Time is running out for the government to realize its 23 percent renewable energy target in the country’s primary energy mix by 2025. As of October 2021, renewable energy only made up 13.54 percent of the energy mix, 12.77 percent of which was used in power plants. Now the government, through state-owned electricity company PT PLN, is speeding up co-firing to raise the share of renewable energy in the mix by 6 percent.

Coal remains the dominant energy source in the country, making up an overwhelming 65.59 percent of energy used in power plants as of October 2021. Gas comes second at 17.89 percent, followed by renewable energy sources such as hydropower at 6.72 percent, geothermal at 5.64 percent, biofuel at 3.75 percent and biomass at 0.19 percent. Other renewable energy sources account for 0.22 percent of the mix.¹ 

To reach the 2025 target, PLN aims to start the operation date of geothermal power plants with 1.4 gigawatt (GW) capacity and hydro/mini-hydro power plants with 4.2 GW capacity in total. It also plans to develop new solar power plants with a total of 4.7 GW capacity and wind power plants at 0.6 GW.² 

As for existing power plants, the company aims to make use of the prevalent coal-fired power plants (PLTUs) by implementing co-firing at 10 percent of capacity in PLTUs across Java and Bali and 20 percent capacity in PLTUs elsewhere. This would create a total of 2.7 GW of power sourced from renewable energy in the PLTUs, which would count for 6 percent of the energy mix in 2025.³ 

As of May 2022, PLN had implemented the co-firing scheme by mixing biomass in 32 PLTUs, producing green electricity equivalent to 487 megawatt hours (MWh). This progress is estimated to have reduced carbon dioxide and greenhouse gas emissions by 184 thousand tons. By 2025, PLN aims to expand the scheme to 52 PLTUs in total, reducing CO2 emissions by 11 million tons.⁴ 

However, expanding this scheme would expose PLN to other threats, such as biomass scarcity. PLN projects its demand for biomass will be 450 thousand tons this year. By 2025, this demand is expected to rise to an astonishing 10.2 million tons of biomass.⁵  PLN has been using sawdust, woodchips, corncobs and solid recovered fuel (SRF) from waste in the co-firing, increasing the risk of deforestation if it cannot secure biomass from agricultural and urban waste at an economic price.

PLN is also exploring new ways of co-firing. The company on Nov. 1 signed a memorandum of understanding (MoU) with Japan-based Mitsubishi Heavy Industries (MHI),⁶  as well as with South Korea-based KEPCO Engineering and Construction Company Inc through its subsidiary PT Prima Layanan Nasional Enjiniring (PLN Enjiniring),⁷  to run a study on using hydrogen and ammonia in co-firing.