Ireland gives backing to reverse compression biomethane plans in boost for developers

The Commission for Regulation of Utilities has confirmed (19-page / 755kb PDF) it will allow reverse compression of biomethane. These measures are being planned as an interim solution while the CRU looks to develop a long-term regulatory framework to enable better integration of rurally-produced gas into the national network.

As set out in Ireland’s biomethane strategy, injection into the gas grid will be via direct injection and through truck and trailer collection and injection. The strategy noted that there is a common problem associated with managing injection supply with gas demand at low pressure networks on the gas grid, which will need to be curtailed.

The strategy also recognised the role that reverse compression could play in enabling biomethane plants to connect to the lower pressure distribution network. This process, developed by Gas Networks Ireland, is aimed at direct grid connected biomethane projects, and can alleviate the constraints faced by anaerobic digestion plants by taking excess gas from the distribution grid for onward transfer of biomethane onto the national higher-pressure transmission network - preventing valuable renewable gas from being wasted.

The CRU has approved initial funding to facilitate low-pressure grid access points to have their output compressed into the national transmission gas network. By extension – greater and more efficient access to injection points facilitates the fundamental economics of the intended roll out of grid connected AD plants.

The biomethane strategy sets out that the majority of grid-connected biomethane plants in Ireland will be  connecting to the low-pressure distribution grid and will likely experience some level of curtailment on their production capacity due to supply exceeding demand on the distribution network, especially in regional, non-city distribution networks where most of the biomethane is likely to be injected.

“While this is just an interim, engineering-focused solution, it will help bring more certainty to investors in the robustness of Ireland’s biomethane sector as the causes of constraints are being tackled,” said Garrett Monaghan, an energy industry expert with Pinsent Masons in Dublin.

“It is a clear message of investment in grid development in Ireland and provides a pragmatic approach for rural sites which would be otherwise prone to bottlenecks and risk having to flare off their gas while producers await the full regulatory approach being confirmed.”

GNI have advised that this move could facilitate up to 437GW/h of production into the national grid – around 7.5% of the national biomethane production target – by the end of the decade.

“Reverse compression is a critical enabler for Ireland’s biomethane industry,” said Gas Network Ireland’s head of business development, Karen Doyle.

“It allows renewable biomethane gas produced in rural areas to flow efficiently through the national gas network, unlocking new supply, supporting farm diversification and strengthening regional economies.”

The CRU decision - although interim - places a cost of €370,000 to be paid at the same time, and in addition to the 30% customer contribution for the overall grid connection, on parties seeking the investment in reverse compression.

That charge of €370,000 is approximately 10% of the cost of the reverse compression installation and is payable by those directly benefiting from the deployment of this solution. GNI will assess applications and offer the reverse compression scheme on a first-come, first-served basis.