Essentially you don't get paid to take the energy of their hands; you get paid to use energy so the grid doesn't overload. Crashing the grid is expensive as it

Essentially you don't get paid to take the energy of their hands; you get paid to use energy so the grid doesn't overload. Crashing the grid is expensive as it means you won't be able to sell power (at 52Hz or so the grid operators start disconnecting larger power sources like nuclear power, above and the grid may have to be collapsed). So it's in the best interests of the power generator sites to sell energy at a loss if there is too much in the grid to push consumers (ie, big production plants) to burn more energy. In the other direction, if there is not enough, the grid operators will disconnect power consumers, so in that case it's in the best interest of generators to prevent people from consuming power, thus raising the price dramatically.