This graphic that comes from the Economist, indicates the great decline of solar power‘s price. According to this chart the price of crystalline silicon photovoltaic cells has fallen from $76.67 per watt in 1977 to $.74 per watt in 2013.
This is a decrease of 99 percent. Alternative, renewable power will start to be seen as normal.
The decline in the price of solar cells is called “the Swanson Effect,” after Richard Swanson, the founder of a large solar-cell manufacturing company called SunPower.
Swanson theorized that as the global manufacturing capacity of solar cells doubles, the cost to generate electricity from solar cells decreases by 20 percent.