Non-conventional sources of energy

The conventional sources of generation of electricity are hydro, thermal and nuclear. For over years, these were the major sources of electricity generation on earth. But technological progress helped us focus on some unconventional methods of power generation. These include generation of electricity by direct means i.e. without rotating parts such as Magneto-Hydrodynamics (MHD), fuel cells. There are non-conventional sources of energy such as geo-thermal energy, tidal power generation and solar energy.

Non-conventional means something which is not like what is usually practiced for years. The usual or conventional way of power generation had lot of issues and undesired effect. To combat the same, some alternative ways had been identified over the past few years. These sources of energy will not exhaust even when used for years and do not cause environmental pollution.

MagnetoHydroDynamics (MHD) – Overview

The word magneto means magnetic field, hydro means liquid and dynamic refers to movement. Hannes Alfven received Nobel Prize in physics in 1970 for his research on MHD. Magnetic field can induce current in a moving conductive fluid like plasmas, liquid metal, salt water or electrolytes. This in turn creates forces on the fluid and changes the magnetic field. The commercial use of this process of power generation is still in a very nascent stage.

Solar Energy – Overview

The Sun offers an unlimited supply of energy and we have to learn how to use it. Several countries have carried out research and development work on utilization of solar energy. The first steam engine using solar energy as its source of power was put into operation in 1915. In Chile, a large solar powered water distillation plant was built in 1972. In various countries, Govt. is patronizing the installation of solar panel in private houses. These panels contain solar photo-voltaic cell, which can convert light from sun into potential difference.

Tidal power generation

For a long time, scientists and engineers were fascinated to harness the tremendous energy in the tides of the ocean. In tidal power plant, sea water is stored during high tide and released through turbine at low tide.

An estuary is closed by a dike incorporating a sluice gate. At rising tide the sluice is opened and the basin is filled. At falling tide, the water flows back but in the process it is utilized to turn the power turbines to generate electricity.

Geo-thermal energy

Geo-thermal power generation is installed where there is manifestation of high temperature on the surface of the earth in the form of hot springs. Springs are normally points of discharge of ground water to the surface either due to gravitational or non-gravitational forces.

Springs of non-gravitational types include volcanic springs associated with volcanic rocks and fissure springs resulting from fracture extending to great depth in the earth’s crust. The water from this spring has temperature which exceeds that of the normal local ground water.

Wind Power stations

The wind power stations convert kinetic energy of wind into electrical energy. The wind power stations which we normally see are propeller type unit.

Propeller type unit consists of two or three large blades mounted on a tower in a nacelle containing the main shaft, the gear box and the generator.

The whole arrangement is free to rotate about a vertical axis so that the blades may be kept into the wind. The blade tip speed may be as much as 6 to 10 times of the wind speed.