Solar grid parity describes the moment when electricity from solar power is less costly than electricity from the existing grid.  It’s a tipping point, when democratization of the electricity system not only makes political and economic sense, but becomes more competitive than using utility-delivered electricity.

We used the following assumptions in the construction of this animated map:

1. The cost of solar in 2011 is $4.00 per Watt installed.
2. Grid electricity price is the average residential retail rate reported by PVWatts for the core city of the metropolitan area.
3. The cost of solar decreases by 7% per year.
4. The grid electricity price increases by 2% per year.

In just 7 years, 1 in 6 Americans living in major metropolitan areas could lower their electricity bill by installing solar –without any incentives. Here comes the sun!

Animated Map