It used to be that a homeowner who wanted to sell electricity to the national grid would set up a solar panel in the back yard, and keep his mouth shut. Guerrilla solar provided the illicit thrill of watching the electricity meter spin backwards as the sun worked its magic, but that's starting to change - for the better. In some US states, you can "net meter" legally, as reported in the Washington Post on 21 Jan 2007:
Federal legislation requires states to consider adopting net metering standards by 2008, though programs are already in place in more than 40 states, according to the Interstate Renewable Energy Council. California is king when it comes to net metering, accounting for 86 percent of the 15,200 customers tallied nationwide in 2004 by the Network for New Energy Choices, a New York City-based renewable energy advocacy group.
This can be a powerful incentive for overcoming the cost of installing photovoltaic solar panels and avoiding the need to buy batteries.
