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                                                                                                Renewable Energy 50 (2013) 938e949

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                                           Renewable Energy

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Technical note

Wave energy resource assessment in the Mediterranean, the Italian perspective

Luca Liberti a,*, Adriana Carillo b, Gianmaria Sannino b

a Institute for Environmental Protection and Research ISPRA, via Vitaliano Brancati 48, 00144 Rome, Italy
b ENEA - Ocean Modelling Unit, via Anguillarese 301, 00123 Rome, Italy

article info               abstract

Article history:           In this paper we present a high resolution assessment of the wave energy resources in the Mediterra-
Received 26 February 2012  nean. The energy resources are evaluated through of a numerical simulation performed on the entire
Accepted 5 August 2012     Mediterranean basin for the period 2001e2010 using a third generation ocean wave model. The model
Available online xxx       results are extensively validated against most of the available wave buoy and satellite altimeter data.
                           Starting from the model results a detailed analysis of wave energy availability in the Mediterranean Sea is
Keywords:                  carried out. The western Sardinia coast and the Sicily Channel are found to be among the most
Wave energy                productive areas in the whole Mediterranean. Simulation results show the presence of significant spatial
Mediterranean              variations of wave power availability even on relatively small spatial scales along these two coastlines.
Italy                      For a number of selected locations in these two areas we present an in-depth investigation of the
Numerical wave model       distribution of wave energy among wave heights, periods and directions. Seasonal and inter-annual
Wave energy resources      variability of wave energy potential are also analyzed and discussed.
Wave energy atlas
                                                                                                                       Ó 2012 Elsevier Ltd. All rights reserved.

1. Introduction                                                                            as the Mediterranean, where lower amounts of wave energy are
                                                                                           available, many technical issues related to extreme sea climate
    Wave energy appears to be one of the most promising among                              could be more easily solved, possibly making wave energy
the renewable resources. It is estimated that it will undergo                              production still economically viable. From this point of view, wave
a significant growth in the next decades as soon as the Wave Energy                         energy production in the Mediterranean is especially appealing for
Converters (WECs) technology becomes more mature [1]. Currently                            countries like Italy having relatively long coastlines. Feasibility
a number of different WECs have been proposed and tested [2] but                           studies of wave energy plants require a detailed knowledge of
large scale commercial installations are not yet in operation. The                         energy occurrence, of its temporal and spatial variability and of its
WECs technology is believed to be at a crucial stage of its devel-                         distribution among different sea states. At present, an extensive
opment cycle when well-established solutions emerge from the                               and accurate estimation of wave energy for the Italian seas is not
realm of research. Research on wave energy production is partic-                           yet available. Wave energy atlases rely on wave measurement ob-
ularly advanced in countries bordering large oceans where the                              tained from buoys, satellite and output from model hindcasts. In
greatest wave energy potential is found. In Europe most of the pilot                       recent years, several authors presented global wave energy atlases,
plants either planned or in operation are located along the Atlantic                       see for instance [4e6] or [7]. These works either don’t include
coast in countries such as Ireland, Portugal, Spain, Norway and the                        results for the Mediterranean or are based on models with a spatial
UK [3]. Energy availability is certainly a major factor affecting wave                     resolution too coarse to capture smaller scale spatial variation in
energy production but high energy potential usually implies                                wave energy availability which are important to identify suitable
exceptional wave conditions during extreme events. Such condi-                             locations for wave energy production in relatively small basins like
tions pose serious engineering challenges to the design and                                the Mediterranean. Wave energy atlases of the Italian coast were
deployment of WECs increasing the costs of development,                                    recently developed using wave parameters measured by buoys
production, installation, maintenance and insurance of these                               located off the coast [8,9]. Wave buoys provide the most accurate
devices. On the other hand, in calmer and semi-enclosed seas such                          and direct measure of waves parameters. However, time series
                                                                                           obtained from wave buoys describe wave climate only locally and
  * Corresponding author. Tel.: þ39 0650074559.                                            often present large data gaps caused by temporary failure of the
     E-mail addresses: luca.liberti@isprambiente.it (L. Liberti), adriana.carillo@enea.it  buoy or by routine maintenance operations. Wave height and
                                                                                           period do not generally show steep spatial gradients in the open
(A. Carillo), gianmaria.sannino@enea.it (G. Sannino).                                      ocean but substantial spatial variations are observed in enclosed

0960-1481/$ e see front matter Ó 2012 Elsevier Ltd. All rights reserved.
http://dx.doi.org/10.1016/j.renene.2012.08.023