OK, if Black Friday can start on Thanksgiving, then we can start making year-end lists on December 1.

We listed the more than 200 VC-funded solar startups back in 2008. We knew that we'd be writing about most of them on their way up -- as well as on their way down.

So here is an updated list of (mostly U.S. and EU) solar companies that have closed, gone bankrupt, insolvent, ended up in assignment for benefit of creditors, or have been acquired at pennies to the dollar. Although there is a macabre element to this list, this is actually positive solar news. The solar companies left standing in 2014 and 2015 will be the stronger firms with viable business plans and sustainable value. They'll have made it through the bottleneck of the early 21st century solar market.

(Of course, there's another long list of relatively unknown Chinese companies closing down as well.)

Here's an incomplete list of the solar firms that have fought the good fight, but have moved on:

2009 to 2010

Bankrupt, closed, acquired

  • Advent Solar (emitter wrap-through Si) acquired by Applied Materials
  • Applied Solar (solar roofing) acquired by Quercus Trust
  • OptiSolar (a-Si on a grand scale) Optisolar’s utility projects acquired by First Solar. Optisolar’s a-Si manufacturing line sold to Novasolar.
  • Ready Solar (PV installation) acquired by SunEdison
  • Solasta (nano-coaxial solar) closed
  • SV Solar (low-concentration PV) closed
  • Senergen (depositing silane onto free-form metallurgical-grade Si substrates) closed
  • Signet Solar (a-Si) bankrupt
  • Sunfilm (a-Si) bankrupt
  • Wakonda (GaAs) acquired by Siva


Bankrupt, closed

Acquisition, sale


Bankrupt, closed

Acquisition, fire sale, restructuring

  • Oelmaier (Germany inverters) insolvent, bought by agricultural supplier Lehner Agrar
  • Q-Cells (c-Si) insolvent, acquired by South Korea's Hanwha
  • Sharp (a-Si) backing away from a-Si, retiring 160 of its 320 megawatts in Japan
  • Solibro (CIGS) Q-Cells unit acquired by China's Hanergy
  • Solon (c-Si) acquired by UAE's Microsol  
  • Scheuten Solar (BIPV) bankrupt, then acquired by Aikosolar
  • Sunways (c-Si, inverters) bought by LDK, restructuring to focus on BIPV and storage


Bankrupt, closed


  • Agile Energy (project developer) acquired by RES Americas
  • Bosch (c-Si PV module) acquired by SolarWorld
  • Diehl (Germany inverters) inverter division sold to PE firm mutares AG
  • Conergy (c-Si module) Astronergy, a part of China's Chint Group, acquired Conergy's PV module group
  • GE-Primestar (CdTe technology acquired from PrimeStar)  acquired by First Solar
  • Global Solar Energy (CIGS) acquired by Hanergy
  • Infinia (Stirling engine CSP) assets acquired by Israel's Qnergy
  • MiaSolé (CIGS) acquired by China's Hanergy  
  • NuvoSun (CIGS) acquired by Dow
  • Suntech Wuxi (c-Si) acquired by Shunfeng Photovoltaic International for $492 million
  • Twin Creeks (kerfless Si) IP and other assets acquired by GT Advanced Technology
  • Wuerth Solar (installer) business turned over to BayWa
  • Wuerth Solar (CIGS line) taken over by Manz
  • ZenithSolar (CHP) acquired by Suncore

Watch List

  • LDK Solar (c-Si) struggling to meet debt payments
  • Solar Junction (semiconductors for CPV) CEO departure amidst continued efforts to sell the firm


Which solar companies are still around and thriving in this fast-growing, 30-gigawatt global market? Most of them will be at GTM's U.S. Solar Market Insight event in San Diego later this month. Register here.