Biomass boilers

The Mayor’s Draft Air Quality Strategy was published for consultation in October 2009. He has formulated a policy based on a threshold of 500kW_th for biomass plant in London.

It is assumed that biomass installations of less than 500kW_th would be too small to warrant the expensive pollution abatement equipment necessary to maintain air quality.

The strategy

With this strategy, the Mayor aims to ensure that measures to improve air quality are embedded in the planning process. This is important for Richmond upon Thames, which has been declared an Air Quality Management Area across the borough.

It is assumed that biomass installations of less than 500kW_th would be too small to warrant the expensive pollution abatement equipment necessary to maintain air quality.

In line with the Mayor’s approach, the borough would discourage all applications for biomass boilers which do not meet these standards for the purposes of air quality protection.

Biomass installations above the 500kW_th

Any biomass installations above the 500kW_th threshold will need to be fitted with the best available emission reduction equipment; and the planning application will need to be able to demonstrate the impacts on local air quality, when compared against that of a conventional gas boiler.

Any applications for biomass installations below this threshold should demonstrate no adverse impacts on air quality.

Biomass boiler requirements

Biomass boilers need to be ‘exempt’ under the Clean Air Act 1993, because the whole Borough has been designated a ‘Smoke Control Area’. However, the exemption process is no longer stringent enough, now that the Borough has now been designated an Air Quality Management Area.

How to submit an application form

In order to ensure that any biomass installation emissions will be acceptable, we will require more information, as outlined below, from Biomass and Air Quality Information for Developers (Environmental Protection UK website).

Applicants will need to submit the information required in the Borough’s ‘Biomass Boiler Information Request Form (MS Word, 986KB)’, which is based on a template from Environmental Protection UK.

Additional information

• A description of the biomass boiler to include the make, model, manufacturer, thermal capacity (kW/MW), efficiency, maximum rate of fuel consumption (kg/hr or m3/hr), the combustion and fuel feed systems, any emissions abatement equipment fitted and whether the system is fitted with an accumulation tank
• A description of the boiler stack (flue) to include the height and internal diameter of the stack, its grid location and exhaust gas efflux velocity (m/s). We may require stack height to be calculated using 'dispersion modelling', a computer modelling technique that looks at how pollutants disperse.  
• A description of the intended fuel to include the type of fuel to be used, its composition, compatibility with the boiler, any standards it meets and arrangements to ensure the quality of the fuel, and arrangements for delivering and storing the fuel.
• Building details to include the height of the building that the stack is attached to and the height and distance away from the stack of neighbouring buildings.
• Maintenance arrangements for the system to include details of the schedule for maintaining, cleaning and de-ashing the system, along with procedures for identifying and rectifying faults with the system.