Alternative Energy—Our Only Alternative—Part IV

SOLAR POWER

“High prices for gasoline and home heating oil are here to stay. The U.S. is at war in the Middle East at least in part to protect its foreign oil interests. And as China, India and other nations rapidly increase their demand for fossil fuels, future fighting over energy looms large. In the meantime, power plants that burn coal, oil and natural gas, as well as vehicles everywhere, continue to pour millions of tons of pollutants and greenhouse gases into the atmosphere annually, threatening the planet. Well meaning scientists, engineers, economists and politicians have proposed various steps that could slightly reduce fossil fuel use and emissions. These steps are not enough. The U.S needs a bold plan to free itself from fossil fuels. Our analysis convinces us that a massive switch to solar power is the logical answer.”

A Solar Grand Plan

The above quote is the opening paragraph from the December 2007 issue of Scientific American Magazine. The subject was considered so vital it dominated the cover of the magazine with the headline, “A Solar Grand Plan.” The sub-headline described the story’s main premise, “By 2050 solar power could end U.S. dependence on foreign oil and slash greenhouse gases.”

Further emphasis was placed on the fact that, “The technology is ready,” adding “If wind, biomass, and geothermal sources were also developed, renewable energy could provide 100 percent of the nation’s electricity and 90 percent of its energy by 2100.” However, the magazine projects that, “The federal government would have to invest more than $400 billion over the next 40 years to complete the 2050 plan and taking into account that the Iraq war has already far surpassed that figure ($520 billion according to the Congressional Budget Office), considering the ultimate benefits — the elimination of all imported oil; a substantial reduction in trade deficits; an easing of political tension in the Middle East and elsewhere; a significant reduction in greenhouse gas emissions from both power plants and automobiles (the latter assumes gas only cars would be replaced with plug-in–hybrids refueled from the power grid), the expense seems quite economical.”

Until recently, most of the activity in the solar field has been driven by silicon based photovoltaic cell technology—panels of glass embedded with solar cells, or with what is known as thin-film technology using less of the polysilicon material. Unfortunately there is a worldwide shortage of silicon that is driving prices higher. Replacing silicon with copper indium gallium diselenide (CIGS) or with cadmium telluride (CdTe) provide lower cost opportunities for several solar producers. I mentioned in a previous article that the use of CdTe instead of silicon has allowed the company, First Solar, to become the low cost producer, and that propelled the company’s stock last year to a 795 percent increase. As of this writing, the current price is still flirting with the all-time high. (The father of the president of the company lives in Boca Pointe).

Burning Mirrors

Although the proliferation of photovoltaic solar power has been the fastest growing alternative energy category over the last two years, much of the more recent growth has been dominated by what turns out to be an ancient technology that has been used for generations. Now known as Solar Thermal Energy or Concentrated Solar Power (CSP), it refers to the use of mirrors to produce heat from the sun.

The April 2008 issue of the online magazine, Salon.com provides several interesting details. It describes that around 700 B.C. the Chinese first use “burning mirrors” to ignite firewood. In 230 B.C. a colleague of Archimedes built a parabolic mirror that focused the sun’s rays to a single point for starting fires. Shortly later, Archimedes supposedly had Greek soldiers use their bronze shields to concentrate sunlight on Roman ships to set them on fire. Leonardo da Vinci, concerned that the earth’s vast forest would be decimated as the major fuel source of his day (was he the first environmentalist?), developed many designs for solar concentrators as discovered in his notebooks.

Research and various inventions continued throughout the centuries, but interest evaporated with the recognition of coal as a cheap and abundant energy source in the late 1800’s. However, as early as the 1930’s, and more aggressively starting in the 1950’s, Israeli universities began to research solar power. One result is that within Israel, there are more than one million houses with solar powered hot water heaters. Every new residence must be so equipped.

In the late 1980’s, an Israeli based company, Luz international, received a contract from Florida Power & Light (FPL) to build nine Concentrated Solar Power plants in the Mojave Desert that would produce almost 350 megawatts of electricity (one megawatt equals one million watts). The project was completed successfully, but by 1991 oil prices had dropped significantly and government incentives for alternative energy projects dried up. As a result, Luz declared bankruptcy.

The concept of concentrated solar power was described in this blog in August, 2006 in the very first JICYMI (Just In Case You Missed It) column. The technology employs solar troughs of curved parabolic mirrors that concentrate the sun’s rays, focusing on fluid filled pipes that become superheated. The resulting 700-degree heat creates steam that enables turbines to create electricity. The JICYMI article referred to what is essentially a company successor to Luz International named Solel, run by Avi Brenmiller, an Israeli engineer who was part of the original Luz team. Now, with fossil fuel prices escalating, and anticipated to continue to do so, alternative energy sources, especially solar, are back in huge demand. Inspired by incentives and California’s mandate for utilities to produce specific amounts of alternative energy, last July, PG&E (Pacific Gas & Electric) contracted with Solel for what then was the largest solar plant in the world (553 megawatts) to be built in the Mojave Desert. The size of this project can be appreciated from these statistics: the solar plot will cover up to 6,000 acres or nine square miles; it will require 1.2 million mirrors and 317 miles of vacuum tubing to capture the sun’s heat.

Another Mirror Solution

Then a funny thing happened on the way to alternative energy solutions. It seems that more than one Luz alma-mater continued to pursue the solar thermal dream. The founder of that company, an American Israeli, Arnold Goldman, established another company named Bright Source, relying on venture capital funding, (it also recently secured investments from Morgan Stanley). Bright Source technology differs from Solel in that instead of concentrating sunlight from parabolic mirrors onto pipe-laden liquid, it uses fields of flat mirrors (a less expensive alternative) that turn with and track the sun. The mirrors then direct the sun’s rays and heat to a very tall tower that basically is a huge water filled boiler. Superheated, the water converts to steam that turns the turbines; the steam is then cooled, condenses back to a water state, and refills the water tower.

Another advantage of the CSP system is the opportunity to resolve one of the detriments associated especially with photovoltaics—how to maintain heat at night or when the sun does not shine. Instead of using water (a medium that loses heat rapidly) to create the steam, a molten salt sludge is used that can retain heat for many hours.

A lengthy article in Salon.com (April 14, 2008) also weighed in on the side of concentrated solar power. It maintained that, “Clearly, the world needs a massive amount of carbon-free electricity by 2050 to stabilize greenhouse gas emissions.” To accomplish this, the industrialized nations will be required to cut carbon dioxide emissions from electricity by more than 80 percent over the next four decades.

The Salon article argues that Concentrated Solar Power best meets the basic requirements for achieving that difficult task. It has the potential of providing thousands of gigawatts of power (one gigawatt equals one thousand million watts); it makes use of a low cost fuel (the sun), and has a vast reserve accessible; it does not require huge amounts of fresh water or arable land (both of which will be scarce as the population increases by 3 billion to over 9 billion by 2050); and costs are expected to become competitive as fossil fuel prices increase and economies of scale develop. It also makes a point cited by several sources that 92 x 92 miles of unoccupied desert land in California and Nevada could generate enough solar power to satisfy all the power needs in the U.S. Admittedly however, a major investment would be required to install high voltage lines to carry the electricity to all parts of the country.

Whre The Big Money Is

That all this is indeed feasible might be inferred from the interest in solar companies by Wall Street and the venture capital companies. There are now close to 100 publicly traded solar companies worldwide (all of them using photovoltaic technology) with most in the U.S. and China. Although First Solar is the best known because of its performance in 2007, the sector is also becoming recognized for its volatility. Only a month ago a more diversified way to consider investing in the solar field materialized. Two Exchange Traded Funds were brought to market. Van Eck’s Market Vectors-Solar Energy ETF tracks the Ardour Solar Energy Index made up of 25 stocks. The other, Claymore’s Global Solar Energy ETF tracks a Melvin & Company index of 25 solar stocks. Also, venture capital investments have skyrocketed from $150 million in 2005 to over $1 billion in 2007.

Nonetheless, as stated in the Scientific American concluding paragraph, “The greatest obstacle to implementing a renewable U.S. energy system is not technology or money, however. It is the lack of public awareness that solar power is a practical alternative–and one that can fuel transportation as well. Forward looking thinkers should try to inspire U.S. citizens, and their political and scientific leaders about solar power’s incredible potential. Once Americans realize that potential, we believe the desire for energy self-sufficiency and the need to reduce carbon dioxide emissions will prompt them to adopt a national solar plan.” We can dream, can’t we?