Technology Focus - On-farm AD
Why technology selection is crucial to on-farm AD success With current and future incentive schemes making the returns for on-farm AD extremely tight, choosing the correct technology is more important than ever, says Cath Anthony, Associate Rural Surveyor for Bidwells. But given the wide choice of technology available, making the right selection can be a minefield. Cath advises would-be operators of the factors to consider before making that crucial investment. On-farm AD expertise from “The type of technology required will be dictated including an assessment of the technology and, ADBA members by the feedstock. Crop or manure-fed plants are potentially, of the contracts. They might require generally simpler, but those with more complex feedstocks will need to consider additional equipment, and potentially different pumps and mixers, etc. Therefore, it’s essential to ensure that the technology selected is capable of taking in the feedstock you propose using. It’s also a good idea to factor in some flexibility in case the feedstocks change in the future. After-care is vital. Whilst there are many very good technology suppliers on the continent you must be confident that their system will work in the UK; that instructions will be available in English; that their technology meets UK standards; that someone will be available to provide assistance on biology and equipment; and that parts are available quickly if something goes wrong. After all, a plant that isn’t producing gas is losing you money. Assistance in the initial phases will also be essential for many on-farm operators, who may need support with planning, permitting, grid connection and Ofgem applications. While some technology providers will give such help for free, others will charge for each service, so make sure you consider this before signing on the dotted line. And while the cost for these services is important, the time taken to respond, given the significance of meeting degression deadlines, is perhaps even more so.
warranties or guarantees and are much more likely to be reassured if the project is being supplied by one turnkey operator (preferably with a good balance sheet), who can be held liable if anything goes wrong, or if elements are not delivered on time. Ensure communication with the banks commences early and discuss technology contracts with them before signing anything, in case they are not acceptable to your funder. Finally, just because a technology is cheap to install does not necessarily mean it will deliver increased returns, as there may be substantially higher costs associated with its operation going forward. Don’t forget to consider expected output, parasitic requirements and lifetimes of parts (and replacement costs). Service and maintenance contracts, biological support, and guarantees and warranties can all provide much-needed certainty, not only to your plant’s outputs but also to your expected costs.”
AD4Energy, a British firm specialising in the design, build and commissioning of small-scale AD plants, offers digesters ranging from 100 kWe to 250 kWe; predominately for the agricultural sector. The company supplies its technology either in the form of a partially buried, rectangular, semi-plug flow digester or as an above ground, circular, CSTR digester. Both types can be tailored to closely match the client’s feedstock and energy requirements, making AD operations more cost-effective and efficient. Four Barns, a recently completed AD4Energy project, is consistently reaching between 95-100 per cent total possible CHP output. The 200 kWe, semi-plug flow AD plant is currently running on maize and produces around 17,000m3 of biogas a week. “Taking the step to build a small-scale AD plant on our farm was worthwhile as the benefits are vast, especially economically,” says Four Barns’ Richard Apps. Continued>>
Four Barns’ 200 kWe, semi-plug flow AD plant from AD4Energy
Experience and track record is another important factor to consider. Ask if you can visit operational plants, especially those which have been running for many years – I find it extremely useful to talk to current operators. Most technology providers who have happy customers will be willing to take you around sites and for you to talk to the operators to confirm their experiences and answer your questions. Training is also essential to ensure output is optimised and any potential issues are identified early. As farmers are more likely to take on the day-to-day operation of their plant themselves, many providers will organise training on other existing plants during the build period, so check that your provider offers this. On-farm AD is much more likely to be funded by a bank and most will require detailed due-diligence, www.adbioresources.org adbioresources.org
june 2016 | AD & Bioresources News
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