1. Section 5: Energy Balance Table Dr. Congxiao Shang Room No.: 01 37P ENV-2D02 (2006):Energy Conservation – power point versions of lectures

2. Main Objectives To understand the different areas of energy conservation using the energy balance table: To learn how to analyse energy use in a location from 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 The waste in converting energy into the form we want Minimum

3. 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

4. 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. 5.1 Introduction What knowledge we can obtain from an energy balance table ?  Energy Balance Tables allow us to estimate the magnitude of the former waste.  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.

6. 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 MTCE = million tonnes of coal equivalent 1 tonne of oil equivalent = 42GJ 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

7. 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)

8. Line F is the delivered energy available, which represents the main energy balance Line F = Line A + Line B + Line C –Line D – Line E Delivered energy available Net energy available Transfer Amount of energy used in supply industries Energy consumed in the conversion Transmission losses

9. 5.3 Derived statistics Efficiency of Electricity Conversion Overall efficiency of energy conversion and transmission Primary energy ratios for oil and gas

10. 6. Heat Transfer – Part 1 Thank you