It's not a buyer, people are paid to take the energy that would otherwise be wasted. And when energy use is shifted it means you need to generate less later, saving money.

The people who pay that cost to the people using the energy are people running energy generators that suffer wear and tear when they ramp down.

Or sometimes it's a subsidy for the use of clean energy being passed on to ensure the clean energy is actually used, not wasted.

All upside, no problems at all.

Because otherwise the incentive structures for solar-as-baseload, sweeping the actual cost on the consumers, collapse. The system is built on putting equality sign between oversubscribed solar and coal/gas backups during times of undersubscription.