What are the advantages and disadvantages of using tidal power as an energy source?

• Tidal stream systems, which use turbines turned by the moving water to generate electricity. Very like wind power.
• Barrage systems. These are like dams built across rivers. After the tide comes in, the gates are closed. When the tide is low enough on the downstream side, the water flows through turbines rather like a hydro-electric dam.

Wave power consists of harnessing the movement of the waves. There are various pilot schemes of this at the moment.

Advantages

The advantages for using tidal and wave energy over different fossil fuels are plentiful, below there are several impressive benefits of using tidal and wave energy, including the factor of replacing a percentage of fossil fuel use.

• It reduces the dependence upon fossil fuels
• Tidal and wave energy is free, renewable, and clean source of energy
  
• It produces clean electricity, with no production of greenhouse gas or pollution.
• Tidal and wave energy generation and consumption creates no liquid or solid pollution
• Highly efficient resource (compared with coal and oil at 30%, tidal power efficiency is about 80%)
• Energy capturing and conversion mechanism may help protect the shoreline
• Energy capturing and conversion mechanism has little visual impact
• About 60 billion watts of energy from tides can be used for electricity generation
• Tides are active 24 hours a day, 365 days a year
• Tidal power is a renewable source of energy.
• It produces energy for free, once the initial costs are recovered.

There are some devices that are very environmentally friendly like for example, the Salter Duck. This is a floating device that moves in a nodding motion with the passage of waves, generating electricity efficiently in the process. It cause no destruction to the marine animals and to the environment. This device can also serve as shelters for fish, seabirds and even seals.

Disadvantages

• It is not cost effective because fossil-fuel power stations do not pay for the cost of their carbon emissions to the planet. This will change as fossil fuel is valued at its real price.
  
• It leads to the the displacement of wild life habitats.
• It can only be used where there is suitable tidal flow or wave motion. So it can not be used inland.
• It only produces electricity during tidal surges.
  
• Barrage systems require salt resistant parts and lots of maintenance.
• The frames of the turbines can disrupt the movement of large marine animals and ships through the channels on which the barrage is built.
• today, power produced from tidal fences is still a bit expensive than that using conventional plants using coal and natural gas (but it can be cheaper if improved technologies and large-scale generation is applied).
• the barrage systems have the disadvantages of disrupting fish migration and killing fish passing through the turbines, therefore, there is also the risk of destruction of ecosystem that rely on the coming and going of tides.
• the ecosystem is disrupted during the construction of building the tidal fence. this affects the fishes and also the fishermen who depends their life on it.
• Fossil fuels can be moved to just about anyplace to create energy on the spot. This is what allows a car to work while moving.
• Tidal energy can only be created on a coast with a good tidal differential. Worthless for a landlocked country, has to be converted to something else to be transported
• It is limited because the tide never speeds up or slows down, and occurs on 6 hour cycles. and also, it is dependent on the fetch distance. the fetch is the distance the tide rises and falls, so some beaches have a very small fetch, and others have a big fetch but hardly any have a large enough fetch to support tidal energy
• The main detriment is the cost of those plants, for constructing and running this facility with an annual output of 3423 GWh, is a cost about 1.2 billions, but this doesn't include operational and maintenance cost (coal and oil are cheaper).
• Construction of strong, cheap and efficient conversion devices may be problematic
• Technology isn't fully developed
  
• Problems exist with the transportation of hydroelectricity
  
• Ecological impacts relating to the alteration of tides and waves is not fully understood
  
• Appropriate waves and tides are highly location dependent
  
• Waves are a diffuse energy source, irregular in direction, durability and size
  
• Extreme weather can produce waves of great intensity

The tide moves a huge amount of water twice each day, and harnessing it could provide a great deal of energy - around 20% of Britain's needs.

Although the energy supply is reliable and plentiful, converting it into useful electrical power is not easy.

There are eight main sites around Britain where tidal power stations could usefully be built, including the Severn, Dee, Solway and Humber estuaries.

Only around 20 sites in the world have been identified as possible tidal power stations.

Despite the fact that it's expensive, the technique isn't fully developed. There are still some uncertainties surrounding the conversion devices.

First answer by ID1452351972. Last edit by ColYoung. Contributor trust: 143 [recommend contributor]. Question popularity: 6 [recommend question]