1. Fuel Cells

2. Fuel Cells
Electro-chemical device for the continuous conversion of a portion of the free energy change of a chemical reaction to electrical energy.
It is distinguished from a battery in that it operates with continuous replenishment of the fuel and the oxidant at active electrode area and does not require recharging.
Main component of a fuel cell are (i) a fuel electrode (ii) an oxidant or air electrode and (iii) an electrolyte

3. Introduction to Fuel Cells
A fuel cell is a device that uses hydrogen (or hydrogen rich fuel) and oxygen to create electricity by an electrochemical process.
If pure hydrogen is used as a fuel, fuel cells emit only heat and water as a byproduct.
Current applications: power passenger vehicles, commercial buildings, homes, and laptop computers.

4. Why We Want to Use Fuel Cells?
Environmental concern of using fossil fuel (e.g. poisonous emissions)
Oil crises
Global warming

5. A fuel cell is a controlled chemical and electrical energy conversion device which continuously converts chemical energy to electrical energy.
In a hydrogen, oxygen fuel cell electrochemical reaction involves the process of ionisation in which atoms or molecules looses or gains one or more electron.
Loosing one electron gives the atom overall positive charge and gaining an electron gives negative charge.
Water can be ionised into hydroxyl ion(-) and hydrogen ion(+) when two dissimilar metal electrodes like sodium, zinc, cadmium is placed in a solution containing ions. Voltage is developed between positively charged electrode.
In fuel cell the reactants are continuously fed to the cell and electrically it is extracted.
Therefore the fuel cell is like a storage battery but with regular supply of fuel and oxygen.

6. Fuel Cell e- H+ H2 O2 H2  2H+ + 2e- ½ O2 + 2H+ + 2e-  H2O Anode
Cathode e- H+ H2 O2
H2  2H+ + 2e-
½ O2 + 2H+ + 2e-  H2O
Electrolyte
Overall: H2 + ½ O2  H2O

7. Membrane-Electrode Assembly (MEA)
Fuel Cell Components
Components
Electrolyte (Membrane)
Transport ions
Block electrons, gases
Electrodes
Catalyze reactions
Transport
Ions, electrons, gases
May be a composite
(electro)Catalyst +
Conductors +
Pore former
electrolyte
catalyst
electrodes
sealant
Membrane-Electrode Assembly (MEA)

8. Fuel Cells
Some of the fuel cells are hydrogen, oxygen(H2O2), hydrazine (N2H4O2), Carbon/coal(C,O2),, methane (CH4,O2).
Hydrogen, oxygen (Hydroxy) fuel cells, are efficient and highly developed.
In the hydrox cell, catalyst is embedded in Nickel electrode.The electrolyte is typically 30% KOH because of its high electrical conductivity and it is less corrosive than acids.
Cell reactions are,
Anode reaction : 2H H+ + 4e-
Cathode reaction : 2H2 + O H2O (vapour) + Energy

9. H2 is fed to one electrode and is absorbed
H2 is fed to one electrode and is absorbed. It gives off free electrons and also reacts with hydroxyl ions of the electrolyte to form water.The free electrons travel towards oxygen electrode through the external circuit.
The two electrons at the external circuit combine with one molecule of water to form 2OH- ions.
These OH- ions migrate towards H2 electrode and are consumed there.
The electrolyte remains invariant. The cell operates at or slightly above atmospheric pressure and at temperature of about 90ºC.These types of cells are called low temperature cells. In high-pressure cells pressure is upto about 45 atmosphere and temperature is upto 300ºC.

10. A single hydrogen, oxygen fuel cell can produce an emf of 1
A single hydrogen, oxygen fuel cell can produce an emf of 1.23 Volt at atmospheric pressure and at 25ºC.By connecting number of cells, it is possible to create useful potential of 100 to 1000 volts and power levels of 1 kW to nearly 100MW.
The overall efficiency of the cell is the ratio of the power generated and the heating value of the hydrogen consumed.

11. Comparison between different types of fuel cells
Aspects
PEMFC
AFC
PAFC
MCFC
SOFC
Type of electrolyte
H+ ions (With anion bound in polymer membrane)
OH- ions (Typically aqueous KOH solutions)
H+ ions (H3PO4 solutions)
CO32- ions (Typically molten LiK2CO3 eutectics)
O2- ions (Stabilized ceramic matrix with free oxide ions)
Typical construction
Plastic, metal or carbon
Plastic, metal
Carbon, porous ceramics
High temperature metals, porous ceramic
Ceramic, High temperature metals
Internal Reforming No
Yes, Good Temperature match
Oxidant
Air to O2
Purified Air to O2
Air to enriched air
Air
Operational Temperature
65 – 85 ºC ºC ºC ºC ºC
Distributed Generation system level
(η %)
Primary contaminate sensitivities
CO,NH3 and sulphur
CO,CO2 and sulphur
CO < 1% sulphur
Sulphur

12. Types of Fuel Cell PEMFC – Proton Exchange Membrane Fuel Cell or
Polymer Electrolyte Membrane
AFC – Alkaline Fuel Cell
PAFC – Phosphoric Acid Fuel Cell
MCFC – Molten Carbonate Fuel Cell
SOFC – Solid Oxide Fuel Cell

13. Fuel Cell Choices
Temperature sets operational parameters & fuel choice
Ambient Temperature
Rapid start-up
H2 or CH3OH as fuels
Catalysts easily poisoned
Applications
Portable power
Many on/off cycles
Small size
High Temperature
Fuel flexible
Very high efficiencies
Long start-up
Applications
Stationary power
Auxiliary power in portable systems

14. How Fuel Cells Work
A fuel cell is a device that uses hydrogen (or hydrogen-rich fuel) and oxygen to create electricity by an electrochemical process.
A single fuel cell consists of an electrolyte sandwiched between two thin electrodes (a porous anode and cathode).

15. Types of Fuel Cells Polymer Electrolyte Membrane (PEM) Phosphoric Acid
Direct Methanol
Alkaline
Molten Carbonate
Solid Oxide
Regenerative (Reversible)

16. PEM Also called SPEFC (Solid Polymer Electrolyte Fuel Cells)
Use a proton exchange membrane as an electrolyte.
Low temperature fuel cells ( C)
Nafion® membranes (developed by DuPont) consists of a polyterrafluoreethylene (PTFE) based structure

17. Polymer Electrolyte Membrane (PEM)

18. Alkali Fuel Cell Electrolyte: KOH in H2O
Liquid in a matrix, or liquid recirculated
Mobile species: OH-
Half cell reactions
anode: H2 + 2OH-  2H2O + 2e-
cathode: ½ O2 + H2O + 2e-  2OH-
Catalysts
anode: Ni, Ni-Pt, Ni-Co, etc.
cathode: NiO, Ag, etc.
unlike other fuel cells, rapid cathode kinetics, slower anode
Features
High power output due to rapid electrocatalysis rates
Inexpensive materials
Highly sensitive to CO2: KOH(aq) + CO2  K2CO3 (ppt)
Used by NASA for manned missions
H2O available in electrolyte

19. Alkaline

20. Molten Carbonate Fuel Cell
Electrolyte: K2CO3, Na2CO3, Li2CO3 eutectic liq ( °C)
Liquid in a LiAlO2 matrix
Mobile species: CO3=
Half cell reactions
anode: H2 + CO3=  CO2+ H2O + 2e-
cathode: ½ O2 + CO2 + 2e-  CO3=
Catalysts
anode: Ni-Al, Ni-Cr alloys
cathode: NiO
like most fuel cells, slow cathode kinetics, faster anode
Features
High temperature  in situ hydrocarbon fuel reforming
Highly corrosive environment
NiO dissolution at cathode & precipitation at anode as Ni
Largely abandoned in the US, but Japan and Europe continue
CO2 recirculated

21. Molten Carbonate

22. Polymer Electrolyte Membrane (PEM)

23. PEM Fuel Cell Electrolyte: Sulfonated, perfluorinated polymer [Nafion]
“water–polymer composite”
Mobile species: H(H2O)n+ [not H+]
Half cell reactions
anode: H2 + 2nH2O  2H(H2O)n+ + 2e-
cathode: ½ O2 + 2H(H2O)n+ + 2e-  H2O
Catalysts
anode: Pt/Vulcan carbon ~ 0.1 mg/cm2
cathode: Pt/Vulcan carbon ~ 1 mg/cm2
like other fuel cells, slow cathode kinetics, fast anode
Features
High power output due to rapid electrocatalysis rates
Expensive materials
Catalyst highly sensitive to impurities: CO
Corrosive environment  degradation, e.g. Pt coarsening
H2O recirculated

24. Solid Oxide Fuel Cell
Electrolyte: yttria stabilized zirconia, YSZ, Zr0.92Y0.08O1.96
true solid electrolyte
Mobile species: O= [or oxygen vacancy]
Half cell reactions
anode: H2 + O=  H2O + 2e-
cathode: ½ O2 + 2e-  O=
Catalysts
anode: Ni + YSZ
cathode: (La,Sr)MnO3-d
like other fuel cells, slow cathode kinetics, fast anode
Features
Relatively high power output
Expensive manufacturing, auxiliary component materials
In principle, hydrocarbon fuels can be directly oxidized
Under steady conditions, little degradation

25. Solid Oxide

26. Advantages Some of the advantages of fuel cells are:
It is a direct conversion process and does not involve a thermal process, so it has high operating efficiency. Present day fuel cell efficiency is 38% and is expected to reach 60%.
The unit is lighter, smaller and needs less maintanence.
Fuel power plants may further cut generation costs by reducing transmission losses.
Little pollution, little noise so that it can be readily acceptable in resident areas.

27. Benefits of Using Fuel Cells
They produce much small quantities of greenhouse gases that contribute to global warming.
None of the air pollutants that create smog and cause health problems.
If pure hydrogen is used as a fuel, ONLY heat and water are emitted.

28. Drawbacks The drawbacks are: Low voltage High initial cost
Low service life

29. Applications Fuel Cell Generator Fuel Cell Bus
Power Generation/Conversion
Fuel Cell Car

30. Hydrogen as a future energy source

31. Reasons for change Reduction in greenhouse gases (CO2, NOx, SOx)
Environment
Energy shortages
Energy security
Reduction in greenhouse gases (CO2, NOx, SOx)
Eco friendly use of waste products
Desire to use renewable energy
Desire to meet emissions goals (eg: Kyoto)
Peak oil running out
Hydrocarbon gas supplies a long way from point of use
Emergence of rapidly developing economies greatly increasing World’s energy requirement
A long term energy solution
Minimising reliance on Imported energy
Changing political climate increases dependence on unstable regimes
Hydrogen can be produced from multiple sources

32. It’s not energy efficient!
Energy Efficiency
Maximum 80% efficient for conversion to H2 from other fuels.
Liquefying H2 uses up to 1/3 rd of it’s energy value!
Liquid storage losses can be 2-3% per day
Compression requires significant energy input input
It’s not energy efficient!

33. It may not be Environmentally friendly !
Environmental issues
Steam Methane reforming produces more CO2 than current Hydrocarbon fuels for vehicles.
Electrolysis can be environmentally friendly depending on how the electricity is produced.
It may not be Environmentally friendly !

34. So why Hydrogen? It will never run out – unlike Oil and Gas.
It can be produced in several ways from different sources.
It provides energy security - any country can make their own.
It can be used in either Fuel Cells (FC’s) or Internal Combustion Engines (ICE’s)
The world wants an environmentally friendly fuel – Hydrogen has the potential.
At some point, Hydrogen will be cheaper than Hydrocarbons.
Clean at point of use

35. Hydrogen as a future energy source
The use of energy may lead to climate changes. It is thus necessary to make the transition to cleaner and environmentally favourable energy carriers.
Hydrogen has the best potential of becoming the fuel of the future. Hydrogen can be produced from sustainable, renewable sources and may contribute to meet the growth in world energy demand.
Hydrogen is an energy carrier for the future. It is a clean fuel that can be used in places where it is hard to use electricity. Sending electricity a long way costs four times as much as shipping hydrogen by pipeline.

36. Hydrogen as a future energy source
Hydrogen is a carbon-free energy carrier. When used in fuel cells, there are no harmful emissions.
The current production of hydrogen is 500 billion m3/year,equivalent to 3.3 million barrels of oil per day. This again is equivalent to 10% of the energy currently used in transportation.
Presently, hydrogen production represents only about 1 percent of worldwide oil production. The only place it has been used for fuel in significant quantity is the NASA space shuttle.

37. H2 as the energy source of tomorrow
A storage medium for heat and electricity:
hydrogen = ideal energy source to bridge the time and distance gaps between supply and demand:
 as a component of water, a resource available in large quantities
 environmentally compatible as part of the biological life cycle
 its oxidation creates pure water
 easily transported and stored in compressed gas form or as a supercooled liquid
 releases chemically stored energy in the form of heat, or in the form of electricity and heat in fuel cells
 high energy content = suitable as fuel for cars

38. H2 as the energy source of tomorrow

39. H2 as the energy source of tomorrow

40. On the way to our energy source of the future

41. On the way to our energy source of the future
Advantages of Sustainable Energy:
 fossil fuel resources no longer burnt
 cyclical system: hydrogen as well as the energy required to generate it are derived from renewable sources
 combustion of hydrogen emits no greenhouse gases
 local power supply in the home and cars

42. The following hurdles may be overcome if hydrogen is to be a viable source of energy in the future:
The long-term nature of the transition may be recognized and a strategy developed now.
Durable and affordable fuel cells must be developed.
On-board storage and safety issues must be resolved for hydrogen – powered cars.
Hydrogen has to be produced cheaply and in such a way that doesn’t use more than it is produced.

43. Energy Conservation and Energy Management

44. Energy Management vs Energy Conservation
Conservation is the reduction of usage.
Management is the judicious and effective use of utilities to maximize profits (minimize costs) and enhance competitive positions.

45. Energy and Financial Management
EM is strikingly similar to FINANCIAL management:
Identify goals;
Select the investments needed to reach the goals;
Establish a blueprint & strategy for goal attainment;
Start early, if only with small efforts;
Maintain regular contributions over time;
Keep track of earnings; and
Defeat risk through reinvestment and diversification of earnings.

46. Energy Management Benefits
Initial Effort (First two years)
5-15% cost savings
Little or no capital expenditure
Long-Term Effort
25% or higher cost savings
Requires management commitment
A never ending process

47. Focusing Energy Management
Focus on COST not USAGE
Pareto Principle
20% of loads account for 80% of costs
Identify these 20% loads
Control and meter these loads
Develop a “Cost Center” mentality
Don’t treat utilities as overhead
Energy is used to achieve some benefit. Find the lowest cost means to reap that benefit.

48. Starting Your Energy Action Plan
Designate an Energy Management
Coordinator
Establish the Energy Management Team
Evaluate cost saving opportunities
Prioritize implementation
Implement
Evaluate success (e.g. benchmarking) and promote

49. Energy Management Coordinator
A single person
Dynamic
Goal oriented
Good manager
Wears other hats

50. GOALS OF THE EMC Architect of the “Energy Action Plan”
Provide effective energy reporting and analysis (energy accounting)
Secure management commitment
Establish “cost center” mentality
Establish energy cost/usage standards
Provide EM training
Set EM objectives (defined goals)

51. EXAMPLE ENERGY MANGEMENT GOALS
Reduce electric cost per unit of production by 10% the first year and 5% in the second
Within 2 years all tenants will be separately metered
Facility will have a contingency plan for gas curtailment by end of first year
All boilers will be examined for waste heat recovery potential the first year

52. ENERGY MANAGEMENT TEAM
Energy Management Coordinator
Technical Support
Steering Group

53. Energy Management
Conservation - reducing the amount we use by insulating, reducing the amount we use and additional control technology
Recovery - using the so called waste - developed patent to recover heat from flue gasses on boiler flue systems
Substitution - renewable technologies - wind (Scarborough), PV arrays (west campus)

54. Which factors does Energy Management deal with?
People
Building
Energy type used
Installed equipment
External factors
Legislation – ‘One will have to comply’
People - the individuals who make choices about energy use and control the energy systems
Building - insulation level, building type
Energy type used - oil or gas …….emission factors
Installed equipment - is the equipment energy efficient, condensing boilers, CFL lamps
External factors - weather, wind speed, solar gain
Legislation – ‘One will have to comply’

55. Energy Conservation

56. Energy Conservation
In economic terms, energy is termed as a demand- derived good.That is, energy is an intermediate good whose demand depends on the demand of the final (end-use) goods and services it produces.
Energy conservation can be defined as the substitution of energy with capital labour or material and time.
Energy conservation can also be defined as the substitution of this generation’s energy with that of future generations, known as “intertemporal substitution” (substitution of this generation energy with that of future generations).
Energy conservation invokes avoiding wastage of energy and adopting methods to save energy without affecting the productivity and comforts of machine / labour.

57. The two points to be considered before demanding more
conservation efforts are:
Whether the depletion of the given resource can be offset by new exploration and findings. That is, is the resource really limited, and hard to replace in a short time.
The intertemporal welfare of consuming this type of energy. That is, is the marginal utility of consuming this energy in this generation larger than the utility of consuming it in the next generation.

58. Principles of Energy Conservation
The two principles governing energy conservation are
Maximum thermodynamic efficiency.
Maximum cost-effectiveness in energy use.
We can maximize this efficiency by the following conservation measures
Using condensers to recapture the heat discharged as many times as possible
Reducing heat loss with better heat exchangers

59. Maximum cost-effectiveness in energy use is achieved if the production factor or intertemporal substitution is made to maximize energy efficiency at the least cost. From this, maximum cost-effectiveness in energy use is determined by two cost components:
Conservation costs (Costs for implementing energy conservation efforts in order to save energy)
Energy costs (Unit energy cost will decline as more conservation measures are implemented to reduce energy use)

60. Energy Use in India
Energy consumption in India is low, though efficiency of use is reasonable
Per capita energy consumption is 530 kgoe; world average is 1770
Energy intensity of Indian economy was 0.18 kgoe/$-GDP(PPP) in 2004; compared to 0.14 in Japan and 0.19 in the EU
Energy demand is increasing due to rising incomes, accelerated industrialization, urbanization and population growth
: Mtoe
: Mtoe
: Mtoe
Meeting the increasing demand only through increases in supply may lead to:
Reduced energy security due to volatility in availability and prices of imported fuels
Adverse environmental impacts
Strain on balance of payments
Energy conservation and energy-efficiency are an essential part of national energy strategy 60

61. IMPORTANCE OF ENERGY CONSERVATION
Energy efficiency/conservation measures can reduce peak and average demand. .
One unit saved avoids 2.5 to 3 times of fresh capacity.
Also avoids investment in fuel, mining, transportation etc.
Keeping the above factors in view and also to provide a policy guidance, Government of India enacted the Energy Conservation Act,2001

62. Application of waste heat for energy conservation
Case study 1 : Distilled water from Engine exhaust heat
CHP delivers electrical and thermal energy in such a way that much more of the energy content of the input fuel is used - by utilizing waste heat.
Diesel engine operates with a thermal efficiency of 40%. So waste heat is 60% of the available heat.
For example, diesel car having the Air, Fuel ratio of 1: 15
Mass of Exhaust gas leaving from the engine = 16 kg/kg of fuel
Engine exhaust gas temperature = 600 C
Specific heat of flue gas = 0.25 kcal / kg K

63. Quantity of heat available if we reduce the flue gas temperature 600 to 300 C
Q = m Cp (T2-T1)
= kcal
Quantity of heat required making the water into steam
(Sensible heat + Latent heat) = kcal / kg
 We are able to get 2 lt of distilled water for every liter of Diesel

64. Application of Renewable energy systems for energy conservation
Case study 2 : Solar water heater for fuel savings
1% fuel can be saved for every 6ºC rise in temperature of boiler feed water.
100 LPD (Litres per day) solar water heater can rise the temperature from 32ºC to 62ºC (ΔT = 30°C), costs around Rs 18,000.
5% fuel saving can be achieved with the help of solar water heater.
100 MW thermal power plant requires 60 tons/hr of coal
5% of fuel saving is 3 tons/hr so Rs 9000/hr is saved.

65. 8000 working hours in a year, saves Rs 7,20,00,000.
100 MW thermal power plant requires 10 tons/hr (2,40,000 lt/day) of feed water.
So 2400 Nos of 100 LPD solar water heater is needed for 100 MW thermal power plant which can rise the boiler feed water to 62°C.
Initial investment for 2400 nos of solar water heater is Rs.4,32,00,000.
Payout time is less than one year. (4,32,00,000 / 7,20,00,000).
Life of the solar water heater is 10 yrs.
The energy conservation method could be thought of wherever there is a demand for process heat.

66. Optimum Utilization of Heat and Power

67. Waste Heat Recovery
Waste heat is defined as the heat rejected from a process which is sufficiently at a higher temperature than the ambient temperature.
Waste heat could include exhaust steam from process industries, heat from power plants and heat generated from various other streams such as agricultural crops, food process waste, waste tyres etc.
Approximately two-thirds of industrial energy is used in process steam and heat, and this is in the form of thermal energy, rather than in the form of power. Consequently, the opportunities for waste heat recovery are plentiful.

68. However in establishing the opportunities, process energy requirements and waste streams technology of recovery need to be evaluated. Their costs and energy savings are vital to the determination of the economic viability of waste heat recovery.
Three temperature ranges are used to classify waste heat.
The high temperature range above 1200°F
The medium temperature range - between 450°F and
1200°F
The low temperature range below 450°F

69. Waste Heat Recovery Sources of waste heat High temperature waste heat
- Aluminium refining furnace, cement kiln, solid waste
incinerators
Medium temperature waste heat
- Steam boiler exhausts, gas turbine exhausts, heating furnaces
Low temperature waste heat
- Cooling water from internal combustion engines, process
steam condensate
There are two basic ways to recover heat from the sources:
Using heat exchangers to transfer heat in one fluid stream to another.
e.g. from flue gas to feed water (economizer) or combustion air (air preheater).
Waste heat boilers to produce steam.

70. Combined Heat and Power
Scheme which combines electrical power generation with utilization of heat for space heating and / or specific industrial process.
The maximum efficiency of the thermal power plant is 30-40%.
The application of the Carnot principle to any heat engine cycle shows that however efficient the cycle may be, the maximum efficiency is given by
carnot = 1-(T2/T1)
T1 = Maximum temperature available (e.g. the
metallurgical limit)
T2 = Lowest temperature available
In a steam power plant, if the heat rejected in the condenser were utilized the overall efficiency would be increased to about 75-80%.

71. The existing power plants, scope for use the heat rejected from the condenser is limited-the reason.
The temperature of heat rejection is low (Lower grade Heat)
Power stations are far away from the recipients of thermal energy

72. Benefits of CHP Local generation of electricity
Improvement in national energy efficiency and preservation of non-renewable energy sources
Cogeneration
Employment opportunities

73. Energy Management and Energy Audit

74. Energy Management & Audit
Energy Management can be divided into 3 process
Analysis, Action & Monitoring
Energy Audit is a part of the Action step. An energy audit is the collection and analysis of data on present energy use, the choice of energy management objectives and of specific measures to meet these objectives and the process used to monitor progress towards these objectives
To convert data into information

75. ENERGY MANAGEMENT ....INVOLVES A COMBINATION OF - MANAGERIAL &
- TECHNICAL/TECHNOLOGICAL
- SKILLS/KNOWLEDGE

76. GLOBAL/NATIONAL BENEFITS
immediate results
lower power plant capacity
reduced load shedding
reduced energy imports
lower foreign exchange needs
use of local equipment
job creation
lower inflation
reduced emissions/pollution
conservation of scarce/limited resources

77. GLOBAL ISSUES ENERGY USE ENVIRONMENTAL DAMAGE NUCLEAR SAFETY/HEALTH
SO2, NO - ACID RAIN, OZONE DEPLETION
CO2 - GREENHOUSE EFFECT.

78. BARRIERS/OBSTACLES TO MANAGEMENT OF ENERGY
Artificially low energy prices.
Little energy consciousness.
Higher priority to “more important” issues (eg., keep plant running).
Automation seen as more important than energy cost management, in plant modernisation of plant.
Lack of energy management expertise
Lack of knowledge of own energy consumption patterns/costs/ potential for saving

79. BARRIERS/OBSTACLES TO MANAGEMENT OF ENERGY
Old, high-energy plant.
Lack of capital.
Other investment priorities.
Local energy infrastructure may not encourage energy saving.
Apathy on the part of managers and staff.
Lack of awareness of energy engineers, technological possibilities, and economics.

80. ENERGY MANAGEMENT
The objective of Energy Management is to achieve and maintain optimum energy procurement and utilisation, throughout the organisation: - To minimise energy costs/waste Without affecting production. - To minimise environmental effects.

81. ENERGY MANAGEMENT INVOLVES FOUR MANAGERIAL FUNCTIONS
... PLANNING ... LEADING ... ORGANISING ... CONTROLLING

82. THE TOTAL ENERGY MANAGEMENT PROCESS
Awareness of
Potential Savings
Top Management Commitment
Preliminary Energy Audit
Detailed Energy Audit
Implement No-Cost/
Low-Cost Measures
Feasibility Studies
-Capital Intensive Projects
Training
Monitor
Implement
Higher-Cost
Measures

83. Conducting An Energy Audit
OUTLINE
Initiating an Energy Management Program
Goals of the Energy Audit
Energy Bills
Steps in the On-Site Energy Audit
Degree Days, Layout, Operating Hours
Equipment List
Systems to Consider
Energy Audit Report

84. Starting an Energy Management Program
Conduct an energy audit
An energy audit (or energy survey) is:
A study of how energy is used in a facility and an analysis of what alternatives could be used to reduce energy costs improve profits

85. Goals of the Energy Audit are to:
Clearly identify types and costs of energy use
Understand how that energy is being used – and possibly wasted
Identify and analyze more cost-effective ways of using energy
- improved operational techniques
- new equipment
Perform an economic analysis on those alternatives and determine which are cost-effective for your business or industry

86. Steps in the On-site Energy Audit
1. Identify layout and operating schedule for facility.
Make a plan or sketch of the building(s) which shows building size, room sizes, window areas, and wall and roof composition and insulation (offices, prod, maint,…)
2. Compile an equipment inventory.
List all energy consuming equipment, with hours of use each year and energy ratings or efficiencies.

87. Steps in the On-site Energy Audit
Determine the pattern of building use to show annual needs for heating, cooling, & lighting.
4. Conduct a room-by room lighting inventory
- light fixtures
- lamp types, sizes and numbers
- levels of illumination
- uses of task lighting

88. Responsibilities and Duties of Energy Auditor
Carry out a detailed energy audit
Quantify energy consumption and establish base line energy information
Construct energy and material balance
Perform efficiency evaluation of energy & utility systems
Compare energy norms with existing energy consumption levels
Identify and prioritization of energy saving measures
Analyse technical and financial feasibility of energy saving measures
Recommend energy efficient technologies and alternate energy sources
Report writing, presentation and follow up for implementation

89. Responsibilities and Duties of Energy Manager
Establish an energy conservation cell & prepare an annual activity plan
Develop and manage training programme for energy efficiency at operating levels
Develop integrated system of energy efficiency and environmental improvement
Initiate activities to improve monitoring and process control to reduce energy costs
Co-ordinate implementation of energy audit/efficiency improvement projects through external agencies
Establish / participate in information exchange with other energy managers of the same sector through association
Provide information to BEE and Designated Agency of the respective States as demanded in the Act

90. Industrial and Building Energy Management

91. Industrial and Building Energy Management
Optimum uses of thermal, Electrical energy in industrial & building activities
In industrial activities, the following is the key elements for energy management
The efficiency improvement
Waste heat recovery potential
Optimum use of steam
Cogeneration
Optimum thickness of insulation
Optimum of natural lighting & ventilation
In Building energy management, the key elements are
Lighting
Heating & Cooling
Construction

92. Some important points in Building Energy Management
Switch off the fans, light and TV whenever they are not in use
Clean the tube light for every fortnight to get a good level of illumination
Clean the dust settled over the fan blade to get a designed amount of air
Use CFL (Compact Fluorescent Lamp) – lead to energy conservation
CFL lamps can be used where maximum duration of lighting is essential
For Street lightings, CFL gives more benefit than our incandescent lights

93. If you use Electronic choke instead of regular choke in Tube light, you can save 16% of Electricity
Use electronic regulator instead of ordinary regulator for fans
Keep your refrigerator 7” away from the wall to save 7% of electricity
Decide the level of cooling you required for the operation of the refrigerator to save power (Low, Medium or High Cool)
Choose the required size of the refrigerator in order to avoid the power for cooling the empty space of the refrigerator

94. Bulb (Watt)
CFL lamp (Watt)
Lumens
Amount (Rs) 40 8
400
215 75 14
900
235
100 18
200

95. Comparison in cost saving of CFL lamp – basis: 8 hours operation /day
40 Watt Lamp
8 Watt CFL Lamp
40 W  8 hours  30 days = 9.6 Units
8 W  8 hours  30 days = 1.92 Units
For 1 year = Units
For 1 year = 23 Units
Cost =  Rs = Rs
Cost = 23.0  Rs = Rs
Cost saving for one year=Rs
Payout Time = l year

96. Energy Management in Lighting

97. Lighting
When a metallic material becomes hot, it emits radiation. This happens in an incandescent bulb when it is switched on. The thin filament is heated to such a high temperature by the electrical energy fed into it that it begins to glow and emit radiation. Some of the radiation is invisible (heat radiation) and some visible (light)
Sources of light:
Light source can be classified as
Natural light – Varies constantly with changing metrological conditions, time of the day, seasons and specific location on earth
Sunlight – light received directly from the sun
Skylight – scattered light received from other luminous parts of the sky

98. Artificial light
Flame based – they evolved from firelight, oil lamps, modern kerosene, gas lamps, candles etc.,
Electrical light – incandescent and discharge lamps

99. Light and Energy
A source of light needs energy, either electrical or heat
Input to lighting – for the flame based systems it is necessary to know the net heating value and rate of consumption of the fuels used or for electrical lighting systems, the power ratings of the lamps
Output energy – it is also possible to measure the quantity of energy that is contained in the output of lighting system, i.e., in the light
It is possible to measure how the emitted energy of a 100W incandescent lamp is distributed over the radiation spectrum
These measurements take the spectral sensitivity of the eye in to account

100. - Total light energy emitted by a 100W bulb is 1700 lumen, which is only a fraction of the 10W energy in the visible range. This quantity is called by definition the luminous flux

101. Wave length (micrometers)
UV Visible Infrared
Energy
Wave length (micrometers)

102. Photometric Quantities
Illuminance - unit Lux (lx)
The luminous flux falling on unit area of a surface and is expressed in lux
Office desk /500 lx
Corridor /500 lx
Classroom lx
Restroom lx
Living room - 50/300 lx
Bedroom lx
Luminous intensity – unit candela (cd)
The luminous flux per unit of solid angle in a given direction

103. Luminous flux – unit lumen (lm)
Total amount of light emitted by a source or received by a surface
Candle – 5 lm
100W incandescent lamp – 1700 lm
60W fluorescent lamp – 3600 lm
Luminance – unit (cd/m2)
Express how bright the source appears
Luminous efficacy – unit (lm/W)
It is the energy to light conversion
In incandescent bulb, it gives 17 lm/W (i.e., 1700 lm/100W)

104. Average illuminance on an area:
It is expressed as,
E = lu/s
where, E – Average illuminance (lx)
lu – Average luminous flux (lm)
s – Surface area (m2)
Illuminance at a point:
The illuminance at a point can be calculated easily when the size of the source is small compared with its distance from the surface

105. E point = (Li / d2)  cosine b
where
E point – illuminance at a point (lx)
Li – luminous intensity (cd)
d – distance between the source of light and the point (m)
b – angle between the beam and a line perpendicular to plane of the surface

106. Spot light d b
Epoint

107. Colour and Colorimetry
A distinction is made between the colour temperature of a light source when you look at the light itself and the colour rendering that it gives to surface when it shines onto them
The colour-rendering index expresses how a light source compares with natural light or daylight in its ability to make objects appear to their natural colours. Put more precisely, it is a measure of the degree to which the colour of surfaces illuminated by a given light source confirm to those of the same surfaces under a reference light. Some form of daylight is taken as the reference source
Perfect agreement between the source being judged and the reference source is given a value of 100

108. CIE colour rendering %
Typical applications
Example of lamps
90 (Good)
Accurate colour matching
Incandescent lamps
80-90 (Good)
Accurate colour judgment or good colour rendering for reasons of appearance
Fluorescent tubes (with triphosphor fluorescent coating)
60-80 (Medium)
Moderate colour rendering
Standard Fluorescent tubes
(Medium)
Little significant colour rendering, but marked distortions of colours unacceptable
High-Pressure mercury lamps
20-40(Poor)
Colour rendering not important and colour distortion acceptable
Low-Pressure sodium lamps.

109. Illuminance for different purposes
The following table gives the scale of illuminance recommended by CIE for use in working interiors:
These standards illuminances are based on consideration of the performance of the respective tasks, the comfort of people doing the tasks, and the time, which the space is occupied

112. Comparison of lighting systems
Type of light source
Energy source
Rate of consumption
Total power
Luminous flux
Luminous efficacy
Color rendering
Equivalent number of lamps(*) W lm
lm/W
Candle
Wax
5.50 g/h 55 1
0.02
Good 75
7.20 g/h 72 16
0.22
Kerosene lantern
Kerosene
0.02 l/h
200 10
0.05 12
0.05 l/h
488
100
0.25
Pressure lamp
0.06 l/h
563
220
0.39
Poor
0.08 l/h
813
1300
1.60
Gas lamp
LPG
28 l/h
350
330
0.94
34 l/h
425
1000
2.35
Biogas lamp
Biogas
0.10 m3/h
639
0.48
0.20 m3/h
1385

113. Examples of electrical lamps
Incandescent lamp
Electrical
100W
100
1200 12
Good 1
Halogen lamp
25W 25
500 20 2
Fluorescent tube
13W 13
585 45
(*) – The equivalent number of lamps is the number of lamps required to produce the same luminous flux as the reference of 100W incandescent electrical bulb (i.e lm)