Meanwhile, Energy Secretary Steven Chu predicted that the cost of solar and wind will be on par with oil, natural gas and coal by the end of the decade. 

(In Hawaii, where electricity prices are three times the national average, unsubsidized photovoltaic energy has already reached — and passed — grid parity, according to Henry Curtis, executive director of Life of the Land.)

From Clean Technica: 

Prices for solar PV modules and panels have been falling fast from 2008 right on through 2012, according to industry data. The marginal weekly spot price of silicon solar modules (panels) was $0.654 per Watt, with a low price of $0.54 and a high of $1.00 per Watt as of January 16, 2013, according to PV Insights data.

The median installed price of residential and commercial PV systems in California dropped between 3% and 7% during the first six months of 2012, following year-over-year reductions of between 11% and 14% in 2011, according to the most recent Department of Energy Lawrence Berkeley National Laboratory’s “Tracking the Sun” report.

Overall, installed costs for home solar PV panels for all of 2012 ranged between $1750 and $2500 per kilowatt (kW), or $1.75–$2.50 per watt, according to Renewable Green Energy Power data.