Vestas Wind Systems A/S (VWS) and Siemens AG (SIE), the biggest manufacturers of offshore wind turbines, and 42 other companies are participating in an initiative to lower power-generating costs for the technology and promote investments that may reach as much as $630 billion by 2035.

The alliance, called Norstec, will meet today for the first time in London, the U.K. Department of Energy and Climate Change said in an e-mailed statement. The number of members has more than doubled since U.K. Prime Minister David Cameron announced the group’s formation in April.

The group is seeking to drive development of offshore wind farms, an industry with the potential to employ as many as 185,000 people in the U.K. by 2020 and spur the laying of 8,000 kilometers (5,000 miles) of high voltage transmission cables in Europe’s northern waters by 2022, Norstec said today in a statement e-mailed by DECC.