Japan has become one of only five countries to have achieved 10 gigawatts of cumulative solar capacity, according to new research released by NPD Solarbuzz.

While aiming to diversify its energy mix, Japan is developing its renewable energy sector, especially as it steers away from nuclear power following the disaster at the Fukushima nuclear power plant in 2011, Eco Seed reported Wednesday.

The development of solar power in Japan slowed in the mid-2000s, partly due to a 10-year energy plan that favored nuclear power.

With a shifting of focus toward renewables, and after a new law approving feed-in tariffs for renewable energy was passed last year, the Japanese government is giving incentives for the use of solar energy.

The policy requires utility companies in Japan to buy electricity from renewable sources like solar and wind at a premium price for the next 20 years.

Only four countries have reached 10-gigawatt capacity, the first being Germany, followed by Italy, China and the U.S.

One gigawatt of solar power is enough to power 139,000 homes, according to the Solar Energy Industries Association. According to an independent equity broker and financial services group, Japan’s solar energy will increase to 19 gigwatts by 2016.

By the end of August, rooftop solar panel installations led the Japanese solar market at 89 percent while the remaining 11 percent were installed on the ground and off-grid segments.

Japan relies heavily on foreign imports of hydrocarbons, mostly coming from the Middle East, and concerns over disruptions in supplies due to tensions in the Persian Gulf makes Japan’s supplies vulnerable. Therefore, it is in Japan’s energy-security interest to diversify its energy portfolio as possible.