The main source of power in the present day world includes fossil fuels like petroleum (oil), coal, propane and natural gas which are categorised as conventional fuels. Of course we also have nuclear materials such as uranium through which we generate power. The fossil fuels, being dependent on hydrocarbon reserves in the earth’s crust, cannot last indefinitely. At the present rate of production and consumption, the oil reserves may hardly last another 20-30 years.
In view of an ever-increasing demand, there is an urgent need to develop non-conventional sources of power, such as solar or geothermal energy and other alternative sources of fuel. Some well-known alternative fuels include biodiesel, bioalcohol (methanol, ethanol, butanol), chemically stored electricity (batteries and fuel cells), hydrogen, non-fossil methane, non-fossil natural gas, vegetable oil and other biomass sources.
These sources are renewable and less polluting alternatives, since petroleum consumption and production of varied organic substances lead to environment pollution.
The Sun is the biggest source of alternative or non-conventional power. It can be harvested in the form of biomass through the use of waste material and also by growing petrocrops. It can also be harvested through the use of microorganisms, which can convert the sun’s power into chemical energy in the form of molecules like glycerol (from salt, H2O, and CO2) and hydrogen (from H2O).
Sunlight falling on the earth’s surface equals 50,000 times the wattage used each year by man. The sun is responsible for tidal, heat, chemical, kinetic and electrical energy.
The power from the Sun can also be harnessed directly. Solar water heaters and solar cells directly harness it from the sun. Only a small part of this reaches the outer layer of the earth’s atmosphere. Nearly half of it is absorbed while passing through the atmosphere and the rest reaches the earth’s surface.