In 2008 BAA completed a £50m refurbishment and extension to Stansted Airport and installed a 2MW Austrian biomass boiler to heat the terminal.
The new boiler replaced the existing gas fired heating system and allowed the building to achieve carbon neutrality.
Fuel: Wood Chip
Fuel Storage: 250m³ capacity
Annual Fuel: 3,000 tonnes
Annual CO2 saving: 1,750 tonnes Supply
Contract: 5 years
The fuel for the boiler system was specified as wood chip to a premium grade to ensure high energy value and to be sourced sustainably to meet BAA’s environmental objectives. The wood chip is produced to European standards in line with the boiler specification and delivered at an average moisture content of 30%. The timber for the airport is all sourced from managed woodlands in the region. The stock is stored, seasoned,processed, quality checked and distributed from a hub situated a few miles from the end of the runway which results in local timber for local heating.This ensures a secure buffer stock of fuel to be produced no matter what the seasonal weather or peak heat demand.
The wood chip is delivered into the boiler’s store at a rate of 1-3 loads per week depending on ambient temperatures. The boiler controls move the chip to the feed augers via an automated walking floor and ultimately into the combustion chamber to produce up to 2MW of energy for heating. The system is automated with the fuel feed process, heat exchanger cleaning and ash removal managed by the boiler’s central control box. The 30 tonnes of ash produced over the course of each year is discharged into bins and taken to a local farm to be mixed for crop fertilization. The biomass system at Stansted Airport replaces the old natural gas boilers as the primary heat source for the terminal and in the process will save approximately 1,750 tonnes of CO2 per annum.