A 50 kWe combined heat and power system, featuring a Bowman exhaust gas heat exchanger has enabled a Scottish farm to become energy self-sufficient, by converting organic waste into renewable energy!
Located in the Scottish borders, east of Dumfries, Allerbeck Farm is a productive livestock farm extending to 430 acres with over 1400 head of cattle. The farm recently took the decision to invest in a renewable energy system for both electricity and heating requirements. The proposal being to use organic farm waste to feed a Bio Digester. The Methane gas produced would fuel an engine powered generating set and waste heat recovered from the engines exhaust stream would provide heating and hot water for the farm and its buildings – as well as for the Bio Digestion process itself.
Renewable energy specialists Quantum ES designed and installed the CHP system based around a Perkins QES62 CHP generating set, incorporating full electrical control systems and a Bowman 6-60-3741-8 exhaust gas heat exchanger, which is capable of recovering up to 101 kW of heat energy.
In addition to its own organic waste, Allerbeck also takes waste from local farms for the Bio Digesters feedstock, which creates Biogas with a concentration of 60-70% Methane.
The Bowman exhaust gas unit has proved to be particularly effective as, in addition to providing district heating and hot water for the farm and the digester, any unused heat is diverted into a ‘heat dump’, which feeds a kiln that dries wood, which is sold locally to home owners for log burners.
Bio Digester based CHP systems, incorporating Bowman exhaust gas heat exchangers, have proved to be popular in agricultural applications, where pay back periods are typically around 18 months.
Additionally, the high quality specification, including 316L grade stainless steel, which is used for every part of the Bowman unit, has proved to be extremely capable of handling aggressive fuels, such as Biogas, ensuring long life durability of the heat exchanger.