Does AD stack up financially?

The short and honest answer to this question is it is a lot tougher than three years ago. Having said that, with the right farming system, building your own AD plant still offers opportunities.

Support

The level of Government support and the types of support have reduced, so income is lower and less accessible than before.

The Renewables Obligation Certificate scheme has closed, Feed-in Tariffs closed in March to new entrants and the Renewable Heat Incentive will end in 2021, although this still gives a small window for applicants.

A new ‘Smart Export Guarantee’ will guarantee payments to renewable energy generators, which are generating up to 5MW annually. From 2020, all energy companies will have to offer export tariffs, so this is a small uplift for the sector.

There is potentially more change coming: Government is generally supportive of biomethane and there is definite interest in AD, particularly with recent announcements to decarbonise the UK by 2050, as well as plans to collect more household food waste.

However, it is more important than ever to be rigorous with finances and select reliable technologies and providers. A solid business plan is essential.

Farming systems

Systems which consume a lot of electricity and generate a lot of waste are most beneficial, because the cost of producing electricity or biogas just for export means with lower incentives it does not pay to rely on just exporting energy. AD works best when it is part of a circular farming system.

For example, it could be integrated into a pig unit with farrowing houses or broiler house which produce waste and needs a lot of heating, a fresh produce business with an energy- intensive packhouse, or a dairy farm which uses lots of electricity to process cheese.

It is important these energy needs are continuous, rather than just one-offs during the year, such as grain drying.

What does not work is something like a 200-head dairy business where cows are out all-year-round. It is too low-input for AD to be useful.

Does scale matter?

The relative cost of building a small AD plant will not make financial sense if your only plan is to generate energy to sell to the Grid. Although this could be financially viable if you also use it to deal with waste and, therefore, reduce waste collection charges. Do your numbers though.

Below 124kW it is very difficult, but it depends on circumstances such as volumes of waste, energy density and digestibility.