To meet rising targets for renewable-derived electricity generation, wind power is currently the preferred technology. However, it is widely accepted that due to the stochastic nature of wind, planning restrictions and the finite availability of suitable sites there is an upper limit to the capacity that can be accommodated within the electricity network before power quality is affected. This paper demonstrates the potential of tidal energy to provide firm power and shows that limiting the capacity of the power generated provides base load supply without compromising power quality. This increases the capacity factor of the installed system, thus improving the economic viability and commercial competitiveness of tidal farms. (c) 2005 Elsevier Ltd. All fights reserved.