There are 130,000 homes in Cardiff in Wales and the annual energy demands of every one of them sit on a computer at the city's university. A team of researchers at Cardiff University can tell you what kind of heating a house uses, whether it has double glazing or roof insulation and can tell you how much carbon dioxide is given off keeping its occupants warm during the winter.
Similar data is held on every office block, factory and shop and mall complex in the city. There are also banks of information on the computer telling the researchers how many cars and trucks drive down what roads and when and how much pollution they give off.
This isn't an example of Big Brother gone mad, spying on the city's citizens. Rather it is an effort to understand the city's combined energy demands and an assessment of the pollution given off as Cardiff and its people heat their homes, drive to and from work and air condition their buildings. "The final goal is to take the energy use and emissions and model them for the entire city," explained Professor Phil Jones, a professor of architectural science at Cardiff University who is heading up the project.
Energy demand and emission studies are more commonly done on single homes, buildings or vehicles. "What we need to do is to get a handle on this across a city."
Professor Jones is a specialist in the sustainability of the built environment. As such, it was a natural progression for him to pursue a model that could potentially encompass the built environment in its entirety.
There were a number of factors pushing this sort of research forward, he said. Various international accords arising from Rio and Kyoto had committed countries to significant carbon dioxide emission reductions.
Having a model which demonstrated how a city performed could be useful in finding ways to achieve the steep reductions demanded. There was also the question of how cities were likely to fair in the face of rising total population and an increased concentration of urban dwellers in the world's cities.
Estimates, he said, suggested that by the year 2000, half the world's population would be living in cities, a trend which had implications for energy use, given the massive energy requirements of urban centres. This trend would also lead to an accumulation of pollutants and emissions, where they could have the greatest health impact over densely populated urban areas.
"The construction and operation of buildings has a great environmental impact," Professor Jones said.
Work on the model began over three years ago, funded by the Engineering and Physical Research Council, Cardiff County Council, Welsh Development and the private sector. The next three-year phase will involve Cardiff University with University College, London, Queens University, Belfast, and Demontfort University in Leicester.
The model is known as EEP, the Energy and Environmental Prediction model. EEP has been assembled as modules, individual components that each provide an element of the overall energy picture of Cardiff. "It is intended to be able to quantify the factors necessary for sustainable development," Professor Jones said.
Four modules have been built so far, providing data on domestic energy demand, non-domestic energy demand, industrial processes and traffic flow and emissions. Two more highly complex modules are to follow, a pollution dispersal model which will show how pollutants move or settle over the city and finally a module which will allow modelling of public health in light of pollution.
The domestic energy module required the team to survey all of Cardiff's 130,000 homes. Each was categorised on the basis of house type and anticipated energy demand and the combined energy requirement of a grouping of houses encompassed within a postal district is used as a model element for calculations.
A similar job was done with non-domestic energy users, including hotels and other commercial properties. Industrial units were categorised in terms of process and associated energy demands and pollution output, as with the other modules.
The traffic flow module was highly complicated and involved monitoring traffic flows on every road through all parts of the city at different times of the day. The module tells the researchers where traffic is likely to be. Modelling will allow planners to play with how flows might be affected by, say, the introduction of a new relief road or the construction of a city centre high rise car-park.
The data is portrayed using ordinance survey maps of Cardiff and the data can be collected and reconfigured on the city map. You could look at pollution "hot spots" for example or at housing type, density or tendency to apply double glazing or insulation.
When completed, it will allow city planners to tinker with the structure of the city. For example, it will be possible to model ways of reducing carbon dioxide emissions by offering insulation grants to reduce energy demand. The system will know what houses might benefit and so total cost versus cost benefit could be calculated.
EEP provided a framework which integrated all of this data into a single unified model, Professor Jones explained. Improvements will be made over time in the various modules but as this happens the old versions can be popped out and the new ones plugged in. It will also link decisions about pollution and road use with their resultant health impact on the general population.
While the model is being developed for Cardiff's local authority, Professor Jones believed the approach would be applicable to any city. It would represent a powerful new tool for urban planners.
