Ocean Thermal Energy
With the increasing amount of energy that is needed to operate everything in society's daily lives, there is a need for multiple sources of energy. For example, the price of coal is increasing, and is not exactly environmentally efficient or friendly. It is also a commodity that society needs to be less reliant on. Ocean thermal energy is a renewable source that works in a way that uses the thermal energy that the ocean naturally receives from the sun and converts it into energy that can be used for electric power.
History
This energy source is not a completely new idea. In fact, in 1881, Jacques Arsene d’Arsonval was a physicist who first proposed the idea of tapping energy from the ocean. Since then, scientists have been creating systems and plants that have been able to efficiently convert ocean energy into electric energy.
How it All Works
Oceans have layers of water, with the surface layer being warm due to being heated by the sun, and the deepest layer being the coldest. Ocean thermal energy conversion (OTEC) plants take the water from the surface and put it into a conversion machine to make steam, which is then put through a turbine in order to make electricity. The surface water is hot enough to boil a fluid such as ammonia (which has a low boiling point), and the pressure from the boil creates enough energy to power a turbine and start a generator. The cold water from the ocean is used to cool the gas, and then the water is returned back into the ocean, making OTEC a clean and renewable energy source.
Benefits
Using OTEC is beneficial to the environment as well as society. The earth is made of 70% water, which makes this technology readily available. OTEC plants can produce energy 24 hours a day, 365 days of the year because it is not affected by the weather like other sources such as wind energy. Buildings that are near to the plants can use the ocean’s cold water as an air conditioning source, and the process also produces fresh water for consumption and use. Smaller island countries can use this energy to be self-sufficient and improve their sanitation and nutrition, which also creating clean water.
Downfalls
Although OTEC provides many benefits to society, there are some downfalls. First of all, the locations of the plants are either on land or in the ocean. The land plants can face damage from incoming waves, and there may be an additional expense of construction and maintenance to carry the mixture of warm and cold water after usage for the proper depth for release. Ocean based plants are more difficult to stabilize; the cables that are necessary to keep the plant afloat are very susceptible to damage. In addition, the cost is something that is fairly high. Although there are no fuel costs, the construction and upfront capital are more expensive than other energy sources.
Further Developments
There are quite a few more things that need to be researched and developed before OTEC can become a highly-used source of energy. Appropriate and efficient plants (including sizes and location); improving the efficiency and cost of heat exchangers; and bettering thermal energy extractions are just a few items that are being researched and further developed. Once solutions to these issues have been found, OTEC will become an energy source that society can be dependent upon in the future.
Tags: ocean thermal energy, OTEC