[logfromblammo]

You are describing some blatantly fraudulent bookkeeping right there.

Let's say you charge $0.15/kWh for "green" electricity and $0.10/kWh for "black" electricity. You can't change the color of the electrons once they are in the grid, just to make more money.

To say otherwise is to end up with stupid schemes like using a sulfur plasma lamp, powered by coal-burning, to shine artificial light on a solar cell. Or run air fans with your nuclear steam turbine to blow air across your wind turbines. Or endlessly pump the same water over a hydro turbine.

Power from pumped storage generates the same "color" of electricity as the electricity used to run the pumps. If the grid was 15% green when it went up, it will be 15% green when it comes down.