Energy & EnvironmentEnergy Conservation Lecture Notes

Engineering Department, QUEST, Nawabshah

ENERGY CONSERVATION

Using less energy in a particular application Energy conservation is the quickest, cheapest

and most practical method of overcoming energy shortage.

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

Conservation and efficient utilization of energy resources play a vital role in narrowing the gap between demand and supply of energy.

Improving energy efficiency is probably the most profitable thing that can be done in short term.

By reducing consumption of energy through energy conservation also helps us to save precious fossil fuel like coal, gas and oil which are used by the generating companies to generate electricity.

Energy Conservation Act

In 2005, the National Energy Conservation Centre (ENERCON) and the Ministry of Environment, Islamabad published a report called “National Energy Conservation Policy 2005”.

This report includes guidelines and possible actions that can enhance end-use efficiency for various energy-consuming sectors of the economy

and also for addressing various cross-sectoral issues that continue to retard promotion of energy conservation.

Energy Conservation Act

The policy is trying to promote energy conservation practices and effective energy savings of observable magnitude at the national level.

The four main objectives of National Energy Conservation Policy are as follows:

• To foster energy conservation through stimulation of resources and regularizing total energy management programmes in all sectors of economy.

Energy Conservation Act

To develop energy conservation market and facilitate commercialization by creating awareness and launching nation-wide demonstration projects.

To maximize the demand for energy from indigenous resources.

To create an enabling environment to reduce energy intensity of different energy consuming sectors through appropriate technological and policy measures, so as to promote sustainable growth.

Aspects of Energy Conservation

Saving of usable energy, which is other wise wasted, has direct impact on the economy, environment and long-term availability of non renewable energy sources.

Energy conservation implies reduction in energy consumption by reducing losses and wastage by employing energy efficient means of generation& utilization of energy

Aspects of Energy Conservation

These are three important aspects of energy conservation:

Economic Aspects Environmental Aspects Depletion of Non Renewable Energy

Assets

Economic Aspects

Reduction in cost of product, energy conservation ultimately leads to economic benefits as the cost of production is reduced.

We must strive for good energy economic using energy efficient technologies.

This will reduce the manufacturing cost and lead to production of cheaper and better quality products.

Economic Aspects

New job opportunities, energy conservation usually require new investments in more efficient equipments to replace old inefficient ones monitoring of energy consumption, training of man power.

Thus, energy conservation can result in new job opportunities

Environmental Aspects

Every type of energy generation/utilization process affects the environment to some extent either directly or indirectly.

The extent of degradation of environment depends mainly on the type of primary energy source.

Thus, energy is generated and utilized at expense of adverse environmental impacts.

Adoption of energy conservation means can minimize this damage

Environmental Aspects

Meeting more stringent environmental quality standards, primarily related to reducing global warming and reducing acid rain.

Thus, 16 pounds of methane produces 44 pounds of carbon dioxide; or 2.75 pounds of carbon di-oxide is produced for each pound of methane burned.

Environmental Aspects

Energy management reduces the load on power plants as fewer kilowatt hours of electricity are needed.

Less energy consumption means less petroleum field development and subsequent on-site pollution.

Less energy consumption means less thermal pollution at power plants and less cooling water discharge.

Depletion of Non Renewable Energy Aspects

The vast bulk of energy used in the world today is drives from fossil fuels, which are non renewable.

The resources were laid down millions of years ago.

This finite, non-renewable is being used up very fast.

In one minute, the world community uses the quantity of fossil fuel; it took the earth a millennium to create.

Depletion of Non Renewable Energy Aspects

Therefore, its prices are bound to go up relative to everything else.

We must abandon wasteful practices in energy utilization and conserve this resource by all means for future generations.

Principles of Energy Conservation

Recycling of waste Modernization of technology Waste heat utilization Judicial use of proper type of energy Judicial use of proper type of fuel Cogeneration Training of manpower Adopting daylight saving time Proper operation and maintenance

History of Energy Conservation

The imperative to conserve energy is as old as the use of energy.

For most of human history, use of energy was limited to the amount of

work that could be done by human beings, usually alone, but sometimes

in large groups. Later, humans learned to use animals

and teams of animals to do the tasks requiring heavy lifting and hauling.

History of Energy Conservation

Neither humans nor animals like hard work. Aversion to work strongly motivated energy

conservation from the beginning. Energy conservation first consisted of doing

less. Then, as intelligence evolved, it included finding easier ways to get work done. For example, the invention of the wheel was an early advance in energy

conservation.

History of Energy Conservation

Fire is the oldest major source of energy, other than muscle, that is

controlled by humans. Since prehistory, fire has been used for

cooking, heating of dwellings, clearing land, smelting and casting metal, and

other applications.

History of Energy Conservation

Controlled fires require a considerable amount of effort for gathering fuel, so efficiency arose in the use of fuel.

For example, the kilns and ovens of many early cultures were quite efficient in their use of fuel.

History of Energy Conservation

Wind power is the oldest major source of mechanical energy, other than muscle.

Its earliest major application was ship propulsion, which began perhaps five to ten thousand years ago.

This made possible the trading of large tonnages of goods throughout the known world.

The Dutch style of wind machine used for pumping water and grinding grain five hundred years ago achieved a large fraction of the theoretical maximum efficiency.

History of Energy Conservation

However, usage is limited by the localized and irregular nature of wind.

The energy of falling or flowing water has been used to a significant extent for over two millennia, becoming a major energy source in the middle Ages.

Unlike wind, which is a nuisance in itself, water is desirable for many important purposes.

As a result, many cultures settled near water supplies, which they learned to exploit for power.

Well designed “overshot” water wheels built 500 years ago have efficiencies that approach the theoretical maximum.

History of Energy Conservation

Water power is limited by the amount of stream flow and by the height of the fall that is readily available.

The technology of building dams tall enough to augment power production was not highly developed until the 19th

century. Steam machinery is another application of fire. It was first

put into practical application during the 18th century. Its development was revolutionary for several reasons. It

enables fire to produce mechanical work. It was the first invention capable of producing mechanical

power in any locale, on land or sea. Virtually any amount of work can be done by building larger

machines. Steam engines can operate whenever work is needed,

independent of climate. To a large extent, steam power created modern civilization.

History of Energy Conservation

However, steam machinery requires fuel, unlike wind and water power.

The ability of mechanics to build large steam engines, and the growth in applications for such engines, led to rapidly

increasing demand for fuel, which could no longer be satisfied by whatever excess wood happened to be in the

vicinity. Fuel cost soon emerged as a dominant limitation to the

application of steam machinery. In response, efficiency also emerged early as a fundamental

issue in the design of steam machinery. In fact, during the 18th and 19th centuries, what we now call

mechanical engineering was largely a search for higher efficiency.

History of Energy Conservation

James Watt and many other engine builders improved efficiency on an empirical basis, while attempting to

understand the underlying physics. Sadi Carnot created the first solid theoretical understanding

of energy efficiency. During the early nineteenth century, Carnot explained the

Second Law of Thermodynamics, which places a severe theoretical limit on the efficiency of converting heat to

mechanical work.

Energy conservation by country

India Petroleum Conservation Research Association (PCRA) 

www.pcra.org is an Indian government body created in 1977 and engaged in promoting energy efficiency and conservation in every walk of life.

In the recent past PCRA has done mass media campaigns in television, radio & print media.

An impact assessment survey by a third party revealed that due to these mega campaigns by PCRA, overall awareness level have gone up leading to saving of fossil fuels worth crores of rupees besides reducing pollution.

Bureau of Energy Efficiency is an Indian governmental organization created in 2001 responsible for promoting energy efficiency and conservation.

Energy conservation by country

Japan Since the 1973 oil crisis, energy

conservation has been an issue in Japan. The Energy Conservation Center promotes

energy efficiency in every aspect of Japan. Public entities are implementing the

efficient use of energy for industries and research.

Energy conservation by country

Lebanon In Lebanon and since 2002 The Lebanese

Center for Energy Conservation (LCEC) has been promoting the development of efficient and rational uses of energy and the use of renewable energy at the consumer level.

New Zealand In New Zealand the Energy Efficiency and

Conservation Authority is responsible for promoting energy efficiency and conservation

Energy conservation by country

United KingdomResponsibility for energy conservation fall

between three Government departments although is led by the 

• Department for Energy and Climate Change (DECC). The Department for Communities and Local Government (CLG) is still responsible for energy standards in buildings, and the Department for Environment, Food and Rural Affairs (Defra)

• The Department for Transport retains many responsibilities for energy conservation in transport.

Energy conservation by country

Pakistan• National Energy Conservation Centre (ENERCON)

is revolving towards an independent authority being developed under the ENERCON Bill 2011.

• ENERCON was established in 1987 and serves as the national focal point for energy conservation/energy efficiency activities in all sectors of the economy, namely industry, agriculture, transport, building and domestic.

CLASSIFICATION OF ENERGY

Primary and Secondary energyCommercial and Non commercial energyConventional and Non-Conventional

EnergyRenewable and Non-Renewable energy

Phases of Energy (contd.)

Example:

Chemical Energy of CoalThermal Energy of

SteamMechanical Energy of

Turbine

Electrical Energy of Generator

Primary Energy

Intermediate Energy

Secondary Energy

CLASSIFICATION OF ENERGY

The energy sources that are available in the market for a definite price are known as commercial energy. (coal, electricity etc )

The energy sources that are not available in the commercial market for a price are classified as non-commercial energy (firewood, cattle dung etc).

CLASSIFICATION OF ENERGY

Power provided by traditional means such as coal, wood, gas, uranium, hydro energy is called conventional source of energy

Non-Conventional sources of energy are opposite of conventional energy

USES OF ENERGY

The purpose of producing energy is to meet three types of societal needs: Mechanical work (electrical equipment); Heating supply; Heat removal (cooling systems);

Units of Energy

S. No. Unit Equivalent

01 1 watt 1 J/Sec

02 1 Cal 4.187 J

03 1 kCal 4.187 kJ

04 1 BTU 0.252 kCal

05 1 kCal ≈4 BTU

06 1 hp 632.34 k Cal (0.736 kW)

07 1 kWh 3.6 X 106 J (3.6 MJ)

08 1 kWh 860 kCal (3413 BTU)

09 1 erg 1 X 10-7 J (1 X 10-7 Nm , 1 dyne-cm)

10 1 eV 1.602 X 10-19 J

11 1 kW 1000 J (103 J)

12 1 MJ (Mega Joules) 106 J

13 1 GJ (Giga Joules) 109 J

14 1 TJ (Terra Joules) 1012 J

15 1 PJ (Peta Joules) 1015 J

16 1 EJ (Exa Joules) 1018 J

Any Queries / Questions