Professor John Sweeney:

Certainly there are some aspects of anaerobic digestion which are very positive. A lot of work needs to be done still on issues such as methane leakage, which is now emerging as an issue for anaerobic digesters.

There is also an issue on the land take and the Deputy mentioned that land will become a dwindling commodity in the future. The current biomethane strategy is looking for 120,000 ha of land to be used for growing inputs for anaerobic digesters. That has implications in how one grows that grass and whether that grass can grow in the absence of fertilisation, for example. There are issues on the digestate. It is an area which needs a little bit more teasing out but I do not see it as the solution.