Frequently Asked Questions

Any object in the sea is subject to different risks. If they are not properly handled, something could go wrong and the unit could end up in the seabed, or alternatively drifting in the ocean, until it could hit another structure or run aground in the coast. Among the different types of risks related to these potential events, we have:

- Flooding: Flooding could be caused by a bad design, by the Acts of God, or by a collision, to name a few. Some floating wind turbines are not conceived to remain afloat in such condition, and they will sink if that happens. Others, like Sea Breeze tech, ensure the damaged unit does not sink in case one tank is flooded. In such conditions, the unit can be towed to port for repair. Regarding a possible failure due to a bad design, this risk is minimized during the design stage through the certification of the unit by a Classification Society. In one of the certification stages, the society performs its own calculations to confirm both the engineering and the society obtain the same level of stress in the structure for every load case. It is after all a third-party validation of the structural analysis.

- Fire: a fire could end up in the loss of the structural integrity, with the possible flooding of more than one compartment. Fortunately, sea-breeze tech uses concrete for the largest part of the structure. Concrete is a non-combustible material with a slow rate of heat transfer. Besides, a fire-fighting system in the unit ensures fires are extinguished.

- Bankruptcy: units in the sea are to be decommissioned by the end of the project, after the unit has fulfilled its operational life. Sometimes crane vessels are required for this stage, increasing a lot the cost of this operation. If the development sees bankruptcy before the project finishes, due to unexpected costs, there will be no money to pay the decommissioning stage. This was the case of some tidal device demonstration projects. Minor problems during the operational stage required expensive O&M operations (with crane vessels), getting the project developer to bankruptcy. The floating wind is less sensitive to this problem because the nacelle can be accessed without taking the unit out of the water in the O&M stage. Besides, Sea-breeze does not need expensive crane vessels for installing, commissioning, maintenance, or decommissioning activities. Tugs are used in these operations.

Finally, it is the duty of the project management team to establish a risk management plan and ensure its control and execution. For every risk identified, there shall be adequate mitigation and contingency measures.

Answer source: Brezo Energy Inc. - Project Developer

Airports need an area around them free of obstacles for the safe operation of airplanes. Wind turbines, due to their height (the tip of the blades is already reaching 200 m for the largest turbines), represent obstacles to the air traffic, and must be marked with aircraft warning lights at night. In this sense, small general aviation aerodromes are usually the ones affected by wind farms, albeit the largest airports may be affected as well. Thus, Obstacle Limitation Surfaces (OLS) around the airports, as well as other areas for protection of flight procedures need to be considered during the selection stage of a potential area for a wind development.

Besides, the blades of a wind turbine generate when they rotate vortices that move downstream, and this turbulence could cause trouble to light aircrafts. Some distance off the farm is also required in this regard.

Wind turbines may also pose radar interferences to communication systems. As such, the air traffic control may be affected, requiring a safe area without turbines around the airport. For the same reason, marine radars could be affected as well.

These restrictions affect an operational area which varies between airports, but which fortunately is greatly avoided when placing the turbines offshore. In any case, specific analyses are performed during the farm impact analysis (IA) to ensure the coexistence of airports, wind farms and communication systems.

Answer source: https://www.airsight.de/projects/item/wind-energy-and-aviation/
And “Impact analysis of wind farms on telecommunication services”, by I. Angulo et al., Renewable and Sustainable Energy Reviews, 32 (2014) 84–99.

Distance of the turbines from the coast is the main factor to ensure the visual impact is small. The Environmental Science Division (EVS) of Argonne National Laboratory and the University of Arkansas Center for Advanced Spatial Technology (CAST) performed a study, funded by the US BOEM, about the visibility of offshore wind farms in the coast of the United Kingdom. The turbines subject of study were approximately 5 to 50 kilometers from the coast, and the coastal sites used in the observations had an elevation between zero to 250 meters.

The results showed that, paying attention, the blade motion could be observed up to about 24 miles (38 Kilometers). The studied also revealed turbines were considered a major focus of visual attention up to 10 miles (16 kilometers), while they were noticeable to casual observers up to 18 miles (28 kiloemters). The image shows Thanet wind facility photographed, as part of the study, from Fayreness Hotel. This site is about 7.6 miles (12.3 kilometers) from the closest turbine. During the nights, the aerial hazard navigation lighting could be seen at distances above 24 miles (38 kilometers).

Answer source: Offshore Wind Turbine Visibility and Visual Impact Threshold Distances, by Robert G. Sullivan, Leslie B. Kirchler, Jackson Cothren, and Snow L. Winters.
https://visualimpact.anl.gov/offshorevitd/docs/OffshoreVITD.pdf

The Fixed Offshore Wind has already taught us several lessons on how to perform routine maintenance, component changes or even perform major repairs at sea.

For the most basic needs, small Crew Transfer Vessels (CTVs) are used. When the sea state is not so good, or a more complex maintenance operation is needed, Walk-to-Work (W2W) solutions aboard Service Operation Vessels (SOVs) are used. W2W are motion compensated gangways that ensure a safe transfer of personnel. Other SOVs, like the Albert Betz in the image, also have boats to access the platforms. SOVs are more expensive than CTVs, so their use must be justified. If an even more complex operation is needed, crane vessel can be used, albeit they are even more expensive. Thus, the best way to ensure that Operation & Maintenance (O&M) costs do not get uncontrolled is to develop large wind farms, or by clustering two or more wind farms. This way, the fleet costs are split through many MW of installed power.

Some floating wind units may have an advantage compared to fixed units. In case a major repair is needed, the unit might be unhooked (disconnection of the mooring system) and towed back to port to perform this maintenance operation.

Answer source: Brezo Energy Inc. - Project Developer

All renewable energies, except for hydropower, can only be obtained when the resource (wind, solar light, waves, etc.) is available, and unfortunately not when it suits us. This is today not a problem because there are many hydropower plants or plants burning fossil fuels which can increase its production in case there is less renewable generation. However, the electric system will greatly change in the next 30 years. On the one hand, electric consumption will approximately double globally. On the other hand, the share of renewable production will increase from approx. 30 to 50%. Thus, renewables, together with natural gas, will be the greatest contributors to this increase in electric production.

With the increasing share of renewables in the energy mix, we will need to deal with the instantaneous differences between electric generation and consumption. Hydropower would help in this regard. However, although this market will increase in the coming years (mostly in Asia), its share in the energy mix will drop from about a 58% today to a 28% by 2050. Hence, hydropower will not suffice, and storage systems will be key. But storage comes at a cost: these systems have both capital and operational costs, and every time we store or recover energy we lose part of it. Therefore, we shall spread the renewable production among different sources to reduce the storage needs. Thus, wind, solar and hydropower will be the three pillars of the renewable mix, all of them being extremely important. Wind production is higher in winter, while solar production is higher in summer, somehow compensating each other.

By 2050, wind energy will represent a 30% of the renewable production. And among the wind developments, offshore wind has a singularity that can help it achieve a larger share in the energy mix. Because the wind blows faster and more sustained offshore, offshore wind turbines can produce its nominal power for about 50% of the time (the so-called capacity factor), while onshore wind (and solar) rates are of about 30%. This means Offshore Wind production will be more spread throughout the year, giving it an additional value in the 2050 energy mix.

Answer source: Figures provided obtained from the ‘International Energy Outlook 2019’, by the US Energy Information Administration (EIA)
https://www.eia.gov/outlooks/ieo/pdf/ieo2019.pdf
https://www.eia.gov/todayinenergy/detail.php?id=42555#

From the perspective of resistance to flooding due to heavy rain or increasing sea level, floating wind platforms are very resilient. Except for platforms using tension tethers, all floating wind turbines move up and down with the sea level, just as they do due to tides or storm surges. Thus, the sea level increase due to climate change will not affect them. Storms will not affect them as well: the units are designed to withstand the worst combination of wind, wave and currents that can occur in the farm area in 50 years. Furthermore, if far from shore and in deep waters, tsunamis will probably not affect them, as tsunamis get tall as the water depth decreases. Heavy rain is neither a problem in offshore structures.

From the socioeconomic resilience perspective, floating wind represents an industry that will help to purse the Paris Agreement objectives, an agreement signed by most countries, making it a priori less prone to socio-political changes.

Answer source: Brezo Energy Inc. - Project Developer

Mooring lines impede some fishing activities, but the wind farms are separated enough to make the farm space quite useful for other activities like aquaculture. Some research projects (https://cordis.europa.eu/project/id/862915 or https://cordis.europa.eu/project/id/862252) are testing the combined use of the marine space for activities like renewable energy, aquaculture, marine bio-resources and biotechnologies, maritime transport, or tourism. Sea-breeze will follow this line, testing several aquaculture approaches combined with the wind platform.

Many countries have performed or are currently performing a re-planning of the marine space. This is intended to sustainably maximize the benefits from the marine resources, while ensuring proper environmental protection.

Answer source: A Sea Change, A Marine Bill White Paper; March 2007; UK Department for Environment, Food and Rural Affairs

Any floating wind farm of 500MW will produce about 2 TW·h every year of clean energy. If substituting a coal-burning power plant, it will avoid, every year, about 48 deaths, 450 cases of serious illness, and 26,500 cases of minor illness. If substituting natural gas, a much cleaner fossil fuel, it will still avoid 6 deaths, 60 cases of serious illness, and 1,400 cases of minor illness every year.

Besides, Sea-Breeze Tech is using a design that reduces, during the floater construction, about 30% of the CO2 emissions compared to other floating technologies

Answer source: Source: Markandya, A. and P. Wilkinson, 2007, Electricity generation and health. Lancet, 370:979-990

The labor requirements for the construction and installation of a 500 MW wind farm is estimated at around 1.5 million person-days. This way, the Offshore wind industry could employ more than 1 million people by 2050. Among these, 0.45 million would be in construction and installation, 0.39 million in manufacturing and 0.17 million in O&M.

Nova Scotia is quite close to the US North East Floating Wind market, allowing its ports to manufacture floaters for this growing market. Sea-Breeze Tech Demonstration project will allow the creation of local construction factories around ports, with a smaller reduced environmental impact, where the entire production process of the platform will be integrated, promoting the creation of local employment and even favoring migration to depopulated coastal areas. It is estimated that only one factory can employ a total of about 800 people. But it will also promote the creation of local commerce and auxiliary services, estimated at a total of about 5,000 people. Every large development will occupy a port for about a year, and there will be about 10 large developments every year in the US from 2030 to 2050, so it will be reasonably easy to permanently occupy a port, meaning lots of stable jobs for the next 30 years. These people will need skills in civil construction and metalworks, which are well known in Canada. But there will be even more jobs required as we consider the rest of the wind turbine (nacelle, blades, tower, generator, gear, etc.). The rising traction of the wind energy industry will also demand a growing array of skills, including technical, business, administrative, economic, and legal, among others.

Answer source: Source: IRENA, 2018, Renewable Energy Benefits: Leveraging local capacity for offshore wind, Abu Dhabi.
Source: IRENA, 2019, Transforming the energy system and holding the line on rising global temperatures, Abu Dhabi

This concern comes from the fact that whales are lost every year as they get entangled with fishing gear. Mammals are entrapped around nets, or alternatively ropes if these have loops or loose ends. For instance, the first submarine cables that were laid in the ocean were too slack, which produced some loops that could trapped some mammals, drowning them. But this practice was stopped about 100 years ago.

Floating wind developments are easily avoiding these problems. Each platform has 3 to 4 mooring lines with no loose ends, and with enough tautness to make no loops. Besides, as they are sited far from shore, there is less life in that area. For instance, the grey whales that migrate between Oregon and California move within the first 5 miles from shore, too close for floating wind developments. Humpback whales, on the contrary, may swim around wind turbines, but due to the size difference, there is little risk of entanglement.

Answer source: Copping, A.E. and Hemery, L.G., editors. 2020. OES-Environmental 2020 State of the Science Report: Environmental Effects of Marine Renewable Energy Development Around the World. Report for Ocean Energy Systems (OES).

Any floating wind turbine will reduce the wind speed close to it, as well as waves and currents. Still, single wind turbines do not have enough size to modify a whole oceanographic system. Wind farms a relevant size, say 40 to 50 units, could have a larger effect, but they are separated from each other to diminish the wake effects between turbines, further reducing the impact on the Oceanographic system. Being as well in deep waters, their main interaction would therefore be with Ocean or Coastal currents, like the California current system. This risk is thus often considered very low, though numerical simulations shall analyze this effect during the development stage.

Answer source: Brezo Energy Inc. - Project Developer

Offshore Wind is, among the marine renewable energies, the only one that will have a relevant share in the global energy mix. According to DNV-GL, it will reach about a 10% of the global electric production by 2050, a 40% of the total wind production. Fixed-bottom offshore wind is already a proven industry, having already installed quite large developments, and proving itself to be economically very competitive. Still, this has been just the tip of the iceberg, and it will grow much more. Floating wind is a few years behind, but will see in the next years the first large farms.

The question that remains unanswered is whether floating wind will reduce its cost in the same way fixed offshore wind has. In case this happens, floating wind may represent up to half of the total Offshore Wind production by 2050.

Cost reduction can be achieved through a combination of mass production, standardization, large farms or clustered farms, scale effects, and life-cycle considerations. Great designs shall consider all these points.

Answer source: DNV-GL Energy Transition Outlook 2019 (https://eto.dnvgl.com/2019/rise-of-renewables) and Brezo Energy Inc.

Cold climates represent a huge technical challenge to wind farms. Ice and snow may accumulate at the blades, modifying their aerodynamic shape and if big enough requiring operation to stop, pretty much like airplanes. The accumulation of ice and snow can also change the dynamic performance of the unit or lead to unbalanced rotor spinning, which increases fatigue and may lead to a global failure. Ice may also form in some components of the turbine. Ice packs on the sea surface may also hit the floater, requiring an extra thickness in the structure. Extreme cold may also induce fragility in the structure as well, or may render wind sensors ineffective.

Many of these problems may simply be avoided by stopping the turbine operation. However, this reduces the amount of energy generated, with its associated economic losses. Therefore, other alternatives may help to reduce turbine downtimes. For instance, low temperatures are easier to deal with by upgrading the quality of the materials. Sea-breeze Tech project will study several ways to de-ice the blades and to protect the structure against ice block collision.

Besides, in the production of the floaters, cold makes the hardening process of concrete more complicated, and slower. There are however several ways to solve this, from additives to insulation of the formwork area during construction. In the coldest days of the year, however, the construction process may better be stopped for a few weeks.

Answer source: “Prepare Your Renewable Plant for Cold Weather Operations”; Power magazine; https://www.powermag.com/prepare-your-renewable-plant-for-cold-weather-operations/
And Brezo Energy Inc, Project Developer

Mooring lines and platforms lie in the whole water column, in the pelagic habitat. Fortunately, their effect is known from other marine activities (submarine grids, Oil&Gas, etc.). Encrusting organisms (biofouling) will grow on the platforms, potentially having also reefing fish, but this is not considered an ecological concern.

Anchors, cable routes and the beginning of the mooring lines are placed at the seabed, in the benthic habitat. This may change some habitats, altering species abundance and patterns of ecological succession. Although it has not been proven, it might even allow non-native species to establish in the area.

Fortunately, the effect from moorings and cables are known from other marine activities (submarine grids, Oil&Gas, aquaculture, etc.). The most important thing is siting: rare/unique habitats and slow-growing habitats must be avoided. Since the mooring lines can have several physically feasible directions, specific analyses of the best direction are done for every mooring line to avoid unique habitats like reefs. Good benthic habitat surveys are thus required in every development. Besides, as you move to deeper waters (as floating wind does), biodiversity drops, making the installation of mooring systems easier.

Benthic and encrusting organisms (biofouling) will grow on these new mooring elements, potentially having also reefing fish, but this is not considered an ecological concern.

This effect is attributed to large farms, so its effect is not fully understood yet due to the absence of large developments. It will not be a problem in Sea-Breeze Tech Demonstration project as we will install just one unit. In the project, this effect will be analyzed for future developments. Scientifics need data to validate their models, so we will monitor several variables to help them in this regard.

Answer source: Brezo Energy Inc. - Project Developer

Collision risks are mostly attributed to the blades, so for wind farms this affects birds and bats. Since floating wind farms are a few miles from shore, bats do not easily reach them, albeit there are always exceptions, and only the largest birds (big gliders like albatrosses or shearwaters) may get close to the farm. Understanding the presence of species at risk will help in every potential wind development. We shall understand how offshore these species get, what is their flight height and what is their migratory pattern. This risk is also influenced by the development variables (technology, location, weather, lighting, or farm layout).

Answer source: Copping, A.E. and Hemery, L.G., editors. 2020. OES-Environmental 2020 State of the Science Report: Environmental Effects of Marine Renewable Energy Development Around the World. Report for Ocean Energy Systems (OES).

During the 3 years of the demonstration project in between 80-85 permanent, direct jobs will be created, about 350 part-time jobs, and 800 indirect jobs.

Source: Brezo Energy Inc, Project Developer

Answer source: Brezo Energy Inc. - Project Developer

Any anthropogenic activity that uses electrical cables in the marine environment is a primary source of EMFs. The cables emit EMFs along their entire lengths, whether transmitting high-voltage direct current (DC) or alternating current (AC). Currently, high-voltage AC (HVAC) electrical cables are used to connect all types of offshore and MRE devices both among units in an array and to marine substations; and HVAC or high-voltage DC (HVDC) can be used to export power to shore. The interactions between EMFs emitted by MRE power generation with the naturally occurring geomagnetic field (GMF) can potentially alter the behavior of marine animals that are receptive to these fields, including potentially altering avoidance or attraction behaviors. It is important to know the intensity of the emitted EMF, which depends on the type of current (DC or AC), the cable characteristics, the power transmitted, the local GMF, and surrounding environmental factors.

Many marine species do not have the apparatus required to detect EMFs. So only certain species are sensitive to EMF, like eels. Studies have shown these species recognize these fields, but its effect seems to be small, not producing a barrier effect. Unfortunately, there are currently no regulatory action thresholds or standards for measurement of EMFs, so further research is needed. Models shall be created for the different power cables, both for AC and DC. Monitoring and sharing information will be key to validate these models.

For export cables, a great way to avoid EMF adverse effects, if any was found, is to bury the power cable, separating the animals from the EMF source. For the dynamic cables, those connecting the floating platform to the seabed, burying is not possible. Fortunately, the power in these cables is considerably smaller than in the export cables, and current models are showing the EMF to die-off within the first meter off the cable.

Answer source: Copping, A.E. and Hemery, L.G., editors. 2020. OES-Environmental 2020 State of the Science Report: Environmental Effects of Marine Renewable Energy Development Around the World. Report for Ocean Energy Systems (OES).

Many marine animals rely on sound for biological functions, including communication, social interaction, orientation, foraging, and evasion. The extent to which marine animals detect and produce sound varies by frequency (spanning roughly four decades from 10 Hz to 100 kHz) and is taxa-specific. Because of the relatively limited data available, hearing sensitivity is often generalized to taxonomic groups (e.g., cetaceans that have low-frequency hearing specialization) (NMFS 2018).

When considering the risks to marine animals that result from any anthropogenic activity, one must consider the amplitude, frequency, and directionality of the noise source, as well as propagation losses, prevailing ambient noise, hearing thresholds, and possible behavioral responses.

In the air, the noise from the rotor is hardly distinguishable from the wind and waves themselves. And just about 10% of this noise, produced by the blades and generator, is transmitted through the tower into the water, making this a quite small concern. Again, scientists need data to validate their models, so in Sea-breeze demonstrator we will measure the noise radiated into the water.

The IEC TC 114, which develops international consensus standards for marine energy conversion technologies, has published its first Technical Specification for characterizing radiated noise from MRE devices: IEC 62600-40 (IEC 2019). The specification, developed over a 4-year period with input from multiple National Committees (Canada, France, Germany, Ireland, Netherlands, Spain, UK, U.S.), describes methods for characterizing received levels in the vicinity of WECs, current turbines (tidal and river), and Ocean Thermal Energy Conversion (OTEC) plants.

Answer source: Copping, A.E. and Hemery, L.G., editors. 2020. OES-Environmental 2020 State of the Science Report: Environmental Effects of Marine Renewable Energy Development Around the World. Report for Ocean Energy Systems (OES).