Slides from webinar: CHP as a carbon reduction tool
Document added 14 May 2010 by Business Operations - Community Manager from the Construction & Real Estate industry
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Document added 14 May 2010 by Business Operations - Community Manager from the Construction & Real Estate industry
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CHP as a carbon reduction tool - what to consider 1© 2degrees Ltd.
CHP as a carbon reduction tool - what to consider
Justin Wimbush, Senior Mechanical Engineer, Arup
Neil Adcock, Associate Director, Rolton Group
CHP and CO2 Reduction
Technical and Commercial Implications
CHP and CO2 Reduction
• Current position: Senior Engineer
at Arup
• Experience:
• 8 years of working on fossil fuelled and
renewable fuelled CHP schemes.
• Project designs.
• Technical feasibility assessments.
• Commercial assessments.
• Planning applications.
CHP and CO2 Reduction – technical and
commercial considerations
Presentation Contents:
• Introduction to CHP
• What is CHP and why is it useful?
• Is CHP the most appropriate way to reduce CO2 emissions?
• Some technical considerations
• CHP and buildings
• CHP and CO2 reductions
• Some commercial considerations
• Cost and payback
• Technology risk
• Electricity market
• Conclusions
Conventional Heat and Power Supply
• Typical UK fossil fuel power stations generate
electricity with an efficiency of about 35%.
• 65% of the energy is wasted to the atmosphere.
• Distribution from out of town power stations to the
consumer results in distribution losses of the order
of 5-10%.
What is CHP?
• Simultaneous production of heat and electricity
(power)
What makes up a CHP system?
• CHP
• Boilers
• Fuel supply
• Thermal Storage
• Electricity distribution
• Hot water distribution
• Pumps
• Sub-stations
• Heat Exchangers (HIUs)
Gas CHP (Combined Heat and Power)
• Provides heat and electricity
• Low CO2 technology but not
renewable
• Stirling engines, fuels cells,
gas engines and gas turbines
• Available from <3kWe to
>3MWe
• Capacity limited by available
heat demand and economics
• Can serve individual buildings
or multiple buildings
Biomass CHP
Four (4) technologies
• wood chip fuel
• steam turbine CHP
• organic rankine cycle turbine
CHP
• gasification CHP
• indirect turbine CHP
Different capacities, heat to power
ratios & commercial maturity
Liquid biofuel CHP
• sustainable?
• commercially viable? Limited by RTFO
Biomass Air Turbine and Gasification CHP
• Air turbine
• 90kWe modules
• Moderate elec efficiency (19%)
• Suitable for 100 homes +
• Single supplier, demo stage
• Gasification CHP
• 250kWe modules
• Moderate elec efficiency (21%)
• Suitable for 200 homes +
• Multiple suppliers, entering
commercialisation
Biomass ORC and Steam Turbine CHP
• ORC turbine
• 400 - 2000kWe
• Low elec efficiency (13%)
• Suitable for 2000 homes +.
• Mature technology
• Steam turbine
• 2,000kWe +
• Low to moderate elec
efficiency (14 - 20%)
• Suitable for 15,000 homes +
• Mature technology
So what sort of CHP is most suitable for your
project?
• Complex range of factors to
consider:
• Why do you want it?
• To provide lower cost heat and
electricity?
• To reduce CO2 emissions?
• Because the Planning
Department look favourably on
it?
So what sort of CHP is most suitable for your
project?
• The capacity of CHP unit depends on your daily and annual
heating profile
• Producing excess heat should be avoided to maintain Good
Quality CHP status and to minimise costs.
0
5 , 0 0 0
1 0 , 0 0 0
1 5 , 0 0 0
2 0 , 0 0 0
2 5 , 0 0 0
3 0 , 0 0 0
3 5 , 0 0 0
4 0 , 0 0 0
4 5 , 0 0 0
5 0 , 0 0 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 25
H
e
a
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D a i l y p r o j e c t h e a t i n g p r o f i l e s
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M a r
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J u n
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So what sort of CHP is most suitable for your
project?
• CO2 emissions reduction potential?
• Gas CHP will reduce overall CO2 emissions by
between around 8% - 20%.
• Biomass CHP will mitigate 20% to 100% of your
CO2 depending on the technology selected.
CHP feasibility and CO2 reductions
• How dispersed are your heat loads?
• Heat distribution pipe is expensive and costs
around £300/m F&R for plastic and £600+/m for
steel.
• Heat losses even for
the most highly
insulated pipes can be
> 20%.
• Need to check that
CHP will save CO2!
- £ 2 . 0 M
- £ 1 . 5 M
- £ 1 . 0 M
- £ 0 . 5 M
£ 0 . 0 M
£ 0 . 5 M
£ 1 . 0 M
£ 1 . 5 M
£ 2 . 0 M
£ 2 . 5 M
£ 3 . 0 M
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35
N
P
V
Y e a r s
G a s & B i o m a s s C H P E S C o N P V C u r v e
So what sort of CHP is most suitable for your
project?
• How much will it cost?
• For an asset that generates both heat and electricity the project whole
life costs should be considered.
• For many projects the whole life costs, including an allowance for
plant replacement, will be lower than the up front capital investment.
• Whether a CHP scheme will pay
for itself depends primarily on:
• The heat density of the site
• Whether a retail electricity
tariff can be negotiated or
the electricity can be used
on your site.
So what sort of CHP is most suitable for your
project?
• How much does CHP cost?
• There are a number of procurement and operation
possibilities:
• Capital purchase – owner operated
• Capital purchase – operated and maintained by FM
company
• ESCo operation
• For new developments cost of
heat distribution is subsidised
by not installing gas network
Summary of Costs / Revenues to be
Considered
• Project capital cost
• CHP
• District heating pipework
• Thermal storage
• Heat exchangers
• Energy Centre
• Procurement of an ESCo
• Operational costs
• Gas
• Biofuels
• Maintenance
• Management
• Billing
• Revenues
• Sale of heat
• Sale of electricity
• Sale of renewable obligation
certificates (ROCs)
• CRC savings
Selling electricity – retail or wholesale?
• Pre 2008 unlicensed “private wire” operation allowed for
sale of electricity to residential networks < 1MVA.
• June 2008 Citiworks ruling by European Court of Justice
questioned legitimacy of private wire.
• Now - private wire still permitted, for new schemes
access must be given to other suppliers, for existing
schemes access must be given where practicable i.e. a
private wire market is in most cases no longer captive.
• Business models usually now assume all electricity
exported is sold at wholesale rates.
CRC and CHP
• Organisations operating CHPs are responsible for the
CO2 emissions associated with the fuel consumed –
electricity generation credits can be claimed.
• Organisations purchasing CHP generated electricity
should rate it at the grid CO2 rate.
• Heat supplied from CHP is zero rated for CO2.
• ROCs or FiTs cannot be claimed if CRC benefit is
claimed.
Cost of Reducing CO2
- £100
- £50
£0
£ 50
£100
£150
£200
C R C 3 M W w in d
t u r b in e
1 0 0 k W w in d
t u r b in e
B io m a s s
b o ile r
( c o m p a r e d t o
o il)
B io m a s s
b o ile r
( c o m p a r e d t o
g a s )
3 M W e g a s
C H P ( n o d h )
3 M W e g a s
C H P ( 1 3 k m
dh)
4 0 0 k W
b io m a s s O RC
C H P ( 1 3 k m
dh)
C
o
st
(
£
/
t
C
O
2
I n d i ca t i v e C o s t s o f R edu ci n g C O
2
E m i s s i o n s
* no allowance made for ROCs, FiTs or RHI revenue
)
Feed-in Tariffs and Renewable Heat Incentive
• No FiTs for CHP.
• Renewable CHP can still claim ROC certificates.
• RHI proposes to fund useful heat (including process
heat) supplied.
• RHI may provide a district heating tariff - tbc.
Gas CHP Rules of Thumb
• Minimum recommended housing density > 50
dwellings per hectare.
• Installed cost for CHP is £450 – 1500 /kWe (not
including the network).
• Installed cost of CHP + heating network is approx
£3000 to £8000 per dwelling served.
• Minimum economically viable operating hours 3,500
– 4,000/year.
Proportion of primary fuel turned into useful
energy
Source: CHPA
Conclusions
• CHP can reduce CO2 emissions and costs
• The extent depends on the energy load density and the
technology selected.
• The denser the load, the greater the benefit.
• Real economies of scale can be realised.
• Cash flows are complex.
• Network economics and regulation are critical.
• A number of procurement options exist but the
ESCo market is immature and risk averse.
The End
Any Questions?
Justin Wimbush
Arup
Telephone: 020 7755 4196
Email: justin.wimbush@arup.com
Engineering the Future
CHP - A Carbon Reduction Tool – Case
Study
Introduction
• Neil Adcock
• 42 year old Chartered Engineer
• BREEAM Assessor
• Over 20 years experience in both
contracting and consulting
• Experience of delivery of projects in the
Industrial, Education, Health and Social
Housing market
CHP – A Carbon Reduction Tool – Case Study
Contents
• Project Background
• Planning Considerations
• Strategic Approach
• Integrating Renewables
• Constructing an Energy Usage Profile
• Selection of CHP
• Commercial Considerations
• Predicted Performance
• Conclusions and Summary
CHP - A Carbon Reduction Tool – Case Study
Project Background
• Client is a Housing Association
• Redevelopment of existing estate within
Kensington & Chelsea
• Providing up to 1100 dwellings, small
amount of commercial offices and retail
• A mixture of social housing & private -
maximum height is 12 storey
• Over a site of 42518m2, a density of 1 person
per 19m2
CHP – A Carbon Reduction Tool – Case Study
Planning
Considerations
• All dwellings in initial phases
to meet Code 4 Sustainable
homes - in excess of the
London Plan
• Future proofing to Code 6
• Requirements of the London
plan
• Decentralised Energy generation
• 20% renewables
• RBKC Urban Development Plan
and Supplementary Planning
Documents
• Location of plant exhausts and
noise sources
CHP – A Carbon Reduction Tool – Case Study
Strategic Approach
BE LEAN- Increase u values and adopt
passive measure to reduce carbon usage
BE CLEAN- Maximise the efficiency of
engineering systems such as energy
efficient lighting and combined heat and
power to reduce carbon usage further
BE GREEN- Install 20% of appropriate
renewables, i.e. ones that meet the planning
constraints and compliment proposed
engineering systems
CHP – A Carbon Reduction Tool – Case Study
Integrating Renewables
Wind - local wind speeds not
favourable, negative planning impact
Biomass/Biofuel - Space not
available for site storage, transport of
fuel to site an issue
GSHP - insufficient space available on
site
ASHP - insufficient space on site
negative planning impact on elevations
Solar Thermal - insufficient roof
space available and this technology is
at odds with CHP
Solar PVC - preferred option as the
required area can be found at roof
level & the FIT assists in the meeting
of commercial concerns
CHP – A Carbon Reduction Tool – Case Study
Constructing a energy Usage
Profile
To optimise the size of the CHP we need
to construct an energy profile this was
achieved by:
• Using the clients likely occupancy
patterns based on existing housing
data
• Utilising the BRE`s Domestic Energy
Model
• Modelling the performance of the
buildings with an IES thermal model
• Exploring the opportunities for local
heat network via the GLA`s heat
mapping models
CHP – A Carbon Reduction Tool – Case Study
Selection of CHP
The selection of the optimum size of
CHP was based around the following
considerations:
• The summertime base energy load –
domestic hot water demand
• The opportunities for exporting heat
to local surroundings does not exist
at this time
• The provision of a thermal store is
used to flatten the daily profile and
thus increase viable CHP size
• No Summertime heat dumping is to
be implemented
• The CHP is to have a Quality Index in
excess of 100 as defined by CHPQA
CHP – A Carbon Reduction Tool – Case Study
Commercial Considerations
Given the considerations previously stated the
solution we have arrived at is as follows:
• A 400 kWe /465kWT gas fired CHP
• 150 000 litre Thermal Store split across the site
between central and local storage
• With a district heating system to meet the
heating and hot water needs of the
development
• Phased to match the project procurement
programme and give future possibilities of heat
networking
• Integrating with roof mounted PVC`s to meet
the renewables requirement
• The site generated electricity shall be utilised
for landlord services with any excess being
exported to the grid, thus maximising the
benefit of the FIT
CHP – A Carbon Reduction Tool – Case Study
Predicted Performance
• Carbon reduction against Building Regs 2006
• Lean = 7% reduction
• Clean = 38% reduction
• Green= 50% reduction
CHP - A Carbon Reduction Tool – Case Study
Lean GreenClean
Summary
• Project Background
• Planning Considerations
• Strategic Approach
• Integrating Renewables
• Constructing an Energy Usage Profile
• Selection of CHP
• Commercial Considerations
• Predicted Performance
• Conclusions and Summary
CHP - A Carbon Reduction Tool – Case Study
Engineering the Future
Thank you for your time
Any Questions?