Sonnen Considering IPO in Bid to Rival Tesla Powerwall Storage

(Bloomberg) -- Sonnen GmbH, a German solar-energy-storage maker that competes against Tesla Motors Inc.’s Powerwall battery, may pursue an initial share sale as early as 2017 to develop additional services.

The company, formed in 2010 in Bavaria, sold its 10,000th battery this year and is taking on new stakeholders ahead of a potential IPO, according to its founder, Christoph Ostermann. Sonnen gained $85 million in a fresh financing round this fall, helped by new stakeholders Envision Energy and Thomas Putter, the former chairman of Allianz Capital Partners GmbH, said Ostermann. 

Sonnen is seeking cash to develop its “virtual utility” business globally, stealing a march on Tesla and challenging conventional utilities, he said in a phone interview Oct. 14. The company is hooking up solar battery owners to allow them to share power and seeks sales in balancing conventional grids, said Ostermann. He envisages an IPO in one or two years.

“We’re not putting ourselves under stress,” he said. 

Sonnen has added the U.S., Australia, the U.K. and Italy to its home market. It may seek a share sale in Germany or the U.S. and has already adopted International Financial Reporting Standards accounting procedures.

Tesla Chairman Elon Musk said in Berlin in 2014 that the U.S., Australia and Germany are focus areas for Powerwall sales and add-on services, a strategy that Sonnen shares. Helped by subsidies, some 32,000 solar batteries were sold in Germany last year.

Envision, which has branched out as China’s second-biggest wind turbine maker into power management solutions, will help Sonnen’s network plans with software expertise, said Ostermann. GE Ventures, another stakeholder, is also advising on technology.

Sonnen battery owners who sign up to the “SonnenCommunity” platform can trade power for about 23 euro cents (25 U.S. cents) a kilowatt-hour, lower than current average rate of about 30 euro cents, the company estimates.

A thirst for investment cash may prompt European power generation and grid companies -- conventional or “virtual” like Sonnen -- to turn to share sales, launching what Goldman Sachs Group Inc. called a “super cycle” of investment in low-carbon power generation and management, in a note last month.

As much as 700 billion euros may be sought by utilities as they boost investment in clean energy, power management, grids and storage, said the investment bank.

The IPO of RWE AG’s grid and renewable energy spin-off Innogy SE this month created Germany’s most-valued utility, bigger than the mother ship where conventional power is located.

Global utility-scale and retail storage capacity may jump to 45.1 gigawatts by 2024 from 2.9 GW this year, with the biggest growth markets being Japan, the U.S., China, India and Germany, according to a forecast this month from Bloomberg New Energy Finance.

To contact the reporter on this story: Brian Parkin in Berlin at bparkin@bloomberg.net. To contact the editors responsible for this story: Reed Landberg at landberg@bloomberg.net, Will Wade