HMP Guys Marsh is located near Shaftesbury in Dorset and can accommodate up to 578 people. The majority of the prison campus was heated from a single energy centre using heavy oil boilers dating from 1977. The heat was distributed to the building via underground heat main.

An appraisal was undertaken to evaluate the technical and economic viability of constructing a new energy centre comprising of a single wood chip boiler system to act as the lead boiler with natural gas boilers providing standby and peaking capacity. New pre-insulated heat main was installed to connect into the existing heat main system. The design settled on a single 1.2MW Binder wood chip boiler with 2 gas boilers each rated at 2400kW of capacity.

The Binder boiler has an excellent turn-down ratio, being able to operate at 20% of the boiler maximum rated capacity while still offering high efficiency. The load profile of the site indicated that there was sufficient base load demand that an accumulator tank would not be required. The boiler features fully automatic operation and ignition, optimised combustion using a lambda sensor, and automatic de-ashing to a box on the front of the machine.