Anaerobic digester (AD) plants in NI would be financially unfeasible without subsidies, a group of MLAs have been told.

Addressing Stormont’s agriculture committee, Mark Logan from Clandeboye Estate gave background to the farm’s 250kW plant, which became operational in 2016.

“The anaerobic digester is financially extremely good for us, but it is totally dependent on ROCs (Renewable Obligation Certificates). If you didn’t have ROCs, I don’t think you would even consider setting one up,” he said.

The AD plant at Clandeboye receives ROCs for generating renewable electricity, plus payments are also received for exporting surplus electricity to the national grid.

Logan explained that the estate received a record-high electricity price last year of 21p/unit and this year’s price of 14p/unit is the second highest the AD plant has brought in.

“Even at 14p for the electricity we sell, and with savings we make [with energy costs], you are possibly at a breakeven point. You are not going to make money,” he said.

Logan said the total cost of the AD plant at Clandeboye was close to £2m and he estimates that the investment paid for itself within five years.

Plants that are accredited under ROCs receive subsidy for 20 years, although the scheme closed for new applicants in 2017, and no support is currently in place for new AD plants.

“Unless there is going to be some sort of support for AD, then I don’t see it being a very viable option,” Logan said.

The committee was told that Clandeboye Estate had enough available land to grow crops for its 250kW plant, which meant additional land did not have to be rented.

“With some of the very big plants that have been built, those people have to go into the market and rent land in conacre. It makes it very expensive for ordinary farmers and can even price them out of the market. I would have been uncomfortable with that,” Logan said.