Another U.S. solar firm goes bust

Solar company Stirling Energy Systems has filed for bankruptcy, another casualty of a brutal global price war which is favoring commodity photovoltaic panels.

The Scottsdale, Arizona-based company filed for Chapter 7 bankruptcy late last week. The utility-scale solar company's largest investor is renewable energy developer NTR of Dublin, Ireland.

Founded in 1996, Stirling Energy Systems makes a large, 38-foot-high reflective dish which concentrates sunlight onto a Stirling engine to generate electricity. The 25-kilowatt SunCatcher dishes are designed to be used as building blocks for utility-scale solar farms in desert areas with sufficient sunlight.

After decades of development including a partnership with Sandia National Laboratories, the solar dishes were put online in 2010 in an Arizona demonstration project with a capacity of 1.5 megawatts.

The solar thermal technology, where heat drives a hydrogen-filled piston to generate electricity, has the advantage of not using water and a scalable design. Two utilities contracted to use Stirling Energy Systems dishes for giant solar projects in the southwest U.S.

But prices for solar power production have dropped precipitously over the past two years, which has contributed to an ongoing shakeout among solar producers, including bankruptcies at Evergreen Solar, Spectrawatt, and Solyndra. Demand for solar has also been soft or uncertain, too, in some countries.

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The price war, led by Chinese manufacturers, is leading to a shift toward solar photovoltaic technology over solar thermal. Silicon-based solar PV panels have rapidly become commodities and have already caused solar developers to abandon solar thermal products.

In August, the project developer for the giant Blythe Solar Power Project in California switched from reflective solar troughs to flat-plate solar panels.

Stirling Energy Systems was been victim of the technology shift toward PV for large projects. Tessera Solar, which is a unit of NTR, lost a contract to supply power for the utility-scale Calico Solar project, which is expected to use PV technology primarily, and another Imperial Valley project appears abandoned, according to Dow Jones.