Identifying solar "grid parity", or the point where solar power becomes cost competitive with energy from the existing grid, is a notoriously tricky business. Whether or not to include subsidies in the equation? how much can we expect solar prices to fall? How much will conventional energy prices rise? Will coal finally be forced to pay for its astronomical social and environmental impact? All these questions and more must be factored in before any kind of figure can be reached.
John Farrell recently argued that, including State and Federal subsidies, many Americans in Metropolitan areas could be beating grid prices with solar right now due to the projected long-term price rises of conventional energy sources. But even without subsidies, cost competitiveness may be nearer than we think.
Farrell has just taken another stab at visualizing the future of solar energy, this time creating an animated interactive map of areas where solar will reach grid parity year-by-year that shows San Diego reaching parity by 2013, followed by New York in 2015, and Riverside, Los Angeles, San Francisco and San Jose by 2017. By 2027, more than 156 million Americans should be enjoying solar energy at prices cheaper than the conventional grid. Farrell makes a number of assumptions in his calculations - including an installed cost for solar in 2011 that's $0.50 higher than his previous post:
The cost of solar in 2011 is $4.00 per Watt installed.
Grid electricity price is the average residential retail rate reported by PVWatts for the core city of the metropolitan area.
The cost of solar decreases by 7% per year.
The grid electricity price increases by 2% per year.
By the looks of things he is not including State or Federal subsidies in his equations. (The more numerically/politically literate among us can correct me if I am wrong.) Either way, we can expect to see a lot more solar in our towns and cities in the coming years—whether or not the fossil fuel industry finally starts paying its way and accounting for its true costs.