Among sources of renewable energy, development of tidal energy has traditionally been plagued by relatively high costs and limited availability of sites with sufficiently high tidal amplitudes or flow velocities. However, many recent technology developments and improvements, both in design (e.g. dynamic tidal power, tidal lagoons) and turbine technology (e.g. new axial turbines, crossflow turbines), showed that the economic and environmental costs may be brought down to competitive levels comparing to other conventional energy sources. It has long been identified that the Bay of Fundy is one of the world’s premier locations for the development of tidal power generating systems, since it has some of the world’s largest tidal ranges. Consequently, several proposals have been made in the recent years to find economical ways to harness the power of tides. Presently, there is considerable interest in installing tidal lagoons in the Bay of Fundy. The lagoon concept involves temporarily storing seawater behind an impoundment dike and generating power by gradually releasing the impounded seawater through conventional low-head hydroelectric turbines. A tidal lagoon will inherently modify the tides and tidal currents regime in the vicinity of the lagoon, and possibly induce effects that may be felt throughout the entire Bay of Fundy. The nature of these hydrodynamic impacts will likely depend on the size of the tidal lagoon, its location, and its method of operation. Any changes in the tidal hydrodynamics caused by a tidal lagoon may also impact on the transport of sediments throughout the region and upset ecosystems that are well adapted to existing conditions. The scale and character of the potential hydrodynamic impacts due to tidal lagoons operating in the Bay of Fundy have not been previously investigated. The present study endeavours to investigate these potential impacts to help the development of sustainable, science-based policies for the management and development of clean energy for future generations. After outlining fundamental aspects of tidal power projects taken in consideration in the Bay of Fundy, an analysis of present knowledge on tidal lagoons was conducted in order to provide a focus for subsequent investigations. Hydrodynamic modeling was used to quantify any of the potential hydrodynamic changes induced in the Bay of Fundy due to the presence of tidal lagoons. In the last part of the thesis, new relationships were derived in order to describe the amount of energy removed from tidal lagoons associated with its hydrodynamic impacts.

The tidal current energy resource is challenging to assess with accuracy and precision. An accepted standard methodology is lacking, which in turn perpetuates uncertainty and hinders the industry’s development. Technical Committee 114 of the International Electro-technical Commission (IEC-TC-114) is working to develop a standard for emerging tidal energy conversion systems. The draft standard prescribes methods for determining, objectively and reliably, the scale and character of tidal current energy resources at a site. The IEC-TC-114 draft standard for tidal energy resource assessment and characterisation has not yet been tested in a real world case study. Hence, it is not yet known whether the proposed methods will yield the desired outcome. This research has adopted the Fundy Ocean Research Center for Energy (FORCE) project in Minas Passage, Nova Scotia, for pilot application of the draft standard on tidal current resource assessment. The Bay of Fundy, located on the Atlantic coast of North America between the Canadian provinces of New Brunswick and Nova Scotia, is known for having the highest tidal range in the world and has long been recognised as an ideal stage for tidal energy development. The thesis is presented in three main parts. Firstly, the latest peer-reviewed scientific literature is summarised and the standard is reviewed in view of lessons learned. The aim of this exercise is to establish a scientific basis for and to develop suggestions towards improving and extending future revisions of the standard. Secondly, a comprehensive assessment of the tidal current energy resource at the FORCE project site is conducted in a manner that is consistent with IEC-TC-114 protocol based on available measurements from static current profiler surveys and a two-dimensional hydrodynamic model of the upper Bay of Fundy developed for this study. Thirdly, a sensitivity analysis is performed to determine the main sources of error and uncertainty affecting resource assessment, a topic which has yet to be addressed in the literature.

No description available.

<p> Cobequid Bay is a macrotidal embayment with a large intertidal sand bar complex at the east end, located at the head of the Bay of Fundy. Two sand bars were sampled in order to observe variations in impact pit densities on the surfaces of quartz sand grains, and to identify the pattern of grain size distribution over two intertidal bedforms. </p> <p> V pit densities obtained by viewing the quartz grain surfaces at magnifications of 10,000 and 5,000X with a scanning electron microscope indicate a linear correlation with grain size. The number of small V's appears to be consistent for all grain sizes, with the result that V's larger than approximately 1/5 micrometer produce the linear variation noted. Two trends of V pits formation combine to produce a "plateau", in which two grain size classes have similar V pit densities. This plateau corresponds to the break-point between the traction population and the intermittent suspension population. Trend one consists of the bombardment of large, well exposed grains (transported in the traction layer), by smaller saltating grains, while trend two consists of grain impacts between smaller grains in the concentrated "rheological layer". </p> <p> Two different grain size patterns were discovered on the two sampled bedforms. A fining upward trend toward the crest on both the stoss and slip faces was observed on an ebb dominated megaripple on Selmah Bar. The exact opposite pattern was noted on an ebb dominated sandwave from East Noel Bar. On this bedform, an upward coarsening trend toward the crest was discovered on both the stoss and slip faces. These two patterns correspond to the patterns observed by Dalrymple (1977) in his studies of intertidal bedforms. </p> / Thesis / Bachelor of Science (BSc)

Anthropogenic climate change is approaching predicted tipping points and there is an urgent need to de-carbonize energy systems on a global scale. Generation technologies that do not emit greenhouse gas need to be rapidly deployed, and energy grids need to be updated to accommodate an intermittent fluctuating supply. Rapidly advancing battery technology, cost reduction of solar and wind power and other emerging generation technologies are making the needed changes technically and economically feasible. Extracting energy from fast-flowing tidal currents using turbines akin to those used in wind farms, offers a reliable and predictable source of GHG free energy. The tidal power industry has established the technical feasibility of tidal turbines, and is presently up-scaling deployments from single isolated units to large tidal farms containing many turbines. However there remains significant economic uncertainty in financing such projects, partially due to uncertainty in predicting the long-term energy yield. Since energy yield is used in calculating the project revenue, it is of critical importance. Predicting yield for a prospective farm has not received sufficient attention in the tidal power literature. this task has been the primary motivation for this thesis work, which focuses on establishing and validating simulation-based procedures to predict flows through large tidal farms with many turbines, including the back effects of the turbines. This is a challenging problem because large tidal farms may alter tidal flows on large scales, and the slow-moving wake downstream of each rotor influences the inflow to other rotors, influencing their performance and loading. Additionally, tidal flow variation on diurnal and monthly timescales requires long-duration analysis to obtain meaningful statistics that can be used for forecasting. This thesis presents a hybrid simulation method that uses 2D coastal flow simulations to predict tidal flows over long durations, including the influence of turbines, combined with higher-resolution 3D simulations to predict how wakes and local bathymetry influence the power of each turbine in a tidal farm. The two simulation types are coupled using a method of bins to reduce the computational cost within reasonable limits. The method can be used to compute detailed 3D flow fields, power and loading on each turbine in the farm, energy yield and the impact of the farm on tidal amplitude and phase. The method is demonstrated to be computationally tractable with modest high-performance computing resources and therefore are of immediate value for informing turbine placement, comparing turbine farm-layout cases and forecasting yield, and may be implemented in future automated layout optimization algorithms. / Graduate