Portland Bill (Dorset, UK) is a promising site for tidal stream energy exploitation; it combines high tidal stream velocities around the headland with a location closer to population centres than other proposed sites. To better estimate available energy resources at the site, a two-dimensional tidally driven hydrodynamic numerical model of Portland Bill was developed using the TELEMAC system, with validation using tidal elevation measurements and tidal stream diamonds from Admiralty charts. The results of the model were used to produce a time series of the tidal stream velocity over the simulation period and may be used in future work to optimize the location of turbine arrays at the site. (c) 2005 Elsevier Ltd. All rights reserved.