Offshore Firms Eye NZ Dairy Power from Gas
(c) 2008 Rural News Group, www.ruralnews.co.nz
A Christchurch company is sparking international interest in its BioGen system for energy recovery from dairy waste.
The system captures methane and carbon dioxide from dairyshed and feedpad effluent to fire hot water boilers and, if economic, to generate electricity.
Natural Systems Ltd reports strong possibilities of a system going to Victoria before Christmas and one to a university-owned farm in the UK.
Managing director Ian Bywater says early adopters of the technology in New Zealand are making contact and a two-shed farmer in Southland is taking the preliminary steps of resource consent and site design.
Generally, larger-herd farms where feed or stand-off pads are used will be the most likely customers, Bywater says.
Farm dairy effluent from wintering sheds is another good opportunity for BioGen methane recovery.
Bywater says.‘Partial or full containment of the dairy herd obviously makes a stronger case for the BioGen system if energy alone is considered the only benefit,’
Bywater cites many benefits: electricity generation (used on-farm or exported), hot water, energy savings, water savings with lower volumes to pump or store, increased fertiliser value and reduced leaching from digestate – compared to farm dairy effluent (FDE) – means cows can return to pasture earlier for grazing, lower solids content than untreated FDE, eliminated risk of breaching discharge consent conditions, standby electricity, reduced greenhouse gas emissions (methane & nitrous oxide), and destruction of pathogens in the heated bio-reactor environment.‘We encourage considering the wider economic benefits from BioGen. Energy is produced and the digestate from the bio-reactor is a high quality liquid fertiliser, more effective and kinder to the environment.’
‘When the many benefits of the BioGen system are evaluated, these more than pay for the installation and operating costs.
‘Extra storage capacity for the digestate (less volume/day than the current FDE volume of the farm) means it can be applied to paddocks when weather suits. Digestate has lower nitrous oxide emissions than FDE when applied to paddocks.’
‘Storing of digestate releases no methane.’
‘Smaller storage capacity ponds are needed with a BioGen system and this can mean less capital outlay for ponds and more land for grazing.’
Natural Systems has not taken into account the implications of the Emissions Trading Scheme at this stage in its economic modelling because the ETS details are still unclear.‘FDE smell is reduced because odorous gases are captured and used. Captured biogas avoids methane emissions from FDE storage ponds.’
www.naturalsystems.co.nz
Tel. 03 376 5547