23 January 2012
Grid parity in cost between solar power and grid-supplied electricity is likely to begin being reached in the US in as little as 2 years, and within the next 25 years, many of the largest metropolitan areas will reach the point where solar is less expensive. An animated map from Energy Self Reliant States shows the picture.
This timeline includes no government subsidies in the calculations. It uses a baseine cost of solar power in 2011 at $4.00 per watt, installed. Using the average residential grid supplied electricity price for each metro area, it makes the two assumptions based on present trends to determine when the price of solar drops below grid: the cost of solar decreases by 7% per year, and the grid electricity price increases by 2% per year.
Based on these assumptions, the San Diego CA metropolitan area will be at solar parity in 2013, and within the next 25 years, many of the largest metropolitan areas will reach the point where solar is less expensive.