Clayesmore School Biomass with District Heating
Wattcraft provided feasibility, concept development, technical specification and owner’s engineer services for a 1MW wood chip biomass boiler energy centre with district heating
The following services were provided:
Feasibility assessment and business modelling of biomass heating options Concept design of 1MW biomass boiler energy centre with oil boiler back-up and district heating concept and performance specification.
Review of ownership models and energy services options.
Production of tender documentation and support with tender process for project.
Drafting of contract and support to school in agreeing the contract with the preferred contractor.
Owner’s engineer services (acting as the school’s technical representative) during project delivery.
Support in setting up biomass fuel (wood chip) supply contracts
The first stage of the work was an overall technical and economic energy feasibility assessment of energy efficiency and energy supply measures. This followed the ‘Energy Hierarchy’, prioritising avoidance of energy consumption and then energy efficiency measures before assessing the potential for renewable energy and other energy supply measures.
An example of reduction of energy consumption measures affecting heating included good practice with respect to the use of doors and opening windows. An example of consideration of energy efficiency measures was insulation, both internal and external. Apart from the environmental benefit of reducing the need for heat, it was important to establish future heat demand with heat demand reduction measures included, in order to size the biomass plant appropriately and to determine the economic case for biomass.
Fuel type selection was an important decision to make for the project. Wood pellet is a consistent fuel that is easy to handle, but is more expensive than wood chip. Wood chip, which is not processed in the way that wood pellet is, requires more attention given to handling in design of the plant, but is cheaper than wood pellet. Wood chip systems generally have higher capital costs and the balance between increased capital costs and reduced operational costs is favourable towards wood chip for installations over a certain size. In the case of Clayesmore the output of the technical and economic assessment, including a review of the local biomass fuel supply chain supported the case for wood chip as a fuel.
Care was taken in the design of the system to establish a robust fuel handling solution that fitted within the space constraints and that also represented best value at the scale of plant proposed. In recognition of future variations in the market for biomass fuel and the availability of biomass, provision was made in the design for the used of wood pellet, if required, giving future flexibility.
The energy efficiency component of the energy assessment had to be compliant with the requirement of the Government ESOS scheme, given that Clayesmore School qualified for ESOS. You can find out more about ESOS here.