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Environment-friendly clean energy

Natural gas fired cogeneration Current status and future overview

in Japan

Yasutaka Kume

The Japan Gas Association

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Contents

1. Outline of natural gas fired cogeneration

2. Positioning in the context of energy and environmental policies

3. Diffusion

4. Cases of application

5. Technology development

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（１） Characteristics of cogeneration

① Supply both heat and electricity

② Distributed power source

③ Deal with various demands such as; communities, factories, offices, homes

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（２） Profile of natural gas cogeneration

Case of conventional power generation systems (thermal power)

Case of cogeneration systems

Electrical power plant

Site of demand

Primary energy (Petroleum, natural gas, coal, etc.)

Transmission loss, etc.

Electrical energy

Unused waste heat (discarding in the

ocean, etc.)

Energy use

Gas production plant

Gas fired cogeneration

Site of demand

Electrical energy

Pipeline

Electricity

Primary energy (natural gas)

Waste heat capable of effective use

Heat

Waste heat incapable of effective use

Energy use

Electricity

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（３） Advantages of natural gas cogeneration

Natural gas cogeneration system

Energy-saving, environment-

preserving characteristics

Economical efficiency

DistributedEnergy system

Reliable supply of energy

Leveling of electrical power load

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（４） Energy-saving and environment-preserving characteristics

Gas fired cogeneration system Conventional system

CO2 emission level: 185 g-C

Primary energy: 3,172

kcal

0.29m3

City gas

Cogeneration

Generating efficiency

30%

Heat : 1.4Mcal

Waste heat recovery rate

50%

Primary energy consumption: 3,172 kcal (▲25%)CO2 emission level: 185 g-C (▲34%)

Primary energy consumption: 4,212 kcalCO2 emission level: 281 g-C

Electrical power: 1kWh

CO2 emission level: 178 g-C Primary energy: 2,450

kcal

Thermal power generation

Primary energy: 1,762

kcal

CoalPetroleum

LNG

City gas

0.16m3

CO2 emission level: 103 g-C

Boiler Efficiency

90%

Demand-end generating efficiency

38%

Figures for efficiency are based on the lower calorific value standard.Notes:1) The efficiency figure for gas fired cogeneration is based on an example (calculated using data from the 1997 edition of the “Quality of

the Environment in Japan”).2) Prime units of CO2 emission:

- City gas: 642 g-C/Nm3

- Electrical power: 178 g-C/kWh (based on thermal power standards and at the demand end; calculated using data from the Federation of Electric Power Companies of Japan)

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（５） Types of cogeneration

Single-effect absorption chiller

Chilled water

Warm water

Electricity City gas

Gas engine

City gas

Double-effect absorption chiller

Chilled water

Steam

Electricity

Warm water

Steam

Chilled water

Electricity City gas

Waste heat boiler

Gas turbine

Fuel cell

Double-effect absorption chiller

System Characteristics

Generating efficiency: 30 - 38% (based on the lower calorific value)

Rate of waste heatcapable of use: 45 - 50%

Waste heat: warm water (with a portion capable of recovery by steam)

Single-system capacity: generally in the range of 15 - 3,000 kW

Application fields: hotels, hospitals, athletic facilities, multiuse buildings, large commercial buildings, large office buildings, etc.

Generating efficiency: 24 - 33% (based on the lower calorific value)

Rate of waste heat capable of use: 50 - 60%

Waste heat: steam

Single-system capacity: generally in the range of 1,000 - 10,000 kW

Application fields: district heating and cooling plants, large buildings, industries

Generating efficiency: 40 - 42% (based on the low calorific value)

Rate of waste heat capable of use: 30 - 40%

Waste heat: warm water, steam

Single-system capacity: generally in the range of 100 - 1,000 kW

Application fields: hotels, hospitals, athletic facilities, multiuse buildings, large commercial buildings, large office buildings (in operation around the clock)

Gas

eng

ine

pow

er g

ener

atio

n sy

stem

G

as t

urbi

ne p

ower

gen

erat

ion

syst

em

Fue

l cel

l pow

er g

ener

atio

n sy

stem

(p

hosp

hori

c ac

id f

uel c

ell)

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２． Positioning of natural gas fired cogeneration in the context of energy and environmental policy

Gas fired cogeneration to be encourage for further diffusion as demand-side “new energy” by the

government and industries

Goal for fy 2010

4,640,000kW

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New energy targets (as of July 2001)

(1) New energy on supply-side Field of energy FY1999 (actual) FY2010 (target) Photovoltaic power generation

209,000 kW 4,820,000 kW

Wind power generation 83,000 kW 3,000,000 kW Incineration heat power generation

900,000 kW 4,170,000 kW

(2) New energy on demand-side Clean-energy automobiles 65,000 vehicles 3,480,000 vehicles Natural gas cogeneration 1,520,000 kW 4,640,000 kW

FY2001(actual) Photovoltaic : 452,000kW, Wind : 312,000kW

FY2002(actual) Natural gas fired Co-Gen : 2,150,000kW

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Measures to promote the diffusion of cogeneration systems in Japan

1. Subsidized projects

(1) Support for new energy companies(New energy)

(2) Projects to promote the input of new district energy(New energy)

(3) Projects for support of companies rationalizing energy utilization

(Energy saving)

2. Tax incentives, and fiscal investment and loans

(1) Tax measures to promote investment for restructuring of the energy supply and demand

(2) Low-interest financing for installation of cogeneration systems, fuel cells, etc.

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３． Diffusion

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Diffusion of natural gas fired cogeneration in Japan

①　 全体（容量）

0

50

100

150

200

250

300

350

400

81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02　年 度

単年度設置容量

020040060080010001200140016001800200022002400260028003000

累計設置容量

産業用（単年度）民生用（単年度）累計

2, 687, 000kwkw（千 ） kw（千 ） Total (installed capacity)

(Thousands of kW) (Thousands

of kW)

Sin

gle

-FY

inst

alle

d c

ap

aci

ty

Cu

mu

lativ

e in

sta

lled

ca

pa

city

Fiscal year

Industrial segment (single-FY)

Non-industrial segment Cumulative installed

capacity

２、１４９、０００ｋ W

Except 　 ST

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Breakdown of installed capacity in the industrial segment by field (total:2.03 million kW)

その他6.6%

食品10.3%

金属2.1%

電機5.1%

機械13.4%

パルプ15.1%

鉄鋼16.6%

化学工業27.0%

印刷1.4%

窯業1.3% 繊維

1.0%Textiles 1.0%

Chemicals27.0%

Ceramics 1.3%

Steel 16.6%

Pulp 15.1%

Machinery13.4%

Food products 10.3%

Other fields 6.6%

Electric machine

5.1%

Printing 5.1% Metals

2.1%

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Breakdown of installed capacity in non-industrial segment by field (total: 650,000 kW)

レジャー2.7%

住宅0.2%飲食店

0.2%

福祉施設1.2%学校

3.1%スポーツ

3.1%

地冷30.8%

病院15.5%物販

14.9%

事務所12.4%

宿泊4.3%

研修研究4.2%

複合4.1%

その他3.3%

Housing

0.2%

District coolingcenters 30.8%

Welfare facilities 1.2% Restaurants

0.2%

Hospitals

15.5%Facilities for sales of goods

14.9%

Offices

12.4%

Leisure facilities

2.7%

Lodging facilities

4.3%

Training/research facilities4.2%

Combined-use facilities 4.1%

Other fields 3.3%

Schools 3.1%Sports facilities

3.1%

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A theme in the cogeneration promotion

CO2 emission factors for commercial electricities

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CO2 emissions factors for commercial electricities

There are mainly two ways of thinking for CO2 emissions factors.

Average emissions factors :AEF

(CO2 emission from nuclear and hydraulic plants ≒0) ）

MEF ＝

CO2 emission amount in thermal power plants

all generating output in nuclear/hydraulic/thermal plants

CO2 emission amount in thermal power plants

generating output in thermal plants AEF is half as much as MEF

From the Midterm Summary by the Target Achievement Scenario Sub-Committee in the Central Environment Council Global

Environment Committee

AEF MEF

0.36kg-CO2/ kWｈ 0.69kg-CO2/ kWｈ（ Demand end conversion) only fuel parts(not LCCO2)

*Japanese power source breakdown thermal:55%, nuclear:35%, hydraulic:10%

AEF ＝

Thermal standard (marginal) emissions factors 　→　　 MEF

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What is the alternative power sources?

Thermal power generation is the marginal Thermal power generation is the marginal power source in the present Japanese power source in the present Japanese

conditioncondition

Thermal annual generating output

responds to the change in annual

electricity demand.

原 Nuclear plants are operated to their maximums since their running costs are low.

TThe operating rate is 99.4% except for the periodic inspection times.

NNuclear and hydraulic are operated by the priority dispatching directive

水 Hydraulic plants are operated to their maximums since their running costs are low.

RThe generating output depends on rainfall/snowfall levels.

需

（ no measure case）（measures adopted case）

annual　demand　decrease

Tota

l an

nu

al p

ow

er g

en

era

ting

ou

tpu

t

T

N

H H

N

T

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How the thermal standard MEF socially recognized?

★“Guideline for calculation of Greenhouse gases(GHGs) total emission amount" based on the law Guideline of Measures to Prevent Global Warming

(Environment Agency in July 1999) AEF is to be used for the calculation of GHGs total emission amount. It is stated that "evaluation of the effect in each measure associated with

electricity use are to be investigated in the future".

★The Midterm Summary by the Target Achievement Scenario Sub-Committee in the Central Environment Council Global Environment Committee(in July 2001)

The effect of each measure is to be calculated using both AEF and MEF

★Guideline of Measures to Prevent Global Warming(in March 2002) The effect of each measure is to be calculated using both AEF and ME

F, and present as in the range of ○○ ～△△ .

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Evaluation of CO2 reduction effect in cogeneration system

Gas fired cogeneration system Conventional system

CO2 emission level : ２２２ g-C

Primary energy: ３，８０７

kcal

０．３５ m3

City gas

Cogeneration

Generating efficiency２５ %

Heat : 1.4Mcal

Waste heat recovery rate

４０ %

Primary energy consumption : 3,807 kcal (▲ 8%)CO2 emission level : 222 g-C (▲20% : MEF) (+ 12% : AEF)

Primary energy consumption : 4,142 kcalCO2 emission level : 277 g-C （ MEF ） 　　　　　　　　　 196 g-C （ AEF ）

Electrical power: １ kWh

CO2 emission level 　 : １７８ g-C （ MEF ） Primary energy: ２，４５０

kcal

Thermal power generation

Primary energy: １，６９２

kcal

CoalPetroleum

LNG

City gas

０．１５ m3

CO2 emission level 　 : ９９ g-C

Boiler Efficiency ９０ %

Demand-end generating efficiency

３８ %

９７ g-C （ AEF ）

nuclear／hydraulic

CO2 emission coefficient: city gas 642g-c/Nm3, electricity 178g-c/kWh(MEF), 97g-c/kWh(AEF); demand-end

Source　:　　Actual　values　in　1995　from　data　by　the　Federation　of　Electric　Power　Companies　of　Japan

generation　efficiency　is　based　on　LHV　

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４．４． Case of Case of applicationapplication

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Overview of Roppongi Hills Energy Supply ProjectOverview of Roppongi Hills Energy Supply Project

(1)Supply electricity depending on the demand of specific

supply site.

Electricity Industry Law amended in 1995

(2)Roppongi 6th square(6-chome) redevelopment project

Cultural city center where people live, work, relax, and create in a safe atmosphere. (3)Final completion in 2003 spring

(4)Area: 12.7ha

Total floor space: 750,000m2

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Building ImageBuilding Image

Complex　building　station　plaza Theater　

building

Broadcasting　Center

Office　building A

Residential　building B

Residential　building C

Residential　building D

Residential　building A

Hotel　building

Office　building B

Roppongi Hills Gate Tower

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Outline of energy supply facilitiesOutline of energy supply facilities

Electricity supply facilities 36,500kWSteam injected gas turbine 36,000kW (6,000kW ×6) 　　　　　　　Back pressure steam turbine 500kW 　

Heat supply facilitiesCooling source Steam absorption refrigerating system 66,810 kW (19,000 RT)Heating source Steam boiler 179,600 MJ/h (79.6t/h)

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Electricity/Heat Supply PlanElectricity/Heat Supply PlanPlanned area Roppongi 6th square section

District cooling/heating facilities & Electricity supply facilities Building for electricity/heat supply Building for heat supply Heat supply pipe Electricity supply line

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５． Technology 　　development

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Classification of energy demand fields, and demand cultivation

Cogeneration system generation capacity

New technology for demand cultivation

Sha

re o

f th

e en

ergy

dem

and

occu

pied

by

elec

tric

al

pow

er

Polymer Electrolyte Fuel

Cells (PEFC)

Micro gas turbines

High-efficiency gas engines and

gas turbines

Residential

Convenience stores

Fast food restaurants

Small-scale, commercial-

use

Offices and stores

Hospitals and hotels

Large-scale commercial-

use

District heating and cooling systems

Factories(metals/machinery)

Factories (paper/food products)

Industrial-use

Fields as yet uncultivated

Fields now being

cultivated

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Micro cogeneration - current status and development situation

Allied Signal社 （マイクロＧＴ）

容量７５ｋＷ 効率 ３０％

1００ ５０1０

１０

２０

３０

４０

Elliot (micro gas turbine)

Efficiency of a 30-kW system: 30%

Elliot (micro gas turbine)

Efficiency of a 30-kW system: 30%

Fuel cell (PEFC)

Efficiency of a 1-kW system: 35%

Electrical efficienc

y

Yanmar (engine)

Efficiency of a 9.8-kW system: 24

%

Capston (micro gas turbine)

Efficiency of a 28-kW system: 26%

Honda Motor (engine)

Efficiency of a 1-kW system: 20%

Capacity (kW)

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Conception of (PEFC) fuel cells for Conception of (PEFC) fuel cells for residential useresidential use

PEFC cell stack

Cut-away view of a 250-W butane-fueled system proposed by Matsushita Electric Works (from the company website)

1-kW hydrogen-fueled system proposed by Sanyo Electric (from the company website)

Fuel cell

Electric power

Catalytic electrode

Solid polymer membrane

Blower

Hydrogen former

Steam generator

Hydrogen reforming catalyst

CO removal catalyst

Pump Water tank

Cassette cylinder

Air feed blower

Power exchanger

Heat exchanger

Air line

Hydrogen line

Separator

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Conception of a residential-use fuel cell Conception of a residential-use fuel cell cogeneration systemcogeneration system

City gas

Storage cell　

PEFC cell　

Inverter　

Reformer　

Electricity

Hot

wat

er

tank　

Fuel cell system Bath Air conditioner Lighting

Supplementary heatingHot water supply Underfloor heating system

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Commercial-use micro gas engine

9.8 kW

Single-phase: 100/200 V

Three-phase: 200 V

24.2kW 21.9kW

23.5% 25.5%

58% 57%

1,460(W)×730(D)×1,610(H)

60dB(A)

Generated output Generated output

Generation voltage Generation voltage

Waste heat recovery

Waste heat recovery

Power generatio

n

Power generatio

n

Heat recovery

Heat recovery

Outside dimensions

Outside dimensions

Noise level Noise level

Eff

icie

ncy

Eff

icie

ncy

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System composition (example)

Multi switcher

System example

Generated power

Com

mer

cial

p

ower

CPU

Synchronization

Detection

Load Load Load Load

Control power source

Gas engine

Gas

Water heating system

Hot water tank

Water heater

Hot water mixer

Water supply

Hot water

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Micro gas turbinesMicro gas turbines

Micro gas turbines are a new type of compact, dispersed power generation system based on proven technologies, including auxiliary power equipment with a record of military and aircraft use, constituent technology applied in heat exchangers for large gas turbines, and mass production technology applied in automotive turbochargers. As such, in recent years, they have become a focus of attention in the power and gas industries overseas, and more than ten firms, consisting of both major manufacturers and venture businesses from inside and outside Japan, are vying with each other in their development. In Western markets, leading overseas manufacturers have already commenced shipments of initial lot products, and are steadily constructing production facilities with a view to getting orders for several tens of thousands of systems before the first half of the decade is over. In Japan, systems began to be installed in restaurant chains in fiscal 2000, and extensive installation in the market as a whole is anticipated to begin in fiscal 2001.

Exhaust gas Waste heat recovery unit

Regenerator

City gas

Generated output

Inverter

(frequency controller)

Combustor

Air bearing

Intake air

High-speed generator

Combustion air compressor Turbine

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• Power wholesalers and retailers (independent power Power wholesalers and retailers (independent power producers, etc.)producers, etc.)

• Waste power generation projectsWaste power generation projects

• Community re-development,heat supply projects,district Community re-development,heat supply projects,district heating/cooling systemheating/cooling system

• Private power generation in the industrial and commercial Private power generation in the industrial and commercial segments (expansion into application areas with a smaller segments (expansion into application areas with a smaller heat-power ratio)heat-power ratio)

• Private power generation at small and medium enterprisesPrivate power generation at small and medium enterprises

• Private power generation for residential usePrivate power generation for residential use

Future outlook for the cogeneration market

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Thanks for your kind attention!Thanks for your kind attention!

Yasutaka KumeYasutaka KumeEnergy System DepartmentEnergy System DepartmentThe Japan Gas AssociationThe Japan Gas Association

Tel: +81 3 3502 2468Tel: +81 3 3502 2468E-mail: kume@gas.or.jpE-mail: kume@gas.or.jp