Section 5: Energy Balance Table
Dr. Congxiao Shang
Room No.: 01 37P
ENV-2D02 (2006):Energy Conservation –
power point versions of lectures
Main Objectives
To learn how to analyse energy use in a location from the
energy balance table;
To understand the different areas of energy conservation
using the energy balance table:
What are the areas that are closely related to energy conservation ?
Losses in
conversion to
secondary fuels
Losses to
distribution of
secondary
fuels
Minimum
The waste in
converting
energy into the
form we want
Secondary fuel: The form of energy generated by conversion of
primary energies, e.g. petroleum from oil, coke from coal, electricity from
gas, nuclear energy, oil etc.
Energy flow graph
5.1 Introduction
What is energy balance?
An aggregate summary of energy consumption,
conversion, and production in an area
Energy balances can be displayed as a standard
format – an Energy Balance Table, a chart, or
an energy flow diagram.
Webpage:
http://forums.seib.org/leap/webhelp/views/ene
rgy_balance_view.htm
5.1 Introduction
What knowledge we can obtain from an energy
balance table ?
 Energy Balance Tables are constructed to show the energy
flows within a country. They provide a useful summary on a
yearly basis to assess where energy losses are occurring.
 Energy Balance Tables allow us to estimate the magnitude
of the former waste.
5.1 Introduction
Energy Balance Tables are best constructed based on heat
supply. The units of calorific values can be different:
1 Millions of Therms = 0.1055 PJ
MTOE = million tonnes of oil equivalent
1 tonne of oil equivalent = 42GJ
MTCE = million tonnes of coal equivalent
1 tonne of coal equivalent = 29.3GJ
Note: check out the calorific value (CV) clearly when
comparing one country with another
UK Energy Statistics now use higher CV
In the Energy balance table:
All energy extracted in primary form is: positive
All energy imports: positive
All energy exports: negative
5.2
Let’s use an energy balance table as an example. The table
is derived from the aggregated Table 1.1 in DUKES (2001)
which gives data for 2000.
(DUKES: Digest of United Kingdom Energy Statistics)
(http://www.dti.gov.uk/energy/inform/dukes/index.shtml)
Line F is the delivered energy available, which
represents the main energy balance
Energy
consumed in
the conversion
Net energy
available
Transmission
losses
Line F = Line A + Line B + Line C –Line D – Line E
Delivered
energy available
Transfer
Amount of energy
used in supply
industries
5.3 Derived statistics
• Efficiency of Electricity Conversion
• Overall efficiency of energy conversion
and transmission
• Primary energy ratios for oil and gas
6. Heat Transfer – Part 1
Thank you