Bioenergy trends

With abundant hydro, wind and geothermal resources, New Zealand has an enviable supply of potential renewable energy sources. However, for a country so blessed with green options, there are still huge sustainability challenges due a massive supply of domestic coal reserves, inefficient residential heating and the large amount of shipping that this island nation is dependent on.

I am a former TNS New Zealand advisor and now Wood Energy Programme Manager for New Zealand’s Energy Efficiency and Conservation Authority (EECA), and am spending some time observing bioenergy trends in Denmark and Sweden.   I have already  visited Sweden and Denmark, where bioenergy is a key part of the energy mix. Sweden, which currently derives 28% of its energy from bioenergy, does so through partnerships between wood energy suppliers, capital equipment manufacturers and combined heat and power (CHP) plants.  Scandinavia also utilises waste-to-energy plants that create heat and power from the incineration of household garbage. 

There are, however, questions that arise when considering these options from a whole-systems sustainability perspective, especially in terms of the ability of natural systems to regenerate at a faster rate than we harvest them.  How much biomass can be removed from the forest for energy and fibre while maintaining nutrient balances?  There has been a good deal of focus placed on ash fertilising – returning the ash from woody biomass combustion to the site of biomass harvesting. But this process is not as simple as it sounds, due to the possibility of accumulation of toxic metals in the ash that is returned to the forest.

While I continue to grapple with the economics and ecological limits of bioenergy from Scandinavia to New Zealand, I am confident that bioenergy will play an increasingly larger role in the world’s energy mix.

For further information on bioenergy, visit:

>www.ieabioenergy.com
>www.bkc.co.nz
>www.eeca.govt.nz/efficient-and-renewable-energy/renewable-energy/bioenergy