Climate defence tour - Oamaru
The last leg of my part of the South Island climate defence tour was in Oamaru. We did a public meeting which was not big(20) but it was an interested crowd.
We also had a fascinating talk by a NIWA scientist who was in the area looking at some of the dairy farms. They were investigating ways to clean up the effluent coming out of the milking sheds using anaerobic and then aerobic ponds. The anaerobic pond was quite deep (3-4m) while the aerobic pond was shallower and was followed by a shallow water race that allowed the sunlight to penetrate the water and finish off the process of cleaning up the waste from the sheds so that it could go into the local stream. The algae that were produced in great abundance could then be used as fertiliser or the input to a biodiesel process.
The interesting part from a climate change point of view was that they were trialling a system of using a membrane to capture the methane coming off the anaerobic pond and using it as an energy source. They were also using a heat exchanger to capture the heat coming out of the milk as it was chilled to heat hot water used elsewhere.
May 10th, 2007 at 1:42 am
I’ve never understood why biodigesters have never been used on dairy farms. I would have thought it would have been cheaper to make your own gas to heat the water than having to pay for the power lines and electricity.
May 13th, 2007 at 6:53 pm
Sounds good Russell, cool to see science used to generate green outcomes.
A bit inconvenient for those who like to call us names - like Luddites for instace - anyone remember that fabulous phrase from HC?
Bring on a sensible approach to our dairy sector so we can be justifiably called Clean and Green and totally clean up on the international markets because of it.
May 14th, 2007 at 11:44 am
How about getting some architects on board and do an analysis of new developments, infill housing etc. This could be where ability to trap and conserve energy is being most wasted.
jh