-light aircraft will use no petroleum fuel. Photo courtesy of Solar Impulse.

"Solar Impulse is not only an airplane that is going to fly around the world on solar power; Solar Impulse is an airplane that's going to fly day and night with no fuel," Piccard boasted during the project's unveiling in Dübendorf.

Piccard is not the only Swiss adventurer with electric dreams. In December, Lucerne school teacher and pilot Louis Palmer aims to complete a drive around the world in his Solartaxi. Two years later, fellow globetrekker Raphaël Domjan, of Yverdon-based PlanetSolar, aims to repeat the feat in a solar-powered catamaran.

The goal of these modern Phileas Foggs (Jules Verne's hero of "Around the World in Eighty Days") is to prove the sun's wherewithal as a clean and reliable energy source for not only today's buildings and gadgets but also tomorrow's planes, boats and automobiles. Sunlight may be free, but converting it into electricity is not always economical. Not yet.

So you might say the adventurers have a chip on their shoulders, being Swiss and all.

Red, white and green

Switzerland ranks as the world's greenest country, according to Yale University's latest Environmental Performance Index of conservation practices, biodiversity, greenhouse gas emissions and other criteria.

Switzerland's lakes are as clean as its trains are ubiquitous. But here is a dirty little secret: Switzerland gets less than 1 percent of its electricity from photovoltaics, despite the Alps' ample sunshine (see map).

"We talk about solar in Switzerland, but we don't do it," Solar Impulse co-pilot Borschberg groused.

Roland Stulz, who runs the Dübendorf green-building think tank Novatlantis, said Switzerland has relied on comparatively cheap power from nuclear reactors and hydroelectric dams for too long.

"Our government decided to leave [solar] up to the market, and we've been surpassed by many other countries," Stulz explained.

That may change with a Swiss target to generate at least 5,400 gigawatt-hours annually from renewable resources by 2030. Starting next January, developers of solar, wind, geothermal and biomass energy projects will receive a federal tariff for every kilowatt they send to the grid.

Borschberg considers the feed-in tariff a good start for Switzerland -- a tiny nation of fewer than 8 million people. But he hopes his derring-do inspires other countries to conserve electricity and develop cleaner generation sources.

"The world will need this energy," he said.

The U.S. Energy Information Administration projects that global energy generation will nearly double to 33.3 trillion kilowatt-hours in 2030. The greatest consumption growth would come from China and other Asian countries whose fast-growing economies are fired by fossil fuels (Greenwire, June 17).

Coal, natural gas and uranium would remain the workhorse fuels two decades from now, with solar, wind and other renewables providing 5 percent of the world's power, collectively, according to the EIA projection.

Boats, planes, trains and automobiles would still rely heavily on petroleum.

EIA foresees world liquids consumption growing 35 percent by 2030 -- with the transportation sector accounting for three-quarters of the increase.

Solartaxi's bronzed and bearded driver Palmer scoffs at such projections. The "era of petrol" is ending, and oil wars are unnecessary, he sniffed last month, while steering his two-seater through Washington, D.C.

"We adventurers believe in the Swiss way, which is education," Palmer explained while zooming down Pennsylvania Avenue. "By showing the potential of solar, we will change transport."

Slogging through torrential rain in Australia and 124-degree Fahrenheit heat in Dubai earned Palmer enough street credibility to earn a meeting with General Motors Corp., which plans to begin selling a plug-in gas-electric hybrid in 2010. The Chevrolet Volt would be able to travel 40 miles on electricity before the internal-combustion engine would need to recharge a lithium-ion battery.

Palmer's car runs entirely on electricity. Half its power comes from a nickel-sodium Zebra battery that Palmer plugs in each evening; the other half comes from the car's 16-foot-long trailer, which is covered with PV cells.

"This is simple, readily available technology -- even a schoolteacher can build it," Palmer said. "You could put solar cells on your roof and charge your car up at night."

Nissan, Chrysler and a handful of other automakers also plan to roll out about a dozen models of hybrid plug-in vehicles during the next decade (Greenwire, Oct. 22). Palmer wants to make sure those vehicles run on solar power and other energy that doesn't produce greenhouse gases.

He has a steep drive ahead.

The world gets about a tenth of 1 percent of its electricity from solar projects today, scientists say. But consider this: The sun shines about 1,000 watts per square meter of the Earth's surface at midday. So hypothetically, an array of photovoltaic panels covering 100 square miles of the desert Southwest could produce all of the power the United States consumes annually.

Such a project is the stuff of science fiction, but Washington State University energy analyst Mike Nelson uses it to illustrate the potential of the sun.

"The fact is," he said, "there are a lot of wasted rooftops out there."

Science of solar power

Today's PV panels are nearly 170 years in the making.

In 1839, the French experimental physicist Alexandre-Edmond Becquerel discovered the photovoltaic effect: that is, that certain materials produce electrons when exposed to photons from sunlight. It wasn't until 1954 that Bell Labs researchers demonstrated the first practical solar cell, a square of silicon that was able to convert about 6 percent of the sunlight that hit it into useful energy.

The vast majority of today's PV cells still consist of silicon layers that are doped with boron and phosphorus to corral free electrons into a current. PV modules on the market have an efficiency range of about 10-22 percent, explained Curt Maxey, a researcher with the U.S. Department of Energy's Oak Ridge National Laboratory.

SunPower Corp. holds the distinction of making and selling the world's most efficient solar modules, which are composed of monocrystalline silicon cells and get about 22 percent efficiency. In two years, the San Jose, Calif.-based company hopes to roll out a reconfigured PV module that has achieved 23.4 percent efficiency in lab tests, noted Helen Kendrick, a company spokeswoman.

Maxey said researchers are approaching the theoretical limit of PV efficiency -- about 30 percent -- but there is still plenty of room to drive down the cost of solar power.

The average generation cost of silicon-based PV is 20-30 cents per kilowatt-hour in the United States, not including state and federal incentives. Coal- and nuclear-generated power costs roughly 2 cents per kWh, while natural gas power costs about 7 cents per kWh, according to the Edison Electric Institute, a utility advocacy group.

Tony Clifford, who runs the Maryland energy services firm Standard Solar Inc., predicts that within a decade the cost of distributed PV generation will reach parity with grid-delivered power.

"Grid parity is going to happen sometime before or after 2015," Clifford predicted. "It's going to vary across the country, depending on utility rates."

Clifford noted that U.S. grid-delivered power -- the bulk of which comes from coal, nuclear and natural gas plants -- averages about 11 cents per kWh nationally and is rising about 7 percent annually. He expects the cost of generating power from rooftops and other "distributed" sites to drop as solar cell efficiency and manufacturing increase and the cost of silicon decreases.

Some PV researchers are seeking cost breakthroughs using nanotechnology -- the science of manipulating matter to about 1/100,000th the width of a human hair.

The Philadelphia-based startup Plextronics Inc. is able to demonstrate 5.9 percent efficiency from organic solar cells that replace silicon with photoactive inks. The 6-year-old company is working with the Belgian technology research center IMEC to develop organic solar cells with 10 percent efficiency by 2012.

General Electric Co. scientists, meanwhile, say they have demonstrated a nanowire-based solar cell that has the potential to achieve up to 18 percent efficiency. The nanostructured solar cells feature silicon nanowires placed on a thin, stainless steel substrate in lieu of the bulk silicon found in conventional solar cells.

GE's theory: Less material means lower cost.

Independent industry watchers caution that solar nanotechnology is perhaps a decade away from making a big commercial splash (Greenwire, Oct. 20). In the meantime, engineering, grit and silicon will be essential to keeping an airplane flying through the night skies and a catamaran cutting through the high seas.

On a wing and a prayer

The Solar Impulse crew plans to begin assembling its ultra-light airplane this fall and to test it in the air next spring.

Solar Impulse's initial flights would be just a few meters above the runway. By next summer, co-pilots Piccard and Borschberg plan to put their airship through its toughest test -- a 36-hour flight that spans day and night.

The airplane's 12,000 monocrystalline silicon PV cells will cover about 200 square meters of wing surface. Borschberg estimates that the PV cells' efficiency would be just 12 percent through the propulsion chain, so each of the airplane's motorized propellers would get about 8 horsepower.

That is roughly the same amount of power the Wright brothers had in 1903 when they made their first motorized flight, he emphasized.

Solar Impulse would climb during the day to about 8,500 meters, where there is more solar radiation and a less variable light spectrum. When the sun sets, the 1,500 kilogram airplane would drop to 1,000 meters and burn off energy stored in lithium-polymer batteries.

"You have the same consumption day and night," Borschberg noted. "If you have no energy left, you sink."

And then you swim.

DOE solar analyst Maxey crunched Solar Impulse's numbers and said the airplane seems plausible.

"It's doable, but you're going to need a lot of runway," said Maxey, who flies a small Cessna.

If Solar Impulse's 36-hour flight is a success, company officials plan to build a slightly larger airplane that would be capable of flying around the world in six days and nights. Borschberg is planning that trip in 2011.

"We view our expedition not as a way to explore the world but to explore technology," he added. "We know we have to change the way we use energy."

Click here to see the map of the solar adventurers' routes.

Building a better boat

PlanetSolar skipper Domjan said the goal of his adventure is simply to build a better boat.

Big and small ships today use PV for auxiliary power. But as solar cell efficiency and battery storage capacity improve, boats of all sizes could conceivably get more power from the sun and reduce their fossil fuel use, he surmised.

"My goal is not to build a prototype; my goal is to show that solar technology can be complementary," said the 36-year-old, who skis, travels and flies gliders in his spare time.

Domjan wants to give today's technologies a push by sailing his catamaran "wave-piercer" around the world in 120 days, not counting brief publicity stopovers in New York, Shanghai and Dubai.

In order to complete the 40,000-kilometer voyage in four months, the catamaran would travel at an average clip of 10 knots. Like Solar Impulse, the flat-topped boat must capture enough sun power in its 900 square meters of PV cells for use at night.

The catamaran would travel close to the equator, where maximum sunlight is available. The boat's wide wings would flip up like a butterfly's to capture light at dawn and dusk.

"PlanetSolar's logo is an infinity symbol," Domjan explained. "We want to prove that with solar power you can go all of the time."

Domjan isn't a household name. So he will sail his catamaran with Gerald d'Aboville -- who earned a place in the record books in 1980 by rowing across the Atlantic Ocean.

Domjan has also lined up high-profile sponsors, including Albert Falco, captain of Jacques Cousteau's "Calypso" research vessel; Jean Verne, great-grandson of the French writer Jules Verne; and Jean-Luc Van Den Heede, who holds the world record for the fastest solo nonstop westward circumnavigation.

"I am sure in 10 or 20 years, solar boats will go around the world faster than ours, but we will be the first to do it," Domjan vowed.

"I am not a famous sailor," he added, "not yet."

Solartaxi's Palmer concedes that his electric car is the most mundane of the three Swiss projects. Traveling more than 50,000 kilometers in 18 months with no gasoline might impress some, but Palmer said he has learned what grabs the most attention.

"The No. 1 question I get is what is the car's top speed," he said with a sly grin.

So for his next adventure, Palmer plans to host an 80-day race around the world. Anyone who can make an electric car capable of traveling at least 200 miles on one charge is welcome to compete.

The catch is that the power must come from renewable sources -- perhaps even the sun.

Click here to see images of the three projects.

Click here to see a map of the project routes.

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