THE ORGANIC waste from a 250-cow dairy herd, if processed for biogas, could supply the electricity demands of 40 homes and reduce greenhouse gas emissions, a conference on using waste for energy was told yesterday.
Teagasc energy specialist Barry Caslin told the Tomorrow's Thinking Todayconference in Tullamore that innovative ways had to be found to reduce waste and convert it to energy.
He said Ireland faced EU fines of millions of euro from next January if it failed to divert biodegradable (organic) waste from landfill. Urgent actions were therefore required now.
These would have to tackle the generation and recycling of food waste from households and businesses, if Ireland was to meet the 2010 target of diverting 500,000 tonnes of waste from landfill.
Mr Caslin told the attendance of over 200 people, including farmers, local authority representatives and engineers, that the target would increase to over one million tonnes by 2016.
“Anaerobic digestion has been recognised in national policy documents and circulars as a preferred treatment option for biological material. Within the agricultural sector, a number of farm waste streams can be digested by methanogen-feeding bacteria to produce biogas from which heat and electricity can be produced,” he said.
“The anaerobic digestion process effectively degasses slurry, and the remaining nutrient digestate can be land spread without any reduction in nutrients and with significantly less odour and less pathogen risk,” he said.
This process was already well-developed and advanced in many parts of Europe, and there were 4,000 digesters in Germany alone.
He said there were four digesters now being privately operated in Ireland, and another up-to-date facility was being built in Co Limerick. “It is totally logical to process farm and other waste into energy . . . cutting down on greenhouse gas emissions, reducing the waste levels going into land fill while creating rural jobs,” he said.
Paul Dykes, of Sustainable Energy Ireland, said energy security and diversification of supply was a key priority of government, and locally generated and distributed low-carbon biogas energy had the potential to contribute to national and international energy targets and improve our indigenous energy pool. “The drive for increased renewable energy coincides with pressures to dispose usefully of a whole range of organic materials, animal byproducts, food waste, farm residues, sewage, and green garden waste. Anaerobic digestion can help meet both energy and waste management needs at the same time.”