NON-CONVENTIONAL SOURCES OF ENERGY
INTRODUCTION OF ALTERNATIVE SOURCES OF ENERGY: We know that by the time conventional sources of energy will deplete soon due to improved technological progress and increased demand. To cater the rising demand, keeping a balance with limited with limited availability of conventional sources is very important. It is mandatory to look up to the alternative sources of energy which we also term as non-conventional sources of energy.
WHAT IS ALTERNATIVE SOURCES OF ENERGY: Nature continuously produce these alternative sources of energy . These are inexhaustible in nature. These type of energy we term as renewable or alternative sources of energy like solar energy, wind energy, hydro energy (tidal energy, sea waves energy, ocean thermal energy), bio fuels (wood, bio gas, alcohol). Here we discuss some alternative sources of energy.
It is the energy which we obtain from the sun. Solar energy provides us heat and light. A little less than half(47%) of solar energy which falls on the top of the atmosphere reaches the earth’s surface. Some parts of light refracts back to the space. It is the universal sources of energy that living organisms use for their survival. Green plants obtain solar energy and by the process of photosysnthesis, they convert it into chemical energy.
The amount of solar energy received by the earth’s surface of 1m2 area in one second is we term as solar constant. The value of solar energy is 1.4 kj/m2 s or 1.4 kW/m2. Here the daily average varies from 4 to 7 kWh/m2 under clear and cloudless sky conditions.
ADVANTAGES OF NON-CONVENTIONAL SOLAR ENERGY
- This energy does not cause any pollution
- Solar energy is available in abundance in a hot country.
- Free available.
DISADVANTAGES OF NON-CONVENTIONAL SOLAR ENERGY
- Energy reaching the surface is very diffused , direct utility is limited.
- Solar energy is not available uniformly all the time and at all the places.
- This energy is not available at night time and on cloudy day.
Now I will discuss some solar energy devices which we use for harnessing sun’s energy like solar cooker, solar panel, solar cell.
SOLAR COOKER IN NON-CONVENTIONAL SOURCES OF ENERGY
It is a box with thick glass sheet as a cover over the box. The plane mirror acts as a reflector in solar cooker . Some solar cookers achieve a higher temperature by using concave mirrors to focus the rays of the sun.
ADVANTAGES OF SOLAR COOKER IN NON-CONVENTIONAL SOURCES OF ENERGY
- It saves fuel.
- Solar cooker does not cause air pollution.
- Since the food is cooked slowly here, the nutrients do not get destroyed.
- It can cook four food items at a time.
LIMITATIONS OF SOLAR COOKER IN NON-COMVENTIONAL SOURCES OF ENERGY
- It cannot be used to cook food on cloudy days and during night.
- We cannot use this cooker to make chapattis and for frying.
- The direction of solar cooker has to be changed from time to time to make it facing the sun.
SOLAR CELL IN NON-CONVENTIONAL SOURCES OF ENERGY
It is a silicon made device which converts solar energy into electrical energy. We can set up this device in remote and inaccessible places easily, where arrangement of power transmission is quite expensive.
USES OF SOLAR CELL IN NON-CONVENTIONAL SOURCES OF ENERGY
- We use this device for many scientific and technological applications.
- It provides electricity in artificial satellites and space probes like mars orbiters.
- We can use them for street lighting, traffic light, signals, operating water pump etc.
- Solar cell provides radio and TV transmission in remote area.
- Calculators and many toys are working with fitted solar cells.
SOLAR PANEL IN NON-CONVENTIONAL SOURCES OF ENERGY
The arrangement where many solar cells are arranged side by side , connected with each other that we term as solar panel. It provides higher power for many practical uses. But manufacturing process is very expensive till now. In A1 cities, people use the solar panel for heating water in multistoried building.
ENERGY FROM SEA IN NON-CONVENTIONAL SOURCES OF ENERGY
Sea acts as source of renewable energy. These are
TIDAL ENERGY OF NON-CONVENTIONAL SOURCES OF ENERGY
Due to the gravitational attraction between Moon and Earth, sea water level rises and falls forming tides. This energy can be harnessed by constructing tidal damacross a narrow opening to the sea.
WAVE ENERGY OF NON-CONVENTIONAL SOURCE OF ENERGY
Due to the blowing of strong wind on the surface of ocean, very fast sea waves are generated. This wave energy, rotates the turbine of generator resulting generation of electricity which is less in amount of solar energy.
OCEAN THERMAL ENERGY IN NON-CONVENTIONAL SOURCES OF ENERGY
The water is poor conductor of heat. During day time, surface water of ocean becomes hated. Same time water at depth becomes comparatively cold. The devices used to harness this form of ocean energy we term as ocean thermal energy conversion ( OTEC) power plants.
GEOTHERMAL ENERGY IN NON-CONVENTIONAL SOURCES OF ENERGY
We can utilize the heat which is coming from interior of the earth in various ways. Hot regons of earth crust pushes the molten rocks or magma. These lava are being stucked in ridges and grooves of earth surfaces. We term those spots as HOT SPOTS. Underground water BECOMES STEAM due to heat of molten rocks or magma. We use this steam to run turbine which is connected to generator to produce electricity.
Energy contained in the nucleus of atom we term as nuclear energy. It is released during a nuclear reaction apparently more than solar energy. A reaction in which composition of the reacting nuclei changes to form new elements with a simultaneous release of large amount of energy we know as nuclear reaction.
In this reaction, a heavy nucleus splits into two or more smaller nuclei. It is bombarded with slow moving neutrons due to which large amount of energy is released.
A reaction in which two or more lighter nuclei fuse to form a heavy nucleus and large amount of energy is released is called nuclear fusion reaction.
HAZARDS OF NUCLEAR POWER GENERATION
Let us discuss the problems associated with nuclear power generation .
- Continuous decaying of radioactive materials like uranium into harmful subatomic particles is a big problem.
- Improper nuclear waste storage and disposal may lead to environmental contamination.
- There is also a risk of nuclear accidents causing due to leakage of nuclear radiation.