Tidal energy for data centers: A sustainable power option

Tidal turbines

The surge of currents as tides rise and fall produces tidal energy. To produce electricity economically and efficiently, there must be a minimum 10-foot difference between the rise and fall of the tide, according to the U.S. Energy Information Administration.

There are three categories of tidal turbines: tidal ranges, tidal currents or streams, and combinations of the two in a hybrid system.

Tidal ranges

Tidal range turbines generate electricity through the height difference of high and low tides. A tidal barrage is similar to a dam and must be closer to land. Water must separate into high and low sides, where water naturally falls over or through a turbine to generate electricity.

Tidal lagoons, reefs and fences are similar to barrages but have flexibility with location -- they can be further in the ocean. The structures consist of retaining walls with low-head turbines encircling a water reservoir. The turbines artificially create a difference in the water height inside and outside the lagoon walls, enabling the exchange of water over or through the turbines.

Tidal currents

Tidal current turbines, or tidal streams, use moving water in streams to generate power. These turbines move similarly to wind turbines, generating electricity as the tidal currents spin blades. They can be set up horizontally or vertically to best capture the movement of the water.

Tidal kites work similarly to tidal current turbines, as they both use currents to generate power. Areas with slower tidal flows are the most efficient. Kites tether to the seabed, and a turbine under the wing creates power from the tidal current.

Oscillating water columns use waves and tides to generate power. They have long tubes that are semisubmerged to the sea below and connected to a power take-off (PTO). A pocket of air is trapped above the hollow chamber, and the waves and tide force the air in the column to move up and down like a piston, forcing high-velocity air into the PTO.

Hybrid tidal turbines

Hybrid tidal systems combine tidal current and range technologies to generate electricity efficiently.

Dynamic tidal power is ideal for areas with tides that flow parallel to the coast. Long dams are built perpendicular to the coast with a t-bar at the oceanside end and turbines built inside the dam. As the tide moves over the dam, the turbines spin from the height difference. The turbines are often bidirectional, meaning they can flip 180 degrees as the tide changes direction.

Advantages of tidal energy

Advantages of tidal energy include the use of renewable sources, predictable energy production, high power output and cost-effectiveness.

Renewable energy

The fluctuating gravitational forces from the sun, moon and Earth's rotation keep water currents constant. Water is a natural energy source that does not produce greenhouse gas emissions, making it a sustainable option for meeting green energy goals by reducing fossil fuel and electric grid use. Tidal turbines also keep land free of use.

Predictable energy production

Tidal cycles are highly predictable, unlike the wind and sun. Although weather, like hurricanes, can change tidal flow, water movement always creates energy. Tidal energy is an intermittent source as large amounts of energy are generated twice a day due to tidal cycles. However, tidal cycles are consistently occurring, which enhances the feasibility of tidal energy as a dependable power source.

High power output

Due to water density, tidal energy has a high power output. This enables more energy generation per unit area, making it an efficient option for large-scale energy production. Turbines generate more power with stronger currents.

Cost-effectiveness

Tidal technology is cost-effective with long-term use. When put in the correct location, tidal energy turbines can operate continuously, reducing power production downtime. Although the upfront cost of materials and installation is an immediate expense, the longevity of material use, consistent power supply and integration of a naturally occurring resource can reduce operational costs over time.

Environmental challenges of tidal energy technologies

The use of tidal energy is not as common as solar and wind. The initial cost, construction and location of tidal turbines are the primary reasons companies look to other renewable sources. Strict government regulations and concerns about marine life disruption also challenge tidal energy integration.

Initial cost

Companies must pay an upfront cost for the design, construction and installation of tidal turbine systems. Expenses also include hiring professionals who can navigate the environment and the materials and equipment that can resist the corrosive properties of seawater.

Location

Tidal energy sites must be built close to land as high tidal currents produce the most efficient power supply. They cannot be in shallow water as the turbulence isn't powerful enough, and there's not enough motion in deep waters. According to a research report in Renewable Energy (Volume 170), the flow speed necessary to create energy efficiently depends on the generational model of the turbine; older models need a flow speed of 2.2 meters per second or above, while newer models need 1.3 meters per second or above.

Political setbacks

Government-held restrictions have set back tidal energy generation projects. For example, in 2020, the Pempa'q Project in Nova Scotia, Canada, received C$28.5 million (approximately $19.8 million at time of writing) in funding from Natural Resources Canada's Emerging Renewable Power Program to research and construct a floating tidal energy array, according to Offshore Energy. The project was rejected due to possible risk to marine life.

Environmental impact

Although tidal generation is a renewable resource and reduces the use of fossil fuels, there are environmental concerns about the technology. Offshore construction projects could change the flow field and water quality. Chemicals in anticorrosion paint, oil and grease from the turbine can leak into the water.

The vibrations of spinning turbines might attract sea life, but they typically cause marine animals to avoid the area, similar to boat propellers. Installation of tidal turbines could harm animal navigation and communication.

Do data centers use tidal generation?

While there have been plans for data centers to use tidal power as a renewable energy source, none are currently running on tidal power. As of late 2024, however, Iron Mountain and SeaQurrent are working together to deploy tidal kites to operate their facilities.

Data centers are not yet operating under tidal energy, but advancements are underway with tidal projects worldwide. According to a report from the International Energy Agency, tidal stream and tidal range technologies are in the commercial operation range in the U.K., Netherlands, France and Korea. The MeyGen tidal energy project in Scotland uses four tidal current turbines to generate enough electricity to power approximately 6,000 homes in the U.K. The only tidal plant in Canada closed in 2021, and the U.S. currently has several test projects at various stages of development.

Tidal power is a promising renewable energy concept, but it's not ready for widespread data center adoption. As technology matures and infrastructure develops, tidal power could become critical to sustainable data center operations in coastal regions.

Julia Borgini is a freelance technical copywriter, content marketer, content strategist and geek. She writes about B2B tech, SaaS, DevOps, the cloud and other tech topics.