The Hydrothermal vents were first found in the year 1977. It was later discovered that these hydrothermal vents contain a large amount of energy which can used in some form to generate energy. However, the hydrothermal energy, oozing out of the vents, was so vast and immense that it was nearly impossible even to estimate its true potential. Moreover at that time, the scientists didn’t have the right kind of technology to harness this massive energy source, tapping the much needed power.
But now an inventor from South California, Bruce Marshall, has patented a system that holds the key to utilize the hydrothermal energy from vents. Practical and simple, the system holds great promises of using the hydrothermal energy from the vents to its fullest.
Vents are formed because of the plate tectonics movement which moves the earth’s continental plates away form each other. As the plates move, the earth surface stretches and becomes weak, resulting in the formation of ridges. These ridges again lead to the formation of vents, allowing the hot volcanic magma present in the earth’s crust to come out with high pressure.
The vents thus formed on these ridges are known as hydrothermal vents.
Construction of Marshall System
The design of the Marshall system is quite simple and easy to understand. The arrangement consists of a floating platform on the surface which is positioned directly on top of the vent. Vertical insulated pipes from the platform go straight down to the vents and cap them with their conical structure. The conical structure is mainly provided to increase the pipes vertical stability, as long pipes can collapse under high pressure. Moreover, side columns are also provided to give additional strength to the structure. The main central pipe collects the hot fluid and sends it up to the hydrothermal plant, wherein the heat energy of the fluid can be utilized to generate electricity.
As the hot fluid transported to the surface through the pipes is in superheated form (about 400 degrees centigrade), flashes off the water into steam when it comes in contact with it. The pressurized steam produced is channelized to turn a steam turbine which in turn rotates alternators, producing electrical power. The cooled steam from the turbine also results in large amount of fresh water that gets produced in the process.
The black smoke that comes out of the vent is actually a mixture of rich metals and minerals, which can be separated using a mining facility provided in the plant’s design. A return pipe is also provided which dumps the residue waste back into the sea after mineral processing.
An alternate design of the system consists of a closed loop circulating clean working fluid. The design, instead of bringing the hydrothermal fluid to the top, uses the closed loop to heat the working fluid by the vent heat. The heated fluid is then passed through a heat exchanger wherein the heat is used to convert it into usable electrical energy.