Environmental performance of Miscanthus as a fuel alternative for district heat production

This study discusses about the environmental performance of Miscanthus conversion to district heat. Life Cycle Impact Assessment (LCIA) is used as a tool to assess the environmental impacts related to the biomass conversion to heat. Energy conversion of Miscanthus is compared in two combustion scenarios: (i) in Combined Heat and Power (CHP) plant and (ii) in a Boiler (producing heat only). Biomass conversion to heat is also compared with the conversion of natural gas (NG). The environmental impact categories considered for the assessment are: Global Warming Potential (GWP), Non-Renewable Energy (NRE) use and Land use (LU). The current study revealed that for 1MJ of heat production, Miscanthus fired in the CHP plant would lead to a GWP at -0.071kg CO₂-eq, an NRE use -0.767-MJ primary, and LU 0.09m²-a (square metre-annual). For the same heat output, Miscanthus fired in the boiler would lead to a GWP of 0.005kg CO₂-eq, NRE use 0.172MJ-primary and land use 0.063m²-a. Miscanthus fired in the CHP plant is better than in the boiler from the stand point of lowering the GWP and increasing the savings in fossil fuel, but with slightly higher LU. A comparison between Miscanthus and NG has showed that despite the biomass possessed advantage in reducing GWP and NRE use, additional land required for Miscanthus could be seen as a disadvantage.