The 2.7 gigawatts (GW) of wind and solar projects are located in France, Spain, Sweden and Poland and represent nearly 80% of Nordex's total project development pipeline. The company was advised by Rothschild & Co on the deal.
At 43% of Nordex's current market valuation, the proceeds will be used to strengthen the group's balance sheet, Nordex Chief Executive Jose Luis Blanco said in a statement on Monday.
Nordex shares rose as much as 23% to their highest since early March.
"We believe this will provide some support for a shift in market sentiment related to any potential liquidity concerns," analysts at Jefferies said, keeping a "buy" rating on Nordex.
The deal, agreed in principle on Friday, marks the first major renewables deal for RWE since the takeover of the wind and solar activities of former subsidiary Innogy and peer E.ON.
The purchase adds to the existing 22 GW pipeline of RWE, Germany's largest electricity maker and Europe's third-largest renewables player, which aims to grow its green energy capacity to 13 GW by 2022, from roughly 9 GW currently.
"Looks like a win-win-deal: RWE profits adding strong capacity to its European core business. Nordex gets a huge, urgently needed cash inflow," said a trader, adding it might also fuel takeover speculation for Nordex.
Nordex, which is 36.41% owned by Spain's Acciona, is the world's seventh-largest wind turbine maker, where it competes with larger rivals Vestas, Siemens Gamesa, General Electric and Goldwind.
(Editing by Maria Sheahan and Louise Heavens, Kirsten Donovan)
By Christoph Steitz