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1
Sustainability Issues
Energy Science Director HSBC Director of Low Carbon InnovationCRed
Carbon Reduction
BreckLand District Council30th July 2007
CRed
Keith Tovey (杜伟贤 ) MA, PhD, CEng, MICE, CEnv
Acknowledgement: Karla Alcantar
2
• Background• Issues of Sustainable Building Construction/
Occupation – Thermal Performance issues
• Future Proofing Buildings - Fabric Cooling?– Management of Building Energy Use– Behaviour of the Occupants
• Renewable Energy and Integration of Design
• Life Cycle issues
• Transport Issues• Conclusions
Sustainability Issues
• Background• Issues of Sustainable Building Construction/
Occupation – Thermal Performance issues
• Future Proofing Buildings - Fabric Cooling?– Management of Building Energy Use– Behaviour of the Occupants
• Renewable Energy and Integration of Design
• Life Cycle issues
• Transport Issues• Conclusions
3
19792003
Climate ChangeArctic meltdown 1979 - 2003
• Summer ice coverage of Arctic Polar Region– Nasa satellite
imagery
Source: Nasa http://www.nasa.gov/centers/goddard/news/topstory/2003/1023esuice.html
•20% reduction in 24 years
4
Actual Nuclear
Projected Nuclear
Actual Coal with FGD
Opted Out Coal
Renewables
New Nuclear?
New Coal ???
0
10000
20000
30000
40000
50000
60000
2000 2005 2010 2015 2020 2025 2030
MW
• Opted Out Coal: Stations can only run for 20 000 hours more and must close by 2015• New Nuclear assumes completing 1 new nuclear station each year beyond 2016• New Coal assumes completing 1 new coal station each year beyond 2016
Our Choices: They are difficult: Energy Security
There is a looming capacity shortfall
Even with a full deployment of
renewables.
A 10-15% reduction in demand per
house will see a rise of 7% in total demand
5
Renewable Electricity Generation in GB
Renewable Generation represented 4.2% of final demand in 2005
6
Renewable Electricity Generation in GB by Region
7
Renewable Electricity Generation by type and County in EEDA Region
The output from Scroby Sands is sufficient to provide 95% of domestic demands of Norwich and Ipswich combined or 30% of demand on average
8
% Renewables
Rank of all districts ex 284
Notes
Breckland 41.45% 11th 36.6% from Thetford
Great Yarmouth 38.05% 12th 36.1% from Scroby
Mid Suffolk 19.12% 27th 15.9% from Eye
GB Average 4.20%
Broadland 4.09% 93rd
Ipswich 2.91% 116th
Norwich 2.59% 129th
Waveney 2.22% 143rd
King's Lynn and West Norfolk 1.45% 170th
South Norfolk 1.31% 175th
St Edmundsbury 1.05% 185th
Forest Heath 0.99% 189th
North Norfolk 0.68% 205th
Babergh 0.00% 284th =
Suffolk Coastal 0.00% 284th =
Proportion of Electricity Consumption provided by Renewables: Norfolk and Suffolk Districts
9
• Background• Issues of Sustainable Building Construction/
Occupation – Thermal Performance issues
• Future Proofing Buildings - Fabric Cooling?
– Management of Building Energy Use– Behaviour of the Occupants
• Renewable Energy and Integration of Design
• Life Cycle issues
• Transport Issues• Conclusions
Sustainability Issues
10
• Thermal performance has improved with better insulation.
• With better fabric insulation, ventilation can represent up to 80+% of heating energy requirements.
• Careful design of ventilation is needed
• lower capital costs vs lower environmental running costs.
• Are ESCO’s a way forward?
• Provide optional environmentally efficient systems within all new buildings.
• Improved control – Smart (Sub) Metering
• Is traditional Cost Benefit Analysis the correct way to appraise low carbon systems?
should insurance issues also be considered?
Thermal Performance Issues: Future Proofing
11
The Climate Dimension
Heating requirements are ~10+% less than in 1960
Cooling requirements are 75% higher than in 1960.
Changing norm for clothing from a business suite to shirt and tie will reduce “clo” value from 1.0 to ~ 0.6.
To a safari suite ~ 0.5.
Equivalent thermal comfort can be achieved with around 0.15 to 0.2 change in “clo” for each 1 oC change in internal environment.
Thermal Comfort is important: Even in ideal environment 2.5% of people will be too cold and 2.5% will be too hot.
Estimate heating and cooling requirements from Degree Days
60
80
100
120
140
160
180
1960-1964
1965-1969
1970-1974
1975-1979
1980-1984
1985-1989
1990-1994
1995-1999
2000-2004
Heating
Cooling
Index 1960 = 100
12
Fabric Cooling using Hollow Core Slabs
The concrete hollow core ceiling slabs are used to store heat and coolness at different times of the year to provide comfortable and stable temperatures
Cold air
Cold air
Draws out the heat accumulated during
the dayCools the slabs to act as a cool store the following day
Summer night
night ventilation/ free cooling
13
Warm air
Warm air
Pre-cools the air before entering the
occupied space
The concrete absorbs and stores
the heat – like a radiator in reverse
Summer day
Fabric Cooling using Hollow Core Slabs
The concrete hollow core ceiling slabs are used to store heat and coolness at different times of the year to provide comfortable and stable temperatures
No air conditioning is needed even though the norm would have been to install air-conditioning
In future, with Global Warming, when air-conditioners may be installed, they will be run over night to pre-cool building and improve efficiency of chillers
14
• Ground Source Heat Pumps are an effective route to low carbon heating – can save 50 – 60% of carbon emissions.
• Work most efficiently with under floor heating.
• Can be used with fabric pre-cooling in summer with very modest air-conditioning
• Can be to provide some inter-seasonal heat store
– i.e. reject heat in summer to acquifer/ground – recover during winter. There is ~ 3 months thermal lag in peak temperature in ground corresponding with early heating season use, and much improved coefficients of performance.
Heat Pumps: A solution for a Low Carbon Future
15
• Background• Issues of Sustainable Building Construction/
Occupation – Thermal Performance issues
• Future Proofing Buildings - Fabric Cooling?
– Management of Building Energy Use– Behaviour of the Occupants
• Renewable Energy and Integration of Design
• Life Cycle issues
• Transport Issues• Conclusions
Sustainability Issues
16
• Heating energy requirement is strongly dependant on External Temperature.
• Thermal Lag in Heavy Weight Buildings means consumption requirements lags external temperature.
• Correlation with temperature suggests a thermal lag of ~ 8 hours.
• Potential for predictive controls based on weather forecasts
0
20
40
60
80
100
120
140
160
180
-2 0 2 4 6 8 10 12 14 16 18 20
Mean External Temperature (oC)
Gas
Con
sum
ptio
n (k
Wh/
day)
0.840.850.860.870.880.890.9
0.910.920.93
0 2 4 6 8 10 12 14 16 18 20 22 24
Time Lag (hours)
Coe
ffic
ient
of
Cor
rela
tion
Thermal Properties of Buildings
Data collected 10th December 2006 – April 29th 2007
17
The Elizabeth Fry Building 1994
Cost ~6% more but has heating requirement ~25% of average building at time.
Building Regulations have been updated: 1994, 2002, 2006, but building outperforms all of these.
Runs on a single domestic sized central heating boiler.
18
0
50
100
150
200
250
Elizabeth Fry Low Average
kWh/
m2/
yr
gas
electricity
User Satisfaction
lighting +25%
air quality +36%
A Low Energy Building is also a better place to work in
Careful Monitoring and Analysis can reduce energy consumption.
Conservation: management improvements –
thermal comfort +28%
noise +26%
19
The Energy Signature from the Old and the New Heating Strategies
0
200
400
600
800
1000
-4 -2 0 2 4 6 8 10 12 14 16 18
Mean external temperature over a 24 hour period (degrees C)
Hea
tin
g an
d h
ot-w
ater
co
nsu
mp
tion
(k
Wh
/day
)
New Heating Strategy Original Heating Strategy
The space heating consumption has reduced by 57%
Good Management has reduced Energy Requirements
800
350
Acknowledgement: Charlotte Turner
20
The Management Dimension:
0
1000
2000
3000
4000
5000
6000
0 100 200 300 400
Degree Days
Hea
t Req
uire
men
t (M
Wh)
• Good Management will analyse data and use bands to identify anomalous behaviour.
• Management Quality Index one standard deviation/mean
0% - very poor control100% - perfect control
• UEA: Low amount of scatter Management Quality index: 88%
• Office in Norwich: 72%• Other Offices in East Anglia: 57%,
69%.
UEA Heat Demand
Office Building in Norwich
-10,000
0
10,000
20,000
30,000
40,000
50,000
0 100 200 300 400
Degree Days
Co
ns
um
pti
on
(k
Wh
)
Example of Good Management
Example of less good Management
21
• Background• Issues of Sustainable Building Construction/
Occupation – Thermal Performance issues
• Future Proofing Buildings - Fabric Cooling?
– Management of Building Energy Use– Behaviour of the Occupants
• Renewable Energy and Integration of Design
• Life Cycle issues
• Transport Issues• Conclusions
Sustainability Issues
22
• Household size has little impact on electricity consumption.
• Consumption varies by up to a factor of 9 for any given household size.
• Allowing for Income still shows a range of 6 or more.
• Education/Awareness is important
0
100
200
300
400
500
600
700
Gol
den
Triang
le
Mile
Cro
ss
Upper
Hell
esdon
Laken
ham
Eaton
Rise
Tucks
wood
Bowth
orpe
kW
h/m
onth
0
200
400
600
800
1000
1200
0 1 2 3 4 5 6 7
No. people
Ave
rage
kW
h/m
onth
Average Norwich
Electricity Consumption
Data from 114 houses in Norwich
23
Target Day
Results of the “Big Switch-Off”
With a concerted effort savings of 25% or more are possibleHow can these be translated into long term savings?
24
Social Awareness Impact on Climate Change
25
• Background• Issues of Sustainable Building Construction/
Occupation – Thermal Performance issues
• Future Proofing Buildings - Fabric Cooling?
– Management of Building Energy Use– Behaviour of the Occupants
• Renewable Energy and Integration of Design
• Life Cycle issues
• Transport Issues• Conclusions
Sustainability Issues
26Annual Solar Gain 910 kWh
Solar Collectors installed 27th January 2004
Options for Renewable Energy: Solar Thermal
27
Options for Renewable Energy: Solar Thermal
• Performance of an actual solar collector 9th December 2006 – 2nd May 2007
• Average gain (over 3 years) is 2.245 kWh per day
• Central Heating Boiler rarely provides Hot Water from Easter to ~ 1st October
• More Hot Water used – the greater amount of solar energy is gained
• Optimum orientation for solar hot water collectors for most houses is NOT due South
Solar Gain (kWh/day)
0
12
3
4
56
7
8
10 17 24 31 7 14 21 28 4 11 18 25 4 11 18 25 1 8 15 22 29
Day of Month
Sol
ar G
ain
(k
Wh
) DecemberJanuaryFebruaryMarchAprilMay
28
Options for Renewable Energy: Solar Photovoltaic
Data based on Actual ZICER Building PV Costs
Actual Situation excluding Grant
Actual Situation with Grant
Discount rate 3% 5% 7% 3% 5% 7%
Unit energy cost per kWh (£) 1.29 1.58 1.88 0.84 1.02 1.22
Avoided cost exc. the Grant
Avoided Costs with Grant
Discount rate 3% 5% 7% 3% 5% 7%
Unit energy cost per kWh (£) 0.57 0.70 0.83 0.12 0.14 0.16
29
ZICER Building
Photo shows only part of top
Floor
• Top floor is an exhibition area – also to promote PV
• Windows are semi transparent
• Mono-crystalline PV on roof ~ 27 kW in 10 arrays
• Poly- crystalline on façade ~ 6/7 kW in 3 arrays
30
Arrangement of Cells on Facade
Individual cells are connected horizontally
As shadow covers one column all cells are inactive
If individual cells are connected vertically, only those cells actually in shadow are affected.
Options for Renewable Energy: Solar Photovoltaic
31
Sometimes electricity is exportedInverters are only 91% efficient
Most use is for computers
DC power packs are inefficient typically less than 60% efficientNeed an integrated approach
Peak output is 34 kW
Options for Renewable Energy: Solar Photovoltaic
32
– Potential to substantially reduce CO2 emissions
– Significant reduction is losses from transmission
• but – problem of heat disposal in summer
– Does not make sense to provide CHP with solar hot water heaters
• Consider using absorption chilling to provide cooling where required
Options for Low Carbon Technologies: Micro CHP
33
• Background• Issues of Sustainable Building Construction/
Occupation – Thermal Performance issues
• Future Proofing Buildings - Fabric Cooling?
– Management of Building Energy Use– Behaviour of the Occupants
• Renewable Energy and Integration of Design
• Life Cycle issues
• Transport Issues• Conclusions
Sustainability Issues
34
• Life Cycle Issues – an issue in Sustainability– Does local sourcing of materials necessarily lead to a low
carbon construction?– In case of PV it emits LESS CO2 if cells are manufactured in
Spain and transported to UK! – despite the transport!!!!– Need to be aware of how fuel mix used for generation of
electricity affects CO2.• UK ~ 0.52 kg/kWh, Spain ~ 0.46 kg/kWh• France ~ 0.06 kg/kWh
• To what extent does embodied carbon from construction and demolition affect total carbon emission?– Example: ZICER Building
Sustainability in Building and Occupation
35
As Built 209441GJ
Air Conditioned 384967GJ
Naturally Ventilated 221508GJ
Life Cycle Energy Requirements of ZICER as built compared to other heating/cooling strategies
Materials Production
Materials Transport
On site construction energy
Workforce Transport
Intrinsic Heating / Cooling energy
Functional Energy
Refurbishment Energy
Demolition Energy
28%54%
34%51%
61%
29%
36
0
50000
100000
150000
200000
250000
300000
0 5 10 15 20 25 30 35 40 45 50 55 60
Years
GJ
ZICER
Naturally Ventilated
Air Conditrioned
Comparison of Life Cycle Energy Requirements of ZICER
Compared to the Air-conditioned office, ZICER recovers extra energy required in construction in under 1 year. 0
20000
40000
60000
80000
0 1 2 3 4 5 6 7 8 9 10
Years
GJ
ZICER
Naturally Ventilated
Air Conditrioned
Comparisons assume identical size, shape and orientation
37
• Background• Issues of Sustainable Building Construction/
Occupation – Thermal Performance issues
• Future Proofing Buildings - Fabric Cooling?
– Management of Building Energy Use– Behaviour of the Occupants
• Renewable Energy and Integration of Design
• Life Cycle issues
• Transport Issues• Conclusions
Sustainability Issues
38
• Car: 5 door Toyota Yaris
• Real performance is best at ~ 50 mph. Saves up to 15% in fuel consumption cf 70 mph.
• Driver 2 has a fuel consumption 8% higher over mid range of speeds
0
10
20
30
40
50
60
70
80
0 10 20 30 40 50 60 70
Average Speed (mph)
(m
pg)
Driver 1
Driver 2
0
0.5
1
1.5
2
2.5
3
3.5
4
02/Jun 22/Jun 12/Jul 01/Aug 21/Aug 10/Sep 30/Sep
km/lt
r
Driver 1
Driver 2
Driver behaviour trials at Banham Poultry
• Driver behaviour affects performance• Driver 2 uses 13.8% more fuel
The Transport Dimension: Behavioural Issues
Yaris: Journey Norwich to Newcastle & return
Driver 1 would save ~ 10+% or 4+ litres of petrol
Extra time per journey < 20 minutes
39
• Distance each tonne has travelled has increased by:– 223% since 1960– 20% since 1990
• Is this increase in movement of freight conducive to optimum economic growth, energy security, and carbon reduction?
0
10
20
30
40
50
60
70
80
90
100
1960 1965 1970 1975 1980 1985 1990 1995 2000 2003
Tran
spor
t of g
oods
km
/tonn
e
Car travel (2004 statistics):• 679 billion passenger kilometres• 398 billion vehicle kilometres
Average occupancy 1.71. (cf 1.81 in 1980)
Raising occupancy to 1980 level would save 3.71 Mtonnes CO2
Raising occupancy to 2 would save 9.9 Mtonnes CO2
The Transport Dimension: Cultural Issues
www.liftshare.com
40
Storeys = 2 & options
Mapping Consumption automatically in existing buildings
41
Mapping Consumption automatically in existing buildings
42
Sustainable Buildings require:• Initial sound design addressing: high insulation standards,
effective control of ventilation: Attention to Future Proofing.• Integration of use of building with provision of services.• Avoidance of combining novel technologies which are
incompatible.• Use of most sustainable materials: Local provision of materials is
NOT ALWAYS best – careful Life Cycle Assessments are needed. • Provision of optional extras for all buildings including renewable
technologies etc perhaps with alternative financing methods.• Provision of SMART sub metering to inform the user.• Improvements in training of users where newer technologies are
used.• a need for awareness raising.
Conclusions
Lao Tzu (604-531 BC) Chinese Artist and Taoist philosopher
"If you do not change direction, you may end up where you are heading."
43
Sustainability Issues
Energy Science Director HSBC Director of Low Carbon InnovationCRed
Carbon Reduction
BreckLand District Council30th July 2007
CRed
Keith Tovey (杜伟贤 ) MA, PhD, CEng, MICE, CEnv
Acknowledgement: Karla Alcantar
This presentation is now accessible on the WEB at:
www2.env.uea.ac.uk/cred/creduea.htm