Wednesday, June 25, 2008

Israeli solar tech to power server farms


Zvi Marom, CEO of Israeli telecom gear company Telco Systems, was looking for a way to cut down on his company’s high electricity bills a few months back when he stumbled onto a green idea. He’d been talking to friends that had worked on solar systems in the 80s and 90s, so he decided to hook up his company’s networking operations to solar technology provided by a newly-formed local startup, Distributed Solar Power (DISP).

Lo and behold, the solar system is now on its way to cutting the company’s annual $750,000 power bill by roughly a third. The system has been so successful, in fact, that Telco and DISP are working on ways to commercialize it, particularly to power server farms (Marom said the details haven’t been worked out yet). In the meantime, DISP is planning on buying the system from Telco and will sell them the solar power in a purchase power agreement. All of which means that Marom has joined the growing number of accidental but proud green innovators, who, when looking to find more efficient or cost-cutting methods, also turn into eco-leaders. Hey, whatever works.

DISP’s solar technology is novel in that it combines a micro solar concentrator, photovoltaic panels and a heat transfer system. A parabolic concentrator focuses sunlight onto panels that generate electricity. The concentrated sun light is also used to heat water, which can be hooked up to power a building’s air conditioning needs. A tracker moves the concentrator to follow the sun throughout the day.

Each of the solar units are small, but as you can see in the picture below, are meant to be hooked together to provide a substantial amount of power. DISP says a typical installation would require 350 square meters of roof space and 100 units that each generate 200 watts of power and 480 watts of heat. That would give the setup a total of 20 kW of electricity and 48 kW of thermal power. This also makes them a good fit to power server farms, and routing and networking stations, as the systems can scale up and down to meet demand.

The units are meant to be located either on rooftops or within 100 meters of the building, which as Marom points out, significantly reduces the amount of energy lost through transport. “It makes sense to have a heavy user of energy close to the power source.”

DISP says the solar system’s advantages are its high efficiency rates: 75 percent for combined heat and power, and a total solar-to-electric efficiency of 28 percent. The heat transfer system is also novel — while many companies are building solar thermal plants that run steam turbines, we haven’t heard of many combining PV and thermal in this way.

Then there’s the low cost of manufacturing the units. Some startups have moved to focus on concentrating photovoltaic systems because they can produce more power with less solar PV material. Traditional silicon solar cells are expensive (and in short supply), so cutting back on the needed PV can lower costs. DISP says the cost of its solar electricity ranges between $1.50 and 1.75 per watt and can be as low as 90 cents per watt if the produced heat is factored in. As DISP points out, a standard PV system can cost around $2.40 per watt.

With such good economics, its not surprising that DISP has a lot of competition. Last week, high-profile, venture-backed firm SolFocus was reported to be raising between $60 million and $80 million in a Series C round for its concentrating solar systems. Other companies include Sunrgi (nanotech goop!), Soliant Energy, GreenVolts, Idealab’s Energy Innovations and Cool Earth Solar.

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