Objective 1.1
Feeding Microalgae


Leader: Dr David Pacheco (AgResearch) 
NZAGRC funding: May 2010 - June 2011


A novel approach to the mitigation of methane is to feed algal species which are high in lipid content to ruminants.  This should, theoretically, suppress methanogen activity.  Scientists harvested algal species from NZ-based wastewater treatment ponds and conducted in vitro studies to assess their potential as methane mitigating animal feed supplements.  Results showed that the algal species tested had insufficient lipid levels to reduce methane effectively.  However, algal species from other sources have been collected and initial laboratory level studies are looking promising.  The next stage of this work will be carried out under the MITIGAS component of an AgResearch SLMACC funded programme.



Objective 1.7
Methane capture and utilisation from dairy effluent


Leader: Dr Rupert Craggs (NIWA) 
NZAGRC funding: May 2010 - June 2011


There is an opportunity to reduce dairy farm methane emissions by capturing biogas from effluent treatment and storage ponds for use as an on-farm energy source.  Under this objective, an assessment of anaerobic digestion technologies to capture and utilise methane emissions from dairy farm effluent was conducted.  The most important factors affecting financial viability are: farm size, feed pad use and presence of existing biogas use equipment (e.g. boiler or generator). The most simple to apply and economically viable options for on-farm biogas use is either a boiler with flare to waste excess biogas, or combined heat and power (CHP) if a generator is also purchased for backup power supply.  Additional funding was secured from the SLMACC fund to continue and extend this study at other sites and install a full-scale covered anaerobic pond at one of these sites.