unit iii. part -b. energy and environmental engineering

7/31/2019 Unit III. Part -b. Energy and Environmental Engineering

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Portion

UNIT III Part b: Energy and environmental engineering: Conventional and non-conventional fuels, per capita and

global consumption pattern, their environmental impacts, alternative energy sources, vehicular emission standards of fuel

consumption, green buildings and rating systems. 03 Hrs

Energy:Energy is defined as the ability or the capacity to do work. Energy is the integral part of our life. It is the

energy that produces work, heat and power. Energy and power are measured in different units which makes thethings confusing sometimes. Let us have look at various units of measurement of energy and power and their

conversion.

Units of Measurement of EnergyEnergy is defined as the ability to do work i.e. energy produces work. As per the second law of

thermodynamics, whenever the work is done by absorbing the energy (heat) from the reservoir, some heat isalways rejected to the sink. The work and heat are also forms of energy; hence the units of measurement of

energy, work and heat are same.

A number energy measurement systems exist at present but most commonly used system is SI. Here arethe units of measurement of energy, work and heat in various systems:

1) MKS system (Metric system): Calories or cal: This unit is very commonly used to indicate the energycontent of the fuel and food, capacity of refrigeration and air-conditioning system, etc. One calorie is the amoun

of heat required to raise the temperature of one gram of water by one degree Celsius. As such calorie is a very

small unit hence larger unit Kilocalories or Kcal is more commonly used. 1Kcal = 1000 cal

2) SI unit system: Joule: This system is most commonly used now. Joule unit has been named after the famous

scientist Joule who has made very important contributions in the field of thermodynamics especially in work and

energy. Even Joule is a small unit; hence kilo Joule or KJ is used commonly. 1KJ = 1000J

3) British thermal unit: Btu: One Btu is the amount of energy needed to raise the temperature of one pound of

water by one degree Fahrenheit.

Conversion from One Unit to the other

1Btu = 1055J or 252cal1cal = 4.187J or 0.003969 Btu

1J = 0.2388cal or 0.0009481 Btu.

Units of Measurement of PowerThe rate at which the work is produced from the energy is called as power. For instance let us suppose that

there are two engines, both of which consume two gallons of gasoline and produce same amount of work i.e. 5KJ.

Let us suppose that the first one produces this work in five seconds and the seconds one produces this work in 10seconds. Accordingly the power produced by the first engine is 5/5 = 1KJ/s = 1KW and the power produced by

second engine is 5/10 = 0.5KW.

Here are various units of power:1) SI unit: The SI unit of power is W. It is the amount of power produced by consumption of one Joule of energy

in one second. The unit W is very small, larger unit like KW and MW are used commonly. 1KW = 1000W and

1MW = 1000KW. SI unit is most commonly used now.2) Horsepower (hp): This unit is more commonly used to denote the power produced by the engine of the

automobiles. 1hp = 746W or 0.746KW


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Classes / forms of EnergyPotential Energy storedenergy or energy of position

Gravitational energy an object or substance has because of its position. Anything up high

Stored Mechanical - stored in an object by the application of force. Must push or pull on an objectNuclear - energy stored in the nucleus of an atom. Holds the atom together

Chemical - energy stored in the bonds between atoms. Holds molecules together

Kinetic Energy energy of motion

Mechanical (Motion) movement of objects or substances from one place to anotherElectrical - movement of electrons. NOT AN ELECTRON PARADE!

Sound - movement of energy through substances in the form of longitudinal/compression wavesRadiant electromagnetic energy that travels in transverse waves

Thermal/Heat internal energy of a substance due to the vibration of atoms and molecules making

up the substance

Energy TransfersEnergy can not be created nor destroyed, only changed.

Energy always transfers from high to low.Energy transfers are never 100% efficient.

Types of energy:-conventional and non-conventionalConventional: Power provided by traditional means such as Fossil fuels, Nuclearenergy, etc.,

Fossil fuels:

1.Coal: Coal is a hard, black coloured, rock like substance. It is made up of carbon, hydrogen, oxygen,

nitrogen and varying amounts of sulfur. There are three main types of coal anthracite, bituminous

and lignite. Anthracite coal is the hardest and has more carbon, which gives higher energy contentLignite is the softest and is low in carbon but high in hydrogen and oxygen content. Bituminous is

in between. The precursor to coal peat is still found in many countries and is also used as an

energy source. Coal is mined out of the ground using various methods. Some coal minesare dug by sinking vertical or horizontal shafts deep under ground and coal miners travel byelevators or trains deep under ground to dig the coal. Other coal is mined in strip mines where huge

steam shovels strip away the top layers above the coal. The layers are then restored after the coal is

taken away. The coal is then shipped by train and boats and even in pipelines. In pipelines, the coalis ground up and mixed with water to make what is called slurry. This is then pumped many miles

through pipelines. At the other end, the coal is used to fuel power plants and other factories.

2.Oil: Oil is another fossil fuel. It was also formed more than 300 million years age. Diatoms are seacreatures in the size of a pin head and the dead diatoms settle on the sea floor. Here they were

buried under sediment and other rock. The carbon from the dead organisms eventually turned into

oil under great pressure and heat. The demand for oil increased with the increasing of the

population. Oil and natural gas are found under ground between folds of rock and in areas of rockthat are porous and contain the oils within the rock itself.

3.Natural gas: Natural gas is lighter than air. Natural gas is mostly made up of a gas called methane

Methane is a simple chemical compound that is made up of carbon and hydrogen atoms. This gas ishighly flammable. Natural gas is usually found near petroleum underground. It is pumped from

below the ground and distributed to larger areas. Natural gas usually has no odour. Before it is sent

to the pipelines and storage tanks, it is mixed with a chemical that gives a strong odour. The odoursmells almost like rotten eggs. The odour makes it easy to smell if there is a leak.

Nuclear energy:Nuclear power plants provide about 17% of the worlds electricity. Some countries depend

more on nuclear power for electricity than other. In France, about 75% of the electricity is generated fromnuclear power. In the United States, nuclear power supplies about 16% of the electricity overall, but some


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states get more power from nuclear plants than others. There are more than 400 nuclear power plants

around the world, with more than 100 in the United States.

per capita and global energy consumption patternThe standard of living of the people of any country is considered to be proportional to

the energy consumption by the people of that country. In one sense, the disparity one feelsfrom country to country arises from the extent of accessible energy for the citizens of eachcountry. Unfortunately, the world energy demands are mainly met by the fossil fuels today.

The geographical non equi-distribution of this source and also the ability to acquire and alsocontrol the production and supply of this energy source have given rise to many issues andalso the disparity in the standard of living. To illustrate the points that have been mentionedit is necessary to analyze some data.Energy Use by Sector

37%: Industry (agriculture, mining, manufacturing,

20%: Personal and commercial transportation

11%: Residential heating, lighting, and appliances5%: Commercial uses (lighting, heating and cooling of commercial buildings, and provision of water and

sewer services)

27%: Energy losses in generation and transmission

In Table 1, the proved reserves of some of the fossil fuels are given on the basis of regions.


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The world energy consumption pattern is also increasing as shown in the Fig.1. The energyconsumption has been increasing and it will triple in a period of 50 years by 2025 as seenfrom Fig.1.

Data on fossil fuel consumption by fuel type are given in Table 2.

Energy Consumption Per capita (GNP) (2004)

India: 0.7 kW; Bangladesh: 0.2 kW (least)The US consumes 25% of the world's energy (with a share of the world population

at 5%).


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environmental impacts of Conventional EnergyThe fossil fuel use as energy source has many limitations. There are a number ofpollutants that have been identified as coming out of the use of fossil fuels and they areserious health hazards. A simple compilation of the type of effects of the pollutants fromfossil fuel sources is given in Table 3.


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The scene of energy resources have been visualized in terms of various parameters. Mainly the populationincrease and also the need to increase the standard of living are the factors forcing to see new and alternate energy

options. The climate change which is threatening the existence of life is another factor forcing to consider

alternate energy sources. However the energy sources to be adopted will have to meet the varying needs ofdifferent countries and at the same time enhance the security of each one against the energy crisis or energy

shortage that have taken place in the past. The factors that need consideration for the search for new energy

sources should include:

(i) The global energy situation and demand(ii) The availability of fossil sources

(iii) The efficiency of the energy sources

(iv) The availability of renewable sources(v) The options for nuclear fission and fusion.

The world population will increase from 6 billion to 11 billion in this century and the life expectancy has

increased 2 times in the last two centuries and the energy requirement has increased 35 times in the same periodThe main drivers of the alternate energy search are the population growth, economy, technology, and agriculture.

This energy demand will be in the non OECD countries and it is expected that in china alone the energy demand

will increase by 20% and this will shift the oil export from west to other non OECD countries. Need for new andcarbon free energy sources and possibly electricity demand will go up in the coming years.

Energy from Nuclear fission though can be conceived as an alternate for the production the necessaryelectrical energy, the current available technologies and reactors may not be able to meet this demand. A globa

integrated system encompassing the complete fuel cycle, water management, and fissile fuel breeding have to beevolved for this source of energy to be a viable option.

The renewable energy sources are not brought into main stream energy resources though occasionally we

hear the use of low quality biomass as a source in some form or the other. The carbon dioxide emission must becontrolled in the vicinity of 600 to 650 ppm in the period of 2030 to 2080. The exact slope of the curve is not a

matter of concern the cumulative amount of the carbon dioxide emission will be a factor to reckon with.

Therefore the alternative for energy supply should include fossil fuel with carbon dioxide sequestration, nuclearenergy and renewable energies. Possibly fusion and also hydrogen based energy carrier system will evolve

However, the costs involved may even force the shift to the use of coal as an energy source in countries like India

and China.The adaptation of new energy sources also faces some limitations. One is not sure of the feasibility and

sustainability of such an energy source, and the learning curve also has very limited gradient making investments

restrictive.

Even though collaborative ventures between nations may be one option from the point of view oinvestment, it is not certain whether any country will be willing to deploy giga watts power not directly produced

in the country of consumption. This is mainly due to the experience from energy disruptions in the past and also

the small elasticity of the energy market. Countries will opt for a diversity of energy supply rather than depend ona mega scale power plants since the possibility of alternate suppliers will be more acceptable than the inter

dependent supplies across countries, economy and administration.

There are a variety of energy resources and energy forms. These include hydro power, wind, solar,

biomass and geothermal for resources and in the energy forms, light, heat, electricity, hydrogen and fuel. How thistransition has to occur depends on many factors but surely the transition has to take place sooner or later. What

kind of mix will be required also depends on the location and also the availability of the resources. Photovoltaic

devises have been advocated as a powerful energy source, but the technology still needs high investment and alsothe reliability and sustainability questions have to be addressed.

alternative energy sourcesAlternative energy refers to energy sources that have no undesired consequences such for example fossil

fuels or nuclear energy. Alternative energy sources are renewable and are thought to be "free" energy sources

They all have lower carbon emissions, compared to conventional energy sources. These includeBiomass Energy
http://www.altenergy.org/renewables/biomass.htmlhttp://www.altenergy.org/renewables/biomass.htmlhttp://www.altenergy.org/renewables/biomass.html


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Wind Energy, Solar Energy, Geothermal Energy, Hydroelectric Energy sources. Combined with the use of

recycling, the use of clean alternative energies such as the home use of solar power systems will help ensureman's survival into the 21st century and beyond.

1. Bio EnergyBiomass is yet another important source of energy with potential to generate power to the

extent of more than 50% of the countrys requirements. India is predominantly an agriculturaleconomy, with huge quantity of biomass available in the form of husk, straw, shells of coconuts wildbushes etc. With an estimated production of 350 million tons of agricultural waste every year,

biomass is capable of supplementing coal to the tune of about 200 million tonnes producing 17,000MW of power and resulting in a saving of about Rs.20,000 crores every year. Biomass available inIndia comprises of rice husk, rice straw, bagasse, coconut shell, jute, cotton, husk etc. Biomass canbe obtained by raising energy farms or may be obtained from organic waste.

The biomass resources including large quantities of cattle dung can be used in bio-energytechnologies viz., biogas, gasifier, biomass combustion, cogeneration etc., to produce energy-thermalor electricity. Biomass can be used in three ways one in the form of gas through gasifiers forthermal applications, second in the form of methane gas to run gas engines and produce power andthe third through combustion to produce steam and thereby power.2. Wind Energy

The evolution of windmills into wind turbines did not happen overnight and attempts to produce

electricity with windmills date back to the beginning of the century. It was Denmark which erected thefirst batch of steel windmills specially built for generation of electricity. After World War II, thedevelopment of wind turbines was totally hampered due to the installation of massive conventionalpower stations using fossil fuels available at low cost. But the oil crisis of 1973 heralded a definitebreak through in harnessing wind energy.

Many European countries started pursuing the development of wind turbine technologyseriously and their development efforts are continuing even today. The technology involvesgeneration of electricity using turbines, which converts mechanical energy created by the rotation ofblades into electrical energy, some times the mechanical energy from the mills is directly used forpumping water from well also. The wind power programme in India was started during 1983-84 withthe efforts of the Ministry of Non-Conventional Energy Sources. In India the total installed capacity

from wind mills is 1612 MW.3. Solar Energy

Solar Power was once considered, like nuclear power, too cheap to meter but this provedillusory because of the high cost of photovoltaic cells and due to limited demand. Experts howeverbelieve that with mass production and improvement in technology, the unit price would drop and thiswould make it attractive for the consumers in relation to thermal or hydel power. The Solar PhotoVoltaic (SPV) technology which enables the direct conversion of sun light into electricity can be usedto run pumps, lights, refrigerators, TV sets, etc., and it has several distinct advantages, since it doesnot have moving parts, produces no noise or pollution, requires very little maintenance and can beinstalled anywhere. These advantages make them an ideal power source for use especially in remoteand isolated areas which are not served by conventional electricity making use of ample sunshine

available in India, for nearly 300 days in a year.A Solar Thermal Device, on the other hand captures and transfers the heat energy available in

solar radiation. The energy generated can be used for thermal applications in different temperatureranges. The heat can be used directly or further converted into mechanical or electrical energy.4. Other Sources

The other sources of renewable energy are geothermal, ocean, hydrogen and fuel cells. Thesehave immense energy potential, though tapping this potential for power generation and otherapplications calls for development of suitable technologies.(i) Geo-Thermal Energy
http://www.altenergy.org/renewables/wind.htmlhttp://www.altenergy.org/renewables/solar.htmlhttp://www.altenergy.org/renewables/geothermal.htmlhttp://www.altenergy.org/renewables/geothermal.htmlhttp://www.altenergy.org/renewables/geothermal.htmlhttp://www.altenergy.org/renewables/hydroelectric.htmlhttp://www.altenergy.org/renewables/hydroelectric.htmlhttp://solarpros.com/http://www.altenergy.org/renewables/wind.htmlhttp://www.altenergy.org/renewables/solar.htmlhttp://www.altenergy.org/renewables/geothermal.htmlhttp://www.altenergy.org/renewables/hydroelectric.htmlhttp://solarpros.com/


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Geo-Thermal energy is a renewable heat energy from underneath the earth. Heat is brought tonear surface by thermal conduction and by intrusion into the earths crust. It can be utilised for powergeneration and direct heat applications. Potential sites for geo-thermal power generation have beenidentified mainly in central and northern regions of the country. Suitable technologies are underdevelopment to make its exploitation viable.(ii) Ocean thermal and Tidal energy (Ocean Thermal Energy Conversion OTEC)

The vast potential of energy of the seas and oceans which cover about three fourth of ourplanet, can make a significant contribution to meet the energy needs. Ocean contains energy in the

form of temperature gradients, waves and tides and ocean current, which can be used to generateelectricity in an environment-friendly manner. Technologies to harness tidal power, wave power andocean thermal energy are being developed, to make it commercially viable.(iii) Hydrogen and Fuel Cells

In both Hydrogen and Fuel Cells electricity is produced through an electro-chemical reactionbetween hydrogen and oxygen gases. The fuel cells are efficient, compact and reliable for automotiveapplications. Hydrogen gas is the primary fuel for fuel cells also. Hydrogen can be produced from theelectrolysis of water using solar energy. It can also be extracted from sewage gas, natural gas,naptha or biogas. Fuel cells can be very widely used once they become commercially viable.(iv) Bio fuels

In view of worldwide demand for energy and concern for environmental safety there is need to

search for alternatives to petrol and diesel for use in automobiles. The Government of India has nowpermitted the use of 5% ethanol blended petrol. Ethanol produced from molasses/ cane juice, whenused as fuel will reduce the dependence on crude oil and help contain pollution. Further, technologyis also being developed to convert different vegetable oils especially non-edible oils as bio-diesel foruse in the transport sector. They are however, in R & D stage only.

vehicular emission standardsHistory of Emission Norms in India

The significant environmental implications of vehicles cannot be denied. The need to reduce vehicularpollution has led to emission control through regulations in conjunction with increasingly environment-friendly

technologies.

It was only in 1991 that the first stage emission norms came into force for petrol vehicles and in 1992 fordiesel vehicles.

From April 1995 mandatory fitment of catalytic converters in new petrol passenger cars sold in the four

metros of Delhi, Calcutta, Mumbai and Chennai along with supply of Unleaded Petrol (ULP) was affected.

Availability of ULP was further extended to 42 major cities and now it is available throughout the country.The emission reduction achieved from pre-89 levels is over 85% for petrol driven and 61% for diesel

vehicles from 1991 levels.

In the year 2000 passenger cars and commercial vehicles will be meeting Euro I equivalent India 2000norms, while two wheelers will be meeting one of the tightest emission norms in the world.

Euro II equivalent Bharat Stage II norms are in force from 2001 in 4 metros of Delhi, Mumbai, Chennai

and Kolkata.

Since India embarked on a formal emission control regime only in 1991, there is a gap in comparison withtechnologies available in the USA or Europe. Currently, we are behind Euro norms by few years, however, a

beginning has been made, and emission norms are being aligned with Euro standards and vehicular technology isbeing accordingly upgraded. Vehicle manufactures are also working towards bridging the gap between Euro

standards and Indian emission norms.

THE PARAMETERS DETERMINING EMISSION FROM VEHICLES

Vehicular Technology

Fuel Quality

Inspection & Maintenance of In-Use Vehicles


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Road and Traffic Management

While each one of the four factors mentioned above have direct environmental implications, the vehicle

and fuel systems have to be addressed as a whole and jointly optimised in order to achieve significant reduction in

emission.

VEHICULAR TECHNOLOGY

In India, the vehicle population is growing at rate of over 5% per annum and today the vehicle population

is approximately 40 million. The vehicle mix is also unique to India in that there is a very high proportion of twowheelers (76%).

FUEL TECHNOLOGYIn India we are yet to address the vehicle and fuel system as a whole. It was in 1996 that the Ministry of

Environment and Forests formally notified fuel specifications. Maximum limits for critical ingredients like

Benzene level in petrol have been specified only recently and a limit of 5% m/m and 3% m/m has been set forpetrol in the country and metroes respectively.

In place of phase-wise upgradation of fuel specifications there appears to be a region-wise introduction of

fuels of particular specifications. The high levels of pollution have necessitated eliminating leaded petrol, through

out the country.To address the high pollution in 4 metro cities 0.05% sulphur petrol & diesel has been introduced since

2000-2001. The benzene content has been further reduced to 1% in Delhi and Mumbai.There is a need for a holistic approach so that upgradation in engine technology can be optimised for

maximum environmental benefits.

Other factors influencing emission from vehicles.

INSPECTION & MAINTENANCE (I&M) OF IN-USE VEHICLESIt has been estimated that at any point of time, new vehicle comprise only 8% of the total vehicle

population. In India currently only transport vehicles, that is, vehicles used for hire or reward are required to

undergo periodic fitness certification. The large population of personalised vehicles are not yet covered by any

such mandatory requirement.In most countries that have been able to control vehicular pollution to a substantial extent, Inspection &

Maintenance of all categories of vehicles have been one of the chief tools used. Developing countries in the South

East Asian region, which till a few years back had severe air pollution problem have introduced an I&M systemand also effective traffic management.

ROAD & TRAFFIC MANAGEMENT

Inadequate and poor quality of road surface leads to increased Vehicle Operation Costs and also increasedpollution. It has been estimated that improvements in roads will result in savings of about 15% of Vehicle

Operation Costs.


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green buildingsGreen, or sustainable, building is the practice of creating and using healthier and more resource-efficient models

of construction, renovation, operation, maintenance and demolition. Read more about green building or use these

links to explore topics:

Components of Green Building

Energy Efficiency and Renewable Energy

Water Efficiency

Environmentally Preferable Building Materials and SpecificationsWaste Reduction

Toxics ReductionIndoor Air QualitySmart Growth and Sustainable Development

Building Types

HomesSchools

Commercial Buildings

LaboratoriesHealthcare Facilities

Rating Systems

GRIHA, an acronym for Green Rating for Integrated Habitat Assessment, is the National Rating System of India.It has been conceived by TERI and developed jointly with the Ministry of New and Renewable Energy,

Government of India. It is a green building 'design evaluation system', and is suitable for all kinds of buildings in

different climatic zones of the country.It is a rating tool that helps people, assess the performance of their building against certain nationally acceptable

benchmarks. It will evaluate the environmental performance of a building holistically over its entire life cycle,

thereby providing a definitive standard for what constitutes a green building. The rating system, based onaccepted energy and environmental principles, will seek to strike a balance between the established practices and

emerging concepts, both national and international. The guidelines/criteria appraisal may be revised every three

years to take into account the latest scientific developments during this period.
http://www.epa.gov/greenbuilding/pubs/about.htmhttp://www.epa.gov/greenbuilding/pubs/components.htmhttp://www.epa.gov/greenbuilding/pubs/components.htm#energyhttp://www.epa.gov/greenbuilding/pubs/components.htm#waterhttp://www.epa.gov/greenbuilding/pubs/components.htm#materialshttp://www.epa.gov/greenbuilding/pubs/components.htm#wastehttp://www.epa.gov/greenbuilding/pubs/components.htm#toxicshttp://www.epa.gov/greenbuilding/pubs/components.htm#indoorhttp://www.epa.gov/greenbuilding/pubs/components.htm#sustainhttp://www.epa.gov/greenbuilding/pubs/buildingtypes.htmhttp://www.epa.gov/greenbuilding/pubs/buildingtypes.htm#homeshttp://www.epa.gov/greenbuilding/pubs/buildingtypes.htm#schoolshttp://www.epa.gov/greenbuilding/pubs/buildingtypes.htm#commhttp://www.epa.gov/greenbuilding/pubs/buildingtypes.htm#labhttp://www.epa.gov/greenbuilding/pubs/buildingtypes.htm#healthhttp://www.epa.gov/greenbuilding/pubs/about.htmhttp://www.epa.gov/greenbuilding/pubs/components.htmhttp://www.epa.gov/greenbuilding/pubs/components.htm#energyhttp://www.epa.gov/greenbuilding/pubs/components.htm#waterhttp://www.epa.gov/greenbuilding/pubs/components.htm#materialshttp://www.epa.gov/greenbuilding/pubs/components.htm#wastehttp://www.epa.gov/greenbuilding/pubs/components.htm#toxicshttp://www.epa.gov/greenbuilding/pubs/components.htm#indoorhttp://www.epa.gov/greenbuilding/pubs/components.htm#sustainhttp://www.epa.gov/greenbuilding/pubs/buildingtypes.htmhttp://www.epa.gov/greenbuilding/pubs/buildingtypes.htm#homeshttp://www.epa.gov/greenbuilding/pubs/buildingtypes.htm#schoolshttp://www.epa.gov/greenbuilding/pubs/buildingtypes.htm#commhttp://www.epa.gov/greenbuilding/pubs/buildingtypes.htm#labhttp://www.epa.gov/greenbuilding/pubs/buildingtypes.htm#health


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Going by the old adage what gets measured, gets managed, GRIHA attempts to quantify aspects such as energy

consumption, waste generation, renewable energy adoption, etc. so as to manage, control and reduce the same tothe best possible extent.

LEED-INDIA is the Indian counterpart of United States Green Building Councils LEED (Leadership in Energyand Environmental Design). It is led by the Indian Green Building Council (IGBC) in India.

The Leadership in Energy and Environmental Design (LEED-INDIA) Green Building Rating System is a

nationally and internationally accepted benchmark for the design, construction and operation of high performance

green buildings.LEED-INDIA provides building owners, architects, consultants, developers, facility managers and project

managers the tools they need to design, construct and operate green buildings. It promotes a whole-building

approach to sustainability by recognizing performance in the following five key areas: Sustainable sitedevelopment, Water savings, Energy efficiency, Materials selection and, Indoor environmental quality.

LEED-INDIA rating system provides a roadmap for measuring and documenting success for every building type

and phase of a building lifecycle.

unit iii. part -b. energy and environmental engineering

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