Catching the Right Wave: Evaluating Wave Energy Resources and Potential Compatibility with Existing Marine and Coastal Uses

Many hope that ocean waves will be a source for clean, safe, reliable and affordable energy, yet wave energy conversion facilities may affect marine ecosystems through a variety of mechanisms, including competition with other human uses. We developed a decision-support tool to assist siting wave energy facilities, which allows the user to balance the need for profitability of the facilities with the need to minimize conflicts with other ocean uses. Our wave energy model quantifies harvestable wave energy and evaluates the net present value (NPV) of a wave energy facility based on a capital investment analysis. The model has a flexible framework and can be easily applied to wave energy projects at local, regional, and global scales. We applied the model and compatibility analysis on the west coast of Vancouver Island, British Columbia, Canada to provide information for ongoing marine spatial planning, including potential wave energy projects. In particular, we conducted a spatial overlap analysis with a variety of existing uses and ecological characteristics, and a quantitative compatibility analysis with commercial fisheries data. We found that wave power and harvestable wave energy gradually increase offshore as wave conditions intensify. However, areas with high economic potential for wave energy facilities were closer to cable landing points because of the cost of bringing energy ashore and thus in nearshore areas that support a number of different human uses. We show that the maximum combined economic benefit from wave energy and other uses is likely to be realized if wave energy facilities are sited in areas that maximize wave energy NPV and minimize conflict with existing ocean uses. Our tools will help decision-makers explore alternative locations for wave energy facilities by mapping expected wave energy NPV and helping to identify sites that provide maximal returns yet avoid spatial competition with existing ocean uses

Economic parameters for net present value (<i>NPV</i>) assessment for the Pelamis wave energy conversion device.

<p>Economic parameters for net present value (<i>NPV</i>) assessment for the Pelamis wave energy conversion device.</p

Wave energy net present value in million USD (black contour lines) over a 25-year life-span of wave energy conversion facilities and wave energy areas of interest (gray contours) modified from British Columbia Marine Conservation Analysis Atlas [20], [35].

<p>Underwater transmission cable landing points (?) are located in Tofino and Ucluelet. Power grid connection point (empty X) is located in Ucluelet.</p

Department of Fisheries and Oceans Canada statistical areas and fishing grounds for groundfish fishing (multiple gears), salmon trolling, and shrimp trawling.

<p>Fishing grounds are shaded by their importance (scale: 1–4); high values indicate more important grounds.</p

Overlap between areas of positive annual net present value over a 25-year life-span of wave energy conversion facilities (black contour lines; value in million USD) and five categories of existing uses or ecological characteristics (gray grids): A) ecological characteristics, B) shipping and transport, C) tenures and offshore energy, D) tourism and recreation, and E) commercial fisheries.

<p>The inset legend indicates the number of existing uses or ecological characteristics in the category that occur in a grid cell.</p

Compatibility analysis between wave energy and fishing annual net values, where A) values are given equal weight and B) fishing values are weighted 50 times that of wave energy values.

<p>Underwater transmission cable landing points (⊙) are located in Tofino and Ucluelet. Power grid connection point (empty X) is located in Ucluelet.</p

Net value (USD) of three commercial fishing layers and wave energy annual net value (thousand USD; black contour lines).

<p>Underwater transmission cable landing points (?) are located in Tofino and Ucluelet. Power grid connection point (empty X) is located in Ucluelet.</p

Degree of spatial overlap between areas of positive annual net present value from wave energy facilities and five categories of existing uses and ecological characteristics.

<p>Overlap is expressed by quartiles (very low, low, moderate and high) of the median and range (minimum to maximum) of the number of existing uses in 2 km² cells (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0047598#pone-0047598-g006" target="_blank">Figure 6</a>) that overlap with areas of positive net present value for wave energy. See text for further explanation and consult <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0047598#pone.0047598-British2" target="_blank">[30]</a> for the full list for each category.</p

Comparison of wave buoy data (X) and WAVEWATCH III model hindcast reanalysis results (lines) for significant wave height (<i>H_s</i>) and peak wave period (<i>T_p</i>) monthly averages at three wave buoy stations: C46132 (solid black), C46206 (light gray), and MEDS103 (dashed).

<p>Comparison of wave buoy data (X) and WAVEWATCH III model hindcast reanalysis results (lines) for significant wave height (<i>H_s</i>) and peak wave period (<i>T_p</i>) monthly averages at three wave buoy stations: C46132 (solid black), C46206 (light gray), and MEDS103 (dashed).</p