Solar energy is en route to grid parity within the next few years, according to a report from London-based business analytics firm Global Data.

Grid-parity means the cost of solar energy will be on par with the cost of other more traditional energy sources.

Solar panel prices have plummeted in the last two years, driving demand higher. Solar is the fastest growing renewable energy source, according to the report. It has grown 56.4 percent in the last five years. There were more than 44 gigawatts of solar installed globally in 2010 and 2011. That’s a sharp increase from 2008 and 2009 when the world installed 14.8 gigawatts, according to the report.

The report predicts that solar photovoltaic projects will reach grid parity in the United States between 2014 and 2017 and in China between 2015 and 2016.

“The capital cost, renewable subsidies and average electricity prices in the US differ state by state,” Global Data alternative energy analyst Prasad Tanikella writes in an email. “The states which have lower capital cost, higher subsidy and higher average electricity prices will reach grid parity first.”

But even the states with the lowest subsidies and capital costs will likely meet grid parity by 2017 because of falling panel prices.

Global Data’s report does factor in existing government subsidies when calculating grid parity, Tanikella said.

“If government does not provide subsidies then the capital cost burden on developers increases resulting in delay in reaching grid parity,” Tanikella writes.

China is uniquely situated to achieve grid parity quickly, Tanikella said.

“China has a huge manufacturing base for renewable equipment,” he writes. “The cost of renewable equipment in China is among the lowest in the world.”

That low cost equipment gets the country closer to grid parity, Tanikella said.

The US and China are expected to take over from Europe as market leaders in renewable energy, accordino to the Global Data report. Tanikella said he and his team have forcast solar energy growth through 2025 and that it is expected to continue to grow at roughly the same manic rate up to grid parity without changing dramitically after reaching parity.