At the request of the Netherlands Environmental Assessment Agency, PBL, a geographical computer model (‘VESTA’) has been developed of energy use in the built environment. In this first phase the emphasis is on elaborating demand for heat. For each post code district the model calculates this demand from building data, distinguishing between housing, utilities and horticultural greenhouses. It is then determined whether waste heat is locally available and whether this can be cost-effectively supplied to the buildings in question. The cost-effectiveness of geothermal energy and heat/cold storage is also calculated. A geographical computer model like VESTA is essential for such calculations, because the cost-effectiveness of heat grids is highly dependent on distance and building density.
CE Delft elaborated the functional design of the VESTA model, including all the required formulae for energy computations and calculations of costs, yields and efficiencies, as well as determining the default values of the various parameters used.