California-based bioenergy company Viaspace has announced completion of the engineering and design work on its giant king grass biogas power plant in Papua New Guinea.

The 2 MW plant is being built for independent power producer Clean Energy Solutions Pacific (CES), which focuses on project development in emerging markets.

Along with the plant, CES will own and operate a giant king grass plantation that will provide 100 per cent of its fuel. Giant king grass (pictured) is a proprietary high-yield energy crop that can be burned directly or in pellet form as a replacement for coal or oil, or processed to produce biomethane for use in generator sets, according to Viaspace.

The Papua New Guinean state-owned utility’s daily load profile and a comparison of peak load with average load determined the size of the digesters, the amount of biogas storage and the number and size of the engine generators, Viaspace said. This information plus the amount of biogas production from giant king grass determined the size of the plantation needed.

The engine generators, electronics and control system, pumps and gas cleanup system will be integrated into 12-metre container modules which will be assembled and tested before shipment to Papua New Guinea.  

Viaspace’s engineering and design work included the giant king grass feeding system, a hydrolysis system, primary and secondary digesters, biogas and substrate piping specifications, biogas treatment, biogas storage, engine/generator sets, monitoring and controls, the transformer substation, digestate handling, trench silos, internal energy consumption, operations and maintenance, and construction and operating costs.

The project has secured a power purchase agreement from the utility, PNG Power Ltd (PPL).