Comparison of Distributed Generation Options for India

Rangan Banerjee∗Visiting Faculty

EPP

CEIC Seminar 16th June 2003 (∗ on leave from IIT Bombay)

Outline of Talkn India- Energy Balance n Power Sector Balance and Trendsn Distributed generation optionsn Non-Renewable Comparisonn Renewable Optionsn Issues

Energy Contentn Average Calorific Value of Indian Coal

4500kcal/kg (18.8 MJ/kg)n Average Calorific Value of Oil

10000kcal/kg (41.8 MJ/kg) n Natural Gas 9300 kcal/m3 (38.9 MJ/m3)n Nuclear, Hydro – Work backwards from

generation based on plant efficienciesn Hydro 85%, Nuclear 25%

Power Generation

n Coal 205.5 Million Tonnesn Oil 2.63 Million Tonnesn Gas 8.11 Billion m3

n Hydro 311 PJn Nuclear 151 PJn Coal 3865 PJ, Oil 110 PJ, N Gas 315 PJn Total Primary 4753 PJ

1997-98

1997-98

Share of Power Installed Capacity (1998) in India

Diesel0.4%

Wind1.0%

Nuclear2.5%

Gas8.7%

Coal62.7%

Hydro24.6%

India - Fossil Fuel reservesFuel Reserves Prodn R/P

ratioCoal(Million Tonnes)

60000 296 ~200+

Oil(Million Tonnes)

660 33.86 19 (9)

N.GasBillion m3

692 26.4 26

Nuclear Nat U ~50

Data Source TEDDY

Electricity Sector in India

n Low per capita electricity consumption(~400 kWh/capita/year)

n Energy and Peak power scarcityn Large number of villages un- electrifiedn Significant proportion of households

without access to electricityn Electricity use linked with quality of life

Electricityn 104 GW Installed Capacity 2002( less than 4%

of World Capacity)Average 0.1 kW of installed capacity/capita

n World installed capacity 0.53 kW/capitan Low electricity consumption – India-

about 340 kWh/capita/yearNepal, Bangladesh & Bhutan –

lower than 100 kWh/capita/yearn World average electricity consumption-

2100 kWh/capita/year

Electricity Sectorn SEB annual loss 2000-1 Rs 20,500

crores (US 4400 million $)n Gap of 92 p/kWh - between cost of

supply and revenue (2c/kWh)n Peak shortage 13%, energy shortage

7%n Estimated requirement of 100,000 MW

additional capacity by 2012

Load curve of a typical day –MSEB(8/11/2000 source: WREB annual report-2001)

10260 MW9892 MW

6000

7000

8000

9000

10000

11000

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

Time hours

Dem

and,

MW

morning peak

Evening peak

India - Electricity Sales

0

50000

100000

150000

200000

250000

300000

350000

1950 1960 1970 1980 1990 2000

Year

Ele

ctri

city

Sal

es (

GW

h)

Se

1 9 6 0 1 9 7 0 1 9 8 0 1 9 9 0 2 0 0 00

1 0 0

2 0 0

3 0 0

4 0 0

5 0 0

H y d ro

T o t a l

Ele

ctric

ity G

ener

atio

n('0

00 G

Wh)

Y e a r

Annual Capacity Additions

0

1000

2000

3000

4000

5000

6000

1960 1965 1970 1975 1980 1985 1990 1995 2000

Year

Cap

acity

Add

ition

(M

W)

Carbon Dioxide Emissionsn Kaya identity: Total CO2 Emissions= (CO2/E)(E/GDP)(GDP/Pop)PopCO2/E – Carbon IntensityE/GDP- Energy Intensity of Economyn Mitigation – increase sinks, reduce sources-

aforestation, fuel mix,energy efficiency, renewables,nuclear, carbon sequestration

n Adaptation

GHG Emissions (Fuel Cycle Analysis)

n Coal Conventionaln Advanced Coaln Oiln Gasn Nuclearn Biomassn PVn Hydro-electricn Wind

CO2 g/kWh960 -1300800-860690-870460-12309-10037-16630-1502-41011-75

Source: John Holdren

Kirk Smith, World Energy

Assessment, UNDP,2001

Distributed Generation Options

n Non-Renewablen IC Engine- dieseln IC Engine- Natural

gasn Micro-turbine-

Natural gasn PEM fuel cell-

reformer - Natural gas

n Renewablen Wind Turbinen Solar Photovoltaic

(PV)n Biomass Gasifier-

Gas Enginen Bagasse -

Cogeneration

Comparison

n Annualised Life Cycle Costs (ALCC) -annual cost of owning and operating equipment

n ALCC = C0 CRF(d,n) + AC f + AC O&M

n CRF (d,n) =[ d(1+d)n]/[(1+d)n-1]n discount rate d, Life n years, C0 Capital

Cost,AC f , AC O&M , annual cost - fuel and O&M

Definitionn Distributed Generation- Installation and

operation of electric power generation units connected to the network on the customer site of the meter [Ackerman,2001]"Dispersed" "Embedded" Generation

n Classification- Non-renewable/ renewablen Based on Prime Mover- engine, turbine, fuel

cell...

Option Capital Cost(Rs/kW)

Life η O&McostRs/kWh

Diesel 25000 20 40% 0.25

Gas Engine 33000 20 35% 0.25MicroTurbine

45000 20 28% 0.25

Fuel Cell 14100010 45% 0.25Discount rate d =0.1,Natural gas price = Rs5200/1000sm3

Diesel price = Rs16/litre, density = 850 kg/m3,LHV = 9700 kcal/kg

($530/kW)

($700/kW)

($960/kW)

($3000/kW)

Cost of Generation

0

1

2

3

4

5

6

7

8

9

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1Load Factor

Rs/kWh

Figure 2. Cost of Generation from Diesel Engine-Generator (d=0.1)

10 c/kWh

15 c/kWh

Rs/

kWh

Schematic of a PEM Fuel Cell -Reformer

0

5000

10000

15000

20000

25000

30000

35000

40000

45000

50000

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

Load Factor

Diesel

Gas Engine

MicroTurbine

Fuel Cell

Figure 1. Comparison of Annualised Life Cycle Costs for Non Renewables (Discount rate =10%)

$960/kW/year

$110/kW/year

Annualised Life Cycle Costs

0

5000

10000

15000

20000

25000

30000

35000

40000

45000

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1Load Factor

Diesel

Gas Engine

MicroTurbine

Figure 3 Comparison of non-renewable options (High discount rate 30%)

$960/kW/year

$110/kW/year

Renewable Power Generation

Wind

Solar SmallHydro

Biomass /Biogas

TidalEnergy

WaveEnergy

Ocean ThermalEnergy

Solar ThermalSolarPhotovoltaic

Installed Capacity of Renewables in India

1267 1341

63 35 15 47210

0200400600800

1000120014001600

Wind

Small

Hyd

ro

Bio C

ombn

Bio C

ogen

Gasifie

rs

Was

te -En

ergy

Solar

PV

Total Renewable Installed capacity 2978 MW 31/3/2001 MNES

Daily Wind Variation

0123456789

0 4 8 12 16 20 24

Time of day (hours)

Avg

win

d s

pee

d m

/s

Daily variation Sanodar (West Coast)

Monthly Wind Output

SITE: SANODAR

0

20

40

60

80

100

Janu

ary

febru

ary

marc

hAp

rilMay

June Ju

ly

Augus

t

Septe

mbe

r

Octobe

r

Nove

mber

Decem

ber

Month

Norm

aliz

ed P

ow

er O

utp

ut

Wind -Cost of Generation

0.1 0.2 0.3 0.45960 6048 6136 6223d=0.1 ALCC Rs

Rs/kWh 6.80 3.45 2.33 1.7815167 15255 15342 15430d=0.3 ALCC Rs

Rs/kWh 17.31 8.71 5.84 4.40Capital cost Rs 50,000/kW, O&M cost Rs 0.1/kWh, Life 20 years

14c 7c 5c 4c

$1060/kW

$130

Load Factor

$320

37c 18c 12c 9c

India- Wind Installed Capacity

0

500

1000

1500

2000

1988 1993 1998 2003

Inst

alle

d C

apac

ity

(MW

)

India- Wind Generation

0

500

1000

1500

2000

2500

1991 1993 1995 1997 1999 2001 2003

Ann

ual G

ener

atio

n (M

Us)

Wind -Trendsn 1999- Wind Energy 24 TWh (13.3%) – World

13.6 GW (20.1% Load Factor)n 1 million Wind pumps , 10000+ small battery

charging wind generatorsn World- Growth rates 27-33%n India 45000 /13000 MW potential estimatedn Wheeling, Third party sale, depreciation 39% (1990-2002), 21% 2001-2 CAGR

Daily Solar Radiation

00.20.40.60.8

11.2

0 2 4 6 8 10 12 14 16 18 20 22 24

Time in hrs.

Sol

ar ra

diat

ion

kW/m

2

Site :Mumbai, May

Monthly Solar Radiation

012345678

1 2 3 4 5 6 7 8 9 10 11 12Month

Avg

Dai

ly S

olar

R

adia

tion(

kWh/

m2/

day)

Site: Mumbai

PV- Cost of Generation

Capital cost/kW 20000025000030000023,93029,803 35,676LF =0.2 ALCC Rs

Rs/kWh 13.66 17.01 20.3624,03929,91235,785LF=0.25 ALCC Rs

Rs/kWh 10.98 13.66 16.34O&M Rs 0.25/kWh, Life 20 years, discount rate =10%

$4300 $5300 $6400

$760

29c 36c 43c

23c 29c 35c

Solar PVn Total Installed Capacity 65 MWn 1999-2000 Prodn 9.6 MW cells, 11 MW modulesn Grid Connected 2.5 MW (2002) - 31 systems -

average 80 kW, largest 240 kW peakn Daily insolation 4- 7 kWh/m2 , 300 sunny daysn Capital subsidies on grid connected systems - 2/3rd

of initial capital cost n Manufacturers - Tata BP, Shell, BHEL, CEL

Gasifier

Ash

Air

Biomass

Gas

Air

Gas &Air

Gas

Cooling & Cleaning

System

Diesel

Power output

Engine Generator

Fig. Schematic Diagram of Gasifier –Engine System

Schematic of Gasifier Engine

Source: Parikh

Biomassn Fuelwood, agricultural residues (rice husk,sugarcane

trash, coconut shells..), animal wastes.n 40% India's primary energy use.n Estimates - residue 16000-18000 MW (6000

hrs/year).n Dedicated plantations - waste land - 500 million

tonnes - 60000 MW (6000 hrs/year).n Atmospheric gasification (incomplete combustion)n Diesel costly - prefer dedicated engine based on

producer gas

Input Data - Biomass GasifierGasifier Engine-generator

Capital Cost (Rs/kW) 20000 33000Life 10 years 20 yearsEfficiency 70% 35%Biomass NCV = 3400 kcal/kg, Price Rs 1/kgDiscount rate = 10%, O&M cost = Rs 0.5/kWh

0

2

4

6

8

10

12

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

Load Factor

Gas Engine

Bioengine

Diesel

Gas Engine

Bioengine

Diesel

Biomass Gasifier Engine Cost

13c/kWh

8.5 c/kWh

4.3c/kWh

0 . 5 T / h r

F e e d w a t e r

P r o c e s s

P r o c e s s

2 a t a

~

S T E A M T U R B I N E

2 . 5 M W

6 a t a

B A G A S S E

5 8 T / h r 2 2 a t a 3 3 0 o C

4 . 5 T / h r 2 7 T / h r

2 6 T /h r

S c h e m a t i c o f t y p i c a l 2 5 0 0 t c d S u g a r f a c t o r y

F la s h e d C o n d e n s a t e

P R D S

P R D S

M I L L I N G

0 . 5 T /h r

F E E D W A T E R

B O I L E R

F e e d w a t e r

Con

dens

er

2 a t a

P R O C E S S

7 5 T P H , 6 5 a t a , 4 8 0 O C

4 . 5 T P H

~

6 a t a

B A G A S S E ( A l t e r n a t e f u e l )

2 a t a

B F P

1 3 M W

B O I L E R

1 .0 M W M i l l d r iv e s

9 . 5 M W P o w e r e x p o r t

2 . 5 M W C a p t i v e l o a d

P R O C E S S

P R O P O S E D P L A N T C O N F I G U R A T I O N : O P T I O N 2

S T E A M T U R B I N E

C O N D E N S E RE S S

Bagasse CogenerationIncremental Capital Cost(Rs/kW)

30000

Life 20 yearsBoiler Efficiency 70%Bagasse NCV = 3400 kcal/kg, Price Rs 1.50/kgDiscount rate = 10%, O&M cost = Rs 0.5/kWh2500 tcd plant 9.5 MW export, 0.93 kg extra/ kWhLoad factor 0.4 0.5 0.6

Rs/kWh 1.20 1.00 0.87

$680/kW

2.6c 2.1c1.9c

0

10

20

30

40

50

60

70

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

Hour of the day.

Lo

ad (

kW)

Residential Electricity Demand Agriculture DemandIndustry demand Total Load

Typical Load Curve (Rural India)

What is a Hybrid Energy System?

n Hybrid –n n. Something heterogeneous in origin or

compositionn n. an offspring of different breeds,varieties

n Hybrid Energy Systems combine two or more different energy conversion devices to provide a common energy service(s).

Why Hybrid ?n Daily and Monthly variation in

Renewable Resource Availabilityn Daily and Monthly Variation in Demand

Profilen Hybrid of two renewables may help

overcome limitations of bothn Retrofitting/ provision of fossil backup

may provide easier acceptability of renewable technology

Hybrid Options

n Several options – e.g. PV Hybrids-n PV- Wind, PV-Diesel, PV-Diesel-Wind,

PV-Micro-Hydel

n Different Devices- Prime Movers –Engines, turbines, fuel cells

n Different Storage Options – Batteries, Pumped Hydro, Flywheels…

MPPTOperating voltage315-378 V

MPPTOperating voltage315-378 V

Bi-directional inverter30kW

Bi-directional inverter30kW

Battery Bank240 batteries2V, 600Ah @C10

Battery Bank240 batteries2V, 600Ah @C10 DG Set

50 kW

DG Set50 kW

RETREATBUILDINGConnected load 90kW

RETREATBUILDINGConnected load 90kW

PV arrays15kW @1000 w/m2

PV arrays15kW @1000 w/m2

TERI’S HYBRID SYSTEM

Criteria

n Autonomy A = 1- HLOL/(HTOT)HLOL no of hours of loss of loadHTOT total no of hours of load

n Emissionsn Costn Trade-off between criteria

Indian Experience -Hybrid

n Wind-Solar PV – 9 systems- 42 kW totale.g 5 kW Chunnambar Island – 3.3

kW Wind, 1.8 kW PV, 800 Ah Batteryn PV-Diesel - Kiltan, Minicoy (100kW)n 500 kW Wind-Diesel – Sagar Island –

West Bengal(10-50 kW wind m/cs with 2 -360 KVA generators)

Possible Applications

n Islands- Existing Diesel gridsn Remote locations – Hilly terrainn Industries with captive power (DG)n 80,000 Non-electrified villages –

relatively remoten Estimate – 100 households – Average

30kW – 540 MW of off-grid systems

Hybrid Cost Comparison

25

27

29

31

33

35

37

39

41

43

0 1 2 3 4 5 6 7 8 9 10

LOLP (%)

Cost

(Rs/

kWh)

Single Photovoltaic System Single Wind Energy System Hybrid Sytem (fpv =0.2)

Renewables- Policiesn Subsidies/Incentives - offered by Govt of

India on Renewablesn Target Oriented - Installation not actual

generationn Only country with separate Ministry for

renewablesn 10% of power generation target by 2010n Preferential tariff for renewablesn Centralised vs Decentralised

Renewable Issuesn Resource Variability Site Specificn Load Uncertaintyn System Selection/Sizing – Incomplete

assessment of options, “Satisficing”n Most Renewables – promoted by individual

technology /component suppliersn Systems Analysis/Load Forecasting –

Software/modelling support required

Renewable Issuesn Load management- cost effective method of

matching supply-demand (DSM)n Experience with Control strategies/R&D

needed –Pilot systemsn Need for indigenous controller & inverter

developmentn Need to have well documented pilot systems

that provide “unbiased” data on actual performance of hybrid systems. Independent assessment and dissemination of results

Hybrid Issuesn Affordability to end-user? How much of costs

to be recovered? Remote areas lower ability to pay- Need to try different models

n Externalities need to be quantified – to level playing field

n Govt- Manufacturers –R& D institutions-partnerships

n Clearly specified criterian Tracking of Hybrid Programme & mid-course

corrections

End-Note

You can never plan the future by the past

Edmund Burke

ReferencesT.Ackerman, G. Andersson, L.Sodder, Distributed Generation: A definition, Electric Power

Systems Research 57 (2001) 195–204.Distributed Generation, The Power Paradigm for the New Millenium, Edited by A.M.

Borbely and J.F.Kreider, CRC Press, Boca Raton, USA, 2001.Assessment of Distributed Generation Technology Applications, Prepared for Maine Public

Utilities Commission by Resource Dynamics Corporation, Vienna, VA, USA, February 2001, available on the web at //www.distributed-generation.com.

Fuel Cell Handbook, Fourth Edition, November 1998, US Department of Energy, Office of Fossil Energy, Federal Energy Technology Centre, Pittsburgh,USA available on the web at //www.fetc.doe.gov/publications.

Ministry of Non-Conventional Energy Sources, Annual Reports, New Delhi, 1993, 2000,2001,2002.

Wind power development in India: Towards global leadership, Ministry of Non-Conventional Energy Sources, New Delhi, October 2002.

Tata Energy Data Directory 1999, Tata Energy Research Institute, New Delhi, 2000PP.Parikh, State of the Art Report on Gasification of Biomass, Report submitted to DNES,

Govt of India, 1984.Status of Biomass Gasification Technology at ASCENT, India, October 1998,

http://www.bgtechnologies.net/ankur.htm.

Thank You