GOING SOLAR

The sun is our light and energy source. It has been providing the earth light and heat energy for billions of years or more. Hence it is quite reasonable and logical to expect the trend to continue.

It is a matter of fact that the sun is the sole provider of energy for all living things. For instance photosynthesis in plants uses the sun energy to convert its resources to stored food energy for the use of mammals, including human beings. So without the suns energy life as we know it would not exist.

The energy in fossil fuels, such as coal, crude oil, wood, natural gas and uranium are in fact bottled solar energy.

Solar energy can be harnessed for use in two basic ways; first by employing solar thermal collector technology to capture the suns energy to dry food and heat water for daily use. This heated water may be used to drive turbines to generate electricity. The second way solar energy can be harnessed is by converting the suns energy directly to electricity using photovoltaic technology.

Solar thermal collectors are classified as low, medium or high temperature collectors. Low temperature collectors are flat plates and are generally used for drying of agricultural products, swimming pools and other product or items in which the heat requirement is low. Medium temperature collectors are also flat plates, but are used for heating water or air for residential and commercial uses. High temperature collectors concentrate sunlight using mirrors or lenses and are generally used for fulfilling heat requirement up to 300 degrees centigrade at 20 bar pressure in industrial use and for electric power production.

However there is a term used for both applications; concentrated solar thermal(CST) for fulfilling heat requirements in industries and concentrated solar power (CSP) where the heat collected is used for power generation.

Generally in its operation, solar thermal collector system gathers the heat from the solar radiation and gives it to the heat transport fluids. The heat transport fluid receive the heat from the collector and delivers it to the thermal storage tank, boiler, steam generator, heat exchanger etc. the thermal storage system stores the heat for a few hours. The heat is released during cloudy hours and at night. Thermal electric conversion system receives thermal energy and drive steam turbine generator or gas turbine generators. The electric energy is supplied to the electrical load or to the AC grid.

The technology of photovoltaic (PV) is essentially concerned with the conversion of the suns energy directly to useable electricity energy. The basic element of a PV system is the solar cell.

Solar cells rely on quantum mechanical process known as the photovoltaic effect to produce electricity. These individual solar cells are the electrical building blocks of photovoltaic modules also known as solar panels.

The photovoltaic mechanism is thus; light is absorbed by the PV cells, causing the flow of an electron or other charge carriers to a higher energy state, an electric potential (or voltage) is produced by the separation of the charges and the light has to have sufficient energy to overcome the potential barrier for excitation, thereby causing flow of electrons. This electron flow generates electric current.

The preference of photovoltaic (PV) technology outstrips the other solar thermal technology by far. Today most solar installation for residential, commercial and industrial use, employ photovoltaic (PV) technology on a wide scale; mainly because they are easier to manufacture, hence are mass produced at economic cost and are also easier to install or deploy for use or on to the grid network.

Despite that solar energy is only available during the day and the need to invest in storage devices to ensure availability of service throughout the day, this drawback is inconsequential when you consider that one hour of sun energy received on earth will power the earth energy need for one year and it is free and available as the air. Going solar is the way to go.