Spatial Analysis of Wave Power Potential in North Carolina by Jeffrey D. Bower Dr. Lincoln Pratson, Advisor May 2010 Masters project submitted in partial fulfillment of the requirements for the Master of Environmental Management degree in the Nicholas School of the Environment of Duke University 2010 ABSTRACT North Carolina is actively pursuing electricity generation from various renewable energy technologies. In 2008 the state’s General Assembly commissioned a study by UNC- Chapel Hill researchers assessing the feasibility of offshore wind power and as a direct result of the study, a project is currently under development in the Pamlico Sound. This analysis is a complementary study evaluating the potential for the use of wave energy conversion devices as another renewable energy technology in North Carolina’s coastal waters. Using GIS, this study assesses the spatial distribution of wave power potential offshore and identifies ecological and human use conflicts prohibitive of development. After calculating generation potential and estimating the costs related to wave farm construction, the economic feasibility of wave power is assessed, based on levelized cost of generation (LCOG). The economic analysis employs the same LCOG model used by the UNC offshore wind study team to provide directly comparable results. The results of the analysis indicate that while there are areas off the coast of North Carolina where wave power development is technically feasible, it is not nearly cost- competitive with other types of generation, including offshore wind. Wave power technology is still in an early development phase, however, and if anticipated future cost savings and efficiency improvements are realized, wave power may become more economically feasible. i TABLE OF CONTENTS I. Introduction.....................................................................................................................................1 A. Wave power resource potential ........................................................................................................1 B. Statewide context ...................................................................................................................................2 1. Marine renewable energy in North Carolina, UNC wind study..........................................................3 II. Project overview...........................................................................................................................4 III. Methodology .................................................................................................................................6 A. Electricity Generation potential.........................................................................................................6 1. Spatial conflicts to development .....................................................................................................................6 2. Wave resource potential.................................................................................................................................. 10 3. WEC device performance ................................................................................................................................ 13 B. Wave farm cost..................................................................................................................................... 19 1. Device costs ........................................................................................................................................................... 20 2. Transmission cost............................................................................................................................................... 21 3. Operation and maintenance costs ............................................................................................................... 27 C. OverniGht cost of plant construction............................................................................................. 28 D. Levelized cost of generation............................................................................................................ 28 IV. Results..........................................................................................................................................31 A. Electricity Generation potential...................................................................................................... 31 1. Spatial conflicts to development .................................................................................................................. 31 2. Wave resource potential.................................................................................................................................. 34 3. WEC device performance ................................................................................................................................ 37 B. OverniGht cost of plant construction ............................................................................................ 39 C. Levelized cost of generation............................................................................................................. 41 V. Discussion ....................................................................................................................................43 A. Spatial results ....................................................................................................................................... 43 B. Economic results.................................................................................................................................. 44 VI. Recommendations ...................................................................................................................46 ii LIST OF FIGURES Figure 1. Total U.S. available incident wave energy flux......................................................................... 2 Figure 2. Wave buoys used in interpolation analysis.............................................................................11 Figure 3. AC and DC transmission cost comparison by distance from shore, based on cost estimates from the Cape Wind DEIS ....................................................................................24 Figure 4. Substations identified for grid interconnection....................................................................26 Figure 5. Ecological/environmental conflict areas identified in UNC offshore wind study.......................................................................................................................................................32 Figure 6. Human use conflicts identified by UNC offshore wind study, with appropriate buffers .....................................................................................................................................33 Figure 7. Complete exclusion zone and MMS blocks eligible for development ..........................34 Figure 8. Mean wave height values interpolated from buoy data ...................................................35 Figure 9. Mean wave period interpolated from buoy data. .................................................................35 Figure 10. Mean wave power calculated with interpolated values..................................................36 Figure 11. Estimated mean wave power, in kW/m, from Defne, et al. ...........................................37 Figure 12. Annual energy absorbed by hypothetical wave farm.......................................................38 Figure 13. Overnight cost of construction, high cost estimates.........................................................40 Figure 14. Overnight cost of construction, low cost estimates ..........................................................41 Figure 15. Levelized cost of generation, high capital cost, low efficiency estimates................42 Figure 16. Levelized cost of generation, low capital cost, high efficiency estimates................42 iii LIST OF TABLES Table 1. Electric Power Industry Generation by Primary Energy Source, 2008 .......................... 2 Table 2. North Carolina REPS requirements................................................................................................ 3 Table 3. NDBC wave buoy stations used in analysis...............................................................................12 Table 4. EPRI analysis: San Francisco site annual occurence of hours per sea-state...............15 Table 5. EPRI analysis: Pelamis wave energy conversion absorption performance (kW) in each sea-state (excluding power take off losses) ..........................................................16 Table 6. EPRI analysis performance assumptions for pilot and commercial phase Pelamis plants................................................................................................................................................17 Table 7. Pelamis WEC device cost components for proposed demonstration and commercial plants........................................................................................................................................20 Table 8. Cape Wind Project transmission cost estimates - AC option.............................................23 Table 9. Cape Wind Project transmission cost estimates - DC option.............................................23 Table 10. Transmission cost summary, 2008$..........................................................................................24 Table 11. Input