While we would all like to believe that the Fukushima nuclear disaster of 2011 is a thing of the past, nothing could be farther from the truth. Millions of humans, animal and sea life and ecological systems are sadly doomed to suffer the consequences for thousands of years to come. The dangerous effects of radiation pose new challenges as to how we will mitigate these invisible poisons in our bodies, in our environment and in all life. What is it going to take for humanity to choose a way of life in harmony with nature? Clearly, nuclear power is an ongoing disaster waiting to happen which threatens the entire gift of life we have all been given. Alternative energies are readily available, and waiting for us to come to our senses. Both geothermal and ocean thermal energies hold the potential for clean, safe power. Renewable energy from our oceans and our Earth supports the path of living in balance with nature as opposed to the endless extraction of fossil fuels which threaten our very existence.
Beneath the Earth’s crust can be found the fluids and rocks which contain this thermal energy. Geothermal energy is quite simply the use of the Earth’s internal heat source. While geothermal energy is generally several miles beneath the surface, it can be found and tapped in shallower ground to generate electricity or the power to heat and cool buildings. The Earth provides a relatively constant temperature within the upper 10 to 15 feet of its surface which allows a heat pump to both provide heat in cold climates and extract heat in warmer climates. Deep wells are drilled into the ground until a reservoir of heat is found, and the heat is regulated and maximized with enhanced grouts backfilled into the drilled holes. This is the common process for residential geothermal use while power plants, designed primarily to produce electricity, have more options: taking dry steam out of ground fractures; creating steam by cooling the hot water sources; or creating vapor with a binary process. While large scale geothermal power plants can produce electricity, home geothermal systems are designed to replace conventional methods of heating and cooling with more efficiency and thus save on electric costs.
The process of geothermal is not new, and has been utilized in other countries for a long time. Italy was the first country to generate geothermal electricity in 1904. Today, while there are at least 20 other countries using geothermal power, Iceland capitalizes on all their many hot springs and geysers to create geothermal power for its residents. Despite the U.S. having the largest geothermal plant in the world in California known as The Geysers, this country has yet to develop geothermal as a common and alternative energy source.
Like many alternative solutions, there can be pros and cons in their usage. The only disadvantages with geothermal are the possibilities of sulphur smells, the cooling of the tapped heat source and tapping toxic materials. Geothermal advantages include its relatively low expense, its non-dependency on available sun or wind, its consistent temperatures and cooling and heating efficiency without burning fossil fuels. Overall, geothermal is an extremely dynamic and safe energy system. For residential use, tax credits can offset installation costs while the efficient system of geothermal heating and cooling can save the homeowner thousands of dollars a year.
Similar to geothermal, ocean thermal taps into the heat sources stored in the ocean to generate electricity. It is a process called ocean thermal energy conversion or OTEC for short. This is also not a new method. But unlike using the Earth’s heat, ocean thermal technology is expensive with only one successful plant in operation today. The first proposition to tap the ocean’s thermal energy was in 1881 by a French physicist named Jacques d’Arsonval. His student, Georges Claude, turned his teacher’s idea into a reality with the first OTEC plant built in Cuba in 1930. This plant, however, succumbed to weather and waves before running successfully. A second attempt occurred in 1956 by French scientists on the Ivory Coast of West Africa, but it was never completed due to the expense. The only remnant of OTEC now is the Natural Energy Laboratory in Hawaii established by the U.S. in 1974. It is the sole experimental OTEC plant in the world which struggles with the same past challenges of high cost.
There are 3 types of OTEC systems: closed cycle, open cycle and the hybrid cycle.
The closed cycle involves low boiling point fluids and warm sea water to create vapor which propels a turbo-generator, then cold deep sea water returns the vapor back into liquid to be recycled through this system.
The open cycle operates without the low boiling point fluids, and the warm sea water itself is turned into vapor and cooled by the colder sea water. This cooled down vapor becomes desalinated, pure, fresh water.
The hybrid cycle is a combination of both the closed and the open cycles wherein the open cycle is used to create steam from warm sea water, then this steam vaporizes a low boiling point fluid to propel the generator for electricity.
OTEC offers beneficial possibilities beyond the production of power such as cooling systems to provide refrigeration and air conditioned buildings; aquaculture where cold water fish and algae can thrive in the deep sea water OTEC process; the production of fresh, pure drinking water out of sea water; and chilled soil agriculture wherein temperate climate plants can be grown in subtropical climates.
A good plan: to replace all the dangerous, toxic nuclear power plants along our oceans with safe OTEC power plants.
While OTEC plants and their process is specifically designed for tropical locations, I have no doubt this technology can be expanded to suit colder climates. So long as corporations and bankers are getting rich from burning fossil fuels, I doubt also we will see further research in OTEC. Perhaps when the day comes, in the not too distant future, when the Pacific Ocean is declared dead and broken, we will realize the real value of our oceans and the land to provide energy and life.