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Low Carbon Strategies:Experience of the University of East Anglia
Visit by Representatives of Norwegian Municipalities
11th September 2008
CRedCarbon Reduction
N.K. Tovey (杜伟贤 ) M.A, PhD, CEng, MICE, CEnv Н.К.Тови М.А., д-р технических наук
Energy Science Director CRed Project
HSBC Director of Low Carbon Innovation
Recipient of James Watt Gold Medal5th October 2007
Original buildings
Library
Student residences
Teaching wall
Nelson Court
Constable Terrace
Low Energy Educational Buildings
Nursing and Midwifery School
Elizabeth Fry Building
ZICER
Medical School
Medical School Phase 2
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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.
66
Conservation: management improvements –
Careful Monitoring and Analysis can reduce energy consumption.
0
50
100
150
200
250
Elizabeth Fry Low Average
kWh/
m2/
yr
gas
electricity
thermal comfort +28%User Satisfaction
noise +26%
lighting +25%
air quality +36%
A Low Energy Building is also a better place to work in
0
20
40
60
80
100
120
140
1995 1996 1997 1998 1999 2000 2001 2002 2003 2004
Ene
rgy
Con
sum
ptio
n kW
h/m
2 /ann
um Heating/Cooling Hot Water Electricity
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ZICER Building
Heating Energy consumption as new in 2003 was reduced by further 50% by careful record keeping, management techniques and an adaptive approach to control.
Incorporates 34 kW of Solar Panels on top floor
Low Energy Building of the Year Award 2005 awarded by the Carbon Trust.
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The ground floor open plan office
The first floor open plan office
The first floor cellular offices
Incoming air into
the AHU
Regenerative heat exchanger
Operation of Main BuildingMechanically ventilated using hollow core slabs as air supply ducts.
Air enters the internal occupied space
Filter Heater
Air passes through hollow
cores in the ceiling slabs
Operation of Main Building
Return stale air is extracted
Return air passes through the heat exchanger
Out of the building
Operation of Main Building
Recovers 87% of Ventilation Heat Requirement.
Space for future chilling
Fabric Cooling: Importance of Hollow Core Ceiling Slabs
Hollow core ceiling slabs store heat and cool at different times of the year providing comfortable and stable temperatures.
Heat is transferred to the air before entering
the room
Slabs store heat from appliances and body
heat
Winter Day
Air Temperature is same as building fabric leading to a more pleasant working environment
Warm air
Warm air
Fabric Cooling: Importance of Hollow Core Ceiling Slabs
Hollow core ceiling slabs store heat and cool at different times of the year providing comfortable and stable temperatures.
Heat is transferred to the air before entering
the room
Slabs also radiate heat back into room
Winter Night
In late afternoon heating is turned off.
Cool air
Cool air
Fabric Cooling: Importance of Hollow Core Ceiling Slabs
Hollow core ceiling slabs store heat and cool at different times of the year providing comfortable and stable temperatures.
Draws out the heat accumulated during the
day
Cools the slabs to act as a cool store the following day
Summer night
night ventilation/ free cooling
Cold air
Cold air
Fabric Cooling: Importance of Hollow Core Ceiling Slabs
Hollow core ceiling slabs store heat and cool at different times of the year providing comfortable and stable temperatures.
Slabs pre-cool the air before entering the
occupied spaceconcrete absorbs and stores heat less/no need for air-
conditioning
Summer day
Warm air
Warm air
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200
400
600
800
1000
-4 -2 0 2 4 6 8 10 12 14 16 18
Mean |External Temperature (oC)
En
ergy
Con
sum
pti
on (
kW
h/d
ay)
Original Heating Strategy New Heating Strategy
O
Good Management has reduced Energy Requirements
800
350
Space Heating Consumption reduced by 57%
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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%
1818
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
1919
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.
2020
Use of PV generated energy
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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EngineGenerator
36% Electricity
GAS
11% Flue Losses3% Radiation Losses
Conversion efficiency improvements – Building Scale CHP
61% Flue Losses
36%
efficient
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EngineGenerator
36% Electricity
50% Heat
GAS
Engine heat Exchanger
Exhaust Heat
Exchanger
11% Flue Losses3% Radiation Losses
86%
efficient
Localised generation makes use of waste heat.
Reduces conversion losses significantly
Conversion efficiency improvements – Building Scale CHP
UEA’s Combined Heat and Power
3 units each generating up to 1.0 MW electricity and 1.4 MW heat
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Conversion efficiency improvements
1997/98 electricity gas oil Total
MWh 19895 35148 33
Emission factor kg/kWh 0.46 0.186 0.277
Carbon dioxide Tonnes 9152 6538 9 15699
Electricity Heat
1999/2000
Total site
CHP generation
export import boilers CHP oil total
MWh 20437 15630 977 5783 14510 28263 923Emission
factorkg/kWh -0.46 0.46 0.186 0.186 0.277
CO2 Tonnes -449 2660 2699 5257 256 10422
Before installation
After installation
This represents a 33% saving in carbon dioxide
2525
Conversion efficiency improvements
Load Factor of CHP Plant at UEA
Demand for Heat is low in summer: plant cannot be used effectivelyMore electricity could be generated in summer
2626
Conversion Efficiency Improvements
Condenser
Evaporator
Throttle Valve
Heat rejected
Heat extracted for cooling
Normal Chilling
Compressor
High
TemperatureHigh
Pressure
Low TemperatureLow Pressure
2727
Condenser
Evaporator
Throttle Valve
Heat rejected
Heat extracted for cooling
High TemperatureHigh Pressure
Low TemperatureLow Pressure
Heat from external source
Absorber
Desorber
Heat Exchanger
W ~ 0
Adsorption Chilling
Conversion Efficiency Improvements
High Temperature
High Pressure
Low TemperatureLow Pressure
2828
A 1 MW Adsorption chiller
• Adsorption Heat pump uses Waste Heat from CHP
• Will provide most of chilling requirements in summer
• Will reduce electricity demand in summer
• Will increase electricity generated locally
• Save 500 – 700 tonnes Carbon Dioxide annually
The Future: Advanced Gasifier Biomass CHP Plant
UEA has grown by over 40% since 2000 and energy demand is increasing.
• New Biomass Plant will provide an extra 1.4MWe , and 2MWth
• Will produce gas from waste wood which is then used as fuel for CHP plant
• Under 7 year payback
• Local wood fuel from waste rom waste wood and local sustainable wood and local sustainable sourcessources
• Will reduce Carbon Emissions of UEA by a further 35%
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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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How many people know what 9 tonnes of CO2 looks like?
5 hot air balloons per person per year.
In the developing world, the average is under 1 balloon per person
On average each person in UK causes the emission of over 9 tonnes of CO2 each year. In Norway 8 tonnes per person
"Nobody made a greater mistake than he who did nothing because he thought he could do only a little."
Edmund Burke (1727 – 1797)
10 gms of carbon dioxide has an equivalent volume of 1 party balloon.
At Gao’an No 1 Primary School in Xuhui District, Shanghai
School children at the Al Fatah University, Tripoli, Libya
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A Pathway to a Low Carbon Future for business
4. Renewable Energy
5. Offsetting
Green Tariffs
3. Technical Measures
1. Awareness
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1000
-4 -2 0 2 4 6 8 10 12 14 16 18
Mean |External Temperature (oC)
En
ergy
Con
sum
pti
on (
kW
h/d
ay)
Original Heating Strategy New Heating Strategy
O
2. Management
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World’s First MBA in Strategic Carbon Management
First cohort January 2008
A partnership between
The Norwich Business School and the 5** School of Environmental Sciences
Sharing the Expertise of the University
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Conclusions• Buildings built to low energy standards have cost ~ 5% more,
but savings have recouped extra costs in around 5 years.
• Ventilation heat requirements can be large and efficient heat recovery is important.
• Effective adaptive energy management can reduce heating energy requirements in a low energy building by 50% or more.
• Photovoltaic cells need to take account of intended use of electricity use in building to get the optimum value.
• Building scale CHP can reduce carbon emissions significantly
• Adsorption chilling should be included to ensure optimum utilisation of CHP plant.
• Promoting Awareness can result in up to 25% savings
• The Future for UEA: Biomass CHP Wind Turbines?
Lao Tzu (604-531 BC) Chinese Artist and Taoist philosopher
"If you do not change direction, you may end up where you are heading."
