“…. Meanwhile, Deutsche bank’s most recent report – released this month – suggests that within 18 months, 75% of the world’s market will be sustainable for solar (no subsidies needed) as costs continue to fall. …”

http://www.forbes.com/sites/peterdetwiler/2013/08/12/lawrence-berkeley-national-labs-solar-costs-continue-their-fall/?ss=business%3Aenergy