New policy and financial support from government will be needed to roll out anaerobic digestion (AD) facilities across the country, a webinar has heard.
The RDS and the National University of Ireland (NUI) Galway hosted the event, which examined the potential of on-farm renewable energy to meet the climate change challenge.
Dr. Cathal Geoghegan from NUI Galway told the webinar that there is an opportunity to replace fossil fuel technology with sources from bioeconomy resources, including forestry, energy crops, agricultural waste, solar and wind power.
Forestry
The webinar heard that forestry can produce wood for heat or power generation through firewood, chips or pellets.
However, Dr. Geoghegan noted that although many forests planted in the 1990s and 2000s are currently ready for thinning, difficulties in the licencing system are restricting the level of wood mobilisation in the country.
Dr. Geoghegan said increased levels of forest planting is necessary to avoid the possibility of forestry becoming a net carbon emitter rather than a source of net carbon sequestration in the coming years.
Currently, 70% of land in Ireland is used for grassland, the vast majority of which is for cattle farming. 11% of land in Ireland is used for forestry.
Some changes in land use in Ireland are inevitable if climate target changes are to be met, Dr. Geoghegan stated.
Anaerobic digestion
The event heard that anaerobic digestion (AD) is a technology that is well-established in Europe, but several barriers exist in Ireland that are preventing its advancement.
9,000 anaerobic digesters are currently operating in Germany, producing both electricity and heat.
Anaerobic digestion breaks down organic matter, such as grass silage, waste feed and slurry, to produce biogas and biomethane.
Dr. Dave Styles from the University of Limerick (UL) said that there is the potential for the digestate produced from AD units to be used as an alternative to traditional fertiliser.
He said that challenges to the benefits of AD at a smaller scale could be offset by developing a hub system, which would combine the benefits of manure treatment and fertiliser substitution with large-scale energy conversion.
However, Barry Caslin, Teagasc energy and rural development specialist, said there has been little support for AD to date and national policy will be needed to develop the technology here.
Caslin felt there would be opportunities for farmers to supply material for AD units, but warned that the system must be well managed.
He told the webinar that AD will be a key technology to help Ireland meet its renewable energy targets.