Yes, one of the problems of renewables is that they are highly correlated as to when they generate power, so the value of the power they produce (per kWh) is much lower than it would be if they were uncorrelated with each other. Since we have all invested so heavily in renewables, there is generally a huge amount of excess power generated at these peak times that has to be burned. The correct marginal price of those joules that have to be burned is $0.

Providing that power back to the grid for free is about the right price for the power, and if you would like to be the one to burn it instead (because that is what the grid is doing with a lot of that power), I assume you are free to do so.