The results of a study, looking at the potential for biomethane production in Northern Ireland, show considerable promise.

However, those involved with the work recognise that the development of schemes to capitalise on these opportunities needs to be fully thought through and costed.

Getting farmer support for future projects will also be crucial.

This week’s publication of the study, carried out by research teams at Queen’s University Belfast and the Agri-Food and Biosciences’ Institute (AFBI), was marked by the recognition of all those involved that rural communities across Northern Ireland must fully buy-in to whatever plans are drawn up for the future.

This is not the case where the current anaerobic digestion (AD) sector is concerned. 

Anaerobic digestion and biomethane

Many livestock farmers in the north claim that such operations are now pricing them out of the land rental opportunities they need to graze animals and make silage for winter feeding purposes.  

Within a scenario where all the housed livestock manure and ‘under utilised’ grass silage is used for anaerobic digestion, the study confirms that the total energy produced in the form of biomethane amounts to 6,124GWh/year.

This equates to 80% of the total gas distribution network demand in Northern Ireland at the present time.

When this figure is refined to take account of AD raw materials that are to be found within 10km of a gas distribution network, this figure drops to 67% of gas distribution demand.

If pyrolysis is also included in a slurry/manure/silage treatment scenario, an additional 200kt of biochar can be produced annually.

Biochar is a well-recognised soil conditioner.

Significantly, AD on its own would act to reduce the global warming potential of livestock farming in Northern Ireland by the equivalent of 845kt of carbon dioxide (CO2) on an annual basis. In addition, ammonia emissions would fall by more than a half.

The inclusion of pyrolysis would further act to reduce the eutrophication associated with the spreading of animal wastes on to land by a factor of almost two thirds.   

All of these figures are extremely significant. But their realisation in full will require a cooperative approach within the farming sectors, the scale of which has not been witnessed up to this point.             

Also required will be a commitment on the part of a future farm minister in Northern Ireland to pump this ‘vision’ with real money.

And this could prove difficult, given the many other demands on public money at the present time.