Transcript Low Carbon Strategies - University of East Anglia

Visit by Representatives of Norwegian
Municipalities
11th September 2008
Low Carbon Strategies:
Experience of the University of East Anglia
Recipient of James Watt Gold Medal
5th October 2007
CRed
Carbon 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
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Original buildings
Teaching wall
Library
Student
residences
Nelson Court
Constable Terrace
Low Energy Educational Buildings
Medical School Phase 2
ZICER
Elizabeth Fry
Building
Nursing and
Midwifery
School
Medical School
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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5
250
gas
200
kWh/m2/yr
150
100
50
0
Elizabeth Fry
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Heating/Cooling
Hot Water
Electricity
120
2
electricity
Energy Consumption kWh/m /annum
Conservation: management improvements –
Low
Average
User Satisfaction
thermal comfort +28%
air quality
+36%
lighting
+25%
noise
+26%
A Low Energy Building is
also a better place to work in
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80
60
40
20
0
1995 1996 1997 1998 1999 2000 2001 2002 2003 2004
Careful Monitoring and Analysis can reduce energy
consumption.
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ZICER Building
Low Energy Building of the Year Award 2005 awarded
by the Carbon Trust.
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
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The ground floor
open plan office
The first floor
open plan office
The first floor
cellular offices
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Operation of Main Building
Mechanically ventilated using hollow core slabs as air supply ducts.
Regenerative heat exchanger
Incoming
air into the
AHU
Operation of Main Building
Filter
Heater
Air passes through
hollow cores in the
ceiling slabs
Air enters the internal occupied space
Operation of Main Building
Recovers 87% of Ventilation
Heat Requirement.
Space for future
chilling
Out of the
building
Return air passes through
the heat exchanger
Return stale air is extracted
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.
Warm air
Winter
Day
Warm air
Heat is transferred to
the air before entering
the room
Slabs store heat from
appliances and body
heat
Air Temperature is
same as building
fabric leading to a
more pleasant
working
environment
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.
Cool air
Winter
Night
Cool air
Heat is transferred to
the air before entering
the room
Slabs also radiate heat
back into room
In late afternoon
heating is turned
off.
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.
Cold air
Summer
night
Cold air
Draws out the heat
accumulated during the
day
Cools the slabs to act as
a cool store the
following day
night ventilation/
free cooling
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.
Warm air
Summer
day
Warm air
Slabs pre-cool the air
before entering the
occupied space
concrete absorbs and stores
heat less/no need for airconditioning
Energy Consumption (kWh/day)
Good Management has reduced Energy Requirements
Space Heating
Consumption
reduced by 57%
1000
800
800
600
400
350
O
200
0
-4
-2
0
2
4
6
8
10
12
14
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Mean |External Temperature (oC)
Original Heating Strategy
New Heating Strategy
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Life Cycle Energy Requirements of ZICER as built compared to
other heating/cooling strategies
54%
Naturally
Ventilated
221508GJ
28%
51%
Air Conditioned
384967GJ
34%
As Built
209441GJ
Materials Production
Materials Transport
On site construction energy
Workforce Transport
Intrinsic Heating / Cooling energy
Functional Energy
Refurbishment Energy
Demolition Energy
29%
61%
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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
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Poly- crystalline on façade ~ 6/7 kW in 3 arrays
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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Use of PV generated energy
Peak output is 34 kW
Sometimes electricity is exported
Inverters are only 91% efficient
Most use is for computers
DC power packs are inefficient
typically less than 60% efficient
Need an integrated approach
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Conversion efficiency improvements – Building Scale CHP
3% Radiation Losses
11%
61% Flue
Flue Losses
Losses
36%
GAS
efficient
Engine
Generator
36%
Electricity
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Conversion efficiency improvements – Building Scale CHP
3% Radiation Losses
11% Flue Losses
Exhaust
Heat
Exchanger
86%
GAS
efficient
Localised generation
makes use of waste heat.
Reduces conversion
losses significantly
Engine
Engine heat Exchanger
Generator
36%
Electricity
50% Heat
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UEA’s Combined Heat and Power
3 units each generating up to 1.0 MW electricity and 1.4 MW
heat
Conversion efficiency improvements
Before installation
1997/98
MWh
electricity
gas
oil
19895
35148
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Total
Emission factor
kg/kWh
0.46
0.186
0.277
Carbon dioxide
Tonnes
9152
6538
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Electricity
After installation
1999/
Total
CHP export
2000
site generation
MWh 20437 15630
977
Emission kg/kWh
-0.46
factor
CO2
Tonnes
-449
15699
Heat
import boilers CHP
oil
total
5783
14510 28263 923
0.46
0.186
0.186 0.277
2660
2699
5257 256 10422
This represents a 33% saving in carbon dioxide
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Conversion efficiency improvements
Load Factor of CHP Plant at UEA
Demand for Heat is low in summer: plant cannot be used effectively
More electricity could be generated in summer
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Conversion Efficiency Improvements
Normal Chilling
Heat rejected
High
Temperature
High Pressure
Compressor
Condenser
Throttle
Valve
Evaporator
Heat extracted
for cooling
Low
Temperature
Low Pressure
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Conversion Efficiency Improvements
Adsorption Chilling
Heat rejected
Heat from external
source
High Temperature
High
High Pressure
Temperature
High Pressure
Desorber
Heat
Exchanger
Condenser
Throttle
Valve
W~0
Evaporator
Absorber
Heat extracted
for cooling
Low Temperature
Low
Low Pressure
Temperature
Low Pressure
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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
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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
wood and local sustainable
sources
• Will reduce Carbon Emissions of
UEA by a further 35%
Results of the “Big Switch-Off”
Target Day
With a concerted effort savings of 25% or more are possible
How can these be translated into long term savings?
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On average each person in UK causes the
emission of over 9 tonnes of CO2 each
year. In Norway 8 tonnes per person
5 hot air balloons per person per year.
In the developing world, the average is
under 1 balloon per person
How many people know what 9
tonnes of CO2 looks like?
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
"Nobody made a greater mistake than
he who did nothing because he
thought he could do only a little."
Edmund Burke (1727 – 1797)
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Energy Consumption (kWh/day)
A Pathway to a Low Carbon Future for business
1000
800
600
400
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200
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4
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10
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Mean |External Temperature ( C)
Original Heating Strategy
1.
Awareness
2.
New Heating Strategy
Management
5. Offsetting
Green Tariffs
4.
Renewable Energy
3.
Technical Measures
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Sharing the Expertise of the University
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
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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?
"If you do not change direction, you may end up where
you are heading."
Lao Tzu (604-531 BC) Chinese Artist and Taoist philosopher
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