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Residential Solar

According to John Thronton, a former engineer at the National Renewable Energy Lab (NREL) in Golden, Colorado, the cost of manufacturing photovoltaic cells has been decreasing, but the market price has remained level or slightly increasing because worldwide demand far exceeds supply.  The U.S. exports 70-75% of its photovoltaic products.  In the long run, however, the high demand will lower prices because it presents a profitable business opportunity, which means there will be a race to manufacture, thus increasing supply.

These claims are based mainly on the traditional semi conductor-grade crystalline-silicon wafers, which dominate the solar technology market. These traditional silicon wafers are expensive to manufacture because of the high energy manufacturing inputs and the high loss of material during production.  The cost of production is one of the impediments in the investment in and the output of solar technology.  According to Thornton, the promising thin-film alternatives could revolutionize the marketing of solar technology.

One type of thin-film technology, the most advanced and widely used, uses amorphous silicon.  An amorphous silicon thin-film solar cell contains only one-three hundredths (0.33%) of the material and takes only one-third (33%) of the energy to produce than the crystalline-silicon PV cells.  As a result, the cost of manufacturing these thin-film cells is much cheaper relative to traditional crystalline-silicon wafers.  One of the drawbacks, however, is that their efficiency is lower.  The best-stabilized efficiencies achieved for these types of solar panels in the U.S. are about 8%, whereas crystalline-silicon cells have efficiencies between 13% and 15%.

However, efforts to find ways to make thin-films more efficient are underway.  Copper indium diselenide (CIS) is a more recent thin-film PV cell material.  CIS modules currently on the market reach an efficiency of more than 11%.  NREL scientists in the laboratory achieved an efficiency of up to 19.2%.  Thus, research now focuses on increasing efficiency, reducing costs, and raising the production yield of CIS panels.  Another material, CdTe, is also promising because it’s less expensive than CIS.  Cells containing this material have reached an efficiency of up to 11%, so now research focuses on improving efficiency and reducing panel degradation.

If progress continues, Franz Karg, research manager at the Shell Solar facility in Munich, Germany, predicts that thin-film technology will eventually cut the present production cost in half per unit kilowatt peak (kWp). This means that a complete system’s cost will be reduced by 35% or more.  And Thornton believes the promise of thin-film technology could significantly reduce the price of solar technology by 2012 in Colorado.

Despite these prospects, there are still many challenges in mainstreaming thin-film technology.  For one, cost-effectively mass-producing thin-film cells is hard due to the difficulty of coating large areas of glass.  Also, thin-film technologies are fairly new, the very first type having only been in the market for about 15 years; therefore, it is hard to compete with the older, more reliable crystalline-silicon cells.  Present economics greatly hinders investment in thin-films.

Meanwhile, Colorado is offering rebates to those who want to install solar systems.  Thornton said it cost him about $5000 to install a 2.2 kW system in his home after an $11,500 rebate from Xcel Energy and a $2000 federal tax credit.  If national and international collaborations between industry and government continue, research could revolutionize the marketing of solar technology and change the economics to reduce the cost even more, not only in Colorado but nationally and internationally as well.

Colorado Public Radio
The Industrial Physicist (

Solar power on Americans’ minds

The Roper Center for Public Opinion Research recently surveyed 1,004 adults regarding their thoughts on solar power installations in new homes. The results include the observation that 87% of Americans believe solar electricity should be an option for all new home construction. That percentage has increased significantly from the results garnered one year ago, in which only 79% of respondents expressed the same view.

The survey, commissioned by Sharp Electronics Corp., has generated additional interest among homebuilders who are under increasing pressure to satisfy consumers’ demands amidst a flat real estate market. As more and more consumers express their interest in solar technology, homebuilders are keen to take notice of increasing trends and sales of solar-powered homes.

However, the survey also highlighted consumers’ misunderstandings of solar powered options, including the misconception that solar power is more likely to be able to power lights and heat bath water than to power home electronics and computers.

Accordingly, Sharp has recently launched a solar informational campaign dubbed “Hello Sunshine in hopes of clearing up many of the misunderstandings that consumers express.

Additionally, the survey highlighted the fact that consumers are much more likely to adopt a solar power installation if they do not have to place a large amount of money down to cover the cost of installation and materials. To address these isssues, Sharp initiated an alliance in 2006 with CitiMortgage, enabling consumers to fund their residential solar power system through a home equity program that allows homeowners to offset the the system costs.

Although we have seen other takes on “no money down” solar installations, the options given by Sharp and CitiMortgage present a much more viable financial strategy as a means to implementing residential solar.

Solar-powered home sales increasing in California

United Press International reports that communities surrounding the Sacramento area are witnessing new home sales double in developments in which SunTile Solar power systems have been integrated into the home designs.

The news comes at a time when nearly 90% of Americans express that solar power should be an option for all new home construction.

California’ state senate has proposed a bill calling for home builders to offer solar installations in new homes beginning in 2011.

The Home Depot offering solar power installations

The Home Depot, one of the United States’ largest retailers of home improvement and construction products, has teamed with BP Solar to offer professionally installed solar power systems. The company offers customers the ability to sign-up online for a free consultation.

Undoubtedly, the marketing efforts of The Home Depot will help to bring solar power options to the attention of mainstream America, and the company’s supply chain and purchasing power may help to reduce costs for average residential solar installations. Furthermore, by generating additional demand for solar installation materials and services, the company promotes further investment into the solar energy market.

Is the promotion of solar energy by one of the largest home improvement retailers a sign that solar energy is beginning to hit prime time? Although solar isn’t currently cost competitive with other energy sources, it will be interesting to observe as solar begins to bloom, especially in states with strong subsidies and incentives for solar installations.

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