The clean energy sector weathered more storms this year, and not everybody made it through.

Here we mark the names of the fallen, those companies that went bankrupt, ceased operations or otherwise exited the sector. The ranks include top-five rooftop solar installers, prominent lithium-ion alternative vendors, a quixotic aboveground compressed air storage play, a solar cell manufacturer with global geopolitical implications, and a couple nuclear plants for good measure.

On the whole, the list was short, a far cry from the bloodbath of 2012. Herman the Solar Death Skull has grown more reclusive, and dedicates much of his time to perfecting his savasana up in the leafy Coast Ranges. Still, once in a while the mountain lions catch a scent, and he follows their silent steps down to the valley to hunt.

The legacy of these companies echoes in the eternity of Greentech Media's comment section.

2017

  • Beamreach (thin-silicon/C&I rooftop): Solexel gave up on thin-silicon cell manufacturing and rebranded as Beamreach, a commercial and industrial rooftop solar pushing a lightweight, easy-to-install module. It had spent $250 million before that business took off. And when debt came due, the company's venture investors walked away.
     
  • OneRoof Energy (residential solar): After raising a lot of money, this firm started winding down following a failure to pay rent on its head office.
     
  • NRG Home Solar (residential): In 2015, it was No. 4 in the U.S. for home solar. Executives promised to give SolarCity a run for its money. Under pressure from investors, the company downsized in May 2016, laying off 500 employees. This year it pulled the plug completely, although NRG will still generate leads for third parties.
     
  • Aquion (saltwater batteries): $190 million from Bill Gates, KPCB and others, frequent media coverage and a factory of its own couldn't keep this long-duration saltwater battery company open. But the story doesn't end there. The firm was bought in June for $9.16 million by a newly chartered affiliate of a Chinese investment holding company. Few details have emerged about where the reconstituted company is headed.
     
  • Sungevity (residential solar): The No. 5 rooftop solar installer raised $200 million in equity, but, after a reverse merger fell through, abruptly laid off almost all its staff before going bankrupt. It was bought for $20 million by private equity firm Northern Pacific Group. The new ownership later resurrected the brand as an umbrella for its solar properties. Engie bought the European operation for an undisclosed amount.
     
  • Westinghouse (nuclear reactors): The maker of half the world's nuclear plants filed for bankruptcy protection following repeated setbacks at its AP1000 projects in Georgia and South Carolina. The bankruptcy created turmoil for the U.S. nuclear industry and for parent company Toshiba, resulting in the spin-off of smart meter company Landis+Gyr via IPO.
     
  • Suniva (PV cells and modules): One of the last U.S. PV manufacturers filed for Chapter 11, which it blamed on competition from foreign imports. It also filed a now-eponymous petition for tariffs with the International Trade Commission, which consumed the solar industry's attentions, raised module prices back above $1.00 per watt and froze investment due to uncertainty.
     
  • SolarWorld AG (PV cells and modules): The German parent company filed for insolvency, citing "ongoing price erosion." The U.S. based subsidiary later joined Suniva's petition for tariffs against foreign imports.
     
  • American Solar Direct (residential solar): A recent round of layoffs aimed at "low producers" failed to produce a healthy balance sheet. The installer filed for Chapter 7 bankruptcy with less than $50,000 in assets and liabilities of between $10 million and $50 million.
     
  • Direct Energy Solar (residential solar): Electricity retailer Direct Energy decided to walk away from its residential installation business, while keeping the commercial unit open. It appears to have been the last national electricity retailer to do so. The strategy to cross-sell solar to retail customers hasn't worked out as planned.
     
  • V.C. Summer Nuclear Station (nuclear power plant): Utility partners Santee Cooper and South Carolina Electric & Gas abandoned the plant, which had been beset by delays and budget overruns.
     
  • Alevo (battery maker): This challenger to conventional lithium-ion tried to both commercialize a new battery chemistry and develop its own projects. It finished its first commercial unit in January, rather than the originally planned 200 megawatts by the end of 2015. The company could not find additional funding to continue operations.
     
  • Exosun (solar trackers): The French PV tracker company entered receivership in France. It is undergoing financial restructuring that the leadership hopes will reposition the company for growth.
     
  • Lee Nuclear Station (nuclear power plant): Duke Energy asked regulators for approval to cancel the development of this two-reactor project in Gaffney, South Carolina due to market uncertainty. Duke spent $541 million on the project, but canceled it before construction began. The company kept the license to build on the site in the future "if it is in the best interest of customers."
     
  • Levy Nuclear Project (nuclear power plant): Duke Energy Florida scrapped a planned nuclear plant in a settlement that included a four-year, nearly $6 billion investment in 700 megawatts of solar PV and 50 megawatts of energy storage.
     
  • Stion (thin-film solar): Founded in 2006, this company raised about $240 million and built the first thin-film solar factory in the Southeastern U.S. It discontinued operations and entered assignment for the benefit of creditors, citing "intense non-market competition from foreign solar panel manufacturers."
     
  • LightSail Energy (compressed air energy storage): This company made sweeping promises about revolutionizing grid storage with air compressed in tanks. After eight years and $80 million from big-name VCs, it ran out of funds before achieving commercial deployment.

Honorable mention:

  • SolarCity (residential solar): The market leader for rooftop solar evaded the possibility of economic collapse through its merger with Tesla. Since then, the new ownership has erased almost every vestige of the solar company. The founders are out, as are leaders like Jon Wellinghoff and Ryan Hanley. Tesla canceled door-to-door sales and orchestrated a shift away from third-party-owned deals, resulting in Sunrun seizing the lead for TPO financing and likely out-deploying SolarCity in Q3. The company still installs solar, but as a shadow of its former self.

Find previous coverage of fallen cleantech companies here.