Keeping track of failing solar companies in 2011 and 2012 bordered on full-time work. That was when solar manufacturing overcapacity and price pressure brutally culled the field. The 2014 dead pool is much smaller and much less painful to view. 

This is an updated list of (mostly U.S. and EU) solar companies that have closed, gone bankrupt, become insolvent, ended up in assignment for benefit of creditors, or have been acquired in less than positive circumstances. Although there is a macabre element to this list, it's actually positive news for the industry. The solar companies left standing in 2015 are the firms with effective business plans and value to add to the marketplace. The survivors made it through the bottleneck of the early 21st century solar market.

Here's the updated list of the solar firms that have fought the good fight but have moved on.


Bankrupt, closed

  • Areva's solar business (CSP) closed -- Suffering through a Fukushima-inspired slowdown in reactor sales, Areva exited its concentrated solar power business. Areva's solar unit consisted of the remains of the acquired startup Ausra. 
  • HelioVolt (CIGS thin-film PV) closed -- HelioVolt was founded in 2001 and aimed to fabricate CIGS solar panels. Thirteen years and more than $200 million in VC later, HelioVolt had shipped no commercial product and finally admitted defeat. A thin-film expert offered this take: "Founded on the idea of a transfer process (FAST) which never worked, HelioVolt went to a two-step process and finally adapted co-evaporation. However, the co-evaporation process the firm decided to copy was that of Solibro -- using point sources and an upward deposition orientation -- something with severe limitations in manufacturing."
  • LDK (vertically integrated module builder) filed for bankruptcy
  • Masdar PV (a-Si) closed its SunFab-based amorphous silicon PV factory in Germany.
  • SolarMax (PV inverters) -- Swiss inverter maker SolarMax's parent firm, Sputnik Engineering, filed for insolvency.
  • Sopogy (small-scale CSP) closed -- Sopogy promised smaller-size CSP for the distribution grid or even the rooftop. The startup collected more than $35 million in VC and strategic financing from investors including Southern California Gas Company, 3M, Mitsui & Co., Kolohala Ventures, Enerdigm Ventures, Black River Ventures, Pierre Omidyar and TWC.
  • TEL (a-Si) withdrew from its a-Si solar business -- In 2012, the a-Si equipment division of Oerlikon was divested to Tokyo Electron (TEL) in a $275 million deal. In 2014, TEL withdrew from the PV panel production equipment business. Low efficiencies (below 11 percent), high costs, and cheap Chinese panels doomed a-Si and Oerlikon's effort.
  • Xunlight (a-Si) went bankrupt -- Xunlight was adept at winning tax credits and government grants but never commercialized its roll-to-roll a-Si BIPV technology.

Acquisition, sale

  • Emcore's CPV business -- Suncore acquired the remaining interest in Emcore's CPV business.
  • RSI (CdTe PV panels) sold to Chinese strategic -- RSI, a VC-funded cadmium telluride thin-film solar module startup formerly known as Reel Solar, was acquired by an undisclosed "Chinese strategic," according to the company's CEO. RSI employs an electroplating process that works at a lower temperature than First Solar's and allows the use of larger glass sizes with an electrodeposition technology "inherited from Monosolar." According to the CEO's viewpoint, larger glass sizes drive down installed costs. 
  • Solar Junction (CPV semiconductors) sold to Saudi strategic -- Solar Junction raised more than $30 million from VC investors ATV, DFJ and NEA, but was sold to Saudi entity KACST and one of its investment arms, TAQNIA, according to sources close to the company. Solar Junction had developed record-setting triple-junction solar cells.
  • SAG Solarstrom, a bankrupt PV project developer, was sold to Shunfeng Photovoltaic, the owner of PV panel builder Suntech, in an $85 million deal. Germany's SAG Solarstrom ranked among the top ten of PV O&M providers in the world in 2013.    

Watch list


And here's the collection from previous years.

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 were acquired by First Solar; its manufacturing line was 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 manufacturing assets. Kawa Capital Management purchased the solar projects business.
  • 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