Tidal Energy Pros And Cons Now & Into The Future

Tidal Energy Pros And Cons Now & Into The Future

As part of assessing the best energy sources for the future, we are looking at the pros and cons of these different energy sources.

This is our guide on the Pros & Cons Of Tidal Energy.


Summary – Tidal Energy Pros & Cons


  • Is renewable and sustainable (unlike fossil fuels which are finite)
  • Is clean energy that doesn’t emit greenhouse gases during operation
  • There is no re-fuelling that needs to take place once tidal energy technology is set up (unlike coal plants for example)
  • Huge potential worldwide for large scale power generation/supply
  • Tides are a reliable and predictable source of power (more so than wind or the sun)
  • Effective at low water speeds
  • Life span is relatively long – meaning the return on the initial investment increase with each year of operation
  • Doesn’t take up land space


  • In early development – technology needs more research and development
  • Final impact on the environment in unclear
  • Limited by how close it needs to be constructed to shore
  • Not an energy source right now for individuals 
  • Not a portable energy source 
  • Currently an expensive energy source for suppliers and consumers – is not yet profitable commercially without larger scales and better technology
  • More of a supplementary power source at this stage

Tidal energy is another green, renewable energy source. Like wave energy, it has big potential for future energy generation on large scales in the long term. However, at this stage, there needs to be further development and technological advances before it become competitive commercially, and before it becomes feasible and effective on a large scale. It’s more a prospective energy source at this stage

*Note – the above pros and cons are broad generalisations. Obviously there are different variables to each specific energy project that impact the final pros and cons (like new technology that reduces emissions for coal power plants just as one of many examples). Each energy project and situation (in different countries and cities) should be analysed individually. Having said that, some broad principles and patterns about the pros and cons of different energy sources tend to stay consistent too.


What Is Tidal Energy

The most common form of tidal energy generation is the use of Tidal Stream Generators. These use the kinetic energy of the ocean to power turbine – underwater turbines that look and act much like wind turbines.

Tidal barrages or more the more recent technology, dynamic tidal power (DTP) are also used.

– renewableresourcescoalition.org, and energyinformative.org


Tidal Energy Pros

  • Is Renewable – relies on ocean undercurrent and tides for power, and not finite fossil fuels (such as coal). High and low tides are a result of the gravitational fields from both the sun and the moon, combined with the earth’s rotation around its axis
  • Is Green Energy – doesn’t produce any waste or greenhouse emissions
  • Big Potential – A report produced in the United Kingdom estimated that tidal energy could meet as much as 20% of the UK’s current electricity demands. The worldwide potential for tidal power is estimated to be 700 TWh a year
  • Reliable and Predictable – Tidal currents are highly predictable. High and low tide develop with well-known cycles, making it easier to construct the system with right dimensions, since we already know what kind of powers the equipment will be exposed to.
  • Effective At Low Water Speeds – Water has 1000 times higher density than air, which makes it possible to generate electricity at low speeds. Calculations show that power can be generated even at 1m/s (equivalent to a little over 3ft/s).
  • Lifespan Seems Long – The tidal barrage power plant La Rance was opened already in 1966 and still generates large amounts of electricity. A long lifespan means the cost these power plants can sell their electricity at is ultimately reduced, making tidal energy more cost-competitive.

– energyinformative.org, and renewableresourcescoalition.org


Tidal Energy Cons

  • In Early Development, & Needs More Research & Development – tidal power is early in the development stages and not able to compete with fossil fuels. It needs more development to realise how effective it can be.
  • Environmental Impact Is Uncertain – Because tidal energy generators rely on ocean levels and current, there’s a possibility they may have similar effects to hydro-electric generators which can impact the ecosystem around them.  Technological solutions that will resolve some of these issues are currently being developed.
  • Currently Need To Be Constructed Closer To Shore – which is a limitation. In the future we’d like to exploit weaker tidal currents, at locations further out in the sea. Technological advancements are being worked on in this regard.
  • Currently Expensive For Suppliers & Consumers – It is projected that tidal power will be commercially profitable by 2020 with better technology and larger scales.



1. http://energyinformative.org/tidal-energy-pros-and-cons/

2. http://efficientgreenpower.com/tidal-energy

3. https://www.renewableresourcescoalition.org/alternative-energy-sources/

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