The line will produce one million modules per year, enough to allow 80,000 households to meet their power needs with renewable electricity, it said in a statement to coincide with an inauguration event.

The company, backed by BMW's billionaire shareholder Stefan Quandt, also presented two new production lines for storage batteries which it started operating recently.

CEO Detlef Neuhaus said demand for photovoltaic systems from residential and commercial customers is rising not only in Germany but worldwide.

"It is therefore extremely important that we have a strong solar industry in this country to drive innovation and to offer solutions which help people get clean energy as quickly and easily as possible," he said.

Two months ago, Solarwatt launched a small system called "Manager flex" that lets homeowners to link rooftop solar panels to power storage batteries and electric vehicles.

This came shortly after it announced a cooperation deal with BMW in which the carmaker supplies battery components also used in BMW electric vehicles for Solarwatt's branded home storage product, called "Battery flex".

As the price of battery technology has come down, it is becoming increasingly economical for householders to store surplus solar power rather than selling it to grid operators and having to buy from the grid when the sun does not shine.

Solar power can also be used to supply electric heat pumps or charge electric cars at home.

Germany is the world's top home storage battery market with 300,000 stationary batteries, a market currently led by Solarwatt rival Sonnen, which is part of Shell.

($1 = 0.8526 euros)

(Reporting by Vera Eckert; editing by Jason Neely)