Biomass can be a cost-effective and carbon neutral fuel choice.
Is biomass a suitable energy option for your proposed or existing development? Is there a good supply nearby? Is the scale and access of/to the site appropriate?
Presention for Ecobuild 2011 by Jude Hassall, Energy Project Manager at BioRegional
3. 2. Use available information
2 Use available information
• www.forestry.gov.uk/england‐woodfuel
• www.carbontrust.co.uk/biomass
• www.biomassenergycentre.org.uk
• www.southwestwoodshed.co.uk
• www.northwoods.org.uk
• www.r‐e‐a.net
6. Boiler utilisation –
Boiler utilisation capacity factor
• Th ft f ll di
They often fall disappointingly below expectations:
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– Poor site selection
– Inappropriate sizing of biomass boiler
– Inappropriate sizing and use of thermal stores
– Poor integration with fossil fuel stand‐by plant
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– Mismatch of fuel and boiler unit
– Poor overall system design and lack of acceptance
– Poor installation and commissioning
P i ll i d i i i
– Poor fuel quality and management thereof
– Irregular maintenance and attention
15. 2. Ensure a value engineered solution
2 Ensure a value engineered solution
• Value engineering reconciliation of:
V l i i ili i f
– Biomass plant capex
– Fossil fuel, heat storage and fuel storage capex
– Unit cost of fossil fuel and biomass fuel
– Organisation drivers to maximise carbon
savings and minimise capex
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• Factors influencing sizing and integration:
1.
1 Which loads are to be supplied
2. When will biomass plant be operated
18. 3. Fuel Characteristics and impact on boiler design
3 Fuel Characteristics and impact on boiler design
• Particle size – affects grate and feeding design
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– Pellets and small chip – underfed hearth
– Large chip – moving grate
Large chip
• Moisture content (MC) – affects choice of grate and temperature
– Low MC – underfed,
– High MC – moving grate
• Ash content and melt temperature – affects combustion temperature and
removal process
– Wood has low ash content with high melt point
• Contamination – affects residence time and materials
– Waste Incineration Directive requires boiler to meet certain
conditions of temperature and residence time
20. 3. Factors affecting price
3 Factors affecting price
Logistics Quality
li Market
k
• Location in
relation to raw • Moisture content • Source type: virgin
material supply; ( );
(%); timber, reclaimed
timber reclaimed
• Delivery duration • Calorific Value; wood, arboriculture
& distance; • Form of delivered arisings, waste, etc.;
• Delivery volume; fuel e.g. slabwood <
fuel e g slabwood < • C
Contracting type:
i
(capacity & woodchip < pellet
contract buying fuel by
(influences
volume); processing labour); weight, volume, or
• Delivery vehicle; energy;
• Quality of
• Delivery woodchip / pellet • Local demand
frequency compared to
(influences
• Seasonal factors processing competing markets.
technology).
21. 4. Optimise woodfuel storage
4 Optimise woodfuel storage
• The successful operation of any woodfuel system
relies on a well designed fuel store, handling and
reception area
• Optimise fuel store volume
• Flexible fuel store reception
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Optimise fuel discharge rates
– Tipped – fastest (1t/min)
– Blower
Blower – slower, noisier but more flexible (1t/8min)
• Once quantity of fuel is known, estimate volume
22. 4. Woodfuel –
4 Woodfuel fuel store sizing
• Dead space 15‐20% of total volume
Dead space 15 20% of total volume
• Good to size fuel store for full delivery load – partial
load may impact fuel price
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• If there is back‐up and or aux plant it may be
possible to reduce number of days of storage
• Various fuel storage designs – discuss with fuel
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supplier, installer and site owner for best option
24. 4. Spatial constraints
4 Spatial constraints
• Access for maintenance
• Space for backup systems
• Proximity to fuel storage
• Vehicle access for fuel deliveries (turning circles and
height)
• Space for buffer tank / thermal storage
• Location and height of flue (taller and wider than
gas/oil flues)
• For existing buildings access for installation
• Conservation areas, listed buildings
– increases cost
25. 4. Boiler house considerations
4 Boiler house considerations
• Boilers physically larger than fossil fuel equivalents
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• Much greater headroom required if access to the top p
of the boiler is required for flueway cleaning on
vertical tube boilers
• Floor space required for:
– Flueway cleaning on horizontal tube boilers
– Feed auger and ash auger removal
– Ash bin(s) cyclone buffer vessel thermal store
Ash bin(s), cyclone, buffer vessel, thermal store,
expansion vessels or spillset
26. 5. Assess necessary permits and consents
5 Assess necessary permits and consents
• Planning consent –
Planning consent contact the LPA as early in the
process as possible
• Building regulations – conservation of fuel & power
B ildi l i i f f l &
• Waste & Pollution
• Health & Safety
29. Good tendering
• Market competition and good tendering practice
– Clear specification to allow cross comparison;
– Comprehensive specification to reduce perceived risk and
associated price loading;
– Site information;
– Appropriate tendering;
– Thorough tender evaluation and CAPEX build‐up;
– Clear identification of CAPEX risk and management
thereof.
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31. Tips for woodfuel procurement
• Th i
There is a need to check both client and supplier are
d h k b h li d li
insured appropriately:
– T&Cs are compatible throughout the supply chain?
T&C tibl th h t th l h i ?
– Levels of insurance is compatible with risks?
– Dust and boiler explosions
– Does the sale of heat and/or power affect clients
commercial status?
• Can inform client of general principles but do not
advise on small‐print and/or policy purchases (FSA
p / p yp (
regulated activity)
32. Woodfuel procurement ‐
Woodfuel procurement insurance
• D
Does supplier/ supplier’s insurers indemnify client
li / li ’ i i d if li t
against:
– Damage to the installed equipment due to supply
substandard fuel?
– Prompt removal of substandard fuel?
– Loss of earnings as a result of down‐time due to
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substandard fuel?
• Client needs to be aware of potential I&I issues at
the FS stage but detailed investigations usually
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made during project development/ negotiations
with suppliers
33. Woodfuel procurement ‐
Woodfuel procurement HSE
• By statute the site owner and/or operator is
responsible for all HSE issues on the site.
• The site management have to put in place SOPs and
conduct risk assessments on all operations
conducted on‐site
o c e t o pote t a S ssues e ue
• Inform client of potential HSE issues re: fuel
deliveries early in process
• Reputable fuel suppliers should be able to supply
their own SOPs and associated risk assessments
34. Woodfuel procurement ‐
Woodfuel procurement documentation
• Term sheet very useful
Fuel specification (inc. variances and details of supplier QA systems)
Tonnage p.a.
Delivery vehicle type(s) and sizes (inc. turning circle and e.g. tipping
clearances) )
Maximum delivery frequency (e.g. loads/week)
Price/ unit (e.g. p/kWh boiler output, £/T)
Duration of contract
Indexing
Conditions of sale (append example contract)
Insurers/ indemnity limit
Recourse for delivery of out of spec. fuel
Earliest date they can start contract
36. Woodfuel procurement –
Woodfuel procurement delivery docs
• All d li i D li
All deliveries: Delivery note
t
Plus (if not bought by boiler heat output)
• Copy of weighbridge ticket with tare, gross and net weights
Or
• Estimation of volume (if not full load)
Plus (if not bought by boiler heat output)
• Moisture content analysis/ estimate (may be sent after
delivery)
38. Tips for operation and maintenance
• Standard O&M contract with installer is common
• Automated systems can reduce attendance time
• Use of high quality fuel, regular checks, avoiding
short‐cycling
• Establish daily, weekly, monthly, 3‐monthly, 6‐
monthly and annual maintenance regime
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• Ongoing performance monitoring using heat
meters
39. Maintenance requirement
• Higher specification = lower maintenance cost
– Automatic ash removal
– Cooled grate designs
– Robust wood feeding
– Boiler tube cleaning
• Low specification can lead to lower system
availability
• Complex systems for fuel feed can also
present reliability issues
t li bilit i
