By Dana Zakshevsky - Staff Writer

perhaps Now more than ever, clean energy must have its day

In simpler times, we used water, wind, and animals to generate the power we needed to survive. As we grew from an agrarian society to an industrial one, our need for different power sources grew as well. We turned to coal and the steam engine, with petroleum soon after and, eventually, nuclear energy.

Our world has become totally dependent on these power sources, and this dependency has caused many an issue. Fossil fuels, for example, are not renewable – we are depleting them at an alarming rate. The burning of these fossil fuels has caused a phenomenon which has come to be known as “the greenhouse effect,” a key contributor to global warming. The problem we face today is we will continue to provide the power that we need to live in the modern world, while protecting our natural resources. Can we recover from the damage we have already caused? Can we slow down the effects of global warming, or even reverse them? 

Clean, renewable energy may just be the answer.

Going back to the basics can provide some of the solutions; using the sun for solar energy, wind for wind turbines and water – likely the biggest source of untapped energy. We’ve used hydropower – from rivers and dams – for centuries, so let’s start looking at the bigger picture. Over 70% of the earth’s surface is covered in water, with the vast majority (about 96.5%) of that being oceans. One type of energy we can use from the ocean is a form of mechanical energy from the ocean’s waves. There are three systems used for wave energy: channel systems, float systems, and oscillating water column systems. Waves are generated by wind, which could be unreliable, but the potential is still staggeringly large. According to a study by the Electric Power Research Institute, wave energy could provide enough power to support millions of homes.

Another form of mechanical energy is one known as “tidal energy.” This form of energy is a form of hydropower that converts the energy of the tides into electricity or other useful forms of power. Tidal energy has been used successfully in many countries, including South Korea with the Sihwa Lake Tidal Power Station - the largest in the world - and La Rance Tidal Power Station in France, which opened in 1966. Recent efforts there have made big waves in developing even more efficient methods of getting the most out of tidal energy. 

Have you ever noticed that the ocean gets colder the deeper you wade? This difference in water temperature creates thermal energy. Ocean Thermal Energy Conversion (OTEC) is another way in which the ocean can be used as a renewable energy source. OTEC is best used in areas surrounding the equator where there exists a constant temperature difference between the top layers and deeper levels of the water, 36 degrees Fahrenheit or greater. The benefit of OTEC is that it is a constant, reliable source of energy, always available to us. Along with power production, OTEC technology provides other benefits, including aquaculture and even the ability to act as air-conditioners for buildings. 

While most of these hydropower ideas aren’t new, the technologies behind them are. Of course, there are obstacles such as cost, building equipment that can handle the harsh elements of ocean life, and keeping both marine life and ecosystems unharmed. The use of ocean energy is also, in some part, limited to countries that have coastlines, but with enough energy produced, the benefits gained could be the start to a more responsible, sustainable future. 
 

learn more about oceans & climate change in our article for the UNited nations development programme (UNDP)

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