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BEAM P
LUS FOR
N
EW
B
UILDINGS
A
PPENDICES
V
ERSION
1.2
8.3 E
QUIVALENT
C
ARBON
D
IOXIDE
E
MISSIONS
12Copyright © 2012 BEAM Society Limited. All rights reserved.
A - 12
8.3 E
QUIVALENT
C
ARBON
D
IOXIDE
E
MISSIONS
There are at present two power companies generating and selling
electricity to consumers in Hong Kong. One of the power companies
uses primarily coal for generating electricity but the other uses natural
gas as well. The carbon dioxide emission per unit electricity consumed,
therefore, depends on from which power company the electricity was
generated. For the purpose of converting electricity consumption into the
equivalent carbon dioxide emission for BEAM assessment, an average
value, weighted by the market shares of the two power companies, is
used irrespective of from which power company an Assessed Building
will be fed with electricity supply. Besides electricity, buildings in Hong
Kong may also use gas for water heating, cooking and other purposes.
Majority of the buildings use town gas but buildings in certain areas may
use natural gas instead.
Where a mix of fuel is used in an existing building, such as a hotel, the
energy performance assessment will be based on the incurred carbon
dioxide emission rather than the amount of energy used. The followings
show the conversion factors to be used for this purpose:
E
LECTRICITY
0.7 kg CO
2
per kWh electricity consumed [1]
T
OWN GAS
0.592 kg CO
2
per unit of town gas consumed [1]
(1 unit of town gas = 48 mega-joules consumed)
N
ATURAL GAS
2.31 kg CO
2
per kg of natural gas consumed
1
Environmental Protection Department. Guidelines to Account for and Report on Greenhouse Gas Emissions and
Removals for Buildings (Commercial, Residential or Institutional Purposes) in Hong Kong, 2008
http://www.epd.gov.hk/epd/english/climate_change/files/CAGuidelines_Eng.pdf