Biomass and CHP District Heating

Blaenau Gwent County Borough Council

The Works: Ebbw Vale is a regeneration project at the former steelworks site in Ebbw Vale. The ambitious project was designed to transform the 200 acre site into a vibrant, distinctive and unique mixed-use area. The Works district heating scheme supplies heat to a school, leisure centre, college, general offices and the Archives Building on the regenerated Works site in Ebbw Vale.


The buildings on the Works site were previously heated by gas boilers and a CHP plant, via a heat network; Blaenau Gwent County Borough Council wanted to increase the amount of low carbon heat supplied via the heat network, and improve the overall financial performance of the scheme.


  • Assessment of the technical and financial viability of integrating biomass boilers into the existing network
  • Detailed design of the integration of the biomass boilers with the existing gas boilers and gas CHP plant
  • Provision of tendering support for the procurement of multiple contractors including development of “Invitation to Tender” documents and contractor interviews
  • Contract management and Client’s Engineer during construction and commissioning
  • Acceptance testing of the completed installation before handover to the client
  • Management of the RHI application process; the installation was accredited for RHI in 2015


The installation comprises 2 x 500 kW wood pellet biomass boilers and a gas CHP plant configured to provide base load heat to The Works heat network, with additional heat provided by gas boilers. Post-installation monitoring of the heat network concludes that during the first heating season in operation, over 65% of the district heat network demand was supplied by the biomass boilers. The system has been designed to provide circa 75% low carbon heat to the network on an annual basis. The Renewable Heat Incentive has also provided a valuable additional income for the Council.

During the initial review stage, it was identified that as well as integrating the biomass boilers, the network efficiency and financial performance of the network could be significantly improved by incorporating thermal storage, and by making modifications to the network control, pumping strategy and CHP integration.