Assessing the Carbon Footprint of the University of Portsmouth Residential Buildings and Identifying how it can be Reduced

ContextClimate change is an important reality of today’s society. As about half of the CO2 emitted by human activity since the industrial revolution has remained in the atmosphere (1), World governments and Non-Government Organisations (NGOs) have produced agreements such as the Agenda 21, Montreal Protocol and Kyoto Agreement to reduce anthropogenic emissions to ‘a level which would prevent dangerous anthropogenic interference with the climate system’(2).

In compliance with the Carbon Reduction Commitment (CRC) energy efficiency scheme, the University of Portsmouth has committed to reducing its carbon emissions by 30% by 2016 (3).

As buildings are responsible for 40% of the GHG emissions, the energy efficiency of the University buildings is a key area for achieving the 30% reduction target(4).

MethodIn order for the carbon emissions and energy efficiency of the buildings to be assessed the electricity and gas consumptions had to be obtained from the University of Portsmouth Estates department.

CIBSE StandardsThe energy efficiency of the buildings was calculated by dividing the average of the total annual electricity and gas consumptions between 2008 and 2011, by the gross floor area of the building (kW h m-2 per year). These values were then compared to the CIBSE standards of ‘good’ and ‘typical’ energy rates for that building type(5).

Carbon EmissionsThe total electricity and gas consumptions between the years 2008 and 2011 were converted into carbon equivalent figures by multiplying the totals by conversion factors of 0.5246kgCO2e for electricity and 0.1836kgCO2e for gas(6).

Degree-dataThe monthly electricity and gas consumptions between the years 2008 and 2010 were plotted against the degree data figures published by the Carbon Trust and based at 15.5°C. (7)(8)

AuditsThe energy audits were compiled based on CIBSE guidelines and encompassed all forms of energy use within the buildings.(5) The audits were carried out in cooperation with environmental management and halls supervisors.

DiscussionFigure 1 and 2 show that Margaret Rule and Trafalgar halls are consuming far more electricity (m2 y-

1) than would be typical, and only Harry Law hall is achieving ‘good’ or ‘typical’ energy consumption (m2 y-1) for both electricity and gas. This may be due to the how CIBSE standards are calculated, the age of the building, amount of occupants and ambient conditions are not considered in the calculations, and may dramatically influence the energy consumption of the buildings.

Figure 3 demonstrates that although between 2008 and 2011 there has been a slight decrease in the CO2 emissions, this has not been uniform. The high CO2 emissions of 2010 may be due to two particularly cold winters within this year. This is reinforced by Figures 4-8 as the degree data shows a 99.9% significance (p<0.001) between the ambient temperature and the energy consumption. This can be combated by an increase in insulation and heating system efficiencies to reduce the dependence of energy consumption on weather conditions.

Figures 4-8 also show a slightly curved relationships throughout, this may mean that there is poor temperature control within the buildings which is leading to waste, the Owner Occupancy Schemes currently in place and the efficiency of heating and electrics may be a target to reduce the wasted energy.

Audits revealed that trial occupancy detector lights and other technologies are being run to potentially reduce the affect of occupants.

References(1) The Royal Society. (2010). Climate Change: A Summary of the Science [Electronic version]. London: Royal Society. (2) United Nations. (2012). United Nations: Framework Convention on Climate Change: Article 2. Retrieved February 8, 2012, from http://unfccc.int/essential_background/convention/background/items/1353.php (3) McCormack, I. (2010). Green Portsmouth. Retrieved January 26, 2012, from http://www.port.ac.uk/departments/services/greenportsmouth/targetsandstatistics/ (4) Houghton, J. (2009). Global Warming: The Complete Briefing (4th ed.). New York: Cambridge University Press. (5) Chartered Institution of Building Services Engineers. (2004). Energy efficiency in Buildings, CIBSE Guide F. Norwich: CIBSE Publications Department. (6) Carbon Trust. (2011). Conversion Factors. London: Carbon Trust. (7) Carbon Trust. (2010). Degree Days for Energy Management. London: Carbon Trust. (8) Carbon Trust. (2010). Historical UK Degree Days Data. London: Carbon Trust. Plates (1) University of Portsmouth. (2009). Bateson Hall. Retrieved February 26, 2012, from http://www.flickr.com/photos/universityofportsmouth/3698503784/. (2) University of Portsmouth. (2009). Harry Law Hall. Retrieved February 26, 2012, from http://www.flickr.com/photos/universityofportsmouth/3698503930/. (3) University of Portsmouth. (2009). Margaret Rule Hall. Retrieved February 26, 2012, from http://www.flickr.com/photos/universityofportsmouth/3698505322/. (4) University of Portsmouth. (2010). Rees Hall. Retrieved February 26, 2012, from http://commons.wikimedia.org/wiki/File:University_of_Portsmouth_Rees_Hall.JPG. (5) University of Portsmouth. (2009). Trafalgar Hall. Retrieved February 26, 2012, from http://www.flickr.com/photos/universityofportsmouth/3698503520/.

Conclusion and Further WorkThe data show that the University of Portsmouth Residential buildings are consuming higher levels of energy than is recommended by CIBSE levels. The degree data and audits show that occupants of the halls of residence may be a key factor in reducing the energy consumption, and enable the 30% decrease in carbon emissions by 2016.

Assessments of how insulation and heating efficiency can be improved, along with occupant’s awareness, would be key to decreasing the carbon emissions.

Plate 1. Bateson Hall Plate 4. Rees HallPlate 3. Margaret Rule HallPlate 2. Harry Law Hall Plate 5. Trafalgar Hall

451718University of Portsmouth

AimThis project aims to suggest ways to improve the efficiency of the residential buildings. The principal objectives are: ◦to determine the energy efficiency of the University of Portsmouth residential buildings and compare them to the Chartered Institution for Building Services Engineers (CIBSE) standards. ◦to identify potential areas for improvement by conducting energy audits and analysing the energy use compared to the ambient temperature (degree-data analysis). ◦to investigate and suggest methods of increasing efficiency and thereby decreasing carbon emissions.

Margaret Rule Hall Trafalgar Hall0

20

40

60

80

100

120

140

160

180

Building

Av

era

ge

Ele

ctr

icit

y C

on

su

mp

tio

n B

etw

ee

n 2

00

8-2

01

1

(kW

m2

y-1

)

Figure 1. Shows the Average Electricity Use of Residential Buildings between 2008 and 2011 compared to CIBSE Benchmarks (kW m2 y-1)

Figure 3. Shows the CO2 Emissions of Selected Residential Buildings for the Years 2008-2011.

Figure 2. Shows the Average Electricity and Gas Use of Residential Buildings between 2008 and

2011 compared to CIBSE Benchmarks (kW m2 y-1)

Bateson Hall Harry Law Hall Rees Hall0

50

100

150

200

250

300

Electricity

Fossil Fuel

Buildings

Av

era

ge

En

erg

y C

on

su

mp

tio

n b

etw

ee

n 2

00

8 a

nd

20

11

(k

W m

2 y

-1)

2008 2009 2010 20110

100000

200000

300000

400000

500000

600000

700000

800000

Bateson

Harry Law

Margaret Rule

Rees

Trafalgar

Ca

rbo

n E

mis

sio

ns

(k

g C

O2

e)

0 50 100 150 200 250 300 350 400 450 5000

50000

100000

150000

200000

250000

f(x) = − 0.646547786637926 x² + 602.174056360634 x + 27799.1226418558R² = 0.859718268098961

Degree-Data

To

tal

En

erg

y C

on

su

mp

tio

n (

kW

h)

0 50 100 150 200 250 300 350 400 450 5000

20000

40000

60000

80000

100000

120000

140000

160000

180000

f(x) = − 0.850887033893495 x² + 611.879227213032 x + 26797.633243685R² = 0.830137567464391

Degree-Data

To

tal

En

erg

y C

on

su

mp

tio

n (

kW

h)

0 50 100 150 200 250 300 350 400 450 5000

50000

100000

150000

200000

250000

f(x) = − 0.473257069702876 x² + 542.391628402036 x + 48517.2272552572R² = 0.885799745610274

Degree-Data

To

tal

En

erg

y C

on

su

mp

tio

n (

kW

h)

Figure 4. Shows the Total Energy Consumption against Degree Data for Bateson Hall (kW h)

Figure 5. Shows the Total Energy Consumption against Degree Data for Harry Law Hall (kW h)

Figure 6. Shows the Total Energy Consumption against Degree Data for Margaret Rule Hall (kW h)

0 50 100 150 200 250 300 350 400 450 5000

50000

100000

150000

200000

250000

300000

350000

400000

450000

500000

f(x) = − 1.19215497821526 x² + 1237.71818548957 x + 72092.9782322312R² = 0.855124426267617

Degree-Data

To

tal

En

erg

y C

on

su

mp

tio

n(k

W h

)

Results

0 50 100 150 200 250 300 350 400 450 5000

20000

40000

60000

80000

100000

120000

140000

160000

180000

200000

f(x) = − 0.293444849500452 x² + 453.380469307015 x + 33475.7276646447R² = 0.912890242867248

Degree-Data

To

tal

En

erg

y C

on

su

mp

tio

n (

kW

h)

Figure 7. Shows the Total Energy Consumption against Degree Data for Trafalgar Hall (kW h)

Figure 7. Shows the Total Energy Consumption against Degree Data for Rees Hall (kW h)