Details of Shepperton Plume Plotter

This page should be read in conjunction with How Plume Plotter Works. It provides more details specific to the Shepperton version of Plume Plotter.

Stacks and buildings

Building measurements are taken from [1]. This image shows the layout of the stacks and buildings modelled. North is at the top; colours and numbers indicate the heights of the buildings and the stacks:

The main stack is for the gasifier. The two gas engine stacks are modelled as a single larger stack, 2 metres north of the gasifier stack.

Stack measurements

All of these are taken from [1]:

• Stack location: 51.406483,-0.44169886. Second stack is 2 m north.
• Stack height: 49 m. Second stack has same height.
• Stack diameter: 1.2 m. Second stack is 0.491 m.
• Stack gas exit velocity: 16.15 m/s. Second stack is 21.19 m/s.
• Stack gas temperature: 138 °C. Second stack is 250 °C.

The following values are used for albedo, Bowen ratio, and roughness length. Roughness length is as specified in [1]:

• Albedo: 0.2.
• Bowen ratio: 1.
• Roughness length: 0.5.

Emissions

The emission rates of pollutants are taken from [1]. These are:

for the gasifier stack. In addition, the two gas engines have a combined emission rate of 0.572 g/s.

Background levels

The background levels of pollutants are taken from [1]. These are:

Weather data

Weather data is taken from METAR reports from a local airport: London Heathrow.

Upper air data is the latest reported by the Herstmonceux upper air station.

References

1. SITA CHARLTON LANE ECO PARK AIR QUALITY ASSESSMENT (4th Issue). Fichtner. September 2013.