holbrook biomass

The Holbrook biomass CHP facility was developed on a brownfield site in Sheffield by the infrastructure investment company Equitix and began generating low carbon heat and power in spring 2017. In 2019, we secured a contract to operate and maintain the facility. Today, the site is owned by Gren and is home to 14 permanent px Group employees and specialist contractors who optimise the management of the plant.

At Holbrook, we have responsibility for the operations and maintenance, performance, emission monitoring and ash disposal from the site, as well as managing the biomass fuel on site.

On taking over the O&M contract, we focused on getting the plant on line as quickly as possible to start generating electricity and securing Renewable Obligation Certificates (ROCs). We are now working with expert contractors to maximise the efficiency and performance of the plant.

The contract supports our strategy to grow our footprint in green energy with partners around the UK.


  • The 6.5MWe biomass fired combined heat and power (CHP) station is designed to provide over 210,000 tonnes of CO2 savings over its project life
  • The renewable energy generated is equivalent to that used to power about 12,000 homes
  • The plant uses around 55,000 tonnes of waste wood per year that may otherwise have gone to landfill
  • The biomass fuel is burned in two water-cooled WID compliant moving grate furnaces working independently of each other to supply up to 30MWth heat in a closed loop thermal oil system
  • The technology used for generating electricity is based on an organic rankine cycle thermodynamic process, which enables useful energy to be recovered at much lower operating temperatures than conventional steam turbine systems.