The insurance for the construction and operation of the wind turbines on the Ford plant at Dagenham has been placed at Lloyd's.
Sources said that insurer AIG and its subsidiary HSB were involved in covering London's first wind turbines.
Neither insurer was available for comment.
Renewable energy broker Nsure Renewables placed the cover, but would not reveal the underwriter involved.
It confirmed that the plant had been "insured by a consortium of Lloyd's underwriters".
The two 85m high wind turbines will generate over 6.7m kWh of electricity every year, providing all the electricity needed to power Ford's new diesel plant. This is equivalent to powering over 2,000 homes.