The post didn't describe net metering
edit: actually I think it did :) ignore me
edit: actually I think it did :) ignore me
They are selling back to the grid, with a smart meter that counts power in both direction. Theres many types of policies in net metering like details about what rate you buy and sell power to the utility. In some less favorable places, the grid sells you power at retail prices but buys it back from you at wholesale. In these places, to achieve a $0 utility bill you would be generating more during the day than you consume at night. If your net metering deal paid back at retail rates you may get a credit, but as far as i understand each utility can offer totally different net metering deals, if they offer it at all.