Is Tidal Energy Renewable?

Is tidal energy renewable or nonrenewable?

Tidal energy is a renewable energy source because it harnesses the movement of the ocean’s tides, resulting from the gravitational pull of the moon and the sun. These natural forces cause the ocean tides to rise and fall in a consistent rhythm, offering an energy source that is inexhaustible over human timescales.

Unlike fossil fuels, tidal power does not consume or deplete any finite resource. As long as the Earth has oceans and the moon continues to orbit, tidal cycles will remain predictable. This makes tidal energy a truly sustainable solution.

These forces will never stop pushing and pulling the tides until either the sun explodes and destroys our solar system, or the moon drifts so far away from the Earth that its mass no longer exerts a gravitational force on our planet. Luckily, these events are either extremely unlikely or would take many billions of years to occur.

Is tidal energy a reliable source of energy?

One of tidal energy’s biggest strengths is its reliability. Tidal cycles are governed by celestial mechanics, which means they are highly predictable months and even years in advance. This allows for stable, forecastable energy output, unlike the variability of solar and wind, which are influenced by weather.

However, tidal energy does come with some limitations. It is geographically constrained. Only coastal areas with a sufficiently high tidal range or strong tidal currents are viable for large-scale development. This restricts the number of suitable deployment sites compared to more flexible renewables like solar panels or wind turbines.

Examples of other renewable energy sources

Tidal energy is just one piece of the broader clean energy mix. Other prominent renewable sources include:

Solar energy: Converts sunlight into electricity using photovoltaic cells or solar thermal systems
Wind energy: Uses the kinetic energy of moving air to spin turbines and generate electricity
Geothermal energy: Taps into heat stored beneath the Earth’s surface to produce power and heating
Hydropower: Generates electricity from the movement of water through dams or run-of-river systems
Biomass: Converts organic material such as wood waste or agricultural byproducts into usable fuel

Each of these technologies plays a unique role in reducing emissions and diversifying the global energy portfolio.

Tidal energy in the U.S. and Texas

The United States has taken early steps in tidal power development, with several pilot projects underway:

Alaska – Cook Inlet: The Department of Energy is funding Ocean Renewable Power Company (ORPC) to deploy 1–5 MW of tidal capacity at East Foreland. This initiative marks one of the first federally supported tidal demonstration projects in the country. The National Renewable Energy Laboratory (NREL) estimates that the local grid can support up to 200 MW of tidal power, with potential to reach 300 MW as infrastructure improves.
Maine: ORPC has also deployed its TidGen® turbine systems in Cobscook Bay and Eastport, delivering the first tidal power to a U.S. utility grid.
New York: Verdant Power’s Roosevelt Island Tidal Energy (RITE) project features six underwater turbines in the East River. It was the first tidal project in the U.S. to receive a commercial license and has generated over 50 MWh of electricity.

In Texas, while tidal potential is limited due to relatively low tidal ranges, foundational work is underway:

Texas A&M University is developing a floating test platform for hybrid renewable systems, integrating tidal, wave, wind, and solar energy.
St. Mary’s University in San Antonio is prototyping small-scale tidal turbines using 3D printing technology.

Texas’s extensive offshore oil and gas infrastructure, combined with its skilled engineering workforce, positions the state to potentially lead in hybrid marine energy innovation.

While the state’s low tidal range limits traditional tidal applications, the existing supply chain, fabrication yards, and offshore permitting frameworks established for oil and gas or wind development can be repurposed for marine renewables. As floating, multi-source platforms integrating tidal, wave, solar, and wind energy progress from concept to reality, Texas could emerge as a strategic hub for testing, assembly, and deployment.

Is tidal energy good for the environment?

Tidal energy has both environmental advantages and trade-offs:

Benefits:

No direct carbon emissions during operation
Minimal land footprint compared to onshore infrastructure
Long operational lifespan once installed

Drawbacks:

Potential disruption of marine ecosystems, including fish migration and benthic habitats
Alteration of sediment transport and water quality near tidal barrages or lagoons
Possible impacts on local hydrodynamics and biodiversity

According to the EPA, any energy infrastructure placed in the marine environment must be carefully assessed to minimize ecological impacts. Mitigation strategies, such as fish-friendly turbine designs or siting projects away from sensitive habitats, are essential to balancing environmental and energy goals.

The future of tidal energy

The future of tidal energy in the U.S. appears promising but requires continued support:

Technological advancement: Floating turbine designs like ORPC’s TidGen® and tidal lagoons are being developed to lower costs and reduce environmental disruption.
Public-private partnerships: Collaboration between federal agencies like the Department of Energy, academic institutions, and companies such as Proteus Marine Renewables is accelerating innovation.
Regulatory and financial frameworks: Programs like the DOE’s TEAMER initiative fund environmental research and device testing, supporting broader adoption.
Expansion potential: With up to 300 MW of capacity forecasted in Alaska and additional prospects in the Pacific Northwest and East Coast, tidal energy could soon provide consistent baseload power to regional grids.

In Texas, while commercial tidal power remains in the research phase, the state’s offshore capabilities, engineering talent, and growing university-led innovation could make it a player in hybrid marine renewable systems. Floating platforms that integrate wave, tide, solar, and wind offer a compelling vision for offshore power generation suited to Texas’s unique coastal conditions.

Written by Graham Lumley

Graham Lumley is the Growth Product Manager at BKV Energy, a retail electricity provider in Texas' deregulated market, where he has worked since 2023. He analyzes customer usage and billing data, helps develop BKV's fixed-rate plans, and creates tools to simplify Texas electricity shopping. He has written over 200 articles on Texas electricity rates, delivery charges, plan types, energy generation, and more to help Texans understand their bills and pay less. With over 10 years of experience in consumer products, marketing, and energy, he explains the Texas electricity market in plain language.