How are Scottish poultry hens generating power?

This innovative approach to powering the farm and managing the regular power cuts that affect the area was developed by the farm owner, James Baxter, using an Organic Rankine Cycle (ORC) system, powered by Novec Engineered Fluids from 3M.

Glenhead of Aldouran is a farm which houses more than 128,000 free-range hens in Stranraer, a beautiful and remote location in Scotland. Chicken manure fires a bed biomass boiler which feeds an E-RATIONAL ORC UHT 111/90kWe system, which in turn generates heat and power. The boiler produces hot water at 150°C, providing 750Wth of heat to be recovered by the ORC.

Novec 7100 Engineered Fluid from 3M is used to absorb heat from the chicken manure. The Novec fluid from 3M is converted into a vapour, which drives a turbine before condensing and being rerouted to the heat source. 

Manure power as back-up for grid outages 
The average electrical power of 65kWe is used on-site for local consumption. The condenser side of the ORC runs on warm water with an average temperature of 65°C. The warm water returning from the ORC is used to heat the chicken sheds of the sites, with a distribution system transferring the heat to the different henneries. 

Furthermore, the ORC machine is equipped with an off-grid cabinet and, in case of power outage, can run in island mode. A diesel generator is used as an emergency unit to assist the ORC and an on-site wind turbine is used for power generation.

James Baxter, owner of Glenhead of Aldouran Farm, explained: “This biomass project is a win-win-win. The chicken manure is processed and the boiler ash can be reused as fertiliser because of its remaining nutrients. The electricity is used on site to save on utility costs and the chicken sheds are heated with the condensing heat of the ORC, therefore we don’t need a separate wood chip boiler to heat the sheds. An additional advantage is that our farm is fully independent in case of failure with the grid connection.”

Solution details
E-RATIONAL, specialists in converting low temperature waste heat into clean energy without emissions, developed the state-of-the-art ORC technology for the Glenhead of Aldouran farm, utilising Novec 7100 Engineered Fluid from 3M. There were several drivers for selecting it as the optimum fluid for this application:

• Thermal stability: Novec fluids by 3M offer long term thermal stability at the maximum cycle temperature, and are non-corrosive, helping to protect the integrity of coils, seals and other system components.
• Safety: Novec fluids from 3M are non-flammable and low in toxicity.
• Sustainable: Novec fluids from 3M have low global warming potential and zero ozone depletion potential, and, unlike HFCs which are also used in ORC applications, are not targeted for phase-down or phase-out.

The E-RATIONAL ORC at the farm has been designed to maximise uptime and efficiency with a minimised operational and maintenance cost. The containerised modular machine is CE-compliant, with plug-and-play connections for easy installation at the farm.

The ORC machines from E-RATIONAL can convert heat from various sources, such as industrial processes, or utilise unused excess heat from district heating networks. In the case of the farm, it’s the chickens’ own waste that is converted into keeping them warm, a virtuous ‘circular economy’ approach that is sure to give other farms inspiration for their own waste management.