Japan will probably become the largest solar market in the world after China this year, boosted by an incentive program that offers above-market rates for energy from renewable sources.

Commercial and utility-scale projects will boost solar installations to a range of 6.1 gigawatts to 9.4 gigawatts in 2013, exceeding an earlier forecast of 3.2 gigawatts to 4 gigawatts, Bloomberg New Energy Finance said in a research note.

"The upward revision was done because of the rapid increase in shipments seen last quarter as well as the fact that the pipeline of projects is even stronger than previously expected," BNEF said in the report released March 29.