Capturing Energy from the Motion of the Ocean in a Crowded Sea

<p>Conversion to renewable energy sources is a logical response to the increasing pressure to reduce greenhouse gas emissions. Ocean wave energy is the least developed renewable energy source, despite having the highest energy per unit area. While many hurdles remain in developing wave energy, assessing potential conflicts and evaluating tradeoffs with the existing uses is essential. Marine planning encompasses a broad array of activities that take place in and affect large marine ecosystems, making it an ideal tool for evaluating wave energy resource use conflicts. In this study, we used a spatially explicit, open source decision support tool to evaluate wave energy facility development off the U.S. west coast. We then used this output to identify potential conflicts between wave energy facilities and the existing marine uses in the context of marine planning. We found that regions with the highest wave energy potential were distant from major cities and that infrastructure limitations (cable landing sites) restrict integration with the existing power grids. We also identified multiple potential conflicts, including commercial fishing, shipping and transportation, and marine conservation areas. While wave energy generation facilities may be economically viable, we must also incorporate costs associated with conflicts that arise with the existing marine uses.</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

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

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