The increase in the trading volume of electricity using renewables was largely attributed to an increase in generation using by-product gas, which accounted for 47.9 percent of the total renewable-based electricity trading volume.

The trading volume of electricity from by-product gas recorded an increase of 113 times from the previous year’s 2,641 MWh to hit 298,468 MWh in 2016, when Korea Western Power started the commercial operation of Taean Integrated Gasification Combined Cycle power plant.

The trading volume of electricity generated from wood pellets, a type of biomass fuel made up of compressed wood waste such as sawdust, also increased by 180 percent to reach 882,786 MWh in the last year, as energy companies tried to meet the government’s renewable energy portfolio standard, a system designed in 2012 that requires power companies that own a 500 MWh facility or bigger, to produce 2 percent of their electricity by using renewables.

Power companies, especially the ones that operate coal-fired power plants, currently prefer to use wood pellets, as they do not have to construct separate facilities and instead just add storage and carriers to their coal-fired power plants, according to industry sources.

“Most wood pellets are imported from overseas countries. Around 1.5 million tons were imported in 2015,” said Lee Sang-hoon, director of Green Energy Institute. “Wood pellets create less pollutants than coal, but still more than other sources like gas,” he added.

The Ministry of Trade, Industry and Energy plans to cut the import volume of wood pellets down the road, its official said.

By Shim Woo-hyun (ws@heraldcorp.com)