Geography Week 8

Alternate Sources Of Energy

(Ryan 2009, 'Tidal Power')

Fossil fuels and their effect on Earth’s climate is not a new phenomenon. In 1896, a Swedish scientist named Svante Arrhenius ‘proposed a relation[ship] between atmospheric carbon dioxide concentrations and temperature,’ suggesting that as the concentration of CO² rises so too does the temperature in the Earth’s atmosphere (Enzler 2011, ¶1). Unfortunately this theory was not verified and its ramifications not fully understood until the late 20^th century, by which time mankind had become completely dependent on fossil fuels. Not only do fossil fuel emissions pollute the atmosphere, they are also non-renewable and ‘will eventually run out because we are using them much faster than they can be restored within the earth’ (Solar Schools n.d., ¶8). Now that climate change has been accepted as a reality, the need to find an alternative renewable source of energy that does not exacerbate the greenhouse gases in the atmosphere is paramount. One possible source is Tidal Energy/Power, whereby the naturally occurring ebb and flow of the tide generates electricity. According to Australian Mines and Metal Association (referred to hereafter as AMMA), there are two methods for generating this kind of power: the ‘Tidal Stream Generator (referred to hereafter as TSD)’ and ‘Tidal Barrages’ (AMMA n.d., ¶4). The tidal barrage system stores energy by holding onto the tide water in an estuary for later use however is less common than TSD ‘because they rely on specific local geographical conditions, e.g. coastal inlets appropriate for damning’ (AMMA n.d., ¶4). TSD generates electricity using ‘large underwater turbines turned by the incoming or outgoing tide’ (AMMA n.d., ¶4). One of the main advantages to utilising this form of energy apart from the renewability and lack of carbon emissions is the predictability factor. Tides can be predicted and therefore the possible electricity output is ‘much more uniform and reliable’ than alternative energy sources such as wind power (Green World Investor 2012, ¶3). Unfortunately there are disadvantages although some have not been fully researched owing to the limited tidal energy sources currently constructed. As with most new technologies, the cost of construction is a major deterrent however if done correctly could pay for itself in the long term (Vella n.d., ¶12). Furthermore construction sites themselves are limited as the geographical requirements for operation are not present in every country (AMMA n.d., ¶4). Another disadvantage and perhaps the most convincing of all is the possible ‘long-term impact on marine ecosystems’ as coastal areas around the plant can experience an ‘increase in silt’ and also the possibility that ‘turbines can also kill fish passing through it’ (Green World Investor 2012, ¶4). Although some of these disadvantages appear to be deal breakers, if a better alternative to fossil fuels cannot be found then tidal energy seems the most natural, efficient and plausible way to progress forward.

References

Enzler, SM 2011, History Of The Greenhouse Effect And Global Warming, http://www.lenntech.com/greenhouse-effect/global-warming-history.htm, [Accessed 2 November 2012]

Green World Investor 2012, Advantages And Disadvantages Of Tidal Energy, http://www.greenworldinvestor.com/2011/03/15/advantages-and-disadvantages-of-tidal-energy/, [Accessed 2 November 2012]

Solar Schools n.d., Non-Renewable Energy, http://www.solarschools.net/resources/stuff/non_renewable_energy.aspx, [Accessed 2 November 2012]

Vella, D n.d., The Advantages And Disadvantages Of Tidal Power, http://www.sustainabledevelopmentinfo.com/the-advantages-and-disadvantages-of-tidal-power/, [Accessed 2 November 2012]

Images

Ryan, V 2009, ‘Tidal Power’, http://technologystudent.com/energy1/tidal1.htm, [Accessed 2 November 2012]