The Sacramento Municipal Utility District and clean energy advocates will square off at the state Capitol Thursday in what is being billed as a fight over the future of solar energy in California.

The Sacramento County electricity provider is asking state regulators to allow some home builders to opt out of the state’s groundbreaking six-week-old rooftop solar panel installation requirement for new houses.

SMUD wants the California Energy Commission instead to approve a SMUD plan to produce power at a few new solar farms around Sacramento County and ship that power to new housing tracts, freeing those builders from having to install panels on house roofs.

The utility says its proposed Neighborhood SolarShares Program doesn’t supplant the rooftop solar mandate, but is a legal alternative under the state regulations for builders of homes or low-rise apartments who find it too expensive or unworkable to mount solar panels on roofs.

The proposal is adamantly opposed by many in the solar industry and by some major environmental groups who call it an end-run around state regulations that will undermine California’s still young rooftop solar effort, and will block many state residents from starting on the path to energy independence from utility companies.

The state’s rooftop solar rule, which went into effect Jan. 1, covers most new housing going forward and is expected to be a focal element of California’s effort to become a largely carbon-free energy state in the next two decades.