Thursday, April 30, 2009

Geothermal electricity production

A power plant is used to generate electricity from various sources of energy. A hydro electric power plant uses running water to generate electricity. Wind energy operated power plants use wind turbines that convert wind energy to electricity. Most of the power plants run on steam. Steam is used to run turbines that in turn power a generator to produce electricity. Geothermal power plants use steam obtained from geothermal reservoirs in the earth to produce electricity.

There are three types of geothermal power plants that can generate electricity. A dry steam geothermal power plant uses steam that is directly pumped from underground wells into the power plant. This steam is then directed into a turbine and generator unit to produce electricity.

Flash steam geothermal power plant uses geothermal reservoirs to get geothermal energy. Hot water from the geothermal reservoirs moves upwards and a part of it condenses into steam. In the power plant, the water and steam are separated and the steam is used to run a turbine and a generator. This produces electricity. These are the most commonly used geothermal power plants.

Binary cycle geothermal power plants use water. The heat from the water is used to boil a working fluid which is usually an organic compound. The working fluid changes to steam and is used to run a turbine. The turbine powers a generator and this produces electricity.

Small scale geothermal power plants can be easily installed and used in rural areas to meet the electricity needs of the population.

The use of geothermal power plants is becoming common for electricity production.

Monday, April 27, 2009

Concentrating solar power systems

Concentrating solar power systems use mirrors or lenses to concentrate or focus a large area of sunlight into a small beam. This focused beam of light is then used in either conventional power plants or in photovoltaic systems. Concentrating solar power systems are divided into concentrating solar thermal and concentrating photovoltaic.

Concentrating solar thermal is used to produce renewable heat by focusing a large area of sunlight into a small beam. This heat is then used in conventional power plants to generate electricity. There are many concentrating solar thermal technologies available but the most commonly used are trough, parabolic and solar power tower. They are the most developed technologies used today.

Concentrating photovoltaic solar power systems use the sunlight on photovoltaic surfaces to produce electricity. Solar collectors are used to collect sunlight and a heat sink is used to store the solar energy in order to generate electricity. The concentrating photovoltaic systems perform the best in proper sunlight. These can be further divided into low concentration photovoltaic, medium concentration photovoltaic and high concentration photovoltaic.

Concentrating photovoltaic and thermal technology can be used to generate heat and electricity in the same system. The thermal power so obtained can be used for heating water for domestic use, for desalination and air conditioning. The electricity generated can also be put to use in a variety of domestic and commercial applications.

Concentrating solar power has been in use for a very long time. It was used to produce steam for the first solar steam engine. Concentrating solar power systems can be used for irrigation, refrigeration and locomotion.

Thursday, April 23, 2009

Solar power cars

With the advancement in technology and the increasing use of solar power, solar power is being applied to applications other than domestic and commercial use. Solar power is being used to power vehicles because it is a renewable source of energy which will be readily available forever. Also solar power does not emit any harmful substances into the atmosphere. The use of solar power in powering vehicles is also viable because it is cost effective and reliable. Solar power also does not cause degradation of the environment.

Solar power cars are being developed for use in the present times and also for the future. Solar power cars use quantum dots. These are a form of nanotechnology. This technology creates tiny solar robots to convert sunlight into energy that can power the vehicles.

The solar power cars combine technology used in aerospace, bicycle, alternative energy and automotive industry. Almost all solar cars till date have been used as solar race cars. A solar power car has place for either one or two passengers. It has features like brakes, accelerator, rear view mirrors, turn signals and a radio for communication. Solar power cars either have gauges or wireless telemetry that can help one to know the amount of solar energy captured, the amount of energy used and other information related to solar energy that powers the car.

Solar power cars are not practical for use in day to day transportation at present but with improvement in technology and increase in demand, they will be used for daily transport.

Wednesday, April 15, 2009

Types of solar energy

The sun produces energy which can be obtained as solar energy in the form of thermal or heat energy and light energy.

There are two types of solar energy being used today, namely, solar thermal and solar photovoltaic.

Solar thermal uses solar energy to heat substances. Solar energy in the form of solar thermal energy can be used for applications like space heating, pool heating and water heating. There are a variety of products that use solar thermal energy. These devices are generally called solar collectors and can be installed on roof tops of buildings. These collectors collect and store solar energy and then use this energy in the form of heat for space heating or to heat water for domestic use.

Photovoltaic is the other type of solar energy that is used. It converts solar energy into electricity. Photovoltaic solar cells convert solar energy into DC voltage. This DC voltage can be stored in batteries or can be converted to AC voltage to supply electricity to homes. The solar energy stored in batteries can be used at night for power supply. Photovoltaic solar cells are made from a silicon material which goes through several chemical processes to finally produce photovoltaic cells.

Both the types of solar energy are used in equipments like calculators, toys, battery chargers, watches, solar pumps etc.

Although solar energy in both forms is readily and freely available, yet it finds only a small amount of usage in devices. The main reason is that cost of capturing solar energy is a lot. Therefore, methods need to be devised to capture and use solar energy at lower costs.

Tuesday, April 14, 2009

Generating solar power

Solar power can be generated by converting sunlight into electricity. This electricity can be put to several domestic and industrial uses. Solar power can be used in both rural and urban areas to meet the power demands. As an important and renewable source of power, it can be used in the future as well to generate massive amounts of electricity.

Solar panels can be used for generating solar power. A solar panel is made up of a number of individual solar cells. Solar cells are also called photovoltaic cells that can convert sunlight into electric current.

Solar panels are usually installed on roof tops where there is sufficient amount of sunlight. This helps the solar panels to generate more solar power because more sunlight can be captured.

Solar energy falls on the solar cells of the solar panel. This results in electron movement in the solar cells and an electric current gets generated because of the two different charges that generated inside the cells. The electric current is collected by a charge controller which controls the amount of electric current being supplied to the batteries. In the batteries, the electric current can be used directly for direct power in the form of direct current. The direct current can also be converted to alternating current by an inverter for alternating power supply.

The amount of solar power generated by solar panels depends upon the amount of sunlight received. Currently, only a small fraction of the total solar power generated is being used in the world. New methods have to be devised so that solar power can be used to its full potential.