FRANKFURT, June 1 (Reuters) - Swedish utility Vattenfall will invest in new heating technology using renewable electricity to supply Berlin in a drive to go green in Germany, where it sold its brown coal-fired power plants last year.
Its German subsidiary would invest almost 100 million euros ($112 million) over two years in a new electricity-to-heat block that would be Germany's biggest and a gas-fired heating block at its Reuter West site in the Spandau area, it said.
Three power-to-heat units with combined capacity of 120 megawatt thermal energy (MWhth) would use electricity from wind turbines in Germany's wind-swept eastern region from the oversupplied public grid in to fire giant boilers, it said.
These units would heat up water that would be piped to homes and businesses in the capital, it said in a statement.
Alongside those units, three gas-burning units with 120 MWth capacity would be built.
Once all the units start up in 2019, a hard-coal fired unit called Reuter C would be shut down, helping Berlin meet a target to be free of carbon polluting coal by 2030 and entirely climate neutral by 2050, Vattenfall said.
"Within the energy transition to renewables, we need a transition not just to power but also to heat," a Vattenfall spokesman said. "This investment is spectacular in its size."
Vattenfall has a third of the market share in providing heat to city, where 1.2 million property units of an average 70 square metres are warmed with so called district heat, using technology established before German unification.
A building boom is adding about 20,000 new flats heated this way each year.
Vattenfall in February decided to invest in a new heating and power plant in the Marzahn district, costing more than 300 million euros, to replace coal with gas.
This unit will start providing 260 megawatts (MW) and 230 MWth from 2020, running alongside Vattenfall's handful of other plants in Berlin.
This is in addition to the firm's role in the market to heat Germany's northern port city of Hamburg.
$1 = 0.8913 euros Reporting by Vera Eckert; Editing by Edmund Blair