1 Sustainability Issues Energy Science Director HSBC Director of Low Carbon Innovation CRed Carbon Reduction BreckLand District Council 30 th July 2007.

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

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• 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




• Future Proofing Buildings - Fabric Cooling?– Management of Building Energy Use– Behaviour of the Occupants




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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

http://www.nasa.gov/centers/goddard/news/topstory/2003/1023esuice.html

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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

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Renewable Electricity Generation in GB

Renewable Generation represented 4.2% of final demand in 2005

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Renewable Electricity Generation in GB by Region

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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

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% 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

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• Future Proofing Buildings - Fabric Cooling?

– Management of Building Energy Use– Behaviour of the Occupants





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• 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

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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

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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

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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

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• 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

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• 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

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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.

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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%

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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

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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

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• 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

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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?

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Social Awareness Impact on Climate Change

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26Annual Solar Gain 910 kWh

Solar Collectors installed 27th January 2004

Options for Renewable Energy: Solar Thermal

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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

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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

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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

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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.


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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


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– 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

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• 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

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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%

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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

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• 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

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• 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

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Storeys = 2 & options

Mapping Consumption automatically in existing buildings

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Mapping Consumption automatically in existing buildings

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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."

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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

1 Sustainability Issues Energy Science Director HSBC Director of Low Carbon Innovation CRed Carbon Reduction BreckLand District Council 30 th July 2007.

Documents

insurance issues

future proofing slide

average slide

occupants renewable

total demand slide

cooling requirements

heating energy requirements

karla alcantar slide