La Flecha, Nov 21 (Scientific Trends) .- The engineer Dominic Michaels has devised an “Energy Island” to extract renewable energy sources from the sea. The design would consist of a thermal energy conversion plant with wind turbines, solar panels and water turbines, which would support the operation of the first. The energy conversion plant exploits the temperature difference between the ocean surface and the water that is in the depths to run steam turbines that would generate electricity. These Energy Islands, 600 meters long and that would require an investment of 600 million dollars, would also function as desalination plants. By Raúl Morales of Scientific Trends.
The oceans store abundant energy in the form of wind, waves and sun. All these energy sources could be united in complexes called Islands of Energy: a kind of oil platform from which instead of extracting the "black gold" renewable energy sources could be extracted.
This is the concept devised by the engineer Dominic Michaelis. The idea came when Michaelis realized that the development of thermal energy conversion (OTEC), a process in which cold water is pumped from the depths of the ocean to generate electricity, was going too slow.
The OTEC is based on the idea of exploiting temperature differences between deep and surface waters to generate electricity. The shallow waters of the ocean can become hot to 29 ° C in the tropics. Only one kilometer below these warm waters, the temperature is significantly lower, with frequent falls below 5ºC.
These extreme temperature differences would be used to run steam turbines, which would activate the generators to produce electricity. Experts estimate that, on any given day, the 60 million km2 of surface occupied by the tropical seas, absorb an amount of solar radiation equivalent to 250, 000 million barrels of oil.
The Energy Island that Michaelis is designing would have an OTEC plant in the center, but it would be surrounded by a 600-meter-long platform on which there would also be wind turbines and collectors solar. Also, water turbines would be installed to capture the energy of the water that would move around that large structure.
Stock a city
According to Michaelis, one of these hexagonal-shaped structures could generate 250 megawatts, enough to supply a small city. But if several islands joined together forming a small archipelago, a small port could be created to dock barges or a “green” hotel for tourists.
The main reason why Michaelis is behind this project is to boost the construction of an OTEC plant. "The main advantage of this technology over others based on the sea is that it is constant, it works 24 hours a day, " he says in statements to LiveScience.
This is because it is not based on the sun, wind or waves, but on the difference in temperature between the water on the ocean surface, heated by the sun, and the water that is in the depths.
The hot water is taken from the surroundings of the Island of Energ a and used to evaporate a fluid, which can be the sea water itself or ammonia. The steam resulting from this process pushes a turbine that produces electricity.
But the process does not end there. To re-condense the steam back into a liquid element, cold water extracted from below the ocean surface is pumped. This condensation creates a pressure drop that allows more steam to pass through the turbine blades, generating electricity again. The process is very similar to what can be seen in a nuclear plant, only that in these facilities the temperature difference is much greater.
The first OTEC plant was built in 1930 on the coast of Cuba and produced 22 kilowatts of energy. Only a few plants have been built since then, the largest of which was in Hawaii and generates 250 kilowatts. None are currently operational.
First designs
The biggest problem with this technology is the inherent inefficiency of converting a relatively small temperature difference into electricity. In fact, some of OTEC's first designs used more energy than they generated.
An OTEC plant requires a lot of energy so that large amounts of water can circulate. One of the Michaelis Energy Islands would need to pump 400 cubic meters of water per second. For this reason, this engineer has incorporated into his project other sources of marine energy that would support the OTEC plant located in the center.
The clean energy generated by the island would be conducted to the coast through water cables. It could even be used to make hydrogen from water. This hydrogen could be transported to produce electricity from fuel cells.
The Island of Energy will also be used as a desalination plant, taking advantage of the evaporation-condensation cycle. Michael calculates that, for every megawatt of energy produced, an OTEC plant will provide more than a million liters of fresh water.
Currently, Michaelis is seeking financing for his project. One of the islands would need an investment of 600 million dollars.
http://www.laflecha.net/canales/ciencia/idean-una-isla-de-energia-para-extraer-del-mar-energia-renovable-e-ilimitada?_xm=newsletter
They devise an Island of Energy to extract
from the sea renewable and unlimited energy
Take advantage of the temperature difference of
ocean water to produce electricity
