'Power' games

'Net metering', a concept gaining in popularity in the US, is an inexpensive solution to the problems faced by home owners who produce electricity with non-conventional means such as solar panels and wind-driven generators. It allows the home owner to deposit excess electricity back into the power grid through the normal meter, which can run forward and backward equally well. The home owners can draw electricity from the grid when the sun is not shining or the wind stops blowing. The power deposited back to the grid is adjusted in the same billing cycle by the power companies ( Scientific American , Vol 276, No 5).