Wave power: Climate change mitigation and adaptation

Wave energy has a great potential in many coastal areas thanks to a number of advantages: the abundant resource, with the highest energy density of all renewables, leading to higher availability factors than, e.g., wind or solar energy, and the low environmental and particularly visual impact, not least in the case of offshore floating wave energy converters (WECs). In addition, a novel advantage will be investigated in this work: the possibility of a synergetic use for carbon-free energy production and coastal protection. All in all, these advantages make wave energy a promising alternative to conventional energy sources. In this chapter the fundamentals of the wave resource and its characterization are outlined. The technologies for wave energy conversion are classified according to three criteria, the most representative WECs are presented, and the technological challenges discussed. Next, the environmental impacts of wave energy extraction are analyzed, with a focus on the reduction of coastal erosion. If there are two main strategies to cope with climate change, mitigation and adaptation, wave farms participate on both. Indeed, wave energy contributes to mitigating climate change by two means, one acting on the cause, the other on the effect: (i) by bringing down carbon emissions (cause) through its production of renewable energy and (ii) by reducing coastal erosion (effect). Given that one of the causes of climate change is precisely coastal erosion - through sea-level rise and increased storminess - the contribution of wave farms to its mitigation is indeed welcome. As for adaptation, wave farms - which typically consist of floating WECs - adapt naturally to sea-level rise; this is a major advantage relative to conventional coastal defense schemes, based on fixed structures (seawalls, detached breakwaters, groynes, etc.).