According to a global price survey, solar energy prices have declined an average of 4% per year for the past 10 to 15 years. There is a progressive increase in conversion efficiencies of cells, and manufacturing economies of scale are the underlying drivers of this price decrease. The Solarbuzz Global Price survey clearly indicates that prices have consistently declined for over the last two years.
A detailed analysis of the worldwide photovoltaic market is present in on the the leading industry reports, the Market Buzz 2009. A residential solar energy system typically costs about $8-10 per Watt in 2009. When government incentive programs exist, and coupled with with lower prices secured through volume purchases, installed costs for solar panels can become as low as $3-4 watt - or some 10-12 cents per kilowatt hour can be achieved. Without incentive programs, solar energy costs range between 22-40 cents/kWh for very large PV systems.
