BUILDINGS - Smarter Facilities Management


Solar Set to Soar

By Lew Tagliaferre


Science has known for more than a century that the radiant energy impacting Earth from the sun supplies more power than produced worldwide by all forms of generation combined. In 2004, worldwide power consumption was estimated at about 15 terawatts, and someone has calculated that the entire planet receives 84 terawatts net of sun power. (A terawatt equals 1 trillion watts: 10>12.) One constraint of using sun power has been the inefficient ways that are available to capture it. For example, it’s been estimated that a silicon-based solar panel array capable of replacing power from a typical centralized coal generator would require about 65 square kilometers of solar collection surface. Another constraint has been the cost per watt that was several times that of a traditional coal power source.

Although solar photovoltaics (PV) are commonly used in lower-power applications and use more silicon than microchips in computers, they have not really captured a large share of the centralized grid-connected renewable power market. Now, that could change dramatically. The basic problem has been attempting to compare solar power to centralized power plants. Instead, when you compare solar technology to decentralized and local or distributed generation, the bottom line looks a lot different. News reports indicate that at least three developments are poised to launch solar power into much faster growth: new technology, capital investment, and support of utility companies. Here’s a summary discussion of each new development gleaned from reports circulating on the Internet.

New Technology
In an electronic media report, Aaron Hand, executive editor, Semiconductor International, described the pending shift to thin-film solar cells. Crystalline silicon (c-Si) technology, comprising both multicrystalline and monocrystalline, presently makes up some 90 percent of the PV market. But, thin-film solar cells are on the rise for several reasons, including a shortage of polysilicon that has kept a growing solar industry from realizing its full potential. Although thin-film silicon solar cells don’t have conversion efficiencies as high as most competing technologies, they offer compelling capabilities in terms of cost per kilowatt-hour of energy. Thin-film silicon panels use a thin layer of amorphous silicon (a-Si) on a glass substrate rather than the bulky substrate of crystalline silicon (c-Si.) Other thin-film technologies use no silicon at all. They rely instead on materials, such as cadmium telluride (CdTe) or copper indium gallium selenide (CIGS). Lowering solar module cost to $1 per watt has been the brass ring for solar power because it's approximately at this point that solar energy will reach grid parity (i.e. the ability to economically compete with traditional fossil-fuel energies).

In addition to thin-film panels being cheaper to produce (largely because of much lower substrate costs), they perform better in some locations. Although module manufacturers often rate performance based on watts, or power output, the utility market is more interested in the kilowatt-hours of energy the module can provide, and that is significantly influenced by the panel's location on the planet. One of the advantages of thin-film technology is that it performs better even in diffuse light. So, even in cloudy areas or less sun-filled climates, you get more effective kilowatt-hours produced using thin-film technologies than you do with crystalline silicon materials.

Capital Investment
A story by Jonathan Shieber, detailing a flock of new venture money infusions financing expansion of solar production, appeared in Clean Technology Investor, published by Dow Jones & Co. Here‘s the rundown.

A second wave of venture-backed photovoltaic technologies flowed to Nanosolar Inc., which raised more than $300 million in its most recent financing. The Palo Alto, CA-based company is using the capital for a massive build-out of its manufacturing capacity in both Palo Alto and Berlin, according to Nanosolar CEO Martin Roscheisen. The company has managed to achieve efficiencies of 14.5 percent with its CIGS process. Nanosolar will have 430 megawatts of available cells in its San Jose, CA, plant and another 620 MW in Berlin after the completion of its first phase of construction. Investors in the massive private-equity financing included Greenwich, CT-based Lone Pine Capital LLC, a hedge fund whose long investment portfolio is worth $8.6 billion, and Paris-based EDF Energies Nouvelles SA, an independent renewable-energy power producer, according to Roscheisen. Sources with knowledge of the investments said additional backers include AES Solar, the $1 billion joint venture of independent power producer AES Corp. (AES), and multi-billion-dollar energy buyout investor Riverstone Holdings LLC. Sources said that buyout firm Energy Capital Partners, which owns the San Francisco-based utility scale solar power project developer NextLight Renewable Power LLC, also participated in the Nanosolar financing.

Earlier this year, Roseville, CA-based thin-film manufacturer Solyndra Inc. quietly announced that it had signed more than $1.2 billion in supply contracts. That company is currently looking for $350 million in new financing. Meanwhile, Intel Capital-backed Sulfurcell Solartechnik GmbH, a Berlin-based thin-film manufacturer, has raised $130 million to build out its own capacity, and Santa Clara, CA-based Miasole is in the process of wrapping up a $220 million round for its own expansion plans.




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