SUNY College of Environmental Science and Forestry Digital Commons @ ESF Dissertations and Theses Spring 4-9-2018 Geographically specific life cycle assessment of electricity from tidal turbines in the United States Breck Sullivan breck.com Follow this and additional works at: https://digitalcommons.edu/etds Recommended Citation Sullivan, Breck, "Geographically specific life cycle assessment of electricity from tidal turbines in the United States" (2018). Dissertations and Theses.edu/etds/29 This Open Access Thesis is brought to you for free and open access by Digital Commons @ ESF. It has been accepted for inclusion in Dissertations and Theses by an authorized administrator of Digital Commons @ ESF. For more information, please contact digitalcommons@esf.edu, cjkoons@esf.
GEOGRAPHICALLY SPECIFIC LIFE CYCLE ASSESSMENT OF ELECTRICITY FROM TIDAL TURBINES IN THE UNITED STATES by Breck Sullivan A thesis submitted in partial fulfillment of the requirements for the Master of Science Degree State University of New York College of Environmental Science and Forestry Syracuse, New York April 2018 Division of Environmental Science Approved by: Marie-Odile Fortier, Co-major Professor Robert Malmsheimer, Co-major Professor Andrea Parker, Examining Committee Russell Briggs, Department Chair S. Scott Shannon, Dean, The Graduate School Acknowledgements I am honored to receive a Master of Science degree from SUNY College of Environmental Science and Forestry. The success of my career at this institution would not have been achievable without the help and guidance from my advisors, Marie-Odile Fortier and Bob Malmsheimer. Their constant encouragement and thirst for knowledge fueled my drive to reach my greatest potential in graduate school.
Thanks is also due to my committee member Tristan Brown and examiner Lemir Teron. The extra time they put aside to assist me in completing my degree is very much appreciated. Thank you to all that made my years at SUNY-ESF such a wonderful experience. i Table of Contents Acknowledgments…………………………………………………………………………………i List of Tables……………………………………………………………………………….iii List of Figures……………………………………………………………………………….iv List of Appendices…………………………………………………………………………….vi Thesis Introduction……………………………………………………………………………….1 Goal and scope……………………………………………………………………….3 Electrical energy generated calculations…………………………………………….1 Baseline results and discussion………………………………………………………19 3.2 Sensitivity analysis results and discussion……………………………….3 Monte Carlo results and discussion……………………………………….4 Comparison to other tidal turbine LCA studies…………………………….5 Comparison to alternative LCA studies…………………………………….6 Implications for sustainable implementation of tidal turbines……………………….7 Limitations and opportunities for future development…………………….46 Supplemental Information References………………………………………………………….108 ii List of Tables Table 1: Modeled tidal turbine installation sites…………………………………………………12 Table 2: Variable parameters used in the tidal turbine LCA model for the 23 LCA case studies… ……………………………………………………………………………………………………13 Table 3: Life cycle climate change impacts and electricity generated, by LCA case study…….23 iii List of Figures Figure 1: Average maximum velocity of tidal currents in 2015 for the Admiralty Inlet and East River……………………………………………………………………………………….8 Figure 2: System diagram……………………………………………………………………….15 Figure 3: Velocity of the tide over time……………………….18 Figure 4: Baseline life cycle climate change impacts of electricity from tidal turbines deployed in 23 U.20 Figure 5: Baseline life cycle climate change impacts of electricity from tidal turbines deployed in three sites in Alaska………………………………………………………………….21 Figure 6: Scatterplot of log-transformed variables life cycle climate change impacts and life cycle electricity generation………………………………………………………………24 Figure 7: Life cycle process’ average percent contribution to the total baseline life cycle climate change impact……………………………………………………………………………25 Figure 8: Probability plot of the distribution of life cycle climate change impacts of generating electricity from tidal turbines in the west coast of the U.29 Figure 9: Probability plot of the distribution of life cycle climate change impacts of generating electricity from tidal turbines in Alaska.…31 Figure 10: Probability plot of the distribution of life cycle climate change impacts of generating electricity from tidal turbines on the east coast of the U.……………33 iv List of Appendices Appendix A: Literature Review…………………………………………………………………70 Appendix B: Additional Graphs…………………………………………………………………84 v Thesis Abstract B.
Geographically Specific Life Cycle Assessment of Electricity from Tidal Turbines in the United States, 120 pages, 5 tables, 42 figures, 2018. Global Change Biology style guide used. Life cycle assessment can be used to determine whether electricity from ocean energy sources has a lower climate change impact than electricity from fossil energy sources. A mathematical model was developed to calculate GHG emissions of electricity from a tidal turbine across its life cycle processes, scaled to a functional unit of 1 kWh.
It was applied to 23 “hotspots” sites on U. Daily peak tidal velocities were used to determine electricity generated over the turbine’s lifetime. The life cycle climate change impacts of electricity from tidal turbines varied significantly across deployment sites. For example, the carbon footprint for a tidal turbine in the Sitkinak Strait (AK) is over 11,000 percent higher than that of the East River (NY).
This shows electricity from tidal turbines can have life cycle climate change impacts comparable to other renewable energy sources, fossil energy sources, or impacts even worse than fossil energy sources. Key Words: Climate change, tidal turbine, tidal energy, life cycle assessment, velocity B. Sullivan Candidate for the degree of Master of Science, April 2018 Marie-Odile Fortier, Ph. Robert Malmsheimer, Ph., JD Department of Environmental Science State University of New York College of Environmental Science and Forestry vi Thesis Introduction Renewable energy plays a key role in combating climate change.
The ocean’s energy, a renewable energy source, provides the opportunity to curb carbon emissions. Ocean energy can generate electricity from six sources: ocean wave, tidal range, tidal current, ocean current, ocean thermal energy, and salinity gradient. Ocean energy’s global development potential is predicted to be 337 GW, with 885 TWh of the electricity generated each year.1 The International Energy Agency (IEA) Ocean Energy Systems Technology Collaboration Programme estimates ocean energy technologies could supply global annual electricity demand if worldwide deployment of the technologies is achieved.1 There is tremendous resource potential in ocean energy, but the amount of commercially installed devices currently does not match this potential. Technological development will boost ocean energy deployment.
Two of the most advanced ocean energy sources are tidal range and tidal current.2 Tidal barrages, which originated in 1966 in France, can be used to generate electricity from tidal ranges, but these technologies have high construction costs and damage aquatic ecosystems, and the installation of tidal barrages removes exposed mud flats, reducing the food availability for birds. Tidal barrages cause obstruction for passage of boats and fish, and electricity generation cannot start until construction is fully completed, which may take years.3 Tidal current technologies are still in development, but their potential is larger than tidal range technologies.1 Tidal barrages require a fixed location that creates a basin to store incoming water. The basin must be hundreds of square meters large to produce power comparable to tidal turbines due to tidal barrage’s low power density in terms of surface area.1 These requirements reduce the number of places for tidal barrage development. Tidal current technologies use tidal turbines to harness energy from the currents which are driven by the gravitational force of the Moon and Sun and the rotation of the 1 Earth.
As a result, this energy source is less intermittent than other renewable sources. The majority of tidal current energy development has occurred in the United Kingdom, with some development in the United States with the installation of a Verdant Power, Inc. tidal turbine in the East River in New York, NY. Additionally, a 2011 Georgia Tech Research Corporation report to the Department of Energy identified hotspots for tidal energy on the coasts of the United States, which will assist in the global advancement of this technology.1,4 While there may be potential sites to deploy this technology, sufficient information on its life cycle environmental impacts is not currently available.
It is important to know the impact that tidal turbines have on climate change if renewable energy sources are aimed to replace fossil fuels on this environmental basis. The life cycle climate change impacts of electricity from tidal turbines must be less than those of fossil fuel-fired electricity generation for it to be a suitable alternative. Life cycle assessment (LCA) is a tool that can quantify these impacts. LCA mathematically models all the phases of a life cycle, using a “cradle-to-grave” approach to account for environmental impacts associated with the extraction of materials, manufacturing, distribution, use, maintenance, and disposal of the product or system.5 Measuring the environmental impacts for each phase emphasizes that renewable energy sources are not truly zero-emission systems and identifies which phases of their life cycle contribute the most to environmental impacts so that alternatives and design improvements may be considered.
There exist few published LCAs for tidal turbines.9 Uihlein (2016), Rule et al. (2009), and Douziech et al. (2016) modeled tidal turbines from cradle-to-grave using their power rating and capacity factor to calculate the energy produced over the turbine’s lifetime. However, a power rating multiplied by a capacity factor is a single value representing a steady average rate.
This method does not appropriately model resource availability as it changes over time. These 2 studies, along with Douglas et al. (2008), also did not consider the life cycle climate change impacts of their device in locations beyond the single one studied in each analysis. The most influential variable in calculating the electricity generated for a tidal turbine is the velocity of the tidal current,26 which changes based on location.
This highlights the need for tidal electricity LCAs to include these geographically specific parameters. This geographically specific LCA study is novel for ocean energy. It investigates how the carbon footprint of tidal turbines changes depending on the location of the device. This LCA models the life cycle climate change impact of generating electricity from a horizontal axis tidal turbine from cradle-to-grave in 23 sites identified as “hotspots” for tidal energy on the continental U.
coasts and Alaska. These 23 LCA scenarios in different geographic locations incorporate differences in potential power generation across sites. The same technology was modeled across these geographic LCA scenarios with a functional unit of 1 kWh. A mathematical model was developed to determine potential electricity generated over the turbine’s lifetime using daily peak tidal velocities from the multiple sites and equations that represent the sinusoidal character of the tides.
Input parameters (including turbine lifetime, distances transported, and daily peak tidal velocities, among others) were varied for uncertainty analyses and sensitivity analyses for each geographic LCA case study. Science is the journal of choice to publish this research. It is an international journal focusing on publishing novel work in all fields of science. This study does not only apply to the United States, but to the global ocean energy industry.
Tidal turbines are an alternative energy source with global potential. Tidal current velocities differentiate throughout the world and affect the electricity generated by a tidal turbine. Thus, these results need a global audience. Science encourages topics that advance the scientific understanding.
This research is the first to study the 3 life cycle climate change impacts of electricity from tidal turbines in different geographic locations and accounting for the change in resource availability. This study matches the scope and produces an article on a subject the journal welcomes. Science gives these novel results a worldwide platform to be presented to the scientific field. 4 Abstract Life cycle assessment (LCA) can determine the climate change impact of electricity from tidal turbines compared to fossil energy sources.
An LCA model calculated the GHG emissions of electricity from a tidal turbine across its life cycle processes for 23 “hotspot” sites on U. coasts, scaled to a functional unit of 1 kWh. Daily peak tidal velocities were used to determine electricity generated over turbines’ lifetimes. The life cycle climate change impacts of electricity from tidal turbines ranged from 43.35 to 4,985 g CO2eq/kWh.
This demonstrates that electricity from tidal turbines can have higher life cycle GHG emissions than electricity from natural gas and coal due to low electricity generation over the turbine lifetime relative to the emissions arising from the life cycle. Introduction The world is heavily dependent on fossil fuels which contribute to climate change. Mitigating climate change requires moving away from fossil fuels and towards renewable energy. Life cycle assessment (LCA) can be performed to determine if a renewable energy source has a lower climate change impact than fossil energy sources.