Major energy users must incorporate 10% of green power in the energy mix in accordance with Renewable Energy Development Act, and OPTC Plant 2 is planning to build a solar power system and biogas power generator. The plant exercised strategic foresight and planned to complete the installation before the end of 2023. The two options provide 4,300 kW of renewable power, of which 2,400 kW are installed capacity from biogas generator and 1,900 kW total capacity from solar power.

The biogas power generation system utilizes biogas generated from the anaerobic wastewater treatment within the plant. In 2021, the plant commissioned ITRI to measure the biogas from OPTC and ITRI estimated the power generation capacity at 2,200 kWh. Since the approval of an environmental impact assessment (EIA) was required during the initial plant construction, modifications made to the production process also require the approval of EIA. After undergoing design, application and review, the plant finally passed the committee review on August 31^st, 2021, and received the approval in December 2021. The project is scheduled to be completed and start generating power during the 3^rd quarter of 2023.