The financing arrangements tax projects like a partnership, but trade their interests like a stock. That helps spread the cost of capital among more investors, in turn minimizing risk among project financiers.

The latest iteration expands on last year’s version, Koski said. Waste-heat to power, carbon capture and storage, biochemicals and energy-efficient buildings would now also be eligible for master limited partnerships, he said.

Koski said the bill is more mature than the one Coons and Moran sponsored last session, adding that he thinks it has a better chance of becoming law.

With Murkowski, the top Republican on the Senate Energy and Natural Resources Committee, on board, and the concept attracting attention from the White House, the bill has a bit of momentum.

The prospect of overhauling the tax code might also bring oil-patch lawmakers behind the bill, the legislation’s proponents have said.

Senators at a bill introduction for last year’s effort said they wanted to convince lawmakers from such states to offer master limited partnerships to renewable energy projects as a concession to keep the mechanism in the tax code.

— This story was updated at 11:19 a.m.