Farming Monthly National July 2018 | Page 41

| Energy made of concrete. It’s long, narrow and rectangular – a significant challenge for good mixing! “This Landia DG chopper pump (with a long shaft nozzle) clocks up some serious hours working this liquor store”, he added. “The tank shape is probably the worst imaginable. It contains the hot (42 degrees C), post-digestion liquor from our AD process, which is then pumped up to our 3000m3 towers, so it is quite a push. It’s a relatively low dry matter (2%) but it is still very intensive due to the restrictions we’re having to work with because of the shape of the tank. It handles 70 tonnes per day. Not many suppliers would be interested in taking on this very arduous 24/7 installation for their pumps”. Approximately 70% of Kemble Farms’ slurry (60 tons per day) is currently used for the (1400m3 digester) AD process, so there is capacity to increase the 300kW electrical plant. At present though, adding more slurry would then see the six tonnes per day of the farm’s maize coming out of the process insufficiently www.farmingmonthly.co.uk digested. Two thirds of the renewable energy generated is exported to the National Grid, whilst the substantial energy costs of running a 19-hour milk parlour are now covered. “Going into AD was a good fit for us”, continued Miles. ‘Very good quality digestate’ “We knew that we could use the slurry as a resource. Subsidies were quite generous at the time and a dairy is expensive to run. We’ve now created a nearly closed-loop system that makes perfect sense – growing maize and grass to feed the cows, who provide the milk that we sell to a supermarket chain. The welfare of our cows has improved, so we have a better increment on milk sales. We feed the cow’s slurry into the digester to create our green renewable energy – and – we also get a very good quality digestate for use as a fertiliser. This has very much offset the cost of buying chemical fertiliser by a substantial amount – and has significantly improved the quality of the farm’s soil. The digestate is an excellent product in itself – very fine – easy to spread. Running an AD plant can be a labour of love, but it’s worth it – and this all the more reason to work with a company such as Landia whose quality of service is as every bit as good as their equipment”. Contact Landia on 01948 661 200 or visit www.landia.co.uk July 2018 | Farming Monthly | 41