Tidal Energy Revealed

An example of a tidal energy production system from the company Marine Current Turbines Ltd (MCT)  Source: http://www.marineturbines.com/3/news/article/31/marine_current_turbines_to_deploy_tidal_farm_off_orkney_after_securing_site_lease_from_the_crown_estate_
An example of a tidal energy production system from the company Marine Current Turbines Ltd (MCT)
Source: http://www.marineturbines.com/3/news/article/31/marine_current_turbines_to_deploy_tidal_farm_off_orkney_after_securing_site_lease_from_the_crown_estate_

We’ve discussed what people can say to discourage solar energy. Disqualifying wind energy can also be quite simple for those renewable energy pessimists — “What if there is no wind?” “Don’t those kill birds?” Well, we will discuss how to argue with those in another post, but for now lets assume you think you are stumped. Until…you imagine your last vacation at the beach and the changes in tide… Tidal energy!

But do you have the facts to back it up? When asking people about alternative forms of energy, I often hear “tidal would be a great idea.” But would it… well that’s what I plan to start revealing tonight. So first — how the heck does this energy work? Obviously the tides are pretty strong, but where does the energy generation come in?

HOW IT WORKS Imagine laying on a soft towel surrounded by warm sand,  listening to crashing waves as the tide is coming in. Depending on where you are, you could be witnessing a potential incredible source of electric energy — if you have the right generator. You should also know how you will be using this generator. There are three ways to obtain tidal energy: tidal streams, barrages, and tidal lagoons.

So which is the most widely used? Most tidal energy generators have turbines that are positioned in tidal streams What is a tidal stream, you may ask? It is a quick flowing body of water that tides often (conveniently for climate conscious humans) create.

tidal-turbine-diagram
Tidal Turbine Diagram. Source: http://www.epa.gov/region1/eco/energy/re_ocean.html

In the Barrage tidal production method, turbines in a generator harness power similar to how dams can capture the energy of a river. Barrages are basically large dams created across tidal rivers, bays and estuaries. The gates of the barrage open as the ocean reaches high tide. They then close before the tide starts decreasing, trapping water in a special tidal lagoon. As water is let out of the barrage, it travels through the barrages turbines, generating electricity.

Finally, tidal lagoons are another type of tidal power source. They involve a natural or manmade object enclosing a body of ocean water. Basically, tidal lagoons are like the super-hippie version of barrages. They work in the same way — turbines spin as water rises and falls in the enclosed area, spinning a turbine for a generator.

THE UPSIDES

  • What is heavier — wind or water? Simple question, right? So you probably already know which is more effective in producing energy — water, since it is more dense.
  • Consider also that tides are extremely predictable, but as any experienced sailor will tell you, winds are often not. It often is better to know when you will have energy for say something important like heating up that box of Easy-Mac (if you call that important you may want to talk to someone about your priorities — but I guess it could be your last food source or something!)
  • While wind turbines can move kill as many as 440,000 birds each year, according to US wildlife ecologist and ornithologist Albert Manville, tidal turbines are not nearly as dangerous for marine life since they move very slowly
  • What about economic benefits? Tidal’s got them! It has the ability to power 15 million homes, save 70 million tones of carbon and create 16,000 jobs in the UK alone

THE DOWNSIDES What in the world could be wrong with this form of energy — you can think of it while relaxing on the beach! Well, unfortunately turbines from tidal generators can have severe impacts on the environment since they work best in shallow water. Of course there are also legal concerns about underwater ownership in the U.S. (who would NOT have thought)

Also, there is a good reason you have not heard of this energy — especially if you are from the U.S. That is because it is quite new to the commercial scene — the first was built in Eastport, Maine in 2012. This technology is still in its earliest phases, so there are not many commercial-sized plants that could handle the demands of the U.S. La Rance, France had the first tidal plant and South Korea currently has the largest called the Sihwa Lake Tidal Power Station ( it can supply electricity to a population of  500,000, for the record)

tidalenergy2 So there you have it — I meant to end with a negative and it became positive, so this must be a pretty Dam good energy source (bad joke because it works like a dam). Anyway, you don’t have to use any corny jokes in defending it — just use some facts from above and of course always keep digging! Extra Source: http://education.nationalgeographic.com/education/encyclopedia/tidal-energy/?ar_a=1

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s