Coastal and Offshore Energy

A comparative assessment of proposed offshore wind power demonstration projects in the United States

Bates A, Firestone J. A comparative assessment of proposed offshore wind power demonstration projects in the United States. Energy Research & Social Science [Internet]. 2015 ;10:192 - 205. Available from: http://www.sciencedirect.com/science/article/pii/S2214629615300141
Freely available?: 
No
Summary available?: 
No
Type: Journal Article

Wind energy development on land has faced local opposition for reasons such as effects on cultural landscapes and wildlife, which can be instrumental in whether or not and the speed with which a project moves toward completion. Offshore wind can generate electricity where onshore wind is limited. Factors leading to support for, or opposition to, offshore wind energy are not well known, particularly for developments that are near-shore and in-view of coastal communities. Here we present results from a survey of 699 residents (35.5% response rate) completed in 2013 in greater Atlantic City, New Jersey and coastal Delaware, United States, where near-shore wind demonstration projects had been proposed. We examined how the public considers the societal tradeoffs that are made to develop small-scale, in-view demonstration wind projects instead of larger facilities farther offshore. Results indicate that a strong majority of the public supports near-shore demonstration wind projects. We find the primary reasons for support include benefits to wildlife, cost of electricity, and job creation, while the primary reasons for opposition include wildlife impacts, aesthetics, tourism, and user conflicts. These factors differ between the two communities and highlight the importance of local, community engagement in the early stages of development.

Economic influence of location in floating offshore wind farms

Castro-Santos L, Diaz-Casas V. Economic influence of location in floating offshore wind farms. Ocean Engineering [Internet]. 2015 ;107:13 - 22. Available from: http://www.sciencedirect.com/science/article/pii/S0029801815003388
Freely available?: 
No
Summary available?: 
No
Type: Journal Article

This paper aims to determine the influence that location has in the life-cycle of a floating offshore wind farm. For this purpose several steps have been considered: determination of the location variables, formulation of the costs whose value depends on these location variables, development of the location economic indexes based on the Levelized Cost of Energy and the Cost of Power, and introduction of the restricted areas where farms cannot be installed. This method will be applied to the particular case of a floating offshore wind farm with semisubmersible platforms and located in the Galician area (North-West of Spain). Results indicate the best location areas where a floating offshore wind farm can be installed in the region selected. This methodology will be useful to determine the importance of the location settings in terms of a floating offshore wind farm.

A methodology for multi-criteria design of multi-use offshore platforms for marine renewable energy harvesting

Zanuttigh B, Angelelli E, Kortenhaus A, Koca K, Krontira Y, Koundouri P. A methodology for multi-criteria design of multi-use offshore platforms for marine renewable energy harvesting. Renewable Energy [Internet]. 2016 ;85:1271 - 1289. Available from: http://www.sciencedirect.com/science/article/pii/S0960148115301762
Freely available?: 
No
Summary available?: 
No
Type: Journal Article

Multi-use offshore platforms (MUPs) combining renewable energy from the sea, aquaculture and transportation facilities can be considered as a challenging way to boost blue growth and make renewable energy (especially wave energy) environmentally and socio-economically sustainable. MUPs allow sharing the financial and other market/non-market costs of installation and management, locally using the produced energy for different functionalities and optimizing marine spatial planning. The design of these solutions is a complex interdisciplinary challenge, involving scientists and technical experts with different backgrounds.

This paper presents a new methodology for the design of a MUP based on technical, environmental, social and economic criteria. The methodology consists of four steps: a pre-screening phase, to assess the feasibility of different maritime uses at the site; a preliminary design of the alternative schemes based on the identified maritime uses; a ranking phase, where the performance of the MUPs is scored by means of expert judgment of the selected criteria; a preliminary design of the selected MUP selected.

An example application of this procedure to a site offshore the Western Sardinia coast, Mediterranean Sea, Italy, is provided. In this site the deployment of a MUP consisting of wave energy converters, offshore wind turbines and aquaculture is specifically investigated.

Evaluating Community Engagement in Wave Energy Siting off the Oregon Coast

Goodwin B. Evaluating Community Engagement in Wave Energy Siting off the Oregon Coast. Corvallis: Oregon State University; 2015. Available from: http://ir.library.oregonstate.edu/xmlui/handle/1957/56347
Freely available?: 
Yes
Summary available?: 
No
Type: Thesis

The ocean off Oregon's coast is a busy place with many activities occurring that can sometimes be in competition or cooperation. Deciding how new uses fit with existing ocean uses is complex, but there are some tools available to help decision-makers. Generating energy from waves is an emerging ocean use and the human dimension effects require further study. In 2011, the Northwest National Marine Renewable Energy Center (NNMREC), in conjunction with Oregon Sea Grant (OSG), began efforts to identify a site for a grid-connected, open-ocean test facility for full-scale wave energy devices. The NNMREC and OSG led a siting process that included meetings with community leaders, public workshops, and the creation of teams of community members to develop siting proposals. This thesis research emerged from a solicitation for an independent evaluation of the siting process. The overall goal of this research was to determine if the siting process was effective. Specifically, using a mixed methods research approach consisting of semi-structured interviews and an online questionnaire, this research answered if participants: (a) where participants involved in the process at the level they wanted to be, (b) did participants understand the process, (c) did participants feel as though they were heard, and (d) did participants feel they had an influence on the outcome of the process? The goal of evaluating this siting process was to provide lessons that can inform future marine renewable energy siting efforts. Logistically, there were several successful aspects of the siting process. Most participants reported they had at least a fair understanding of the process and felt they had enough information. The most frequently used sources of information about the process came from public meetings and personal communications with process leaders. On average, participants reported they wished they had been more involved in the process, but most participants reported that this less-than-desired involvement was due to personal or professional constraints, not the process itself. On average, respondents understood the process and felt heard, but they neither agreed nor disagreed they had an influence on the process. As existing and new uses compete for space in the ocean, more social science research is needed to understand how best to choose sites for new uses. Research about stakeholder engagement in the process of siting marine renewable energy facilities is an emerging field of study, and gaining a better understanding of how to design and implement processes that effectively engage communities in wave energy siting could lead to more successful siting efforts in the future.

Decision support tools for collaborative marine spatial planning: identifying potential sites for tidal energy devices around the Mull of Kintyre, Scotland

Janssen R, Arciniegas G, Alexander KA. Decision support tools for collaborative marine spatial planning: identifying potential sites for tidal energy devices around the Mull of Kintyre, Scotland. Journal of Environmental Planning and Management [Internet]. 2015 ;58(4):719 - 737. Available from: http://www.tandfonline.com/doi/abs/10.1080/09640568.2014.887561
Freely available?: 
No
Summary available?: 
No
Type: Journal Article

The expansion of offshore renewable energy production, such as wind, wave and tidal energy, is likely to lead to conflict between different users of the sea. Two types of spatial decision support tools were developed to support stakeholder workshops. A value mapping tool combines regional attributes with local knowledge. A negotiation support tool uses these value maps to support stakeholders in finding acceptable locations for tidal energy devices. Interactive value mapping proved useful to address deficiencies in data and to create credibility for these maps. The negotiation tool helped stakeholders in balancing objectives of the various stakeholders.

Simulating and forecasting ocean wave energy in western Canada

Reikard G, Robertson B, Buckham B, Bidlot J-R, Hiles C. Simulating and forecasting ocean wave energy in western Canada. Ocean Engineering [Internet]. 2015 ;103:223 - 236. Available from: http://www.sciencedirect.com/science/article/pii/S0029801815001687
Freely available?: 
No
Summary available?: 
No
Type: Journal Article

While the technology now exists to harvest wave energy in coastal regions, the capital expenditures for wave farms can be substantial, so it is important to be able to simulate the power in advance. Further, to integrate wave energy into the grid, utilities need to forecast over short horizons and calculate reserve requirements. Wave farms are simulated at three locations in British Columbia, Canada. Power series are calculated for six types of wave energy converters (WECs), four that operate in deep water, and two in shallow water. Forecasts are run using a physics-based model and statistical models. Five major conclusions emerge from the analysis. First, given the intermittency of buoy data, physics model hindcasts are an effective method of interpolating missing values. Second, the power output from converters does not have the same properties as the wave energy flux. Instead, the power output is a nonlinear function of the wave height and period, with fewer large outliers. Third, time series models predict well over near-term horizons while physics models forecast more accurately over longer horizons. The convergence point, at which the two types of models achieve comparable degrees of accuracy, is in the area of 2–3 h in these data sets, lower than in most prior studies. The recommendation is to use time series methods to forecast at the horizons required for reserves, and physics models for long-term planning. Fourth, the predictability of the power output can differ substantially for individual converters. Finally, wave energy is found to be significantly less costly in terms of reserves than wind and solar.

Valuation of ecological and amenity impacts of an offshore windfarm as a factor in marine planning

Börger T, Hooper TL, Austen MC. Valuation of ecological and amenity impacts of an offshore windfarm as a factor in marine planning. Environmental Science & Policy [Internet]. 2015 ;54:126 - 133. Available from: http://www.sciencedirect.com/science/article/pii/S1462901115300034
Freely available?: 
No
Summary available?: 
No
Type: Journal Article

Integrated marine planning, which must take into consideration environmental and social impacts, is being introduced widely in Europe, the USA, Australia and elsewhere. Installation of offshore windfarms creates impacts both on local marine ecosystems and the view of the seascape and is one of multiple activities in the marine area that must be addressed by marine planning. The impacts on people's values (and hence welfare) of changes in ecology and amenity that could arise from the installation of a windfarm in the Irish Sea were assessed using a discrete choice experiment administered through an online survey. The ecological changes investigated were: increased species diversity resulting from artificial reef effects, and the effect of electromagnetic fields from subsea cables on marine life; whilst the amenity change was the visibility of offshore turbines from land. Respondents expressed preferences for ecological improvements but had less clear preferences regarding the height and visibility of the turbines. In particular distance decay effects were observed with respondents further away from the coast being less concerned about visual impact created by offshore turbines. Understanding ecological and amenity impacts and how they are valued by people can support the decisions made within marine planning and licensing.

Tidal energy leasing and tidal phasing

Neill SP, M. Hashemi R, Lewis MJ. Tidal energy leasing and tidal phasing. Renewable Energy [Internet]. 2016 ;85:580 - 587. Available from: http://www.sciencedirect.com/science/article/pii/S0960148115301130
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

In addition to technical and economic constraints, tidal energy leasing is generally governed by demand for sites which contain the highest tidal streams, and does not take into account the phase relationship (i.e. the time lag) between sites. Here, the outputs of a three-dimensional tidal model are analysed to demonstrate that there is minimal phase diversity among the high tidal stream regions of the NW European shelf seas. It is therefore possible, under the current leasing system, that the electricity produced by the first generation of tidal stream arrays will similarly be in phase. Extending the analysis to lower tidal stream regions, we demonstrate that these lower energy sites offer more potential for phase diversity, with a mean phase difference of 1.25 h, compared to the phase of high energy sites, and hence more scope for supplying firm power to the electricity grid. We therefore suggest that a state-led leasing strategy, favouring the development of sites which are complementary in phase, and not simply sites which experience the highest current speeds, would encourage a sustainable tidal energy industry.

Statistical guidelines for assessing marine avian hotspots and coldspots: A case study on wind energy development in the U.S. Atlantic Ocean

Zipkin EF, Kinlan BP, Sussman A, Rypkema D, Wimer M, O'Connell AF. Statistical guidelines for assessing marine avian hotspots and coldspots: A case study on wind energy development in the U.S. Atlantic Ocean. Biological Conservation [Internet]. 2015 ;191:216 - 223. Available from: http://www.sciencedirect.com/science/article/pii/S000632071530001X
Freely available?: 
No
Summary available?: 
No
Type: Journal Article

Estimating patterns of habitat use is challenging for marine avian species because seabirds tend to aggregate in large groups and it can be difficult to locate both individuals and groups in vast marine environments. We developed an approach to estimate the statistical power of discrete survey events to identify species-specific hotspots and coldspots of long-term seabird abundance in marine environments. We illustrate our approach using historical seabird data from survey transects in the U.S. Atlantic Ocean Outer Continental Shelf (OCS), an area that has been divided into “lease blocks” for proposed offshore wind energy development. For our power analysis, we examined whether discrete lease blocks within the region could be defined as hotspots (3 × mean abundance in the OCS) or coldspots (1/3 ×) for individual species within a given season. For each of 74 species/season combinations, we determined which of eight candidate statistical distributions (ranging in their degree of skewedness) best fit the count data. We then used the selected distribution and estimates of regional prevalence to calculate and map statistical power to detect hotspots and coldspots, and estimate the p-value from Monte Carlo significance tests that specific lease blocks are in fact hotspots or coldspots relative to regional average abundance. The power to detect species-specific hotspots was higher than that of coldspots for most species because species-specific prevalence was relatively low (mean: 0.111; SD: 0.110). The number of surveys required for adequate power (> 0.6) was large for most species (tens to hundreds) using this hotspot definition. Regulators may need to accept higher proportional effect sizes, combine species into groups, and/or broaden the spatial scale by combining lease blocks in order to determine optimal placement of wind farms. Our power analysis approach provides a general framework for both retrospective analyses and future avian survey design and is applicable to a broad range of research and conservation problems.

Underwater Noise from a Wave Energy Converter Is Unlikely to Affect Marine Mammals

Tougaard J. Underwater Noise from a Wave Energy Converter Is Unlikely to Affect Marine Mammals. PLOS ONE [Internet]. 2015 ;10(7):e0132391. Available from: http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0132391
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Underwater noise was recorded from the Wavestar wave energy converter; a full-scale hydraulic point absorber, placed on a jack-up rig on the Danish North Sea coast. Noise was recorded 25 m from the converter with an autonomous recording unit (10 Hz to 20 kHz bandwidth). Median sound pressure levels (Leq) in third-octave bands during operation of the converter were 106–109 dB re. 1 μPa in the range 125–250 Hz, 1–2 dB above ambient noise levels (statistically significant). Outside the range 125–250 Hz the noise from the converter was undetectable above the ambient noise. During start and stop of the converter a more powerful tone at 150 Hz (sound pressure level (Leq) 121–125 dB re 1 μPa) was easily detectable. This tone likely originated from the hydraulic pump which was used to lower the absorbers into the water and lift them out of the water at shutdown. Noise levels from the operating wave converter were so low that they would barely be audible to marine mammals and the likelihood of negative impact from the noise appears minimal. A likely explanation for the low noise emissions is the construction of the converter where all moving parts, except for the absorbers themselves, are placed above water on a jack-up rig. The results may thus not be directly transferable to other wave converter designs but do demonstrate that it is possible to harness wave energy without noise pollution to the marine environment.

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