Biomass CHP – best practice Conclusions and recommendations Anders Evald, Janet Witt, Kati Veijonen Harrie Knoef, Johan Vinterbäck, Elvira Lutter Vienna 9 March 2006
Biomass CHP – best practiceConclusions and recommendations
Anders Evald, Janet Witt, Kati VeijonenHarrie Knoef, Johan Vinterbäck, Elvira Lutter
Vienna 9 March 2006
Project aims
• Promote biomass CHP in Europe and highlight plants with the best operation
• Provide e.g. authorities and future plant owners with information about typical plant performance and about best available technologies.
• Enable benchmarking, identify the improvement potential of the existing European CHP plants
• Replicate best practices• Challenge: collect reliable data
Different technolgies covered
• 19 biogas and landfill gas plants• 4 gasification plants• 10 CFB (circulating fluidized bed) plants• 11 BFB (bubbling fluidized bed) plants• 15 grate-fired steam boiler plants using
uncontaminated biomass• 8 grate-fired steam boiler plants using
municipal solid• waste (MSW) as a fuel• 1 dust fired steam boiler plant
Fuels covered
• Solid biomass– Forest fuels– Forest industry by-products such as bark, sawdust
etc.– Wood pellets– Agricultural residues such as straw, husk etc.– Municipal solid waste– Landfill gas– Manure etc. for biogas plants
• Fossil fuels– Heavy fuel oil– Natural gas– Coal
Key performance indicators
• availability• utilisation period• total efficiency• fuel input: biofuels vs. fossil fuels• nominal efficiency vs. operational efficiency• own power consumption• total efficiency on monthly basis
Gasification plants
Utilization factor: the extent, to which installed power is utilisedAvailability factor: the extent, to which the plant is available for operation
Availability and utilisation factor
0%
20%
40%
60%
80%
100%
56 23 54 1
ave
rag
e u
tilis
atio
n f
acto
r &
ave
rag
e av
aila
bil
ity
utilisation factor availability
Nominal efficiency and operational efficiency
0%
20%
40%
60%
80%
100%
effi
cien
cy
operational electric efficiency operational heat efficiency
nominal electric efficiency nominal total efficiency
Total efficiency of individual plant over 24 month
0%
20%
40%
60%
80%
100%
120%
sep-
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Oct
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nov-
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jan-
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apr-
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maj
-04
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jul-
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aug-
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sep-
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Oct
04
nov-
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Dec
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05
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tota
l ef
fici
ency
per
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nth
56 23 54 1
Gratefired boiler plants
Availability and utilisation factor
0%
20%
40%
60%
80%
100%
41 4 6 20 60 14 57 82 5 16 22 45 35
utilisation factor availability
Nominal efficiency and operational efficiency
0%
20%
40%
60%
80%
100%
120%
effi
cien
cy
operational electric efficiency operational heat efficiency
nominal electric efficiency nominal total efficiency
Ranked to increasing capacity
Annual energy production and operational efficiency
0
50000
100000
150000
200000
250000
300000
350000
41 4 6 20 60 14 57 82 5 16 22 45 35
ave
rag
e en
erg
y p
rod
uct
ion
[M
Wh
/a]
0%
20%
40%
60%
80%
100%
effi
cien
cy
power production heat production total efficiency electric efficiency
heat production: 606 GWh/a
Total efficiency of individual plants over 24 month
0%
20%
40%
60%
80%
100%
120%
sep-
03
Oct
03
nov-
03
Dec
03
jan-
04
feb-
04
Mar
04
apr-
04
maj
-04
jun-
04
jul-
04
aug-
04
sep-
04
Oct
04
nov-
04
Dec
04
jan-
05
feb-
05
Mar
05
apr-
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maj
-05
jun-
05
jul-
05
aug-
05
tota
l eff
icie
nc
y p
er
mo
nth
41 4 6 20 60 14 57 82 5 16 22 45 35
Cross technology comparison
Min./max. net power output of participating plants for six conversion technologies
0
20
40
60
80
100
bio- andlandfill gas
plants
gasificationplants
CFB plants BFB plants grate firedboiler plants
MSW gratefired boiler
plants
net
po
wer
ou
tpu
t [M
Wel
]
AverageMax. value: 200 MWel
Plant size
Min./max. electric efficiency of participating plants for six conversion technologies
0%
10%
20%
30%
40%
bio- andlandfill gas
plants
gasificationplants
CFB plants BFB plants grate firedboiler plants
MSW gratefired boiler
plants
ann
ual
ele
ctri
c ef
fici
ency
Average
Electric efficiency
Min./max. total efficiency of participating plants for six conversion technologies
0%
20%
40%
60%
80%
100%
bio- andlandfill gas
plants
gasificationplants
CFB plants BFB plants grate firedboiler plants
MSW gratefired boiler
plants
ann
ual
to
tal
effi
cien
cy
Average
Total efficiency
Min./max. electric utilisation factor of participating plants for six conversion technologies
0%
20%
40%
60%
80%
100%
bio- andlandfill gas
plants
gasificationplants
CFB plants BFB plants grate firedboiler plants
MSW gratefired boiler
plants
ann
ual
ele
ctri
c u
tili
sati
on
per
iod
Average
Utilization
Min./max. availability of participating plants for six conversion technologies
50%
60%
70%
80%
90%
100%
bio- andlandfill gas
plants
gasificationplants
CFB plants BFB plants grate firedboiler plants
MSW gratefired boiler
plants
ann
ual
ava
ilab
ilit
y
Average
Availability
Conclusions and recommendations
1. Bigger is better– Higher efficicency– Lower own consumption– Better availability– Lower specific investment– But constrained by heat marked, and not
necessarily true for biogas plants
Capacity and utilization
• Plants are bigger than simply justified by the heat market– High electricity price– Optimizing tariff income– Heat accumulator
• Plants built for the future• Plant nominal capacity is too optimistic – very few plant
perform anywhere near their anticipated (nominal) efficiency in practical operation
• Economic optimization– Not too small– Not too big
• Low utilization = poor payback on invested capital
CHP or not CHP
• Many plants are not 100% dependent on heat market (combined heat and power only as a fraction)
• German biogas plants produce very little heat, and they don’t meassure it
• Premium price for electricity not allways require full combined production– Incentive for RE, but not for the most efficient RE
• Large plants (MSW) cannot connect enough heat demand
Balancing heat and power
• Energy efficiency: electricity is the premium product; heat is a by-product
• Valid also money-wise• But not allways: nordic heat markets show
high value for heat• Industrial facilities might see steam as the
main product and electricity as a byproduct
Choosing the right technology
• Large difference in electric efficiency• Low electric efficiency is compensated by
more heat• Heat market set the framework• Steam cycles: go for high steam data• Retrofitting old equipment to improve
efficiency and reduce own consumption
Industrial systems
• A more fragile heat market• Industries change• Operated according to steam demand – less
power and low utilization
Reducing own consumption
• Big difference depending on choice of technology
• Option for improvement in old plants• Low efficiency lead to high own concumption
Operational problems
• New challenges for plant operators• Fuel quality problems (feed systems, moisture
content, flue gas fans etc.)• Sintering bed material• Fouling heat transfer surfaces
– Decrease efficiency and high temperature corrosion
• Result: lower efficiencies, higher maintenance
• Exchange experience!
Some concluding remarks [1]
• Technology implemented must be mature – Proven prototype models– Long-term duration tests
• Adequate infrastructure– Local manufacturing capacity– After-sale service– Training facilities– Sustainable feedstock supply
• Motivated & skilled labor – Operators, Management– Incentives
Some concluding remarks [2]
• Information & knowledge exchange – Performance, limitations, opportunities– Evaluation with competing options– Set-up monitoring program of successes in India, China
• Clear regulations– Permitting procedures– Emission according to “ALARP”– Health, Safety & Environment
• Sale of electricity and heat– Any legal obstacle should be removed– Long-term fixed price is prerequisite
Some concluding remarks [3]
• Product quality must meet client specifications– Technical performance– Financial/economic performance– Operational performance– Gaining confidence
• Certification – stimulation– product must meet defined quality standards
• Scale-up, demonstration, replication, optimization– Economy of numbers (instead of economy of scale)– Reduced capital costs– Improvement from learning by doing
Some concluding remarks [4]
Do not repeat the mistakes from the past– learning by doing and not by a scientific approach
(cooperation is prefered)– too optimistic approach of the economics, efficiency and
availability, projections: 7000 hrs of operation in 1st year– no optimal cooperation of the ownership-consortium and
conflicting interests (who is responsible for what). • Manufacturer versus plant owner• Plant owner/technology supplier versus permitting
authority
Health, Safety & Environment
Powerto Local Grid
Gas Utilization
Gasifier
GasCooling
Exhaust gasto Chimney
Biomass
Agents(air, steam etc.)
Waste Water &
CondensatesCondensates
Flare
GasCleaning
Gas Engine
Waste Water
TreatmentWaste Water
to Canalisation or Disposal
Heatto District Heating
Process Automation
GeneratorHeat
Int. DemandDusts
Gas fired Boilers
Powerto Local Grid
Gas Utilization
Gasifier
GasCooling
Exhaust gasto Chimney
Biomass
Agents(air, steam etc.)
Waste Water &
CondensatesCondensates
Flare
GasCleaning
Gas Engine
Waste Water
TreatmentWaste Water
to Canalisation or Disposal
Heatto District Heating
Process Automation
GeneratorHeat
Int. DemandDusts
Gas fired Boilers
www.gasification-guide.eu
Success stories CHP gasifiers [1]
• More than “5 installed” systems:– Bioneer [district heating]– Co-firing [at power stations]– Biomass engineering, UK– Eqtec, Spain– Xylowatt, BE– Mothermik, DE– Pyroforce, CH– Güssing concept, AT– Volund (DK, DE, Japan, Italy))– India, China (thousands, but unfavourable
emissions)
Success stories [2]
0
1000
2000
3000
4000
5000
6000
7000
8000
2002 2003 2004 2005 2006 2007
ho
urs
of
op
era
tio
n
gasifierengine
Success stories [3]
Thank you for your attention!
Harrie KnoefBTG biomass technology group [email protected]: +31-53-4861190