Ever try starting a fire on a paper or twig with a magnifying glass? It's a very simple construct. The convex lens concentrates the sun's light and heat energy onto a single point (the paper or twig), increasing the temperature until, well, there's smoke and fire. But the same principal behind this pastime may expand the possibilities of solar technology.
For decades, solar panels have been a one-trick pony. Yes, they convert photons to electrons, transforming the sun's rays into electricity. But they also produce heat. Not in searing amounts; just enough to heat large doses of water. The lost energy often represented wasted potential.
Electricity From Scalding Temperatures
Now two researchers at MIT, Professor Evelyn Wang and student Nenad Miljkovic, have released an analysis showing it's possible to generate electricity and scalding temperatures in unison with a hybrid solar thermoelectric system.
If their work pans out into a viable device, large homes and residential buildings could be heated and powered by a single unit, or factories could get their electricity and melt metals in one location, according to Miljkovic.
It's a possible leap in a sector more acclimated to tiptoeing towards ubiquity. Solar panels have, for good or ill, traveled a familiar but slow technological road, and still only make up 1 percent of the electricity market in the U.S. But manufacturing advances, booming investment and falling prices could, after nearly six decades, make solar panels the new normal. Kind of like boys or girls starting a fire with a magnifying glass.
First Solar Cells: Cumbesome, Inefficient
When Bell Labs developed the first functioning solar cell in the 1950s, the equipment was rather cumbersome, primitive and inefficient. It remained so for the better part of several decades. Innovations such as thin-film, a smaller, cheaper and quicker-to-produce technology, have changed the game. Big players who once stood on the sidelines have jumped in.
The traditional solar electric technologies seem to be tapped out, and most of the focus now is more towards commercializing and bringing the high-efficiency cells to the commercial outlets, said solar market analyst M.J. Shiao of GTM Research, an alternative energy analysis firm.
The cost of producing electricity via solar technologies has fallen 60 to 70 percent over the last few years, according to Danielle Merfeld, a solar business leader for General Electric (GE) Energy's Renewable Business. It has averaged an 18 percent drop in price for every doubling in capacity, she added.
The evolution to affordability has led to a boon in public and private investment. Last year, $211 billion worldwide was invested into renewable energies, according to the United Nations Environment Programme Global Trends Renewable Energy Investment 2011 report.
Government incentives have particularly spurred interest and investment, according to Sarah Kurtz, interim director of the National Center for Photovoltaics.
The immediacy of Solyndra's bankruptcy remains a warning sign about the volatility of the industry -- there are no safe bets. But that has not deterred further government involvement.
On Thursday, the Obama administration identified 17 sites on public lands for solar projects. This follows, among other steps, the Energy Improvement and Extension Act of 2008, which, combined with the American Recovery and Reinvestment Act, extended a 30 percent corporate and individual tax credit for purchasing a solar PV system.
Germany: About 25% of Power From Solar
In Germany, a feed-in tariff, which is design to accelerate investment in renewable energy, has created a surge in solar installations. So much so that on a bright, sunny day, about one-quarter of all electricity used across the nation comes from solar technology, Kurtz said.
The same government incentives, which many predicted would lead a solar boom in Germany and worldwide, also led to a solar bust when the global economy tanked -- much to the consumer's benefit.
Low-cost manufacturing in Asia, over-investment at home and abroad, fiscal troubles and waning government subsidies in Europe have sharply decreased demand in Germany, the world's biggest solar market, according to The Associated Press, creating a glut of supply in the market and driving prices down.
GE Makes A Commitment
Adding to the price decrease is the increase in major players willing, now, to compete within the industry.
General Electric spent years monitoring the solar industry, trying to decipher the right moment to jump in, Merfeld said. On Oct. 13, it announced the buyout of Colorado's PrimeStar Solar Inc., and will invest $600 million in thin-film solar technology.
We've been looking at solar for over a decade now, Merfeld said. First we tried to understand if this is a real industry, then decided that it's time to invest in it and try to grow.
The biggest difference: It is much cheaper to manufacture and has the potential to be as efficient. We're looking at this in the long-haul.
Still, the solar market has proven to be anything but stable, Kurtz said.
If you can imagine that you're in an industry that some year doubles, some year grows by 10 or 20 percent, it makes it very difficult to guess what is a good time to invest.
With government incentives drying up, Business Week reported companies may pull back on their solar bonanza next year.
The drop in price has sprouted a new business model. Now companies install and maintain solar panels on private homes, keeping ownership of the system while charging homeowners as a utility, often charging them less.
Solar has undergone a transformation from something that is interesting as an alternative source whereas now it's an advantage, Merfeld said.
The changes have given solar technology a chance at becoming banal.
Oh, they will become ubiquitous, Kurtz said. We just need a little time. A sea change like that is not something that happens in one year. We will see that transition happening in other parts of the world. I don't know how many years it will be.
Which brings us back to Professors Wang and Miljkovic.
The prototype for Wang and Miljkovic's HSTE system. Photo by Dominick Reuter for MIT
Magnifying Glass Technique: What's Old Is New
Their work incorporates the same magnifying glass principles children use to start a fire with a magnifying glass with the sun's light to concentrate solar energy and increase its heat capabilities. Perhaps it's a fitting mark of solar technology's evolutionary end that its next leap simply marries its two strengths.
It provides more heat and less electricity, which is actually good because in your home a majority of the energy you expend is heat, Miljkovic said. It could really change the whole ball game.
But not all are ready to hail the discovery.
There's this common misconception that solar is a new technology and there's a lot of innovation left to uncover, Shiao said. The technology that's being used in the markets right now has been mature for a couple of decades. For new technologies to try to enter the space, it really takes a lot. It's exciting when new stuff comes up, my caveat is you always have to be careful when you say something is a 'game changer.' But it could definitely open up some new avenues.