This indicator provides information about the amount of energy produced from forest biomass and the extent to which it offsets the need to burn fossil fuels, thereby benefiting the global carbon budget and lowering carbon emissions.
Forest biomass plays a relatively small role in New Zealand’s consumer energy supply. While the total energy provided in 2013 has increased by about 44 percent since 2008, strong increases in supply from other sources have meant the percentage of national supply from wood has remained relatively stable at around 7 percent.
Of the 57.8 petajoules of energy supplied from wood, around:
Biomass, usually wood waste, is also supplemented by fossil fuels such as coal and gas. The use of biomass for process heat and electricity generation also has the advantage of reducing waste disposal costs while utilising a renewable resource. Co-firing is used to improve boiler performance when using low-quality primary fuels. In 2013, the Census reported that over 36 percent of New Zealand households use wood to heat their homes.
The use of biomass can be considered as avoiding use of fossil fuels, thereby benefiting the national carbon budget and lowering carbon emissions. However, there are some complexities in calculating avoided emissions. The biomass energy could be replaced by renewable sources (geothermal, wind and hydro) or fossil fuels, hence avoided emission depends on the choice of the energy source.
If it is considered that all the current biomass energy used in industrial processes (45.6 petajoules in 2013) was replacing coal, the avoided emission would be about 4 million tonnes of CO2 equivalent, using an average emission factor of 89.4 kilotonnes of CO2 equivalent per petajoule.
Woody biomass remains a constant proportion of New Zealand’s primary energy but has increased in its energy supplied: