Here is a compilation of essays on ‘Energy Conservation’ for class 8, 9, 10, 11 and 12. Find paragraphs, long and short essays on ‘Energy Conservation’ especially written for school and college students.
Essay on Energy Conservation
Essay Contents:
- Essay on the Introduction to the Energy Conservation
- Essay on the Role of Transport Sector in Energy Conservation
- Essay on the Energy Conservation in Rural Areas
- Essay on the Energy Conservation in Urban Areas
- Essay on the Industrial Energy Consumption
- Essay on the Power Generation and Distribution
- Essay on the Energy Efficient Building
Essay # 1. Introduction to the Energy Conservation:
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Energy conservation refers to efforts made to reduce energy consumption. Energy conservation can be achieved through increased efficient energy use, in conjunction with decreased energy consumption and/or reduced consumption from conventional energy sources.
Energy conservation can result in increased financial capital, environmental quality, national security, personal security and human comfort. Individuals and organizations that are direct consumers of energy choose to conserve energy to reduce energy costs and promote economic security. Industrial and commercial users can increase energy use efficiency to maximize profit.
Standard economic theory suggests that technological improvements increase energy efficiency, rather than reduce energy use. It is said to occur in two ways. Firstly, increased energy efficiency makes the use of energy relatively cheaper, thus encouraging increased use. Secondly, increased energy efficiency leads to increased economic growth, which pulls up energy use in the whole economy. This does not imply that increased fuel efficiency is worthless, increased fuel efficiency enables greater production and a higher quality of life.
Efficient energy use, sometimes simply called energy efficiency, is the goal of efforts to reduce the amount of energy required to provide products and services. For example, insulating a home allows a building to use less heating and cooling energy to achieve and maintain a comfortable temperature.
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Installing fluorescent lights or natural skylights reduces the amount of energy required to attain the same level of illumination compared to using traditional incandescent light bulbs. Compact fluorescent lights use two-thirds less energy and may last 6 to 10 times longer than incandescent lights. Improvements in energy efficiency are most often achieved by adopting a more efficient technology or production process.
Energy saved is energy produced. Therefore, substantial energy savings can be achieved through energy conservation measures. Energy savings can be considered as additional source of energy. This will also help in reduction of environmental pollution.
Energy savings can be achieved by:
i. Modifying the consumer behavior and avoiding unnecessary energy consumption.
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ii. Employing energy efficient and high performance equipment and plant. The specific energy consumption and energy intensity should be reduced.
iii. Using waste heat recovery plant.
iv. Using energy management system and reducing energy losses. Plenty of opportunities exist for energy conservation at the level of end use, supply of energy and structural improvements. The problem of energy conservation can be best tackled by study of suitable measures in various sectors of energy consumption.
Essay # 2. Role of Transport Sector in Energy Conservation:
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Transport swallows major part of all imported oil causing great problems in the balance of payments. Lack of planning has resulted in the congestion of cities causing extremely low energy efficiencies in urban transport. There is a large potential for energy savings in transport sector of the order of 20-25%.
The opportunities for conservation differ per means of transport. The driver’s style and conduct can save much energy in trucks and buses. In case of passenger cars more energy can be conserved by improving the performance of these cars. The possibility of fuel conservation potential has been projected in Table 19.1.
i. Infrastructure Improvements:
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1. The Energy Conservation should be Part of Planning:
Physical distances and choice of mode of transport determine energy consumption. The location of facilities in a city for housing, working, shopping, entertainment, etc. has great effects on energy use.
2. Traffic Regulation:
Decrease of traffic congestion by planning of traffic lights, one – way traffic, limited parking, etc. can reduce energy consumption.
3. Telecommunications:
Efficient telecommunication can reduce travelling and freight transport.
4. Construction and Maintenance of Roads, Bridges and Tunnels:
Proper roads can shorten travelling distances, faster speeds and reduced tyre friction.
5. Construction and Maintenance of Waterways and Ports:
Transport by ship is very efficient as compared to surface transport and can be an important energy conservation measure.
6. Construction, Renovation and Maintenance of Railways:
Railways are capital-intensive but considerably more energy efficient than roadways. It is important to rehabilitate, maintain and upgrade railways.
ii. Improvement of Road Transport:
1. Promoting Non-Motorized Transport:
Promotion of use of bicycles is possible through public education, good and cheap bicycles availability. The animal cart design should be improved.
2. Discouraging Private Cars:
This can be achieved through efficient public transport, car-pooling and restricted parking.
3. Improved Buses, Trucks and Cars:
Preventive maintenance, tuning of ignition and carburetor, right tyre pressure, etc. can reduce fuel consumption.
4. Availability of New Vehicle Models:
The new models of vehicles of streamlined bodies, air shields, nose cones consume less fuel (15% or more). The commercial vehicles should run on diesel rather than gasoline.
5. Public and Freight Transport:
The energy efficiency can be improved through optimum routes, less trip frequency, location and distribution of freight distribution centres.
iii. Sea Transport:
1. Promotion of Sea Transport:
Ships are 5 to 10 times more energy efficient than trucks.
2. Navigation Speeds:
The optimum speeds of ships and firing of engines are important for fuel saving.
3. Proper Maintenance of Vessels:
Energy savings can be affected through proper maintenance of engines and clean and smooth hulls.
4. Modifications in Vessels:
The old engines can be replaced by more efficient engines.
iv. Railways:
1. Promotion of Rail Transport:
Transport by rail is more energy efficient than by road.
2. Rationalization of Fares and Tariffs:
Lower fares and tariffs can shift the load to railways.
3. Proper Maintenance of Trains:
Maintenance of locomotives is very important for energy savings.
4. Electrification:
The intensely used lines should be electrified.
Essay # 3. Energy Conservation in Rural Areas:
The major energy consumption in villages is by households followed by agriculture and cottage industries. The main energy consuming activities are given in Table 19.2. The main energy sources are wood, dung and agricultural residues. The energy balance of a village Pura in India is given in Table 19.3.
The use of commercial fuels is very low due to high cost and non-availability. Cooking accounts for major rural energy consumption (70 to 8%). Therefore, conservation of cooking energy is very important. The other areas of interest are lighting, space heating and cottage industries.
i. Cooking:
1. Improving Combustion Efficiency:
The oxygen supply for hearths should be controlled. The size and shape of wood logs, briquetting of agricultural residues and moisture content of fuels influence the combustion efficiency.
2. Stoves:
Improved cooking stoves can save much energy.
3. Cooking Method:
Depending upon the type of food, the method of cooking has influence on energy requirements. The food can be boiled, fried, stewed or baked.
4. Cooking Efficiency:
Use of pressure cooker can save the energy three fold. Similarly use of pots and pans of high thermal mass and conductivity will save energy.
5. Food Quantity:
Cooking in large quantities offers more opportunities for energy saving.
6. Type of Food:
Use of millet in place of rice can save energy.
ii. Food and Fuel Production:
1. Optimum Use of Land:
The land should be suitably divided for agriculture, animal grazing and fuel production depending upon the energy requirements.
2. Cultivation Methods:
The use of seeds, fertilizers, water and pesticides should be reduced by better timing as per soil conditions and type of crop.
3. Energy Crops:
Cross-breeding and choice of plant requiring minimum inputs can save energy indirectly.
4. Agriculture Machines and Implements:
Better design and cooperative use of machines and implements can save energy and costs.
5. Draught Animals:
The efficiency of draught animals should be improved by crossbreeding and better feeding. Replacement of tractors by draught animals can save energy.
iii. Processing, Storage and Transport of Food:
1. Post-Harvest Losses:
Reduction of food losses between harvest and consumption is an indirect method of saving energy.
2. Processing and Distribution:
Reduction in requirement of transport, storage, processing of food by optimization can save considerable energy.
3. Energy Efficient Techniques:
Energy can be saved through use of alternative techniques of drying, presetting before cooking, recycling of packing material.
4. Equipment Design:
Improvement in design of equipment for processing, carts, cooking can save energy.
iv. Cottage Industry and Handicraft:
1. Energy Efficient Kilns:
Energy requirements for brick making and charcoal production can be reduced by use of modern steel kilns.
2. Tools and Implements:
Simple improvements of tools and implements used for making of handicrafts can save energy and work.
3. Appropriate Technology:
Appropriate technology should be used to save energy in village industries.
v. Lighting:
1. Kerosene Lamps:
Improved kerosene lamps help to save fuel.
2. Alternative Energy Sources:
Vegetable oils and animal fats can be used for lighting to save kerosene.
Essay # 4. Energy Conservation in Urban Ares:
Urban energy includes hot water, cooking, lighting, space conditioning and electrical appliances. Use of electricity and LPG with higher efficiency of cooking ranges and hot plates help save energy. The largest savings are possible in restaurants, hospitals and school hostels where large scale cooking is employed. Hot water is less of a basic need than cooking. If hot water is used only in winter, integration with space heating becomes rational.
In poor households same fire is used for cooking and water heating. Fluorescent lights in place of incandescent lights should be used where possible. In large buildings, optimal use of day light, changes in working hours and cogeneration of heat and electricity can result in large energy savings.
Space conditioning including cooling, heating, ventilation and air purification plays an important role in middle and high income group households. The energy consumption for air-conditioning may be ten times that for lighting. Cleaning and maintenance of air-conditioners can save large energy quantities.
The introduction and use of household appliances like TV’s, refrigerators and washing machines is becoming more and more widespread. Large amounts of energy can be saved by controlling the product specifications, quality, taxes and education at Government level.
i. Cooking:
1. Improved Stoves:
Shift from wood stoves to kerosene stoves saves energy. Similarly LPG hot plates are efficient.
2. Food Preparation:
Pressure cooking is energy efficient technique.
3. Pans:
More efficient cooking pans should be used suited to the type of fuel used.
4. Cooking Customs:
Cooking customs change when a family moves from the village to a city.
ii. Hot Water:
1. Waste Prevention:
The water temperature must be adjusted as per its use. Leaking of pipes and taps of hot water should be avoided.
2. Geysers:
Solar water heaters should be used in conjunction with geysers.
3. Insulation:
Insulation of boilers and pipes are very important for energy saving.
4. Cogeneration:
In large buildings, cogeneration of heat and electricity and recycling of waste heat from air-conditioning and space heating plants should be used for water heating.
iii. Lighting:
1. Use of Day Light:
Properly located and sized windows and cleaning of glass panes can reduce need for electrical lighting.
2. Efficient Lamps:
Use of fluorescent lamps is an energy and money saving measure.
3. Electricity:
Electric lights are more efficient than kerosene lamps, however electrification leads to use of more lights.
iv. Space Conditioning:
1. Building Construction:
Proper design and construction of buildings and use of vegetation have favourable climatic effects.
2. Air-Conditioning Equipment:
Proper setting and control of temperatures in air-conditioning and space heating equipment save energy.
3. Replacement of Old Equipment:
Replacement of old and obsolete equipment by new equipment can save energy.
4. Insulation of Buildings:
Insulation of buildings can reduce heat losses in cold countries and inlet of heat in warm countries.
v. Electrical Appliances:
1. Change of Habits:
Washing of clothes at lower temperature, use of less detergent, proper food preservation outside refrigerator can save energy.
2. Appliances:
Refrigerators should be placed in cool rooms and washing machines and refrigerators should be set at optimal rates.
3. Models:
Different models and makes of washing machines, refrigerators and TV sets may consume different amounts of electricity
vi. Municipal Supplies:
The local authorities can plan and save large amounts of energy in water supply, sewerage, waste disposal, street lighting and public transport services.
Essay # 5. Industrial Energy Consumption:
The large and medium scale industries are more energy intensive and labour extensive whereas small scale industries are relatively labour intensive Process industries are more energy intensive than engineering industries. Metallurgical plants are very sensitive to quality of energy. The energy conservation measures will depend upon the technology level of individual plants. However some measures are common to all industries. Most energy is consumed by large industries and that is where most energy can be saved.
I. Industrial Development:
a. Policy Matters:
The project reports for new industries should also be based on energy policy. Recycling of waste heat, energy intensities and conservation should be included.
b. New Technologies:
The procurement of latest technology should be encouraged by tax rebates, subsidies, import permits. The new technologies are most efficient technologies.
c. Plant Location:
Proper plant location can help a cooperative cogeneration plant for different industries. It can also make the use of waste heat from the neighbour.
d. Small Scale Industry:
High unemployment makes labour intensive and energy and capital extensive small scale industries very attractive.
II. Operation Management:
a. Reduction of Process Time:
By increasing the productivity, the saving in operation time is always associated with saving in energy consumption.
b. Training of Operators:
Training of machine operators can make them energy conscious.
c. Maintenance Management:
Preventive maintenance of machines and energy equipment is necessary for energy efficient operations.
d. Energy Management:
Proper load management, reduction of start-up losses and efficient process heat utilization can help in energy savings.
e. Thermal Insulation:
Insulation of furnaces, boilers and piping can save large amount of energy.
f. Continuous Operations:
Continuous operations are more energy efficient as compared to batch operations.
g. Waste Heat Recovery:
Waste heat can be used to heat air, water by heat exchangers.
h. Energy Cascading:
The waste heat discharges from one equipment can be used as input to another lower temperature process.
i. Co-Generation:
Cogeneration of heat and electricity from the same power plant is a very powerful energy conservation tool.
j. Electrical Equipment:
Replacement of obsolete electrical equipment can improve energy efficiency and load factors.
k. Recycling of Materials:
Reduction and recycling of waste materials save energy directly or indirectly.
l. Internal Transport System:
Internal transport system of an industry can consume large amounts of energy and optimization can help conserve energy.
m. Lighting:
Factory lighting should be designed with automatic switching, optimal use of daylight, proper lamps, regular cleaning of lights. These measures can save more than 50% energy.
n. Water Heating:
Hot water is needed in factory canteen and energy conservation measures should be used.
o. Space Conditioning:
It is necessary to ensure proper working conditions for workers and products and processes. Waste heat can be used for space heating.
Essay # 6. Power Generation and Distribution:
The maximum efficiency of thermal power plants is 35 – 40% and 60% of energy is lost as waste heat. The average generation efficiency in India is 27%. By superimposing 23% transmission and distribution losses, the overall efficiency is only 21%. The decentralized power generation by autonomous power plants working on commercial fuels as well as local resources of solar, wind, hydro, biomass, etc. can help to save lot of energy.
i. Power Generation:
1. Preventive Maintenance:
Absence of preventive maintenance at power plants due to lack of trained workers spare parts and finances results in heavy energy losses. Better training of personnel and detailed operating instructions can contribute to energy efficiency.
2. Operating Parameters:
Better control of pressures and temperatures in the steam turbine cycle are needed to achieve higher efficiencies.
3. Unit Size:
Installation of a number of smaller units in place of large unit can save energy by operating at full capacity.
4. Prime Movers:
Replacement of gas turbines by diesel engines and use of cogeneration can help save energy.
5. Energy Source:
Replacement of oil fired plant by hydropower, wind turbines and plants using local fuels can save lot of energy.
ii. Power Supply Management:
1. Peak Shaving:
The peaks in demand can be shaved by energy storage system and electricity pricing.
2. Autonomous Power Generation:
Use of autonomous small capacity generators having low efficiencies should be discouraged by ensuring high quality public supply of electricity.
3. Captive Power Plants:
These plants can become technically feasible and economically viable if excess electricity is returned to the power grid.
4. Types of Generators:
Use of different types and sizes of generating units for base and peak loads will increase overall efficiency.
5. Grid Size:
The grid size should be increased by interconnection of power plants for better utilization of base load units. Autonomous power generators are a better alternative when demand is low on the grid.
6. Load Management:
Use of computer is necessary to avoid overloading.
7. Incentives:
Sufficient incentives should be provided to the consumer by differential pricing to encourage energy saving.
iii. Power Transmission and Distribution:
1. Grid Maintenance:
Regular maintenance of power lines, transformers and capacitors can save energy.
2. Capacitors:
High quality capacitors can be installed to improve power factor above 95%. These should be located near to generating units.
3. Transformers:
The no-load losses in the old transformer can be prevented by installing transformers with 15% impedance.
4. Size of Distribution System:
The length of distribution lines should be less than 500m. Increase number of transformers and split the distribution lines to achieve the above target.
5. Conductor Size:
The diameter of cables should be increased to reduce losses in the distribution lines.
6. Voltage:
Resistance losses are lower at higher voltages.
7. Distribution Losses:
Twenty five to fifty percent of distribution losses are due to inaccurate metering and theft. Better management and control can reduce these losses.
Essay # 7. Energy Efficient Building:
A residential or commercial or institutional building requires electrical energy for lighting, air-conditioning and gadgets (refrigerator, TV set, washing machine, computer, etc.) and thermal energy for space and water heating. The annual energy requirements in a cold place can be as high as 220 to 270 kWh per m2 of building floor area.
The annual energy load depends upon:
i. Shape and size of the building.
ii. Thermal properties of building materials.
iii. Energy storage capacity of the building envelope (walls, windows, celling, roof, floor, basement).
iv. Efficiency of air-conditioning, heating and ventilation system.
v. Use of solar energy.
vi. Behaviour of the residents or users.
The following factors can reduce the energy requirement:
1. Shape and Size:
The energy requirement for space conditioning of a building can be reduced by proper architectural design. A cube shape of a building has the lowest ratio of exposed surface to the volume of the building. Any deviation from cubic shape will lead to heat transmission through the envelope; more heat loss in winter and more heat load in summer.
2. Multi-Story Compartment:
Flat in a multi-story building has lower overall thermal transmittance than a bungalow or a cottage.
3. Thermal Design:
The thermal design of a building based on use of passive solar energy and proper building materials and components (windows) can help reduce the annual energy requirements. The thermal insulation of the walls and the ceiling can further help in lowering the energy requirements.
The annual energy requirements of new houses have been reduced to 40 – 75 kWh/m2/year by following proper design guidelines.
i. Low Energy Building:
A low energy building has the following features. Although the additional building costs are higher by 3 to 8% but annual energy requirements of 50 – 70 kWh/m2/year are achieved.
i. Compact building design.
ii. Airtight and energy efficient windows.
iii. Thermal insulation of the building envelope.
iv. Passive solar energy utilization.
v. Use of construction materials with high thermal resistance.
vi. Elimination of materials and components of low thermal resistance in any part of the building.
vii. Mechanical ventilation without infiltration of outside cold air.
ii. Passive Solar House:
The annual energy requirements of a passive solar house have been reduced to 15 kWh /m2/year.
This has been achieved by:
i. Effective thermal insulation.
ii. Airtight windows.
iii. Controlled ventilation.
iv. Combination of active and passive solar energy use.
iii. Zero Energy Building:
A zero energy building uses only natural energy and no fossil fuels. The natural energy sources can be solar, wind, biomass, and ground and water heat.
It has the following features:
i. Thermal protection.
ii. Use of internal energy resources.
iii. Waste heat recovery.
iv. Use of solar photovoltaic and captive thermal plants for water heating and space conditioning.
v. Seasonal heat storage.
Heating Load of a Building:
The heating load of a building is the difference between building heat loss and energy gain from solar energy and internal energy sources. The building heat loss is the sum of heat loss by transmission through the envelope and heat loss due to infiltration of cold air.
The heating energy of a building is given by:
Qh = (Ub Ab + Cp Z Vp)(ti -to) [W]
where,
Ub = Overall heat transfer coefficient of the building [W/m2-K]
Ab = Total exposed area of the building envelope [m2]
Cp = 0.34 Wh/m3 – K = Specific heat of air.
Z = Air exchange rate (l/h)
Vb = Building space [m3]
ti = Indoor temperature [°C]
t0 = Outside air temperature (°C)
The transmission heat loss can be calculated as:
Qtr = 24 × 3600 Ub Ab DD (J)
Where 24 × 3600 = the time factor [s/day]
DD = Heating degree-day for a month [K-days]
The Ub of a building can be calculated as:
Example 1:
A home has total space volume of 350m3, envelope area is 378 m2, design indoor temperature 18°C and outside temperature – 3°C. The annual heating hours are 1570 hour. Calculate the design heat load and annual energy requirements of the building. Take Ub = 0.65 W/m2 – K and Z = 0.5 l/h.
Solution:
1. Design heat load.
2. Annual energy requirement.
Thermal Insulation of a Building:
The thermal resistance of a component of a building can be calculated as:
