BOSTON >> Solar energy companies are pushing the Legislature to break a logjam they say is stalling thousands of solar projects in Massachusetts.

Industry representatives arrived at the Statehouse on Tuesday with thousands of petitions and letters seeking final passage of legislation that would lift "net metering" caps.

Versions of the bill cleared both the House and Senate but a six-member conference committee has been unable to forge a compromise.

The net metering program allows solar developers and municipal governments to sell excess power they generate back to the electrical grid in exchange for credit. Existing caps have been reached in much of the state.

The main sticking point appears to be the reimbursement rate. The House wants developers compensated at the wholesale rate while the Senate favors a higher retail rate.