Perhaps it's time to allow Herman, the solar obituary skull, to return to the catacombs from whence he came. He's witnessed the corporate demise of more than 100 solar firms that were knocked down by greed, delusion, bad luck or bad timing.

We're seeing far less of him lately.

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 was much smaller, while solar attrition in 2015 has subsided to mature market levels.

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.

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


  • Enecsys (microinverters) bankrupt -- Enecsys raised more than $55 million in VC from investors including Wellington Partners, NES Partners, Good Energies and Climate Change Capital Private Equity for its microinverter technology.
  • QBotix (trackers) closed -- QBotix had a two-axis solar tracker system where the motors, instead of being installed two per tracker, were moved around by a rail-mounted robot that adjusted each tracker every 40 minutes. But while QBotix was trying to gain traction, single-axis solar trackers were also evolving and driving down cost. QBotix raised more than $19.5 million from Firelake, NEA, DFJ JAIC, Siemens Ventures, E.ON and Iberdrola.
  • Solar-Fabrik (c-Si) bankrupt -- German module builder
  • Soitec (CPV) closed -- France's Soitec, one of the last companies with a hope of commercializing concentrating photovoltaic technology, abandoned its solar business. Soitec had approximately 75 megawatts' worth of CPV projects in the ground.
  • TSMC (CIGS) closed -- TSMC Solar ceased manufacturing operations, as "TSMC believes that its solar business is no longer economically sustainable." Last year, TSMC Solar posted a champion module efficiency of 15.7 percent with its Stion-licensed technology. 


  • SkyFuel (parabolic troughs for CSP) -- China's Sunshine Kaidi New Energy Group acquired SkyFuel’s parabolic trough technology. 

Watch list

  • Spire Corp. -- According to an SEC filing, on October 22, 2015, "Spire Corporation announced a small reduction in force and, due to insufficient financial support, the suspension of all non-essential operations until further notice. Certain employees will continue to work to maintain day-to-day activities. As previously announced, the Company has engaged an investment banking firm for the purpose of assessing strategic alternatives for the Company, including, but not limited to, a potential sale of the Company or certain of its assets." 
  • Andalay Solar -- OTC stock price is currently $0.00.
  • Abengoa -- Seeking bankruptcy protection

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
  • 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


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. Its space business was purchased by SolAero Technologies (formerly known as Photon Acquisition), an affiliate of private equity firm Veritas Capital.
  • 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.