Energy is an attribute of objects and systems which define their capacity to do work. Energy is subject to a conservation law. Every living organism does work and needs energy from food or photosynthesis. All human activities also require energy. Man uses machines to perform various types of works for them and the machines work form the energy they derive from fuel. Joule is the standard unit of energy in electronics and general scientific applications.
There are several different forms of energy which exist all around us and are stored in different ways. Various forms of energy are often named after a related force. All forms of energy are broadly categorized as either Kinetic or Potential. However, this theory is not accepted by various institutions and scientists.
- Kinetic: It is the energy contained in a moving mass or in a moving particle. Example - Walking or Running.
- Potential: It is the energy stored within a physical system and has the potential to be converted into other forms of energy. Example - Petrol contains energy.
- Thermal: It is the energy related to temperature, the higher the temperature, the greater the molecular movement, and the greater the energy. Example - Volcano.
- Gravitational: It is the energy of a position or a place. Example - Water stored in the reservoir of a dam is a source of Gravitational Energy.
- Sound: It is the movement of energy through substances in longitudinal (compression/rarefaction) waves. Various sounds like barking, shouting etc.
- Light: It is electromagnetic radiation, particularly radiation of a wavelength that is visible to the human eye. Example - Lightbulbs.
- Nuclear: It is the energy stored in the nucleus of an atom. The energy can be released when the nuclei are combined or split apart. Example -Nuclear power plants split the nuclei of uranium atoms in a process called fission.
- Chemical: It is the energy stored in the bonds of atoms and molecules. Example: natural gas.
- Elastic: It is the energy stored in objects that are stretched, compressed, bent, or twisted.Example - Car Shocks.
- Electromagnetic/Radiant Energy: It is the energy present in an electric field or magnetic field. Example - Radio waves.
Sources of Energy
Sources of Energy are generally categorized into two categories these are Non-Renewable Energy Sources and Renewable Energy Sources.
Non-Renewable Energy Sources: These are those sources which are not easily renewed or recreated. These include:
- Coal: It is used to produce electricity.
- Fuel Oil: It is a product of an oil refinery after crude oil has been processed. It is used to power various machines including vehicles etc.
- Heavy fuel: oil also known as Residual or Bunker C, is usually burnt in the furnace of a steam generator which supplies steam to a turbo-generator.
- Distillate: A lighter fraction of Fuel Oil, Distillate is used to generate electricity by being burnt in a gas turbine.
- Kerosene: Also known as Jet Fuel, it is the lightest fraction of fuel oil which drives a generator.
- Gas: Gas is an important energy resource, as it is a source for electricity generation, industrial processes, business and residential consumers. It includes natural gas, coal seam methane and LPG (liquefied petroleum gas).
Renewable Energy Sources: These are those sources which are replenished constantly.
- Solar: Solar systems are powered by energy from the sun. Solar power is used for producing electricity.
- Wind: Wind energy systems convert the wind's kinetic energy into mechanical or electrical energy.
- Water: Water-energy systems use the energy contained in the water resource. These include Tidal energy, Ocean Waves etc.
- Biomass: Biomass is a regenerative organic material used for energy production. These include agricultural and forestry residues and municipal and animal wastes. Bagasse (the waste from the crushing of sugar cane) has been used for many years in the sugar industry as boiler fuel for the generation of steam and electricity for use in the sugar mill during the crushing season.
Energy Conservation
Energy Conservation means using it in an efficient manner. We need to save energy so that we can use it for a long time and also for the future generation as well. Saving energy, by default means that we are saving money spent on our bills. But above all, by using energy wisely we can cut down on pollutants and make a better environment for everyone.
Methods of Conservation of Energy
A lot of energy can be saved by following the steps given below:
- Shut lights and television when you leave the room.
- Open the curtains and use the sunlight instead of turning on the lights during the day.
- Close the windows and doors when the heater or air conditioning. By not doing so the furnace and AC have to work harder to heat and cool a room.
- Dry clothes in the sun instead of using the dryer during sunny days.
- Always close the taps properly so that the water is not dripping.
- Turn off the dishwasher right before the drying cycle and let the dishes air dry.
- Don't leave the refrigerator door open.
- Once a week have a sandwich night instead of cooking as this too saves gas and electricity.
- Plant Deciduous trees (trees that lose their leaves) and shrubs as these trees are best to block the sun in the summer and in the winter when the leaves fall they let the sun shine through thereby helping to warm our houses.
- Replace incandescent bulbs with compact fluorescent lights (CFLs), which use only about one-third of the electricity. CFLs also generate less heat.
- Use task lighting rather than illuminating the whole room while doing desktop work.
- Cool the rooms to no less than 24°C as it will give you the most comfort at the least cost. You spend up to 5% more electricity for every degree set above 24°C.
- Always keep your refrigerator or freezer full. An empty fridge cycle on and off more frequently without any mass to hold the cold. If you have fewer items then keep a container of ice in the freezer.
- Refrigeration temperature should be set between 3°C and 5°C and the freezer temperature between –18°C and –15°C. Lowering the temperature below these units only wastes electricity.
- Check your water heater. If its surface is hot or even warm, some of the energy used is being wasted. Wrap it in an insulating blanket.
- Always install hot-water tank as close as possible to the kitchen, laundry, and bathrooms as heat is lost in long pipe runs. Reducing the length of a hot water pipe from 10m to 3m will save enough energy in one month to heat water for 10 showers. Similarly, thin pipes are more energy-efficient than thicker ones: larger amounts of hot water are trapped in thicker pipes, therefore more heat is lost.
- Heat only the required amount of drink instead of overfilling the kettle.
- Use your washing machine or dryer with full loads. Drying smaller loads uses just as much energy and overloading will increase drying time.
- Computers in sleep mode use up to 70% less electricity as compared to screensavers.
- Devices such as TV sets, VCRs, DVD players and mobile chargers use maximum power even on standby.
- Remember to switch off the computer when not in use, or when idle for more than two hours. A computer switched on for an hour consumes as much energy as a 14-watt compact lamp for 24 hours
- Buy rechargeable batteries as these batteries last longer as compared to others.
- Use Hybrid cars as they are not only economical but environment-friendly.
- Use cycle or walk for short distances. This will help the environment and help your health too.
- Buy only those equipment which has a good rating of energy efficiency.
- Use Car Pool while going to Office, School etc.
- Don't water your lawns in the morning as plants and soil loose moisture very quickly in the afternoon. Afternoon watering is effective.
- Use a bucket to water plants instead of a hose a lot of water is wasted with a hose.
- Similarly, use a bucket to clean your vehicles.
- Remove unnecessary Lighting in your home, office etc.
- Get your vehicles serviced regularly.
- Maintain a good tire pressure in your vehicles as these are also fuel savers.
