Can Anaerobic Digestion Reduce a Dairy Farm's Electricity Bill?

Why dairy farms are interesting for this

Dairy operations can consume electricity continuously — milk cooling, robotic milking, vacuum pumps, water heating, refrigeration and slurry pumps all draw power around the clock. This can suit continuous AD generation particularly well.

Real examples

At Alderstone Mains Farm in southeast Scotland, six robotic milkers create a continuous electricity requirement that its Biolectric AD plant was specifically chosen to help meet. Biolectric reports that Bays Leap Farm in Northumberland, an organic dairy farm with around 1,000 cows, cut its electricity bill by around 90% after installing its slurry-fed system. A separate Biolectric case study reports Rosconnor Dairies, a roughly 680-700 cow farm, reducing its electricity bill by around 96% with its 44kW installation, with the remaining share mainly attributed to the farmhouse not yet being connected to the system.

These are individual, manufacturer-published case studies and should be read as examples of what's possible under the right conditions, not a promise that another farm will achieve the same saving.

What determines the saving?

Generation (how much electricity the system actually produces), self-consumption (how much the farm can use directly), the electricity tariff being displaced, export value for any surplus, plant availability, and the plant's own parasitic load all combine to determine the real-world saving.

Why energy data matters before sizing a system

Before designing around a claimed output, it's worth gathering annual bills, half-hourly data where possible, day and night consumption, and seasonal demand. The best outcome isn't necessarily the biggest generator — it's often the system whose production most closely matches the farm's actual demand.