Deepwater Wind LLC is proposing to pair Tesla Inc. batteries with massive offshore wind turbines as part of a bid to supply the state of Massachusetts with clean energy generated at sea. The 144-megawatt development would stockpile electricity produced late at night, then deliver it when the grid needs it most, Deepwater Chief Executive Officer Jeff Grybowski said in an interview Monday. Deepwater submitted its bid last week in response to a request from National Grid Plc, Unitil Corp. and Eversource Energy for about 9.45 million megawatt-hours of annual clean energy supply. The contracts — open to hydro-electric, solar and other forms of clean energy — require the majority of power to be delivered during late winter afternoons and evenings. “Those hours are very valuable to the grid,” said Grybowski, who plans to use a 40-megawatt storage system. “The battery will ensure that we can do that.” Massachusetts will award the contracts in December and is expected to make the bids public this week, Grybowski said. Deepwater, which built the first U.S. wind farm off Rhode Island, also plans to compete later this year for contracts limited exclusively to offshore wind developers to comply with a Massachusetts law to aggressively develop the nascent industry in the U.S.