Renewable resources

different types of renewable resources

1. Renewable resources

2. Energy is the amount of force required to move an object from one place to another place . Energy exists in every single objects whether it is a living or non-living things e.g. machine, table or a human beings , animals etc. Energy exist in many forms such as kinetic, potential, light, sound, gravitational, elastic , or nuclear.

3. Generally all the currently available energy sources fall into following two categories: Nonrenewable resources : These resources are available in limited amount and will vanish in the future which cannot be replaced within a short period of time. The energy which is generated from these sources is called nonrenewable energy. These forms of energy are available in form of fossil fuels deposits. However, these fuels are not environmental friendly and can have serious effect on human health. Fuels generated from these resources are still the preferred source of all the power used globally due to high energy content in them.

4. ii ) Renewable resources : These are natural resources or non-conventional forms of energy sources. The energy generated from these sources is called renewable energy. These resources are replenished in a shorter period and are abundantly available. Moreover , these renewable resources are the cleanest forms of energy in today’s world.

5. The renewable energy is defined by US EPA as the resources that rely on fuel sources that restore themselves over short periods of time and do not diminis h. These energy sources are also non – conventional sources of energy . Characteristics of a renewable energy sources Renewable energy sources are regenerated in natural processes It can be used indefinitely. These are available in great amount or abundant in nature and It develops in a relatively short period of time. These include solar energy; wind energy; ocean thermal power; wave and tidal energy; geothermal energy ; hydropower etc. They are capable of solving the twin problems of energy supply in decentralized manner and helping in sustaining cleaner environment.

6. There are six main renewable energy sources: • Solar energy • Wind energy • Hydropower energy Bioenergy Geothermal energy Tidal and Wave energy

7. Solar Energy Solar energy is the energy derived from the solar radiation where radiation is converted into power, either directly using photovoltaic system, or indirectly by using solar power cells. The Sun’s energy comes from nuclear fusion reaction where Hydrogen nucleus fuses into helium nucleus. Among renewable energy sources, the easily accessible and most important is the solar energy. It can be used directly or indirectly. The direct solar energy is the radiant energy whereas the indirect solar energy is the energy obtained from the materials such as biomass , in which sun's radiant energy has been incorporated by the plants.

8. Direct Solar Energy . On global scale, 15 days of solar energy is roughly equivalent to the energy stored in all known reserves of fossil fuels on the earth. The continuous input of the energy from the sun is 1, 67,000 times greater than the current consumption. Solar energy can be used for direct heating . Alternatively, the heat can be converted into the electricity-the thermal electric generation. Photovoltaic cells-the solar cells or solar batteries covert direct solar energy into electricity. Other types of solar energy devices are solar power pumps and solar pond electric power plant . Thus the solar energy can be harnessed for domestic, commercial or industrial purposes. India installed largest solar steam cooking system for cooking food for 15,000 people per day at Tirupati Temple in Andhra Pradesh .

9. Indirect Solar Energy (Biomass) ; Biomass energy, where solar energy is utilised indirectly, has been the major source of energy to human beings. Biomass energy is the outcome of the photosynthesis. in the materials such as live plant material and their dried residues; fresh water and marine algae; and agricultural and forest residues of plant and animal origin. Apart from these materials, biomass also includes biodegradable organic wastes from industries like sugar mills, breweries etc. Biomass fuel may be solid such as wood, animal dung, peat, charcoal etc. used for burning; liquid such as methanol or ethanol used in internal combustion engines of automobiles; or gas such as animal waste produced biogas: a mixture of gases mainly methane and some carbon dioxide produced in biogas digesters. Biogas is a clean anaerobic fuel of organic origin whose combustion produces fewer pollutants than other combustible energy sources.

10. it’s a renewable energy source and abundantly available and sustainable as well as environmentally friendly . It is expensive and intermittent source of energy. As access to solar radiation is limited e.g. morning and night in varies. It requires space and storage and back-up are necessary.

11. Wind Energy : The process by which wind wave is used to generate power where kinetic energy due to moving of air into get converted into mechanical energy. Preferred locations for wind energy are areas where winds are more constant and strong .

12. Now , wind is used to generate electricity in various countries. Harvesting wind energy is possible only in the areas that receive fairly continuous winds such as islands, coastal areas and mountain passes . When gigantic fans, raised on tall towers, are rotated by the wind, its energy can be used for generation of electricity. wind power has the potential to give tremendous energy, India occupies the fourth, after China, USA and Germany in wind power generation . Wind mills are used in Rajasthan to draw subsoil water for irrigation

13. It’s a clean source of energy (produces zero greenhouse gases). It’s a Renewable Source and cost effective to build and operate. Provide extra savings for land owners. It has rapid growth and huge potential for scale up. Wind Reliability hence intermittent energy source. It could be a problem to human and birds It is responsible for noise and visual pollution. It is expensive to set up. It is suitable source only to certain locations or regions.

14. Hydro Energy : This form of energy is generated from water dam and the energy obtained is get converted into power. In a hydroelectric dam, water coming down from a high altitude directly hit the turbines which in turn rotate and as a result energy is generated with the help of a generator .

15. Water falling from a height turns turbines at the bottom of dams to generate electricity. Presently water power is widely used all over the world and produces approximately one-fourth of the world's electricity . Electricity produced by hydro-power is much cheaper than electricity produced by thermal power. Water power is a clean energy source as it does not cause environmental pollution and the electricity produced can be transmitted to long distances through wires or cables . But building a dam leads to several environmental problems such as submergence of plant and animal habitats and displacement of local inhabitants including tribals . The hydrothermal energy is the largest source of domestic electricity production in some countries rather than thermal power.

16. But building a dam leads to several environmental problems such as submergence of plant and animal habitats and displacement of local inhabitants including tribals . The hydrothermal energy is the largest source of domestic electricity production in some countries rather than thermal power . It is cheaper to produce. It is a reliable source of energy which means it can be used any time. It sometimes slightly change the direction of water flow that could be harmful to flora and fauna in the water.

17. Bioenergy (Biofuel): It is the energy obtained from plant biomass where it can be directly used as fuel. Biomass is organic material e.g. wood, sugarcane waste, or any plant by-products. There is several form of bioenergy such as biofuel or bioethanol, Biobutanol , etc . Biofuels or bioethanol : Liquid bio-fuels such as bio-ethanol can be produced from agriculture residues such as lignocellulosic residues through the process of alcoholic fermentation.

18. Biomass as an energy source : Several types of biomass are considered as an alternative energy source e.g. Corn/Sugarcane are called 1st generation energy source, Lignocellulosic biomass as 2 nd generation and algal biomass are considered as 3rd generation energy source. Several other different applications of Biomass: - Direct heating: This is the traditional method used for cooking. - Gasification : The biomass is heated and converted into a flammable gas and after purification can be used as an energy source. - Microbial decomposition : The biomass used as feedstock for fermentation reaction where it get converted into organic gaseous materials or biogas, [CH4 (60%) and CO2 (40%)].

19. Bio-Diese l: Biodiesel is made from waste oils or fats obtained from plant and animals. It is used as fuel for vehicles or as diesel additive to minimize the emission levels of particulate matters, CO and hydrocarbons from diesel run vehicles. Commercially , it is made from soybean, rapeseed andsunflower oil. It has a great potential to be developed as a world's transport fuel . Algae based Biofuel: Algae are photosynthetic aquatic organisms that grow in presence sunlight and take CO2 as carbon source . . Algal biomass will be valuable source of algal oil that can be converted into biodiesel which will be a viable alternative to conventional fuels. algae-based biodiesel will yields significantly more energy in compare to biofuel from other sources. The advantage of this technology is that algae can be cultivated on land that is unfit for agricultural activities.

20. Advantage of biofuels: It’s a renewable source of energy and are naturally available in nature in abundant quantity with low starting cost and can easily be cultivated domestically for energy production . Since it contain low carbon , so it’s a clean energy source. It can also turn organic waste into fuel, therefore it can help in minimizing the waste disposal. Disadvantages: Algal cultivation requires large amount of water for algae to grow and when burned releases some quantities of harmful gases (NOx, soot, ash, CO, CO2). Probably it could compete with the food crops for land requirements. The whole process of biodiesel production is very expensive with costly scale up process.

21. Geothermal Energy: The earth’s crust at some places contains huge quantity of stored heat energy that energy can be obtained by trapping the heat energy and that energy obtained is called geothermal energy. There are two types of geothermal energy deposits: Hydrogeothermal and petrogeothermal . Hydroresources are the deposits of hot water and steam at lower depths. Petroresources are the hot dry rocks around 200 °C and depth ~2000 meter depth.

22. The natural heat from the interior of earth can usefully be converted into energy . This natural heat comes from the fission of radioactive material present in the rocks in the interior of the earth .. Natural internal heat of the earth was harnessed by geo-hydro-thermal conversion, hot igneous and geo-pressured systems .. Heated groundwater flowing upwards as hot water stream and hot springs-the nature's geysers, can be used to turn turbines and generate electricity. In India, natural geysers are common in Kullu and Manali , Manikarn , Sohana and some other places. deep drilling at potential geothermal sites, would be required before these site can be taken up for development for geopower generation

23. Ocean Tidal and Wave Energy : Ocean tides, produced by gravitational force of sun and moon, contain enormous amount of energy . The high tide and low tide refer to the rise and fall, respectively of the water in the oceans. Tidal energy is harnessed by construction of a tidal barrage . Darns built across the mouth of a river confluence with oceans, permits sea water to flow through small opening filled with propellers, connected to electric turbines . During high tide the sea water flows into the reservoir of barrage and turns the turbines which in turn produces electricity by rotating the generators. During low tide, when the sea level is low, the sea water stored in the barrage reservoir flows out into the sea and again turns the turbines. Power of ocean waves, which operates on the principle of oscillating water column, has not been exploited to its full potential except as power supplies for navigational aids. India has initiated the wave energy project off the Vizhinijam Fishery Harbour near Trivandrum in Kerala as an indigenous effort . It was expected that on the completion the project would be able to derive an energy output of

24. During high tide the sea water flows into the reservoir of barrage and turns the turbines which in turn produces electricity by rotating the generators. During low tide, when the sea level is low, the sea water stored in the barrage reservoir flows out into the sea and again turns the turbines. Power of ocean waves, which operates on the principle of oscillating water column, has not been exploited to its full potential except as power supplies for navigational aids. India has initiated the wave energy project off the Vizhinijam Fishery Harbour near Trivandrum in Kerala as an indigenous effort. It was expected that on the completion the project would be able to derive an energy.

25. Ocean Thermal Energy Conversion (OTEC ): The sun warms the oceans at the surface and wave motion mixes the warm water downward to depths of about 100 meters and this mix layer is separated from the deep cold water formed at a high latitudes, by a thermocline. Thus, the resulting temperature distribution consists of two layers separated by an interface with temperature differences between them ranging from 10°C to 30°C.

26. The higher values are found in equatorial waters. And these two enormous reservoirs in some oceanic regions, provide the heat source and heat sink required to operate heat engine. The engine using this energy is referred to as OTEC which makes use of the difference in temperature between the two layers of the sea to harness energy which in turn is used to drive turbines for generating electricity. OTEC can also be used to desalinate water, support deep water mariculture and provide refrigeration and air conditioning facilities and can prove as an aid to mineral extraction

27. Global Impact of using renewable resources: Since, renewable resources and the energy obtained from them are clean energy with no adverse environmental effects. However , the major concerns with utilizing these clean resources on a large are the effectiveness. Therefore , it needs to be cost-effective for any country to be used on large scale basis .

28. Thank you