What is Cape Sharp Tidal?
Cape Sharp Tidal is a partnership between Emera Inc. and OpenHydro (a Naval Energies company). We are pursuing one of Canada’s most exciting renewable energy projects today: demonstration-scale tidal energy in the Bay of Fundy. We are one of four berth-holders at the Fundy Ocean Research Centre for Energy (FORCE) .
What are the project’s objectives?
Our aim is to demonstrate that with we can successfully grid-connect in-stream turbine arrays that produce energy silently, invisibly and without environmental harm.
The demonstration project at FORCE is to better understand if in-stream tidal technology has a long-term future in Nova Scotia, and that means satisfying Nova Scotia residents, our stakeholders and decision-makers that the technology is both safe and viable.
Our specific objectives are:
- Demonstrate how in-stream tidal technology works;
- Generate renewable energy for Nova Scotia; and
- Determine what, if any, are the environmental effects, and development of mitigation techniques, if and as needed.
Will this project lead directly to a commercial-scale operation in the Bay of Fundy with hundreds of turbines?
No. A commercial project is a one that has achieved a Levelized Cost of Energy that delivers renewable energy at an affordable price for the market in which it operates. There cannot be a commercial project with a demonstration scale project first, and a pre-commercial phase follows demonstration phase.
A key objective to a commercial operation is to produce power at a large scale. The key objective to a demonstration project is to increase understanding about a variety of considerations, such as optimizing monitoring technologies, refining operations methodologies, and demonstrating that interconnected turbines can export power through a single export power cable.
It’s very early days in technology development and we have much to learn about how they operate in extreme environments like the Minas Passage. These are highly complex engineering challenges that we must study. And that cannot be achieved in one or two years. Ours is a small-scale 4MW demonstration project. The outcomes of the demonstration phase will help inform the path forward for tidal development.
Does this project have a net benefit to the Province of Nova Scotia?
Yes. The Cape Sharp Tidal project has been a catalyst for economic activity in this emerging industry. As part of our commitment to spend 70% of phase 1 project costs in Nova Scotia, Cape Tidal has announced contract awards of $33 million to Nova Scotia firms. This includes:
- $25 million to Aecon and Lengkeek Dartmouth – Lengkeek for barge design and Aecon to manufacture the turbines – employing more than 150, including 100 new positions
- $4.6 million to Hawboldt of Chester to design heavy-lift winches
- Atlantic Towing Ltd. of Dartmouth for its marine operations support
- Hundreds of other contracts awarded for services, manufacturing, technology and more. More than 125 Nova Scotia companies make up our supply chain.
- Additionally, studies like the Value Proposition for Tidal Energy Development from the Offshore Energy Research Association of Nova Scotia (OERA) point to a potential economic benefit to the province in the range of $1.7 billion while creating 22,000 new jobs.
There is also a research economy supported by ongoing scientific exploration of tidal energy and the environment in the Bay of Fundy. These are just some of the examples:
- More than $15 million has been invested—particularly by FORCE and Offshore Energy Research Association of Nova Scotia (OERA)—in environmental research, data analysis, monitoring equipment and more to advance scientific understanding of the area.
- The Fundy Energy Research Network (FERN) is an independent non-profit organization initiated by academic and government researchers as a forum to coordinate and foster research collaborations, capacity building and information exchange to advance knowledge, understanding and technical solutions related to the environmental, engineering and socio-economic factors associated with tidal energy development in the Bay of Fundy.
- Acadia University in Wolfville is home to the Acadia Tidal Energy Institute (ATEI), a non-profit organization conducting tidal energy research, training, education and outreach to support sustainable development of the emerging tidal energy industry.
If the 4MW project is a success, what will happen next in terms of more turbines?
Cape Sharp Tidal is a multi-phase project. What we learn here can change global understanding of how safely, responsibly and economically generate power from the oceans. Our next phases will go forward when the economics are attractive and the environmental effects are better known. Each phase and associated monitoring program will build on the knowledge of the previous phases and will advance in an adaptive manner and through the appropriate regulatory processes.
How are this project and turbines different than those on the Annapolis River in Nova Scotia?
Hydroelectric dams and tidal barrages are both entirely different than in-stream tidal technologies. Here are a few of the key differences:
- With barrage/dam technology, water is held back and electricity is generated by releasing the flow and relying on falling or forced flowing water to turn the turbines. By contrast, in-stream tidal devices (the ones being tested at the FORCE site) resemble slow-moving wind turbines (not jet engines) sitting on the sea floor, and they use the passive kinetic energy of the natural water flow to generate electricity.
- With barrage, 100% of the water flows through a narrow passage, whereas with our project at FORCE, our turbine takes up less than 0.001% of the cross section of the passage. Around 99.87 percent of the water passing through the Minas Passage does not go through the turbines.
- Another important difference is that there are no large pressure changes around an in-stream tidal turbine, as has been observed in barrage installations.
- You can read more about the differences between in-stream and barrage technology here: Tidal Energy Generation .
Will you export this Nova Scotia resource to the United States market?
No. The power generated from the Cape Sharp Tidal demonstration project will stay right here in Nova Scotia. This will also apply to the other developers at FORCE. Under Nova Scotia regulations, all the energy generated at FORCE must be produced and consumed in the Province.
Have key stakeholders been consulted prior to this project going forward?
Yes. We’ve undertaken extensive outreach activities to engage a broad stakeholder network in our plans. Since 2007, consultations and engagement about in-stream tidal development have been ongoing around Nova Scotia. Since the Cape Sharp Tidal demonstration project began in 2014, we’ve met in community fire halls, on fishing wharves and around kitchen tables to listen and share directly with those who have a stake in our plans, and with whom we have common goals to safeguard the Bay of Fundy:
- Hosted direct community engagement with public, advertised open houses (Pictou, Parrsboro, Halifax, Wolfville) and information sessions around the Bay of Fundy;
- Participated in public meetings held by third-parties;
- Shared updates online through our newsletter, website, FAQ, blog, social and traditional media.
- Opened a community office in Parrsboro to meet directly with local residents and business owners; and
- Present to environmental, fishing and industry groups at local, regional and international conferences and 1:1 briefings.
Our outreach is in addition to OERA’s Strategic Environmental Assessment (2007), the Mi’Kmaq Ecological Knowledge Studies, the FORCE Environmental Assessment (2009) all which provided more than a hundred opportunities for public engagement and consultation, Cape Sharp Tidal is a participating member of the FORCE-led Fishers Liaison Group, Community Liaison Committee and Fundy Energy Research Network.
As well, we paused our deployment plans in summer, 2016 to allow even more opportunities for more engagement with the fishing community. Together with FORCE, we made an extensive effort to address concerns and answer questions. We committed to listen, and to learn from what we heard. As a result, we made several additional commitments to enhance our monitoring program and improve the engagement process for the benefit of all Bay of Fundy users. The details of those commitments were shared in advance with many of those fishing groups ahead of our deployment and are posted online here: capesharptidal.com/commitments/ .
Our extensive outreach activity is our commitment to keep stakeholders apprised of our plans, include them in our decisions and offer opportunities for knowledge sharing, feedback and dialogue. We will continue to maintain and strengthen relationships with all stakeholders after deployment with ongoing engagement and consultation activity.
Do Nova Scotians support tidal energy development in the Bay of Fundy?
In an effort to gauge public understanding and support for the Cape Sharp Tidal demonstration project, we commissioned Corporate Research Associates to undertake public opinion research in summer 2016 and spring 2017. Reports of that research is posted on the FORCE research website. Some of the key findings include:
- There is strong support for the development of tidal energy in Nova Scotia;
- Support for the development of tidal energy is consistently high, even among those who place critical importance on key environmental and community factors;
- Support for the development of tidal energy is primarily driven by it being a renewable / clean energy, while opposition centres on concerns about marine life and environmental impacts;
- Nova Scotians recognize the potential tidal energy presents for the province, both in terms of economic contribution and energy generation;
- Nova Scotians generally support moving forward with the project and most believe that enough is known about the impact of tidal energy on the Bay of Fundy;
- Nova Scotians strongly believe that any tidal project must include environmental monitoring and be respectful of local fishing and Mi’kmaq communities;
- While all evaluated factors are deemed important, protecting the environment, generating a clean / renewable energy and ensuring a viable fisheries are deemed most critically important;
- There is resounding agreement that a small tidal test program is a reasonable way to test the concepts’ viability in a clean and environmentally safe manner, and
- Nova Scotians overwhelmingly endorse moving ahead with the tidal energy project if all government and environmental approvals are received.
How much will this project cost Nova Scotia Power customers?
The Province of Nova Scotia has developed a Developmental Feed-in-Tariff program to encourage technology development in this new industry. Five developers have received approval through the Program for a certain allotment—ours is for 4MW of produced power at $0.53 per kilowatt hour, a rate set by the Nova Scotia Utility and Review Board. You can read more online about Nova Scotia’s Developmental Tidal Feed-in Tariff Program .
This initial phase of development will help us confirm the costs and production associated with tidal. The objective is to be able to produce tidal energy more economically as development progresses. As with all new technology and innovation, there’s some upfront investment to develop new and innovative ways to meet our environmental challenges. And like all other renewables, the cost to produce tidal energy is expected to come down significantly over time, just as it has for solar and wind. This is a normal part of clean technology development.
The Cape Sharp Tidal demonstration project is largely a private investment between OpenHydro/Naval Energies (80%) and Emera Inc. (20%). The two project partners have invested tens of millions into Nova Scotia’s supply chain so that benefit for this project stays local. And we’re proud of meeting our commitment to spend at least 70% of those phase 1 costs in Nova Scotia. In that process, we’ve brought 125+ Nova Scotia companies on board, and employed 300+ people.
In 2015, Sustainable Development Technology Canada, a not-for-profit foundation that finances and supports the development and demonstration of clean technologies, awarded OpenHydro $6.3 million in support for technology development.
What is the cost of tidal energy vs. other renewable sources?
This initial phase of development will help us confirm the costs and production associated with the turbines. Like all other renewables technologies, the cost to produce tidal energy is expected to come down significantly over time. The objective is to be able to produce tidal energy more economically as development progresses. Deployments from other turbines around the world indicate tidal energy could be cost competitive with offshore wind in the future. The Province of Nova Scotia has a clear need for clean, renewable energy. As we move closer to the 2020 deadline to achieve 40% renewables, tidal can play a role in that.
Would you consider doing the next project phases in another province?
Our focus and intention right now is to build a tidal sector in Nova Scotia. We’ve only begun to scratch the surface in terms of the expertise and skilled workforce. Nova Scotia workforce can help us build an entire industry around tidal. By developing local expertise and businesses in the early phases – we think there’s huge potential to build a global industry, and long-lasting economic opportunities.
Is your project covered by insurance?
Yes, we have a range of insurance coverage that is standard in large scale marine projects. That includes commercial general liability, environmental impairment, policies related to marine operations and others. Additionally, as a condition of our sublease agreements with FORCE, developers each provide a site reclamation security.
Cape Sharp Tidal Technology
Can you describe the technology being used?
The Cape Sharp Tidal project uses Irish marine firm OpenHydro’s Open-Centre Turbine. The device is an eighth-generation turbine comprised of four key components: a horizontal axis rotor, a direct-drive permanent magnet generator, a hydrodynamic duct and a subsea gravity base foundation. Simplicity is a key advantage of the design with no lubricant, seals, or gearbox which means reduced maintenance requirements. The turbine base sits directly on the seabed floor, out of the way of ships, and remains stationary under its own weight and without drilling or substrate preparation.
The predominantly steel turbine is 16 metres in diametre, weighs 300 tonnes and has 10 blades made of glass-reinforced plastic. The rated output of each device is 2MW. The base weighs about 700 tonnes, and together the base and turbine stand about 21 metres high. They are designed to be deployed for 15 years with a five-year maintenance schedule.
OpenHydro’s design philosophy is to keep the turbine as simple as possible, resulting in a device which has a low cost and low requirement for maintenance. In keeping the turbine simple, we also achieve a high level of efficiency, all of which adds up to deliver a low Levelised Cost of Energy (LCoE) – the key measure when comparing tidal turbines.
What is the Turbine Control Centre (TCC)?
The TCC is a sub-system attached onto the subsea base and connected to the turbine which allows us to transform the raw electrical power from the generator into grid compatible AC power. By treating information coming from the multiple sensors located within the turbine system, the TCC is used to optimize the power output in any operating conditions. This is the first deployment of this pioneering and vital technology anywhere in the world. Its design has been a critical step forward in being able to generate electricity from multiple turbines at sea and export to shore via a single export cable.
What is the purpose of the open centre design? Is it to provide room for the fish to go through the turbine?
No, that’s not its purpose. Efficiency and safety are the reasons for the open-centre of the turbine design. The turbine is designed with simplicity in mind. We believe the design ultimately leads to the lowest cost of energy. By using a cantilevered design (meaning anchored only on one side) to reduce force on the blade, we can increase efficiency and make manufacturing quicker and simpler. That leads to lower cost energy.
How fast do the turbines turn?
The turbine makes about 6-8 rotations per minute, which is a comparable to a fast walking speed. You can see video footage of a similar turbine here .
Will marine life get pulled into the turbines?
No. This is a common misconception. There is no hydrodynamic ‘pull’ from the turbine or significant pressure drop around the turbine, as has been observed in barrage technology that employs a completely different turbine technology.
The turbine blades move slowly—approximately 6-8 RPM—which is about walking speed. This is much slower than wind turbines, for example. In fact, we expect it’s more likely that fish will move around the turbine, following natural water flow or currents. Early indications are that fish are only present around the turbines when water is moving slowly (slack tide). Click here to see footage of how fish shoal around another OpenHydro turbine currently deployed at another test site in Scotland .
Why aren’t the effects of in-stream turbines better known?
This is relatively new technology and much of it is in the early research and development phases. Until now, much of the research on in-stream tidal turbines has been limited to computer labs, models and predictions as well as direct observation at facilities like the European Marine Energy Centre (EMEC) in Scotland. Having turbines in the water at the Minas Passage will significantly improve the understanding of the potential effects of turbines, and will enable companies like Ocean Sonics to continue to innovate in the marine technology field. Cape Sharp Tidal is and its partners are pioneers in our efforts to advance this important research.
Will two turbines displace any GHG emissions?
Yes. Tidal can play a role in achieving Nova Scotia’s goal of 40% renewables by 2020 with a reduction in GHG emissions. Two Cape Sharp Tidal demonstration turbines will reduce CO2 emissions in Nova Scotia by 6,000 tonnes per year. That’s like taking 1,100 cars off the road for a year, and the same amount of C02 released by burning more than 2,000 tonnes of coal for electricity.
How do you address plants, animals or fungi attaching growing on the structures underwater?
The Cape Sharp Tidal subsea bases are about two metres off the sea floor so organisms can move freely around them. We expected some degree of colonisation on non-moving parts, which is normal for submerged marine structures and the turbine is designed to allow for. However, upon inspection of most recently retrieved turbine, there was little to no biofouling. This is likely due to the speed or force of the current in the Minas Passage.
Is there any electricity going into the water or excess power ‘leaking’ into the environment?
No. The only route for electricity is in to the grid. There is no mechanism to transmit electricity into the water. The turbine manufacturers have modelled and fully understand how the turbine is designed and how it generates electricity from the oceans. It has been erroneously stated there is a large gap between the rotor and stator causing an electric current to enter the seawater. That is not the case. In fact, EMF is captured—that is how we generate electricity—and the generator is magnetically fully shielded. In fact, any metallic substance for use in seawater is protected by cathodic protection and the turbine uses materials approved for marine use, and which are not known to electrolyse seawater.
Can you explain what it means for the turbine rotor to be in free spin vs. generating mode?
Free spin means the turbine rotor is turning but not generating electricity. Generating mode means that the turbine rotor is turning while generating electricity.
How fast does the rotor turn when in free spin?
Whether when generating or free spin, the speed varies with the velocity of the current. The turbine rotor would typically turn at less than 7 RPM when in free spin.
What percentage of the time is the turbine rotor in free spin?
Under normal operating conditions, the amount of time the turbine rotor is in free spin is minimal, typically less than 1% of the time for each tide. There is a short period of approximately 30 to 60 seconds between when the turbine rotor starts moving and when the turbine starts generating. The same is true, although typically for a shorter period, at the end of the generating cycle. Short periods of free-spin (less than 60 secs) are a regular part of the turbine’s operation. They occur at the start and end of each generating cycle and are low RPM (less than 7 RPM).
The Fundy Ocean Research Centre for Energy (FORCE) Site
Is there adequate baseline data to assess potential effects of turbines on marine life?
Yes. The FORCE test site is one of most studied tidal energy sites in the world, with more than 93 baseline studies and 20 reports related to the Crown Lease Area. Research began in 2007 as part of FORCE’s Environmental Assessment (EA) approval, including a Strategic Environmental Assessment and two Mi’kmaq Ecological Knowledge Studies.
In May 2016, the Nova Scotia Offshore Energy Research Association (OERA) published a report by Dr. Graham Daborn summarizing the extensive tidal-energy related research undertaken in the Bay of Fundy since 2007: “Researching Tidal Energy – Marine Life: The Nova Scotia Experience.”
As a developer, our adaptive management monitoring approach is based on the results and predictions of the FORCE Environmental Assessment but all baseline research will be useful in understanding the environmental interactions that could occur once in-stream devices are deployed.
Our role is to work with FORCE by combining FORCE’s mid and far field environmental monitoring with our monitoring efforts in the near field area of the turbines (0-100 metres), for the project’s demonstration phase.
Are there other potential tidal sites around the world that don’t have the same rich ecosystem diversity of the Bay of Fundy that may be more appropriate for tidal development?
The Bay of Fundy is a unique resource with one of the highest tidal ranges in the world. Studies (like this Value Proposition from the Offshore Energy Research Association of Nova Scotia (OERA): Value Proposition for Tidal Energy Development) show that that tidal energy extracted from the Minas Passage could reduce our dependence on fossil fuels and create a new industry that offers significant socio-economic benefits to rural communities in Nova Scotia, Atlantic Canada, and even across the nation. By monitoring and understanding tidal development in the Bay of Fundy, we have potential to develop clean, renewable energy without harm to the ecosystem.
Is the FORCE site an important spawning ground?
The Minas Passage is not a spawning or nursery area. Baseline studies completed for the environmental assessment confirmed this. However the Passage is used as a migratory path for various species to areas upstream in the Minas Basin. The important thing to remember is that our turbines make up 0.001% of the 5.5 km stretch between land points and are therefore not expected to have a negative effect on migrating species.
How will the turbines affect the commercial fisheries which are such an important contributor to Nova Scotia’s economy?
One of the objectives of our monitoring program is to address the predictions of the FORCE environmental assessment which concluded that no significant effect to fisheries would occur. FORCE is also testing these predictions, but the scope of our program and accountability is precise: to study fish, mammals and turbine acoustics in the near-field of our turbines (0-100 metres.) Our program is absolutely appropriate for a demonstration-scale phase of just two turbines within the Minas Passage, which is the scale equivalent of two tennis balls on the surface area of a tennis court. The Minas Passage is 5.5 kms wide—and our turbines are not expected to pose a risk to other Bay of Fundy industries, including the commercial fishery.
Isn’t the Minas Passage one of the most fertile and ecologically sensitive regions in Canada?
It has long been recognized that the Bay of Fundy is a rich and ecology diverse region overall. The Minas Passage is located in the Inner Bay area and connects the Minas Channel with the Minas Basin. Although the Passage is part of the Bay it functions mainly as a throughway for fish species to move from the Outer area to the Minas Basin for access to mud flats and saltmarshes. Baseline studies indicate that there are no sensitive habitats within the Minas Passage such nursery or spawning areas and that the bottom habitat is mainly scoured bedrock with low biodiversity. Those baseline studies are accessible on the FORCE website .
Is there a loss of fishing area due to the implementation of safety zones at FORCE?
No. FORCE and local fishers have worked together to establish mutual understanding of a safety zone around the Crown Lease Area that is intended to protect fishing gear and subsea equipment from damage and liability. FORCE has provided more information on site safety on its website here .
How does Cape Sharp Tidal plan to monitor effects of its turbines on marine life in the Minas Passage?
In consultation with international, national and local academics and tidal energy experts, we’ve developed an environmental monitoring program to study fish and marine mammal behaviour responses, and turbine acoustics.
We’re using a combination of sonar and hydrophone data that will better enable fish and marine species detection as it approaches the turbine. Our project uses the icListen passive acoustic device and the Gemini Sea-Tec active acoustic (sonar) device as well as several acoustic Doppler current profilers (ADCPs.) More detailed information about the sonar schematic and technology is available on our project website.
The scope of the Cape Sharp Tidal monitoring program is precise. It’s appropriate for a 4MW demonstration-scale project. It was developed and vetted with the FORCE Environmental Monitoring Advisory Committee (EMAC) which, by design, is an independent review committee. It has been implemented in conjunction with the FORCE EEMP to address the predictions of the environmental assessment specific to wildlife interactions with in-stream turbines and operational sound.
We are using the most advanced technology available to answer the important questions raised in the EEMP review process and the regulatory Environmental Assessment process. With turbines in the water, we can advance that research with objective, meaningful scientific data.
What is an Adaptive Management Approach to environmental monitoring?
Adaptive management is an environmental monitoring approach for multiphase projects to enable them to build on the knowledge and learnings of the previous phases. This approach uses informed, science-based decisions to modify monitoring as knowledge is gained. The approach reflects difficulties inherent with research and development projects and for those projects gathering data in tidal environments such as the Minas Passage. The approach allows for adjustments and constant improvements to be made as ecological knowledge and environmental interactions become known.
The approach also adapts through the appropriate regulatory processes. Outcomes will be reviewed continuously with NSE, DFO, FORCE’s EMAC and others and, where required, approaches and methodologies will be revised on the basis of accumulated experience and observed progress toward achieving the monitoring objectives. What we learn from the first phase will change global understanding of how safely, responsibly and economically generate power from the oceans.
Can you prove that fish and mammals won’t be harmed?
The best evidence that we have on in-stream tidal is from other deployments around the world, where there have been no negative effects to marine wildlife. This includes a 10-year deployment at EMEC in Scotland where monitoring is conducted by an independent scientific agency. Preliminary analyses of some data at the EMEC site for the Open Centre Turbine indicate that fish are only present around the turbines when the water is moving slowly (slack tide.) Scientific models support these results. You can see a short video of this evidence here. However, the studies that have been done are only preliminary. We must continue to monitor and assess potential effects.
Are you planning to monitor fish mortality or can you make predictions about the probability of strikes?
There’s no evidence to suggest vast numbers of fish will be killed. In fact, all the research points to the opposite – that fish will use the turbine structure for feeding and other strategies during times of slack tide and lower flows and will move away from the turbine when the flows exceed a certain speed. Our monitoring program will look at how fish and other marine life interact as they approach the turbine.
However, we recognize there are concerns. We will monitor for potential affects within the limits of existing technologies including behaviour as fish and other marine fauna approach the turbine. When the turbines are pulled up for routine maintenance, we can look at what newer technologies might be available. These newer technologies are already under development and early research is promising.
The purpose of the EEMP is to test the predictions of the environmental assessment which found that effects to marine life, if any, would not be significant. Members of the scientific community, local regulators and international experts all agree the monitoring program is appropriate for a demonstration-scale project.
What is the acceptable number of fish you are allowed to kill with this project?
None exists because that is not an expected outcome of this demonstration and research project. The project has been assessed by DFO against the Fisheries Act and Species at Risk Act and determined it was unlikely to be harmful to fish or fish and fish habitat.
Could pressure changes injure or kill fish or zooplankton, including lobster larvae, if they travel through the centre of the turbines?
Unlike hydro dams, there are no meaningful pressure changes around any part of the Open Center in-stream tidal turbine that would cause injury or mortality to fish or larvae if they happen to pass through the turbine centre or around it. In fact, the turbulent waters of the Minas Passage itself may present more natural significant pressure changes than the turbines as fish move throughout the water column.
Recent tests of in-stream tidal turbines in the Muskeget Channel in Massachusetts were found to have no significant difference in the total number or size distribution of zooplankton, including fish larvae, indicating turbines did not cause significant mortality. That study also suggested that effects of a commercial size tidal energy project upon zooplankton populations in Muskeget Channel may be negligible (Schlezinger and Howes, 2013).
Most fish can tolerate different ocean pressures because the gas in their swim bladders enables them to equalize with their environment, and allowing them to comfortably make small and quick up or down movements in the water column. Fish naturally adapt to small, natural pressure changes constantly including changes from wave action or tidal fluctuations.
Unlike tidal barrages and hydro dams the pressure differential created by in-stream turbines is negligible.
Your environmental monitoring program is looking at the underwater acoustics of turbines. Is that because it can affect fish hearing and tissues?
Sound production in the aquatic environment is a known stressor to many types of aquatic life, so it is important to understand the potential effects.
Past studies have indicated no effects to marine life from the sound of an operating turbine. A 2011 study of juvenile Chinook salmon and an OpenHydro six-metre turbine indicated no effects on hearing sensitivity. Furthermore, the greater the distance from the turbine showed even less risk as sound levels decrease on an order of 6 dB per doubling of distance. (Halvorsen, Carlson and Copping, 2011).
The Minas Passage is a very loud environment with sound being created from the tides and from shifting objects, such as boulders. So far, we have measured low frequency sound and found that operational sound is indistinguishable from flow noise below 60 Hz. We are now looking at high frequency sound and will report those results shortly.
We’ll compare operational sound to sound measurement from a control and to baseline research on existing sound (natural sound created by the environment). FORCE will also measure sound at other locations in the Crown Lease Area during turbine deployment for a near and mid field effects comparison.
What risks are there for other environmental pollutants around the turbine?
The turbines do not use oils, which eliminates any possibility of contamination to the environment.
Could small numbers of fish mortalities affect populations in years to come?
Based on the scientific evidence and our experience to date, this is not expected. All Bay of Fundy marine life faces threats from habitat loss or degradation, climate change, agricultural contaminants, shipping, predators and overfishing, and other natural and human causes. The important thing to remember is that, with our investment in monitoring and the research we and FORCE have in place, our project could increase the knowledge about populations, ecological relationships and processes in the Bay of Fundy, and even attract future funding to strengthen research and conservation efforts.
Can your acoustic sonar ‘hear’ whale calls?
Yes. Primarily it will identify the click trains and whistles of the harbour porpoise as we expect that this will be the most likely marine mammal present at the FORCE site, but it can also record the lower frequencies of the larger whale species.
How can your sonar ‘see’ marine organisms in the water?
The Gemini imaging sonar is an active acoustic device. It is a high-frequency multi-beam sonar technology that uses reflected sound (similar to an echo or an ultrasound) to build up a picture of an underwater environment. Images created by these high-frequency sonars are low resolution when compared with contemporary video technologies; however when there is insufficient light or high turbidity [cloudiness or haziness of water caused by suspended solids (sand)] video cameras lose the ability to create a clear image. Subsea environments have limited light and the Minas Passage is very turbid, but these factors are not as much of a problem for high-frequency sonars.
A multi-beam, high-frequency sonar typically sends out a ‘ping’ (an acoustic pulse transmission) up to 30 times per second. Each ping is used to create an image that visualizes the different intensities of the reflected sound as it bounces back. This means light and turbidity do not affect the sonar’s ability to detect objects. The Gemini sonar performs detection based on reflection of sound from objects in the water and then uses a ‘geometric approach’, meaning it focuses on size, shape and movements of each object. A specialized software program, SeaTec, examines the sonar data and extracts moving targets before performing a classification (i.e., concluding that an object is likely to be a fish or other marine wildlife or seaweed or moving rocks).
The sonar on the CST turbine looks ahead approximately 60m and has a view plane width of 104m. Identified objects are tracked as they move into the view plane and toward the sonar.
Why is hard to use cameras in the Minas Passage?
The water is very turbulent and can contains a lot of sediment, making visibility difficult. However, we are open to testing technology and as a result have mounted a video camera on the subsea base facing the rotor. While the camera is a high definition unit used for live monitoring of underwater areas and has a wide view angle, we want to caution that we may not be able to see anything meaningful because of turbid water and the lack of light at the depth of the turbine. Our sonar technology, by comparison, is in many ways better than a camera because the image it produces is not as sensitive to turbidity or low light. The sonar will track organisms if they are in the vicinity of the turbine, and give us meaningful data about their behaviour around the turbine.
Will Cape Sharp Tidal rely on an independent third-party to analyze the environmental monitoring results?
Yes. Environmental monitoring analysis will be completed by independent third-parties. In addition, our environmental monitoring plan was developed with local and international third party experts in in-stream tidal technology and monitoring.
Will the public be able to access the data you collect?
The raw data will not be useful without specific software and expertise. However, our results will be provided in quarterly reports and an annual project monitoring report to be submitted for review to NS Environment (NSE) and Department of Fisheries and Oceans (DFO). We will also integrate our early findings into ongoing consultation and engagement discussions with our stakeholders and Mi’kmaq interests. In addition to this, ongoing meetings with DFO and NSE will take place throughout the monitoring program to ensure ongoing collaboration and understanding. We will post our reports on our website.
In the Environmental Effects Monitoring Program (EEMP) report for its third-quarter of operations, Cape Sharp Tidal (CST) said that the sonar on its turbine needed repositioning. When did CST notify regulators that it needed to adjust the sonar position to better capture more of the water column and less of the seabed?
Cape Sharp Tidal first told regulators the sonar position was being assessed and may need to be adjusted in a report submitted on December 7, 2017, one month after deploying the turbine. Data analysis was still in the early stages at this time so we needed to clarify how much of the water column could be studied. We confirmed with government that the Gemini sonar needed to be repositioned during meetings in early 2017 and also noted this in the EEMP report for the turbine’s first quarter (Q1) of operations, submitted on April 1, 2017. In the Q1 report, the need to reposition the sonar was noted, along with a commitment to do so during the turbine retrieval planned for spring 2017. The need to reposition the sonar was also noted in the second-quarter EEMP report, submitted on July 1, 2017.
CST’s tidal turbine project is focused on research. We are testing and assessing environmental monitoring devices as well as turbine technology. Repositioning the sonar is a priority for us as we prepare the next turbine for deployment. We take an adaptive approach to environmental monitoring. That means we are always looking for new and better ways to gather data and to add to the data collected by the devices already on the turbine and its subsea base.
Is the sonar you are using well-suited to the conditions in the Minas Passage?
Our approach to environmental monitoring is based on feedback and involvement from international experts in the field of tidal energy. The Gemini high-frequency sonar has been used successfully at other tidal energy test sites. These sonars have been part of the overall strategy for environmental monitoring around tidal turbines since 2009. This is when they were first used in Strangford Lough by Marine Current Turbines, as part of the SeaGen installation.
High-frequency sonars like the Gemini are particularly useful in aggressive environments where there is low visibility and constant monitoring is needed to satisfy regulatory requirements. There are other high-frequency sonars (such as one made by a company called Didson), but the Gemini sonar’s ability to track targets with good resolution at increased distances makes it the best sonar for this project. Cape Sharp Tidal’s monitoring is focused on tracking marine life that approaches the turbine. The Gemini has a maximum range of 150 meters while still providing good resolution, which makes it the best sonar for this type of monitoring.
The Gemini was successful during Cape Sharp Tidal’s initial turbine deployment. The sonar operated the entire time, it was not damaged and it successfully and continuously collected data. We have also learned a lot and will be using those lessons and applying that knowledge towards the next turbine deployment, when we will again be using the Gemini device.
In the data collected by the Gemini, could a false-positive actually be a fish strike?
No. False positives are not fish strikes. False positives take place when the Gemini’s automatic target tracking feature mistakenly identifies a target as swimming marine life. When a researcher validates the data as part of our data validation protocol, the target is confirmed to be non-living. False positives are most commonly found to be marine flora, rocks or water turbulence. False positives are more common when the sonar field of view includes the seabed. This is why our data from the last deployment had many false positives. Cape Sharp Tidal’s Gemini sonar will be repositioned for the next deployment to capture less of the seabed and more of the water column. Adjusting the sonar position will reduce how many false positives occur.
Is there any way to check for fish or marine mammal strikes or to see if fish or marine mammals go through the center of the turbine?
When we deploy our next turbine we are studying the possibility of deploying a research platform with imaging sonars to achieve a side view of a turbine. The objective of this targeted imaging is to better understand potential interactions between marine life and the turbine. The feasibility and usefulness of this set-up was tested during summer and fall 2017 through three stages:
- Low flow (intertidal zone of the FORCE beach – 2 metres per second (m/s))
- Intermediate flow (between the FORCE beach and Black Rock Island – 4m/s); and
- High flow (in the turbine deployment region – 6m/s).
Additional studies using a similar approach are being tested in Scotland.
Could you use a camera to view the seafloor to see if there are fish mortalities?
Using a camera to monitor fish mortalities in this way would not be effective for two reasons:
- The visibility in the Minas Passage is poor due to sediment in the water and lack of light.
- Even in good viewing conditions, in this high flow environment a fish would not sink to the seafloor and remain by the turbine.
Regulators and scientists agree that the best thing to understand at this stage is potential interactions between fish and turbines rather than fish mortalities. For this reason, our Environmental Effects Monitoring Program (EEMP) is focused on collecting information about potential interactions. But we are also exploring additional components for the monitoring program that may lead to a better understanding of marine wildlife interactions close to the turbine.
Were any large whales seen by the sonar during the last turbine deployment?
No. Nothing large has been identified in the sonar data we have analyzed to date from the last deployment. The hydrophones (which listen for vocalizing marine life) also did not detect any large whales, although harbour porpoises were detected.
The science on Bay of Fundy species
Could protected fish species face greater threats with turbines in the water?
The best evidence we have on in-stream tidal turbines is from other deployments around the world, where there haven’t been any negative effects on marine wildlife populations. All Bay of Fundy marine life face threats from habitat loss or degradation, climate change, agricultural contaminants, shipping, predators and overfishing, and other natural and human causes. The important thing to remember is that, with our investment in monitoring and the research we and FORCE have in place, our project could increase the knowledge about populations, ecological relationships and processes in the Bay of Fundy, and even attract future funding to strengthen research and conservation efforts.
We remain in contact with different researchers and recovery teams associated with protected marine species in order to share project information and understand issues facing these species.
What is the effect of electromagnetic fields (EMFs) on marine life?
The international research on the subject of electromagnetic fields overwhelmingly shows that marine life is not adversely affected by EMFs. There have also been studies in the Minas Passage on this topic. More information is available on the FORCE website.
What impact could this project have on Striped Bass, Sturgeon or inner Bay of Fundy salmon?
The Bay of Fundy’s Striped Bass population is not listed under the Species at Risk Act (SARA) but is considered Endangered under COSEWIC. The COSEWIC status reports states that the main threats to this species are overfishing (directed, by-catch, and poaching), habitat loss and degradation (e.g., dredging), agricultural or industrial contaminants and migration barriers. In spite of their status, there is still a large recreational fishery supported by the population. Two demonstration scale turbines are not expected to have a population-level effect on this species.
Shortnose sturgeon is listed as Special Concern by COSEWIC and under SARA. The species is known to prefer the south side of the Minas Passage, which decreases the chance for turbine interaction should they happen to move through the Minas Passage. COSEWIC considers that the main threats to this species are hydroelectric facilities, by-catch in alewife and shad fisheries, and poaching. (COSEWIC 2005) The Maritimes population of Atlantic sturgeon are not listed under SARA. COSEWIC has assessed this species as Threatened noting commercial fishing and pollution may have been the most significant factors that caused suspected declines in Atlantic sturgeon populations in the past. (COSEWIC 2011)
Inner Bay of Fundy Atlantic salmon are considered Endangered by COSEWIC and under SARA. Threats are related to substantial but incompletely understood changes in marine ecosystems, and negative effects of interbreeding or ecological interactions with escaped domestic salmon from fish farms. (COSEWIC 2010) Although the species uses the Minas Passage for migratory passage, the area is not considered critical habitat. During migration the species utilizes the upper portion of the water column and are not expected to come in contact with the turbines which are bottom-mounted at approximately 40 metres below the surface. Negative effects to this species from the CST tidal turbines are not expected.
Is the Minas Passage a ‘hot spot’ for marine mammals like harbour porpoises?
No. While porpoises are found in the Minas Basin and Minas Passage, they are known to prefer the Outer Bay of Fundy. Studies by Acadia University and SMRU consulting for marine mammals in the Minas Passage from 2011-2014 includes 2,700+ days of passive acoustic monitoring (using CPODs) across seven sites including year-round coverage at key sites. Harbour porpoise density in the Minas Passage is estimated to range from 0 to 1.4 per km2. The total number of porpoise present in a single tidal cycle can range from 0 to 42, a lower estimates than those reported in known focal areas of the Outer Bay of Fundy that are preferred by harbour porpoise, which confirms that the area is not a hot spot for harbour porpoises. (Johnston et al. 2005). The Minas Passage acts as a feeding ground for some of the porpoises found further out in the Bay of Fundy, which is why it is important to understand how these animals interact with the turbine.
The harbour porpoise is currently considered to be a species of Special Concern under the Species at Risk Act; Schedule 2 meaning that a reassessment is required using new criteria. The COSEWIC report states that the most important threat to Harbour porpoises in eastern Canada is bycatch in bottom-set gill nets used to capture groundfish. This threat has decreased substantially with the depletion of groundfish stocks and consequent reductions in fishing (COSEWIC 2006).
Is there a possibility that endangered right whale might be injured or killed by a turbine?
Whales, in general, are extremely rare visitors to the Upper Bay of Fundy. It would be highly unlikely that a right whale would approach a turbine at the FORCE site.
This West Coast of Canada study considered an orca-turbine collision. It was determined, in that instance, an orca would not experience significant injury from colliding with a turbine fin.
Our Environmental Effects and Monitoring Program research will advance marine research and understanding of the frequency and habits of marine mammals and fish that use the Minas Passage or approach a turbine.
Is the Minas Passage a critical wintering habitat to Striped Bass or a major nursery for lobster larvae, sea scallops, cod, haddock, gaspereau, and other fisheries?
In terms of its importance to most species—including the Striped Bass—the Minas Passage is a migratory route, but there is no evidence to suggest it’s a critical winter habitat. Studies have confirmed that the Minas Passage is neither a spawning or nursery area. It is unlikely that population-level threats to any fish species will occur.
Because there are so few numbers of Striped Bass, wouldn’t even one fish death pose a threat to the entire population?
This would not pose a population level threat. This population is not considered at risk under the Species at Risk Act. Additionally, there is still a recreational fishery supported by this species in the Bay of Fundy.
Do winter ice blocks in the Minas Passage present a risk to the turbine?
The presence of neutrally buoyant ice floes or “ice cakes” are a small risk for most in-stream tidal devices, which have been designed in consideration of ice effects, particularly for devices like ours that sit on the sea floor. Ice formations can occur at low tide when the intertidal zone is exposed. When the tide floods, shore ice can refloat, break or pile up to form multi-layered ice blocks. Blocks can be several meters high and can become grounded in the intertidal zone when the tide falls, causing the surficial sediments to scour. When temperatures are extremely cold, the surface of the sea may freeze forming large floes that move with the tides.
The 2009 FORCE EA determined ice floes were not anticipated to have significant effects at the FORCE site. The Canadian Ice Service also initiated studies on this type of ice in the Minas Basin/Passage, begin an ice/sediment sampling program, and to track ice movements to study the dynamic behavior and understand the risks to tidal energy. A baseline study completed in 2012 states that there has been no direct observation of ice cakes that are near neutrally buoyant and/or are drifting near the middle of the Minas Passage water column. The report also notes that, qualitatively, the near-neutral buoyancy ice cakes pose a small part of the total risk to tidal test turbines and that this risk should not delay or prevent installation of the turbines.
Regulations, Permits and Guidelines
Can your turbine be removed if there are negative environmental effects?
Yes, the turbine can be removed. It would not be acceptable to us if Cape Sharp Tidal turbines were found to have caused significant adverse environmental effects on marine species. That determination is set out in the guidelines of the FORCE Environmental Assessment and the Fisheries Act. While Nova Scotia Environment has the discretion to order the turbines removed, we would not wait for that order to be made – we would voluntarily remove them from the FORCE site.
What input have you had from Fisheries and Oceans Canada?
The Department of Fisheries and Oceans reviewed the Cape Sharp Tidal project application under the Fisheries Act and the Species at Risk Act, and stated it was of the view that our demonstration-scale project would not result in serious harm to fish and fish habitat. DFO has stated support of CST’s adaptive management approach to addressing some of the existing research gaps, after turbines are deployed and objective, scientific data is available.
The 2010 OpenHydro/Nova Scotia Power test project
What happened in the 2010 project?
Analysis of the data from the turbine following recovery showed that we had underestimated the flow within the Bay of Fundy. This resulted in the turbine being exposed to greater tidal force than originally anticipated. The turbine was not designed to withstand the tidal flow it was exposed to and therefore the blades failed. As a result, OpenHydro has invested heavily in researching tidal flow measurements. The Cape Sharp Tidal turbines are larger, stronger and re-engineered for the FORCE site.
Were any large mammals like whales killed in the 2010 project?
No, although there has been much speculation about this. A deceased fin whale washed ashore in the Minas Basin in June, 2010–a full five months after the turbine stopped functioning. While a formal necropsy was not performed on the recently-deceased animal, the Marine Animal Response Society did examine it and noted that the injuries to the whale were identified as being post-mortem. More details are offered by MARS on its Facebook page: https://www.facebook.com/marineanimalresponsesociety/posts/680063945501876 .