Stirling Energy Systems, the Scottsdale, Ariz., maker of a reflective dish that concentrates sunlight onto a Stirling engine, has reportedly filed for Chapter 7 bankruptcy—making it the fourth solar company to fall this year amid the plummeting price of solar photovoltaic (PV) panels.

Operations were halted at the company’s 1.5-MW demonstration plant in Peoria, Ariz., last week around the time of the bankruptcy filing, The Arizona Republic reported. The company and its partner, Tessera Solar, had struggled as the cost of PV panels dropped and the companies failed to secure a $1 billion federal loan guarantee.

In September, Solyndra, the manufacturer of cylindrical solar PV panels, which had been granted the Department of Energy’s (DOE’s) first ever loan guarantee funded by the American Recovery and Reinvestment Act, filed for bankruptcy protection.

Evergreen Solar had filed for bankruptcy just weeks before, saying it couldn’t compete in the cost-cutting war with Chinese competitors. Spectrawatt, a company backed by Intel Corp. and Goldman Sachs, days later filed for bankruptcy, citing similar reasons. Other companies are showing signs of struggle: Germany-based SolarWorld and Solon plan to shutter U.S. plants, and QCells and Renewable Energy Corp. said they will cut production in Europe, reported.

In April 2008, Ireland’s NTR acquired a majority stake in Stirling Energy Systems for $100 million. Stirling Energy Systems made the 25-kW SunCatcher, solar dishes designed to be used as building blocks for 1,500-MW utility-scale solar farms planned for California and Texas.

But like several other developers of concentrating solar power, Tessera Solar eventually sold its 709-MW Imperial Valley project to AES Solar, which plans to redevelop it with PV panels. Another project, the 850-MW Calico project was also later bought by K Road.

Sources: POWERnews, The Arizona Republic,