4.2 Scenario-based approach
4.2.2 Identification of data required and compilation of a database
The data that were necessary to determine the energy consumption by fuel/energy type for the different sectors, subsectors and end-uses were obtained from the SoER and the GHG Inventory 2005/2006.
However, where missing gaps could be filled, data were acquired from other sources.
Households
For the household sector the total energy consumed by fuel type was taken from the SoER, except for electricity consumption, which was taken from eThekwini Electricity, as this was found to be more accurate. This is because the eThekwini Electricity is the direct source of electricity consumption and the SoER and GHG Inventory based their information on different start and end dates for the year. The energy types consumed were broken down into lighting, heating and cooking using the Stats SA Community Survey (2007), which provides the percentage of households that use a particular fuel type for different end-uses, as shown in Table 4.1. The study by Simmonds and Mammon (1996) was used to break down electricity, biomass and LPG consumption into end-uses and the study by Robert and Wentzel (2006) was used to determine average paraffin consumption by end-use.
Table 4.1: Percentage of households by type of energy/fuel for cooking, heating and lighting consumed
Energy Source Cooking (%) Heating (%) Lighting (%)
Electricity 82.7 80.8 87.2
Paraffin 14.8 10.3 3.4
Wood 1.3 4.4 0.0
Gas 1.1 0.5 0.1
Coal 0.1 0.2 0.0
Candles 0.0 0.0 8.9
Other 0.0 3.8 0.4
Source: Stats SA (2007)
Industrial and commercial sector
For this sector it was necessary to determine the energy consumption by fuel/energy type for the manufacturing and commercial sectors separately. The GHG Inventory and the SOE were used to determine the total energy consumed for this sector. Gaps in this sector were however identified. The GHG Inventory assumed that all bulk electricity falls under the manufacturing sector and the SOE did not differentiate between the manufacturing and the commercial and service sector. Therefore a list of approximately 750 of the largest electricity consumers was obtained from eThekwini Electricity (Table
4.2) and was broken down into the manufacturing industries and commercial and service sectors (Appendix 1). This illustrated that the commercial and service sector used more electricity than previously assumed.
The other missing gap was that the GHG Inventory and the SOE based coal consumption on an estimate.
According to Antoni (2007) there is a need for a database of coal consumption and distribution in the Durban area. A list of coal consumption for Durban was obtained from the Natal Associated Collieries (Table 4.2), which was also divided into manufacturing consumption and commercial and services consumption (Appendix 2).
Furthermore, the GHG Inventory assumed all other fuels such as LPG, HFO, paraffin and Sasol methane rich gas (MRG) were consumed in the manufacturing sector. Springlights, which is a supplier of Sasol gas in the eThekwini area, was contacted to determine the breakdown of MRG consumption for Durban.
It was confirmed that MRG is only consumed in the manufacturing sector. LPG consumption was broken down based on informal telephonic interviews with the LPG Association, an LPG distributor and the Energy Research Centre (ERC) in Cape Town (Table 4.2). It was assumed that approximately 75% of LPG was consumed in the industrial, commercial and service sector, primarily by hotels and restaurants and 25% was consumed in the residential sector. Additionally, as in the GHG Inventory, it was assumed that all HFO and paraffin was consumed in the manufacturing sector (Appendix 2).
Other fuel types, which include bagasse, biomass and refinery gas, are all consumed within the manufacturing sector.
In order to determine the energy intensity (GJ/R ‘000), GDP data were needed, which were provided by the Economic Development Unit (Table 4.2). These data included recorded GDP per sector for Durban from 1996 to 2008, and forecasted GDP for 2009-2013 (Appendix 3). Once the fuels consumed were distributed into the manufacturing and commercial subsectors, the energy intensity of these subsectors was calculated using the following equation:
Energy Intensity (GJ/ R 1000) = Total Energy Utilised (GJ) by subsector/ GDP of subsector (R '000)
Table 4.2: List of distributors or organisations contacted and the data received Distributor /
Organisation
Contact person/Author
Date Contacted
Information obtained ELECTRICITY
eThekwini Electricity
Nyaniso Mlilo 2009/03/09 Electricity consumption of the top 750 electricity consumers (which represents 70%
of the electricity consumed in the industrial and commercial sector). Total electricity consumption for main sectors.
LPG
Afrox (Handigas) Steven Ferreira 2009/04/01 Stated that the main sectors that consume LPG are the hospitality, manufacturing and low- income households.
LPG Association Bob De Lange 2009/03/31 Stated that the LPG Association kept no records of the distribution of LPG, but observed that large quantities of LPG are consumed by hotels and restaurants.
Energy Research Centre (ERC)
Andrew Marquard 2009/05/19 Estimated that approximately 50% of total LPG is consumed in the industrial and commercial sector and the other 50% is consumed in the residential sector.
COAL
Natal Associated Collieries
Garth Loades 2009/04/16 Provided a detailed breakdown of the coal distribution in Durban.
METHANE RICH GAS
Springlights Pradashnee Govindsamy
2009/03/26 According to Ms Govindsamy all MRG in Durban is consumed in the manufacturing sector, primarily in the South Durban area.
BAGASSE
Tongaat-Hulett Allan Ferguson 2009/08/18 Provided data of bagasse used to generate electricity and the calorific value of the bagasse.
ECONOMIC DATA eThekwini Economic
Development Unit
Denny Thaver 2009/01/21 Provided detailed GDP data for eThekwini (1997-2008) and South Africa (2000-2008) Provided population data for eThekwini Provided data on growth trends in the economic sector.
Local Authority
The data used for the local authority sector were taken from the GHG Inventory 2005/2006. This sector was divided into municipal buildings, street and traffic lights, water and sewage, vehicle fleet and distribution losses. Waste is not included as the scope of the project involved focusing on emissions as a result of energy consumption.
Transport
The fuel consumption for road transport was taken from the GHG Inventory, and is based on the total fuel sold within the municipal area. This was not divided further into end-uses due to a lack of data on vehicle kilometres travelled by vehicle type within the municipal area. The methodology applied is consistent with the Tier 1 approach as stipulated in the 2006 IPCC Guidelines for National Greenhouse Gas Inventories (IPCC, 2006).
Fuel consumed for marine transport was obtained from the National Ports Authority , which includes jet fuel, diesel and petrol. The main activities that fall within this sector are dredging, the tug boats and the container sector. The jet fuel consumed by the harbour helicopters was also included in the marine fuel consumption (Appendix 2.2).
Lastly, estimates for air transport fuel consumption were taken from the GHG Inventory 2005/2006.
Limitations and assumptions
Assumptions, based on information gained from informal interviews with key informants, were made in order to distribute these fuels into subsectors. The assumptions were:
Heavy fuel oil is utilised only within the manufacturing sector to operate boilers,
75% of total LPG is consumed in the industrial and commercial sector and 25% in the residential sector. This was based on conversations with Andrew Marquard, Bob de Lange and Steven Ferreira (Table 4.2).
20% of total paraffin consumption in Durban is consumed in the industrial and commercial sector, whilst the remaining 80% is consumed in the residential sector.
The transport services subsector consists solely of air, rail and water transport, due to difficulties in allocating liquid fuel consumption for freight and passenger transport by road. Freight and passenger transport was incorporated in the transport sector.