The costs incurred in the lifetime of a wave or tidal energy farm may be classified into four categories: pre‐operating cost; capital cost; operation and maintenance (O&M) cost; and decommissioning cost. The cost of the wave energy converter (WEC) structure depends on the material and the total weight. As for tidal energy converters (TECs), the vast majority are turbines ‐ although there are some based on other principles of operation. The rotor, power take‐off (PTO) and foundation are subjected to greater loadings, which increases the mass of steel and overall cost of the tidal stream turbine. Due to the particularities of each technology, a standard that enables various technologies to be compared is of crucial importance. One such standard is the levelised cost of energy (LCOE). The LCOE of tidal stream and wave energy is far from the grid costs, which are driven primarily by carbon‐based technologies. This chapter analyses why externalities are often disregarded and not generally internalised into the price of the electricity, if they can lead to optimal electricity production and prices.
This is a chapter from Wave and Tidal Energy.