Energy production and emergy–based sustainability of an off–shore Oscillating Water Column power plant

Abstract

Emergy methodology provides with a reliable assessment of the sustainability and renewability of any energy production system, based on thermodynamic and economical parameters. That analysis allows an objective quantification of the sustainability and renewability, which in turn allows an objective comparison of different energy production systems in terms of use of resources from Nature. Although this methodology has been applied to different energy production systems, no emergy assessment of an Oscillating Water Column (OWC) has been developed. Therefore, this work deals with the emergy assessment of an OWC power plant, as well as its comparative analysis with different power plants. For that purpose, a hypothetical OWC power plant has been designed considering that this technology renders more efficiency under mild climate conditions, which in addition allows to simplify the design and reduce the implementation and subsequent maintenance costs. After the assessment of this hypothetical OWC power plant, different emergy indexes have been obtained and compared with other energy power plants —analyzed by previous authors—. The values of those indexes for the OWC power plant should not be considered as exact values, but as orders of magnitude, since this research starts from a hypothetical design of an OWC power plant. However, the value of the different indexes obtained in this emergy analysis reveal that OWC farms can be at least equally efficient as any other renewable power plant in terms of the use of resources from Nature, as well as in terms of GHG emissions.