By

Kiran R Patil

Under the guidance of

Sri B. Aprameya SwarupAsst. ProfessorS.J.C.E, Mysore

IntroductionEnergy the prime mover

For the progress of any countryAny industryAny sector

Rising costs of new generating plants has led toFinancial constraintsDifficulty in production of electrical energyHigher energy bills

Cont…….Generated Energy has to be used

EfficientlyReduce the energy consumptionReduce the losses by end users

For many companies energy is the significant operating cost

Bills of 1.5crores through 2crores are not uncommonFlour milling is one of the largest energy intensive industry after raw material costsBut, energy is the most controllable production costs.

Cont…….We cannot reduce man power by fractions but we can achieve significant savings by reduction in energy consumptionsConsider the flour mill

The energy billing is high and penalty is also highEnergy is the direct charge on companies operating budget“Every 1 unit saved is equal to 2 units generatedReducing energy bills accrues an increase in bottom line profit Improved electrical efficiency is the key to saving energy in any industry or flour mills

Concept of Energy Audit

Why Energy Audit?To reduce the cost of productionTo identify areas of excess energy consumptionTo suggest ways for minimizing energy consumption

Indicative Saving PotentialGood house keeping - 5 - 10%Minor investment - 10 – 15%Reasonable investment - 20 – 25%

Methodology AdoptedUnderstanding the process of the millInspection and Data collection of machineriesObservation on general conditions

FacilityEquipmentQuantification

Month wise energy consumption and production data from financial year April 2006 through March 2010Identifying and verifying the major energy consumption areasDiscussions with electrical and production personnel to make necessary arrangements to take measurements

Cont…….Measurement of electrical parameters like voltage, current, power factor, kW, kVA, kVAr, Hz and Harmonics on all identified motors

Detailed calculations, analysis and assumptions

Validation from the electrical personnel and energy auditor

Identify the potential energy saving area and analyzing the saving proposals with plant personnel

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Main processesWheat reception and storage

Cleaning and conditioning

Milling and sieving

Blending, flour storage and packaging

Annual energy consumption in C-mill19,11,222.41 units out of 46,58,530 units

Annual demand chargesRs. 16,47,900/-

Energy cost @ Rs. 4.65 per unitEnergy cost this year

Rs.1,98,24,457+ Rs.10,73,617.875 taxEnergy bill (app.) Rs. 16,52,038.1/monthSEC in a month( app.) 58.145kWh/tonEC kWh/Ton per day - 2.32kWh/tonAverage power factor maintained 0.97

Energy scenario

Energy consumption in kWh from April 2006 – March 2010

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2006 2007 2008 2009

Financial year

Total kWh

C-mill kWh

Lighting kWh

other electronic goods kWh

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lion

unit

s

Energy bill and demand charges from April 2006 - 2010

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20

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Energy Cost C mill Energy cost

Tax Demand charge

2006

2007

2008

2009

Rupe

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Cost of Sections

Monthly peak demand from April 2009-March 2010

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MD

Rea

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in k

VA

Break up of energy use

Milling and grinding 44%

Pneumatic conveying 32%

mechanical conveying 9%

Compressed air7%

Particle separation 5%

Services 3%

Factors governing Energy useWheat quality

Impurities, moisture content and quality of wheat

Product qualityNeed for blending and wheat products

Mill loading

Atmospheric conditionsHumidity, temperature and pressures

Operation schedule of machinesSection Wise HP

Wheat Cutting to A-Mill Silos 44

A-Mill Silo to C-Mill 22.5

Washing 103.75

Tempering 13.5

B1 Petty 26.5

General Exhaust for Dust 17.6

Refraction Grinding 69.5

Grinding section 421

Redressor section 34

•Washing section: 17 hours per day

•Other Sections: 21 hours per day

Need of determining motor load and efficiency

Motor accounts for more than 80% load in a plant

Motors are mismatched or oversized for particular load

Motors might have rewound multiple times

So To compare the operating costs of an existing standard motor And replace with appropriate sized Energy Efficient motorMotor load and efficiency is to be determined.

Constraints of energy AuditingNo proper information

No real time data

Energy Auditing is based on the principle of“We cannot manage, what we don’t measure”

One time energy auditing is not sufficient

No continuous monitoring

Monitoring & TargetingIt is a management technique which helps to

Control energy consumption

Control any resource

Continuous monitoring

Gather continuous information

Indicate the continuous varying pattern“Without Compass and Map we are dead men in the Desert”.

Installation of Monitoring System

800kVA

Smart server or Data concentrator It is used to

Control

Monitor

Manage any electronic device

Remotely access data

Manage the entire control system

Energy Nodes and Sensor gatewayEnergy meter which helps in collecting around 10 electrical parameters for R, Y, B phases

Voltage, current, powerActive power, Reactive powerFrequency, power factorPlots the load variations for the connected machines

Sensor gateway gives the physical parameters

Pressure, Temperature, Flow

How the monitoring system worksConsidering the Smart Server

Two types of internet protocolsStatic internet protocolDynamic internet protocol

Static internet protocol is used to access local works either for LON or the LAN

Dynamic Internet protocol is used to access globallyExample Broad Band

Cont…….

Motor (Blower Fan)

Compressor

Electrical Panel

Sensor Gateway

Energy Node

Smart Server

Personal Computer

Cont…….A particular machine

Motor or Compressor connected to energy meter or sensor gateway respectively through electrical panel.

Panel is connected to Smart Server

Smart Server is connected to PC to access data

Connections are done through communication cable Communication cables are used to inter connect server and machines as well.

Cont…….PC should be installed an application called as OPIUM energy

This helps in accessing data

Plotting the graphs automatically

Smart Servers can be used as occupancy sensorsThe application can be used

To Control lighting system

To Control Fans and other electronic goods which saves energy

Advantages of Monitoring and TargetingExpected Benefits

Guidance to reduce excess energy consumption

Identify the default equipments

Power factor improvement

Current reduction and reduction in line losses

Load balancing and minimizing of neutral current

Maintaining SEC and creating bench marks

Determining the future energy use when planning changes

Diagnose specific areas of wasted energy

Energy saving proposal 1

Investment = Rs. 3,50,000/-Annual energy consumption = 19,11,222.41 kWh

Expected savings through EMS @ 5 – 15% but assuming= 95,561.12 kWh

Annual cost savings @ 4.7/unit = Rs. 4,49,137.264/-

Pay back period= Investment/ annual savingsRs. 4,00,000/4,49,137Approximately 10 months 18days

It is worth to invest in this monitoring system

Investment on energy monitoring system

Energy saving proposal 2Conversion of Delta to Star

For lightly loaded motors (Below 50% Load)In Delta: 10 hp Motor, 7.26kW, operating hours 16In Star: 6.55kW, operating hours 16Difference in kW 0.71kW, 0.71*4800 h = 3408 kWh

Similarly, 7.5 hp, saved energy = 4416 kWhFor, 5hp, saved energy = 1344 kWh

Annual savings: 3408+4416+1344+1836 = 11004 kWhAnnual cost savings @4.7/unit =Rs.51,718.8/-Investment nilPayback period immediate

Load variations are common in flour milling industries

Considering the 10 hp motor Rated speed = 1440 rpm

This motor is operated at less speed due to requirementReducing speed up to 1100 rpmCannot be achieved by reducing the pulley size

Therefore the VSD is used in order to quantifyEnergy savings and reduce the losses

Energy saving proposal 3Installation of Variable Speed Drive

Cont…….Energy consumed without VSD = 6.323 units/hour

Energy consumed with VSD = 3.670 units/hour

Difference in Energy consumption = 2.653 units/hour

Total annual Energy savings by VSD

= 2.653 * 16 * 300

=12,734.4 units/year

Annual cost savings@ Rs.4.7/unit = Rs. 59,851.68/-

Approximate investment required = Rs. 65,200/-

Payback period = 13 months

Replacement of existing Less efficient motors by Energy Efficient motors

Replacement model is concerned with replacementMachines and Equipments

Replacement is done dueTo their decreasing efficiencyFailuresBreakdown of equipment partsLow performance

This model helps us to findOptimum replacement periodOptimum cost

Cont…….There are two types of failures

Gradual failure

Sudden failure

We are concerned with gradual failure which includesGradual decrease in the efficiency of equipmentsIncreased maintenance(operating and running costs)Decreased productivityDecrease in resale value which represents the depreciation

Calculation of optimal replacement period

Optimal replacement periodAverage cost incurred from the time of the implantation of the machines

Money value has been taken into accountPresent Value Factor (PvF) = 1/(1+r)(N-1)

Where ‘r’ is the discount rate (the rupee value depreciates at a constant rate i.e. 9%(standard))

‘N’ is the number of years

Replacement of 50 hp motor

Energy saving proposal 4Replacement of less efficient to EEM

Cont…….Total Annual Energy Savings

18 hours motor operation for 300 days per annum= 10 kWh * 18 * 300= 54000 kWh

Annual cost savings @4.7 = Rs. 2,53,800/-Price of Energy Efficient motors obtained from M/s Siemens Ltd. Is given below

10 hp, 6 poles = Rs. 32,640/-15 hp, 6 poles = Rs. 40,570/-15 hp, 4 poles = Rs. 31,640/-20 hp, 6 poles = Rs. 58,270/-30 hp, 2 poles = Rs. 87,990/-

Cont…….Investment required for 10 number of EE motors

= Rs. 32,640 * 4= Rs. 40,570 * 3= Rs. 31,640 * 1= Rs. 58,270 * 1= Rs. 87,990 * 1

Total cost = Rs. 4,30,170/-

Payback Period = 20 months

Advantages of Energy Efficient Motor

Saves Energy and Money

Covers up to uniform Efficiency from 50% - 100% of full load

Ensuring savings at part load conditions also

Short Payback period

Substantial savings after Payback Period

RecommendationsReduce system load e.g. by using more efficient fan

Minimizing the amount of air used by pneumatic systemsReducing leakages from compressed air systemsReducing pressure drops in pneumatic and compressed air systems

Improve maintenance schedule and proceduresSwitch of when idling

Soft starters can be usedEnsure that motor is not oversized for the jobReduce motor losses

Replace with energy efficient motorsIf repaired or rewound, ensure efficiency losses are minimized

Cont…….Reduce motor running speed by using variable speed drives

Advantages includeSignificant cost savingsAutomatic or manual controlVersatilityReliability

Use Multi speed Motors (MSMs)Can be used when two or more speeds of operation, particularly effective if speeds are carefully matched to the characteristics of fan

Operate at full load for shorter periodsOperate with a high loading to maximize efficiency

Cont…….Lighting systems connected to the Smart servers act as occupancy sensors which controls the lighting circuitsMaximum demand charges can be reduced by managing the load at peak timesThe whole mill is inter connected to one another

if one machine shuts off complete mill should be shut downseparate connections to separate sections of the machinereduces high amount of Maximum demand charges.

RefurbishmentsKeep conveying and transfer routes as short as possibleMinimize transfer distances for wheat and flour

so that each processing area is next to the previous one

Minimize the number of lifts of wheat and stock

Copper catalyst at the end of the exhaust of general dust exhaust minimizes the effect of dust to the environment

Install the process control and monitoring equipment

Cont…….

Summary

Future Scope

Cont…….

Bloom Energy is a solid oxide fuel cell server

Uses solid, liquid or gaseous fuel

It produces electricity which is cleaner form of energy

If used renewable fuel form of energy,

It is more cheaper and more cleaner form of Energy

Cont…….This solid fuel cells can generate 100kW through MW of Electricity

Fuel cell converts Hydrogen, Natural gas any fuel to electricity

This is an “ELECTRO-CHEMICAL PROCESS”

The bloom energy is 67% clean if used hydrocarbon fuels

If renewable fuel cells are used, 100% clean and cheaper energy can be produced and used which is abundant

ReferencesEnergy Auditing concepts of M/s Kovilpatti Lakshmi roller Flour Mills Ltd. Gangaikondan (Tirunelveli), Energy Audit conducted by, Central Scientific Instruments Organization, CSIR Madras complex, Govt. of INDIA.

Guide Books for the National Certificate Examination for Energy managers and Energy Auditors (set of four books available at http://www.energymanagertraining.com/new_course.php)

J.C. Andreas, Energy Efficient Motors. Marcel Dekker publication, New York1992

Cont…….Good practice guide 212 for improving Energy Efficiency and reduce Energy costs in Flour Milling, Energy Efficiency enquiries Bureau, Oxfordshire, UK.

Typical performance data of premium Energy Efficient (EE) Motors and standard motors from Bharath Bijlee Ltd. Motors for general applications.

Official Website of the Bureau of Energy Efficiency, Govt. of INDIA, www.bee-india.nic.in

Quick start guide to Energy Monitoring and Targeting (M&T), www.oursouthwest.com

Detailed information and case studies on energy audits, www.energymanagertraining.com

Energy monitoring and targeting (M&T), www.mt.wikipedia.org/wiki/monitoring_targeting

The energy conservation act, 2001, http://powermin.nic.in/acts_notification/energy_conservation_act/index.htm

Cont…….

www.en.wikipedia.org/wiki/energy_audit

Website of Ministry of Power, http://powermin.nic.in/energy_audit

“Bloom Energy” – What is it and how does it works? http://peswiki.com/index.php/Directory:BloomBox_Fuel_Cell_by_Bloom_Energy.

Cont…….