Abstract
Given proper care in siting, design, deployment, operation and maintenance, wave energy conversion could become one of the more environmentally benign sources of electricity generation. In order to accelerate the adoption of these emerging hydrokinetic and marine energy technologies, navigational and environmental concerns must be identified and addressed. All developing hydrokinetic projects involve a wide variety of stakeholders. One of the key issues that site developers face as they engage with this range of stakeholders is that, due to a lack of technical certainty, many of the possible conflicts (e.g., shipping and fishing) and environmental issues are not well-understood.
In September 2008, re vision consulting, LLC was selected by the Department of Energy (DoE) to apply a scenario-based assessment to the emerging hydrokinetic technology sector in order to evaluate the potential impact of these technologies on the marine environment and navigation constraints.
The project’s scope of work includes the establishment of baseline scenarios for wave and tidal power conversion at potential future deployment sites. The scenarios capture variations in technical approaches and deployment scales to properly identify and characterize environmental effects and navigational effects. The goal of the project is to provide all stakeholders with an improved understanding of the potential range of technical attributes and potential effects of these emerging technologies and focus all stakeholders on the critical issues that need to be addressed.
By identifying and addressing navigational and environmental concerns in the early stages of the industry’s development, serious mistakes that could potentially derail industry-wide development can be avoided. This groundwork will also help in streamlining siting and associated permitting processes, which are considered key hurdles for the industry’s development in the U.S. today. Re vision is coordinating its efforts with two other project teams funded by DoE which are focused on regulatory issues (Pacific Energy Ventures) and navigational issues (PCCI).
The results of this study are structured into three reports:
(1) Wave power scenario description
(2) Tidal power scenario description
(3) Framework for Identifying Key Environmental Concerns
This is the first report in the sequence and describes the results of conceptual feasibility studies of wave power plants deployed in Humboldt County, California and Oahu, Hawaii. These two sites contain many of the same competing stakeholder interactions identified at other wave power sites in the U.S. and serve as representative case studies.
Wave power remains at an early stage of development. As such, a wide range of different technologies are being pursued by different manufacturers. In order to properly characterize potential effects, it is useful to characterize the range of technologies that could be deployed at the site of interest. An industry survey informed the process of selecting representative wave power devices. The selection criteria requires that devices are at an advanced stage of development to reduce technical uncertainties, and that enough data are available from the manufacturers to inform the conceptual design process of this study. Further, an attempt is made to cover the range of different technologies under development to capture variations in potential environmental effects. Table 1 summarizes the selected wave power technologies. A number of other developers are also at an advanced stage of development, but are not directly mentioned here.
Many environmental effects will largely scale with the size of the wave power plant. In many cases, the effects of a single device may not be measurable, while larger scale device arrays may have cumulative impacts that differ significantly from smaller scale deployments. In order to characterize these effects, scenarios are established at three deployment scales which nominally represent (1) a small pilot deployment, (2) a small commercial deployment, and (3) a large commercial scale plant.
It is important to understand that the purpose of this study was to establish baseline scenarios based on basic device data that was provided to use by the manufacturer for illustrative purposes only. Devices need to be optimized to a particular site and most device manufacturers are pretty flexible in adapting their technology to a particular site (such as using a different mooring system). No such optimization has been carried out and this report should therefore not be used to compare parameters such as performance. The references to PG&E's WaveConnect are for awareness and information only. These references are based upon an early conceptual design in the public domain. Many specifics and design details are currently under development. No conclusions should be drawn from this report to the permitting process presently underway because scale, installation duration and engineering details may differ significantly from this study.
The four technologies and scales at the selected site results in a total of 24 deployment scenarios outlined in this report. The approach to developing the individual scenarios has followed a typical conceptual level design and performance assessment methodology previously utilized by the Principal Investigator for studies carried out for the Electric Power Research Institute