As the country’s efforts to combat climate change come under particular scrutiny in the lead-up to the United Nations’ Conference of Parties (COP21) forum in Paris next month, analysts have questioned whether Japan is doing enough to help meet its goals on curbing emissions over the next two decades.

Japan’s industry ministry is discussing rules that will require all new stations to have a thermal efficiency equivalent to at least 40-42% of levels seen in ultra-super-critical plants, which are being installed throughout Asia Pacific – except Australia – as part of efforts to reduce emissions.

These new rules would hit the construction of small plants with a capacity below 112,500 kilowatts, which generally have a maximum efficiency of about 36%.

However, consultancy GlobalData said while thermal sources would contribute the majority of Japan’s installed capacity, with an expected overall share of 54.7%, other renewable sources – excluding hydropower – would more than double by 2025.

Renewable installed capacity will rise from 37.8GW this year to 83.3GW by 2025, rising at a compound annual growth rate of 8.2% – the largest growth in Japan’s energy sector.

“Despite the new Japanese government’s rethink on the decision to phase out nuclear power after the Fukushima disaster, there is still a focus on promoting renewable power, not only to reduce reliance on the nuclear sector but also to tackle the huge cost of importing natural gas and oil,” GlobalData senior analyst covering power Chiradeep Chatterjee said.

“A new feed-in tariff system introduced in July 2012 will drive renewable installed capacity growth, as utility companies must purchase power from renewable energy sources, including solar, wind, small hydro, geothermal and biomass, at pre-set premiums for up to 20 years.”

Higher rates for renewable power are consequently being passed on in the form of inflated power bills, which adds extra burden to the consumer.

By contrast, GlobalData believes thermal power will continue to be a major contributor to Japan’s power mix, with installed thermal capacity forecast to reach 213 GW by 2025.

“While gas will be the dominant thermal source, contributing 36% of thermal capacity by 2025, coal is expected to witness the highest capacity growth after 2020, increasing at a CAGR of 4% between 2021 and 2025,” Chatterjee said.