A feed-in tariff is the amount that the grid managers (the local utility or government agency) pay to generators, in this case, small generators, such as people with solar panels. Generally, they require the grid manager to pay a premium(more than the current going rate) for the excess power generated by small producers(fed into the grid).

Feed-in tariffs have been very effective at increasing investment in solar (the systems are running at a profit!), and at encouraging people to overproduce power, especially in Germany and are catching on in the developing world too. They can be somewhat expensive though.

Unfortunately, due to a lot of different regulations that require us to treat anyone feeding power back into the grid as a separate power entity, we don’t have feed-in tariffs here in CA or the rest of the states. Hopefully regulation will catch up with current practice soon.