Carbon Reduction Strategies at the University of East Anglia NBS-M017 - 2013 N.K. Tovey ( 杜伟贤 ) M.A, PhD, CEng, MICE, CEnv Н.К.Тови М.А., д-р технических.

Carbon Reduction Strategies at the University of East Anglia

NBS-M017 - 2013

N.K. Tovey ( 杜伟贤 ) M.A, PhD, CEng, MICE, CEnv

Н.К.Тови М.А., д-р технических наукSchool of Environmental Sciences / Norwich

Business School

Recipient of James Watt Gold Medal2007

2

Original buildings

Teaching wall

Library

Student residences

Nelson Court

Constable Terrace

4

Low Energy Educational Buildings

Elizabeth Fry Building

ZICER

Nursing and Midwifery

School

Medical School4

Medical School Phase 2

Thomas Paine Study Centre

5

The Elizabeth Fry Building 1994

8

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.

Would have scored 13 out of 10 on the Carbon Index Scale.

6

Constable Terrace - 1993

• Four Storey Student Residence

• Divided into “houses” of 10 units each with en-suite facilities• Heat Recovery of body and cooking

heat ~ 50%.

• Insulation standards exceed 2006 standards

• Small 250 W panel heaters in individual rooms.

Electricity Use

21%

18%

17%

18%

14%

12%

Appliances

Lighting

MHVR Fans

MHVR Heating

Panel Heaters

Hot Water

Carbon Dioxide Emissions - Constable Terrace

0

20

40

60

80

100

120

140

UEA Low Medium

Kg

/m2 /y

r

7

Educational Buildings at UEA in 1990s

Queen’s Building 1993 Elizabeth Fry Building 1994

Elizabeth Fry Building Employs Termodeck principle and uses ~ 25% of Queen’s Building

8

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

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.

The ZICER Building –Main part of the building

• High in thermal mass • Air tight• High insulation standards • Triple glazing with low emissivity ~ equivalent to quintuple glazing

10

The first floor open plan office

The first floor cellular offices

1111

Operation of Main Building Mechanically ventilated that utilizes hollow core ceiling slabs as supply air ducts to the space

Regenerative heat exchangerIncoming

air into the AHU

1212

Air enters the internal occupied space空气进入内部使用空间

Operation of Main Building

Air passes through hollow cores in the

ceiling slabs空气通过空心的板层

Filter过滤器

Heater加热器

1313

Operation of Main Building

Recovers 87% of Ventilation Heat Requirement.

Space for future chilling

将来制冷的空间 Out of the building出建筑物

Return stale air is extracted from each floor 从每层出来的回流空气

The return air passes through the heat

exchanger空气回流进入热交换器

1414

Operation of Regenerative Heat Exchangers

Fresh Air

Stale AirA

B

Stale air passes through Exchanger A and heats it up before exhausting to atmosphere

Fresh Air is heated by exchanger B before going into building

14

1515

Fresh Air

Stale Air

B

A

Stale air passes through Exchanger B and heats it up before exhausting to atmosphere

Fresh Air is heated by exchanger A before going into building

After ~ 90 seconds the flaps switch over

Operation of Regenerative Heat Exchangers

15

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.

热量在进入房间之前被传递到空气中板层储存来自于电器以及人体发出的热量

Winter Day

Air Temperature is same as building fabric leading to a more pleasant working environment

Warm air

Warm air

16

Heat is transferred to the air before entering the room

Slabs also radiate heat back into room

热量在进入房间之前被传递到空气中

板层也把热散发到房间内

Winter Night

In late afternoon

heating is turned off.

Cold air

Cold air



17

Draws out the heat accumulated during the day

Cools the slabs to act as a cool store the following day

把白天聚积的热量带走。冷却板层使其成为来日的冷存储器

Summer night

night ventilation/ free cooling

Cool air

Cool air



18

Slabs pre-cool the air before entering the occupied space

concrete absorbs and stores heat less/no need for air-conditioning

空气在进入建筑使用空间前被预先冷却混凝土结构吸收和储存了热量以减少 / 停止对空调的使用

Summer day

Warm air

Warm air



19

2020

0

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

Good Management has reduced Energy Requirements

800

350

Space Heating Consumption reduced by 57%

原始供热方法新供热方法

建造209441GJ

使用空调384967GJ

自然通风221508GJ

Life Cycle Energy Requirements of ZICER compared to other buildings

与其他建筑相比 ZICER 楼的能量需求

Materials Production 材料制造 Materials Transport 材料运输On site construction energy 现场建造Workforce Transport 劳动力运输Intrinsic Heating / Cooling energy

基本功暖 / 供冷能耗Functional Energy 功能能耗Refurbishment Energy 改造能耗Demolition Energy 拆除能耗

28%54%

34%51%

61%

29%

21

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

Life Cycle Energy Requirements of ZICER compared to other buildings

Compared to the Air-conditioned office, ZICER as built 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

22

• Mono-crystalline PV on roof ~ 27 kW in 10 arrays• Poly- crystalline on façade ~ 6.7 kW in 3 arrays

ZICER Building

Photo shows only part of top

Floor

23

242424

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.

Cells active

Cells inactive even though not covered by shadow

24

02040

6080

100120140

160180200

9 10 11 12 13 14 15Time of Day

Wh

01020

3040506070

8090100

%

Top Row

Middle Row

Bottom Row

radiation

0

10

20

30

40

50

60

70

80

90

100

9 10 11 12 13 14 15Time of day

Wh

0

10

20

30

40

50

60

70

80

90

100

%

Block1

Block 2

Block 3

Block 4

Block 5

Block 6

Block 7

Block 8

Block 9

Block 10

radiation

All arrays of cells on roof have similar performance respond to actual solar radiation

The three arrays on the façade respond differently

Performance of PV cells on ZICER

25

0

2

4

6

8

10

12

14

16

18

20

8.00 9.00 10.00 11.00 12.00 13.00 14.00 15.00 16.00

Elev

ation

in th

e sky

(deg

rees)

120 150 180 210 240Orientation relative to True North 26

0

5

10

15

20

25

6.00 7.00 8.00 9.00 10.00 11.00 12.00 13.00 14.00 15.00 16.00Time (hours)

Elev

ation

in th

e sky

(deg

rees)

January February March AprilMay June July AugustSeptember October November DecemberP1 - bottom PV row P2 - middle PV row P3 - top PV row

27

Use of PV generated energy

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

Peak output is 34 kW 峰值 34 kW

28

Original Way Heat was supplied to UEA campus

29

• Three 8MW oil fired boilers - 83 – 85% efficient on full load, but only ~25% on low load.

• Heat distributed via ~ 4 km of pipe work which was originally poorly insulated leading to losses of 500 kW or more – now ~ 200 kW.

• ~ 1984 small 4 MW boiler added for use at times of low demand

• 1987 all boilers converted to run on either gas or oil

• 1998 – one boiler removed and 3 CHP units installed

• 2004 – absorption chiller installed to provide cooling throughout campus

EngineGenerator

36% Electricity

50% Heat

Gas

Heat Exchanger

Exhaust Heat

Exchanger

11% Flue Losses3% Radiation Losses

86%

Localised generation makes use of waste heat.

Reduces conversion losses significantly

Conversion efficiency improvements – Building Scale CHP

61% Flue Losses

36%

30

31

UEA’s Combined Heat and Power

3 units each generating up to 1.0 MW electricity and 1.4 MW heat

32

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

32

333333

• Low Energy Buildings

• Effective Adaptive Energy Management

• Photovoltaics

• Combined Heat and Power

• Absorption Chilling

• Advanced CHP using Biomass Gasification

• World’s First MBA in Strategic Carbon Management

Low Energy Buildings

Photo-Voltaics

Efficient CHP Absorption Chilling

Trailblazing to a Low Carbon Future

Low Energy Buildings

3434

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

34

A typical Air conditioning/Refrigeration Unit

节流阀Throttle Valve

冷凝器

绝热

Condenser

Heat rejected

蒸发器

为冷却进行热提取

Evaporator

Heat extracted for cooling

高温高压

High TemperatureHigh Pressure

低温低压

Low TemperatureLow Pressure

Compressor

压缩器

35

Absorption Heat Pump

Adsorption Heat pump reduces electricity demand and increases electricity generated

节流阀Throttle Valve

冷凝器

绝热

Condenser

Heat rejected

蒸发器

为冷却进行热提取

Evaporator

Heat extracted for cooling

高温高压

High TemperatureHigh Pressure

低温低压

Low TemperatureLow Pressure

外部热

Heat from external source

W ~ 0

吸收器

吸收器

热交换器

Absorber

Desorber

Heat Exchanger

36

37

A 1 MW Adsorption chiller

1 MW 吸附冷却器

• Reduces electricity demand in summer

• Increases electricity generated locally

• Saves ~500 tonnes Carbon Dioxide annually

• Uses Waste Heat from CHP

• provides most of chilling requirements in summer

The Future: Biomass Advanced Gasifier/ Combined Heat and Power

38

• Addresses increasing demand for energy as University expands

• Will provide an extra 1.4MW of electrical energy and 2MWth heat• Will have under 7 year payback• Will use sustainable local wood fuel mostly from waste from saw

mills• Will reduce Carbon Emissions of UEA by ~ 25% despite increasing student numbers by 250%

3939

Photo-Voltaics

Advanced Biomass CHP using GasificationEfficient CHP Absorption Chilling


4040

1990 2006 Change since 1990

2011 Change since 1990

Students 5570 14047 +152% 16000 +187%

Floor Area (m2) 138000 207000 +50% 220000 +159%

CO2 (tonnes) 19420 21652 +11% 14000 -28%

CO2 kg/m2 140.7 104.6 -25.7% 63.6 -54.8%

CO2 kg/student 3490 1541 -55.8% 875 -74.9%

Efficient CHP Absorption Chilling


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?

41

42

UEA’s Pathway to a Low Carbon Future: A summary

5. Offset Carbon Emissions

0

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

2. Good Management

3. Improving Conversion Efficiency

1. Raising Awareness

4. Using Renewable Energy

43

Conclusions

UEA has achieved Carbon reductions by:

• Constructing Low Energy Buildings• Effective adaptive energy management which has typically

reduced energy requirements in a low energy building by 50% or more.

• Use of Renewable Energy: Photovoltaic electric generation but opportunities were missed which would have made

more optimum use of electricity generated.• The existing CHP plant reduced carbon emissions by

around 30%• Adsorption chilling has been a win-win situation reducing

summertime electricity demand and increasing electricity generated locally.

• Awareness raising of occupants of buildings can lead to significant savings

• By the end of 2013, UEA should have reduced its carbon emissions per student by 70% compared to 1990.

Carbon Reduction Strategies at the University of East Anglia NBS-M017 - 2013 N.K. Tovey ( 杜伟贤 ) M.A, PhD, CEng, MICE, CEnv Н.К.Тови М.А., д-р технических.

Documents