In November 2011, an IEA report entitled "Deploying Renewables 2011" said "renewable energy technology is becoming increasingly cost competitive and growth rates are in line to meet levels required of a sustainable energy future". The report also said "subsidies in green energy technologies that were not yet competitive are justified in order to give an incentive to investing into technologies with clear environmental and energy security benefits". The renewable electricity sector has "grown rapidly in the past five years and now provides nearly 20 percent of the world's power generation", the IEA said. The IEA's report disagreed with claims that renewable energy technologies are only viable through costly subsidies and not able to produce energy reliably to meet demand. "A portfolio of renewable energy technologies is becoming cost-competitive in an increasingly broad range of circumstances, in some cases providing investment opportunities without the need for specific economic support," the IEA said, and added that "cost reductions in critical technologies, such as wind and solar, are set to continue."