What is the future for farm-scale AD in Northern Ireland?

editorial image

With the Anaerobic Digestion and Biogas Association (ADBA) having held their first Northern Ireland national conference in Belfast on 5 October, the focus is once again on AD.

However, before I go any further, existing AD plant owners need to be made aware of the fact that several on-farm AD plants in Northern Ireland, (built under Permitted Development) have been visited by NIEA and have been asked to provide a Waste Management Licence (WML).

As part of the WML, ammonia modeling may be required and there could be an application fee. Farmers may need to consider these additional requirements and potential costs.

Last 10 Years – the story so far - The last 10 years has seen a rush to install AD on Northern Ireland, with 30 farm-based AD operational. These range from 180kW to 500kW capacity.

The attraction of AD to the farming sector was the contribution to fossil fuel/greenhouse gas emission reduction as well as the potential role that it plays in slurry management. There was vast initial interest in on-farm AD from 2008 onwards and this was evident at the swathe of well-attended information events rolled out throughout the country. However, hefty upfront capital costs, as well as a combination of grid connection and planning problems meant that the majority of local farmers never progressed from their initial interests in AD.

These plants have been working well, but many are asking as to how many more will appear in the countryside in the future.

Sub-30kW AD - The economies of scale were stacked against those wishing to get on the AD train and ROC tariffs were stacked in favour of largest installations. From the outset, the UFU felt that small scale should have been closer to 30kW and below. Yet this capacity-end of the market has never been developed nor made available to farmers here in Northern Ireland. Instead, we have had to look on as bespoke micro installations popped up in GB and they never got this far.

The UFU are continuing to look for a smaller-scale on-farm solution. This is particularly relevant with the current weather conditions putting pressure on slurry store capacity and this scale of AD would go some way to improving slurry management. Such capacity would utilise on-farm produced feedstocks and contribute to improved slurry management and crucially there would be little if any reliance upon subsidy.

What could the future look like? - The UFU believe strongly that we need to take an alternative look as to how renewables could be better utilised in rural Northern Ireland countryside.

The UFU will be pressing for research and development not just on micro-scale AD installations, but also to consider how best to add value to both the gas and digestate. The RoI for example are looking at gas injection to the grid.

In the future, the UFU envisage a situation where a tanker might take gas away to be upgraded, bottled and then sold. If this was to happen, the on-farm AD sector could have a sustained and improved presence, unlocking the still to be realized further potential here in Northern Ireland.