Actually, If they really wanted it they wouldn’t doo it via sponsoring... they would do it by awarding a cash-prize (tax-free) to the entity that accomplished the goal they wanted.
IE, Say that Government wanted 20% of our energy provided by solar; so they offer $50bn to the entity that put 20% solar energy into the grid. (With some specs, of course.) Then award the money to whomever does it. In a situation like one company providing %11, and one providing 14%... they might be able to file for it jointly, as their combined input is 25% of the grid, which exceeds the 20% mark they wanted.
Just my idea there.
I have nothing against renewable energy, but it needs to be competitive in cost with no subsidy. Using renewable energy to feed power grids isn’t smart, IMHO. They are intermittent and make the required convenional power source less efficient because they have to generate a relatively constant power load. Solar and wind could add to a peak load, or generate hydrogen from the hydrolysis of water, IMHO.