Tidal energy could be huge – why isn't it?

Summary

Off the coast of Scotland, tidal turbines harness the energy of moving water with the tides, offering a predictable and powerful renewable energy source. Tidal power has the potential to significantly contribute to global energy needs, but currently, it powers less than 400,000 homes worldwide. Challenges include high costs, environmental impacts, and the need for substantial infrastructure. However, advancements in technology and supportive policies could make tidal power a competitive and eco-friendly solution for coastal and island nations.

Takeaways

• 🌊 Tidal power harnesses the energy from moving water caused by the rise and fall of tides.
• 💡 The potential of tidal energy is enormous, enough to power all homes in the United States twice over.
• 🔍 Existing tidal power plants worldwide can currently power less than 400,000 homes.
• 🌕 Tides are highly predictable due to the gravitational pull of the moon and the Earth's rotation.
• 💧 Tidal power generation involves placing turbines in the water to convert the kinetic energy of moving water into electricity.
• 🏭 Tidal range power uses the difference between high and low tides, often by building a dam across a bay or estuary.
• 🌉 The oldest tidal range generator, La Rance in France, has been operational since 1966 and is still producing power.
• 🌍 Top regions for tidal range power include the Bay of Fundy in Canada, the Northwest Australian Shelf, and the Northwest European Shelf.
• 🚧 Infrastructure and geography are significant barriers to the widespread adoption of tidal range power.
• 🌿 Environmental concerns, such as impact on migratory fish and local ecosystems, have led to opposition against large-scale tidal power structures.
• 💸 The cost of tidal power is currently high, but the industry is working towards making it commercially viable and competitive with other renewables.

Q & A

What are tidal turbines?

Tidal turbines are devices that sit on the seafloor and harness the energy in the moving water that comes in and goes out with the tides.

How much energy could tidal power potentially capture?

It's estimated that tidal energy could be captured enough to power all homes in the United States twice over.

Why isn't tidal power more widespread despite its potential?

Tidal power is not widespread yet due to the high costs of installation, the need for specific geographic conditions, and the relatively young industry with fewer established supply and manufacturing chains.

What is the principle behind tidal power generation?

Tidal power generation works on the principle that moving water makes the turbine spin, which then powers a gearbox and a generator to turn mechanical energy into electricity.

What is the role of the moon in causing tides?

The moon's gravity pulls at the Earth and water, causing bulges towards it, which results in the tide coming in or going out.

How predictable are tides and how does this benefit tidal power?

Tides are highly predictable and consistent, which allows for easier integration into the energy grid compared to less predictable renewable sources like wind and solar.

What are the two main ways to extract power from tides?

The two main ways to extract power from tides are tidal stream power, which uses underwater currents, and tidal range power, which takes advantage of the difference between high and low tides.

What is the significance of the La Rance tidal range generator?

La Rance, built in 1966 in France, is the oldest tidal range generator and is still operational, providing power for a town of around 250,000 inhabitants.

What are the environmental concerns associated with tidal power plants?

Environmental concerns include the potential disturbance of migratory fish, changes in soil composition, and the impact on local communities and marine life.

How do tidal stream power projects differ from tidal range power?

Tidal stream power projects use underwater currents caused by tides and can have simpler devices like breeze turbines, underwater kites, or floating stream turbines, whereas tidal range power involves building dams across regions where seawater meets land.

What are some of the engineering challenges associated with tidal power?

Engineering challenges include the need for robust materials to withstand corrosion and biofouling, the high costs of underwater operation, and the potential impact on marine life.

What is the current state of tidal power in terms of cost and efficiency?

Currently, tidal power is more expensive than other forms of renewable energy, but the industry is working towards reducing costs to make it commercially viable, with a target of $0.10/kWh by the end of the decade.