The exponential population growth and increasing world energy consumption has prompted the world to search for new forms of renewable energy that could curb our dependence on fossil fuels, in order to safeguard the world’s environment from the looming threat of climate change. Tidal energy is arguably one of the most promising renewable solutions to replace and diversify part of the energy supply. This is due to the tide’s high predictability and technological immaturity when compared to other renewable sources, as it is an untapped market with room for development. The main ambition of this work is to explore the viability of powering the river-side urban areas, namely Oeiras and Lisbon, through the Tagus estuary’s tidal energy. Such is accomplished by modelling the Tagus estuary’s hydrodynamics through MOHID, a water modelling software developed by MARETEC, at the Instituto Superior Técnico. Different simulations were made, for different river water discharges throughout the year, so as to determine the behavior of said tidal farm over the course of one year. To simulate the energy production that this solution would generate, two calculation modes were used – one through the use of theoretical equations to predict the energy production of a tidal farm, and the other through the use of MOHID’s built-in tool to assess a tidal turbine’s energy production. In the end, an economic assessment of such a solution is presented, based on current tidal energy costs.