Renewables and waste management

Lets talk renewable energy & waste management ♻️ 💩


⚡️Mawley Town Farm produces almost all the electricity it needs (and more than it needs on sunny or windy days!) from renewable sources.  We have invested in a wind turbine, roof mounted solar panels, and more recently, an 80kw anaerobic digester (AD).

Wind turbine and biodigester at Mawley Town Farm

We wanted a waste management system for the cow slurry that could utilise the naturally occuring gases (mainly methane 👃🏻).  A small independent business based in the Midlands installed and commissioned the digester, which runs purely off cow slurry.  Many large-scale digesters need extra inputs, such as maize, but we wanted a system that would be sustainable and run off the waste we already had on the farm.

relaxed cows

Slurry from the cattle housing is collected through channels,It is then pumped into the AD and held warm for 30 days for the bugs to break down the slurry, releasing the gases which are captured in the domed roof.

The gases are filtered and compressed to run a methane/converted diesel engine which runs the electric generator.  💦 To keep the engine from overheating, cold water is circulated (like a car’s radiator) to take heat away.  This heats the water to around 80℃ which we heat the digester and utilise excess to preheat the boilers for washing the dairy, parlour, and frost-proof the cow sheds in winter

Seed drill being refilled with maize seed

Once the gases are out of the slurry we are left with digestate which is pumped into a store.  Digestate is a nutrient rich soil conditioner, containing nitrogen, phosphate and potash, the three main ingredients needed to grow crops.

Running 24 hours a day, the AD provides us with steady generation of electricity that doesn’t rely on weather as the turbine and solar panels do.

Digester facts – 33㎥ of slurry is pumped into the tower daily and retained for 30 days (rolling).  The tower stores 1 million litres of slurry!

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