1 INTRODUCTION The Mediterranean Sea is a semi-enclosed basin with high climatic variability. The central area, where Italy is located, is subject to a temperate cli- mate with seasonal variation of weather conditions. In particular, at the Tyrrhenian Sea the most relevant wave conditions are from the third quadrant, due to the larger fetch (Peviani et al., 2011). The wave propagation to the nearshore depends on several fac- tors, such as coastal morphology and angle of inci- dence of waves, bathymetry and shape of the sub- merged beach. In particular, the Northern Latium coast is characterized by the presence of Capo Li- naro, which determines a variability of coastal orien- tation and the morphology of submerged beach. As for other renewable sources, a thorough resource as- sessment is a prerequisite for the successful exploita- tion of wave energy (EU-OEA, 2010). The object of this work is the assessment of wave energy potential from offshore to nearshore. A detailed study was performed at Civitavecchia, taking advantage of off- shore wave buoys that allow to study offshore wave power and wave propagation from deep to shallow water through numerical model simulations. The proximity of a power plant, the presence of indus- trial activities and a large port infrastructure makes this area attractive for wave energy exploitation. Moreover, the deployments of coastal wave buoys allow comparing numerical results with measured data at the nearshore zone. The wave climate is in- vestigated in detail, characterising each sea stage that provides the energy resource in terms of wave height, period and direction. In order to assess the nearshore wave energy distribution, it is important to evaluate their propagation from deep to shallow wa- ters, taking into account the modifications of waves due to refraction, shoaling, diffraction (in some cases) and related physical processes (Dean & Dal- rymple, 1991). To this concern, nearshore wave power patterns are investigated applying the SWAN wave model. It is found that the variability of sea- bed's slope of the Northern Latium region leads to the concentration of wave energy in certain near- shore areas, while others are left with a relatively low resource. The knowledge of the wave energy distribution is a fundamental issue to select the op- timum site for wave energy exploitation. 2 METODOLOGY The proposed methodology to evaluate the wave energy potential from offshore to nearshore is com- posed of five phases. In Phase I the largest possible amount of measured data was gathered from avail- able datasets; the integration of three datasets al- lowed to designing the Italian wave power atlas, the most accurate atlas among the existing ones, as a re- sult of Phase II. The phase III introduces the use of numerical models for the detection of wave propaga- Evaluation of wave energy potential applying a numerical modelling down- scaling methodology in Central-East Tyrrhenian Sea F. Paladini de Mendoza, F. M. Carli, S. Bonamano, M. Marcelli Laboratory of Experimental Oceanography and Marine Ecology, University of Tuscia. Civitavecchia, Rome M.A. Peviani RSE, Research on Energy System, Milan. ABSTRACT: This work propose an approach to assess the available wave power on the eastern side of Tyr- rhenian Sea from offshore to nearshore using the methodology of numerical modelling downscaling. In the first phase the largest possible amount of measured data was gathered from available datasets; the integration of the datasets allowed to designing the Italian wave power atlas. Subsequently, is introduced the use of nu- merical models downscaling for simulate wave propagation from offshore to nearshore. The wave potential assessment has been performed in two different scales. The large scale, lead to the elaboration of the Italian Wave Power Atlas while the small scale, focusing on the wave power of eastern side of Central Tyrrhenian Sea and the definition of nearshore hot spots useful for the planning of devices installation along the Latium coast. The numerical models are useful tool for the analysis of wave propagation in transitional and shallow areas, for describing the dynamics at local scale. The downscaling analysis has shown a good ability to de- scribe the dynamics at small scale, enhancing the resolution of information on coastal features. The results show a greater amount of energy available for offshore installations than nearshore, but the presence of infra- structures (power plant, harbour etc.) with easier accessibility, leads to lower costs of installation, operating and maintenance for wave energy converters.