1Generation capacity and energy share in South Africa in 2010 and in 2030a. http://sajs.co.za/index.php/SAJS/article/downloadSuppFile/603/3058
2Generation life cycle cost of various generation technologies compared with the current and future (2030) generation mix.11http://sajs.co.za/index.php/SAJS/article/downloadSuppFile/603/3059
Liquid fuel Unlike in most other countries where crude oil is the only source for petrol and diesel, a significant amount of liquid fuel consumed in South Africa is made from coal and natural gas by way of coal-to-liquid and gas-to-liquid processes, from which Sasol and PetroSA have contributed close to 36% of the total liquid fuel market.14 There is no report available for South Africa that analyses the life cycle emissions of synthetic liquid fuel, which are very different from those of conventional fuel. Synthetic liquid fuel produced via the Fischer–Tropsch process has a very low sulphur content (less than five parts per million), which is lower than the sulphur content requirement in the current fuel quality standards.15,16 When carbon capture and sequestration technology is not applied, the life cycle carbon emission from synthetic fuel is higher than that of conventional liquid fuel.17 The NOx and particulate emissions from an engine using synthetic fuel are close to, or lower than, those of conventional fuel.18,19 Because of a lack of detail regarding the life cycle assessment of synthetic liquid fuels, as well as to simplify the calculation, we assumed in this study that the introduction of electric vehicles in South Africa will initially replace only the market share of the imported conventional liquid fuel that is made from crude oil. Emissions from synthetic liquid fuel are therefore not included in this study. The environmental standards for liquid fuel quality in South Africa are low. The current refineries in South Africa produce petrol and diesel based on the dated Euro III specifications, which are reflected in SANS 1598:2006 for petrol and SANS 342:2006 for diesel. The sulphur content of petrol and standard diesel is set at 500 mg/kg. The sulphur content of high-quality diesel is set at 50 mg/kg, but this diesel is available in only some parts of the country. There has been commitment from the South African Petroleum Industry Association to progress towards Euro IV-compliant fuel, which has a sulphur content of 50 mg/kg,20 or even Euro V-compliant fuel, which has a sulphur content of 10 mg/kg.21 It is presumed in this study that the sulphur content of petrol and diesel in South Africa in 2030 will meet the Euro V-compliant standard, which is less than 10 mg/kg. The emissions from light passenger vehicles in South Africa are regulated in SANS 20083:2007, which is equivalent to the Euro III standards.22 It was presumed in this study that the Euro VI-compliant23 emission standards will apply in South Africa in 2030. The relevant emission limits are listed in Table 3. There is no report on the overall petroleum refining and distribution efficiency in South Africa. A study conducted in Europe reports an energy consumption of 0.155 MJ/MJ with 14 g CO2eq/MJ emissions for diesel fuel and an energy consumption of 0.125 MJ/MJ with 12 g CO2eq/MJ emissions for petrol.17 Crude oil refining accounts for most of the energy costs and the CO2 emissions. These values were adopted in our calculations for 2010. A 20% efficiency increase was estimated for 2030, which gives an amount of 11 g CO2eq/MJ for diesel. These emission estimations are obviously different from that in South Africa and our calculations should be reconsidered when the local value is available. The SOx, NOx and particulate emissions during the refining and distribution of liquid fuel are unknown and were not considered in this study.
3Emission standards for light passenger cars. http://sajs.co.za/index.php/SAJS/article/downloadSuppFile/603/3060
Fuel efficiency The National Association of Automobile Manufacturers of South Africa provides the fuel efficiency and carbon emission data of all the cars in the South African market on its website.24 The fuel consumption for 1.6 L – 1.8 L petrol-engine light passenger cars is close to 7 L/100 km, with CO2 emissions close to 165 g/km. The fuel consumption for 1.6 L – 1.8 L diesel-engine light passenger cars is close to 5.2 L/100 km, with CO2 emissions close to 135 g/km. The fuel efficiency and CO2 emission values used in this study were therefore, respectively, 7 L/100 km and 165 g/km for petrol engines and 5.2 L/100 km and 135 g/km for diesel engines. The only hybrid petrol passenger car in South Africa is the Toyota Prius Hybrid. The fuel efficiency of the Prius is 4.1 L/100 km, with CO2 emissions of 94 g/km.24 The Prius has a special design for better fuel efficiency and therefore cannot be used here for comparison. There is no report available on the on-road efficiency of other petrol hybrid electric vehicles and electric vehicles in South Africa. The first South African made electric vehicle, Joule, is expected to be available in 2013.25 The Joule is a light passenger car with five seats and a 230 km to 300 km range. It can be regarded as comparable to the 1.6 L – 1.8 L conventional fuel light passenger cars, but the energy consumption of the Joule has not yet been released on its manufacturer’s website. The ratios of the fuel efficiency values of hybrid electric vehicles, electric vehicles and conventional vehicles in the Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) Model26 were adopted on the basis of the same class of vehicle, as well as the same driving conditions. At the moment, there are no regulations for CO2 emissions in South Africa, and therefore no regulations for the fuel efficiencies of vehicles. The European Union had a voluntary agreement with the European Automobile Manufacturers Association, which was to achieve a fleet average for CO2 emissions of 140 g/km (equivalent to 5.8 L/100 km for petrol) in 2008 for new passenger cars. This target was not achieved. The ultimate target is now 130 g/km CO2 emissions for all new passenger cars by 2015. The European Union is pushing for a new target of 95 g/km for a new car fleet average in 2020.27 In this study, we assumed that by 2030, petrol-engine light passenger cars in South Africa will have achieved the CO2 emission target of 130 g/km (5.6 L/100 km for petrol). The fuel efficiencies of the diesel-engine vehicles, petrol hybrid, and electric vehicles for 2030 were adjusted according to the fuel efficiency ratio in 2010. The rated fuel consumptions of conventional petrol internal combustion engine vehicles (ICEVs), diesel ICEVs, petrol hybrid electric vehicles and electric vehicles are listed in Table 4.
4Assumptions of fuel efficiency and CO2 emissions of light passenger vehicles. http://sajs.co.za/index.php/SAJS/article/downloadSuppFile/603/3061
Comparison The life cycle CO2, SOx, NOx and particulate matter emissions (PM) for vehicles are listed in Table 5. The analysis from GREET indicates that more than 97% of the SOx emissions for electric vehicles are from electricity generation. Only SOx emissions from electricity generation were considered in our calculations and only NOx and PM emissions from electricity generation were considered for electric vehicle pollution in this calculation. The CO2 equivalent (CO2eq) was also listed. The CO2eq is calculated as the CO2 emission plus the CO2eq of NOx. The global warming potential of NOx is 298, which is used in the Fourth Assessment Report (AR4) of the Intergovernmental Panel on Climate Change.28CO2 emissions It has been shown that when the current grid in South Africa is used to charge electric vehicles, there is an increase in CO2 emissions of between 17% and 64%. The actual increase in CO2 emissions by electric vehicles might be less than this amount because there are many inefficient cars on the roads in South Africa. Petrol hybrid vehicles perform the best with respect to CO2 emissions, with a 30% reduction in CO2 emissions; the adoption of petrol hybrids is therefore the direction that should be encouraged in the near future. With the application of advanced electricity generating technologies and fewer coal-fired power plants in the generation mix, the CO2 emissions from electric vehicles can be reduced significantly from the current level. In the case of the proposed policy-adjusted IRP in the IRP 2010 Revision 2, electric vehicles will be the low carbon emission option in 2030, producing only 69% of the CO2 emissions of a petrol ICEV and 97% of the CO2 emissions of a petrol hybrid electric vehicle per kilometre travelled. SOx emissions When electric vehicles are charged with the current grid in South Africa, 35 to 50 times more SOx (1.86 g/km) is emitted than from ICEVs (0.04 g/km – 0.05 g/km). SOx pollution, which leads to acid rain, is a more serious environmental problem than GHG emissions as it affects plant ecosystems, including agricultural ecosystems, in a very short time. With the application of advanced technologies, as well as a cleaner grid, the life cycle SOx emissions from electric vehicles can be reduced to 0.793 g/km. Such a reduction still makes the SOx emissions from electric vehicles more than 10 times higher than the current SOx emissions from the ICEVs, and the emissions more than 1000 times higher than those from the ICEVs in 2030 (0.0006 g/km – 0.0008 g/km) if the new low sulphur fuel standards are implemented. NOx emissions When electric vehicles are charged in the current grid in South Africa, the NOx emissions are two to six times higher (0.96 g/km) than those of the ICEVs (0.15 g/km – 0.50 g/km). As the grid becomes cleaner, the NOx emissions can be reduced to 0.34 g/km if the policy-adjusted IRP scenario proposed in the IRP 2010 Revision 2 is implemented. This number is in the order of the NOx emissions from the ICEVs in 2010 but is still four to six times higher than those of the ICEVs in 2030 when new emission standards are applied. Particulate matter emissions There are no PM emissions from petrol ICEVs and petrol hybrid electric vehicles unless direct injection engines are used. The petrol vehicles using direct injection engines are just entering the South African market and were not considered in this calculation for current (2010) petrol ICEVs emissions. If electric vehicles are charged from the current grid in South Africa, the PM emissions are double those of diesel ICEVs. In 2030, the PM emissions from an electric vehicle are 12 times higher than those of a diesel ICEV, and 6 times higher than those of a direct injection petrol ICEV, although a two-thirds emission cut can be achieved from the grid compared with that of 2010. It can be argued that PM emissions are not as serious as the other pollutants, as the PM emissions from the power plants are normally located in remote areas. The effects of the PM emissions in those areas cannot be compared directly with the PM emissions from the diesel ICEVs, which are located in the city, but there are large settlements around coal fields and coal-fired power plants in South Africa; these ‘remote’ areas are actually peri-urban. The PM emissions, together with the NOx and SOx emissions, will result in smog, which is already a serious problem in those areas. Greenhouse gas emissions Because of the very high greenhouse potential of NOx and the high emission level of NOx from electric vehicles, the total life cycle GHG emission measure of CO2eq of electric vehicles (511 g/km) is 65% to 115% higher than that of ICEVs when electric vehicles are charged with the current grid. A 60% reduction (to 207 g/km) in the total GHG emission is proposed in the policy-adjusted IRP scenario in 2030. This value is in the order of the total GHG emission of hybrid electric vehicles in 2010 (182 g/km to 310 g/km), but is 25% higher than petrol ICEVs, 41% higher than diesel ICEVs, and 70% higher than hybrid electric vehicles in 2030.
5Life cycle CO2, SOx, NOx and particulate matter emissions in 2010 and 2030.http://sajs.co.za/index.php/SAJS/article/downloadSuppFile/603/3062
Conclusions The major advantage of electric vehicles is that there is no emission at the user end, which will help to improve the air quality of urban areas. The pollutants from ICEVs and hybrid electric vehicles that affect the air quality are CO, hydrocarbons and PMs. The emissions of the CO and hydrocarbons from electric vehicles were not studied here as the emissions of such pollutants at the user end are zero. PMs may only affect the areas surrounding coal-fired power plants, but these areas are normally peri-urban; the PM pollution, together with SOx and NOx emissions, will result in smog in these areas. In terms of CO2, SOx and NOx emissions, whose effects are not limited to the point of pollution, the environmental benefits from electric vehicles are very limited in the current situation. The worst case scenario is that 35 to 50 times more SOx will be emitted when conventional vehicles are replaced with electric vehicles in the current grid. The CO2 emissions from electric vehicles in the current grid are higher than those of vehicles using conventional liquid fuel. NOx emissions will be at least double those of ICEVs and hybrid electric vehicles. The total GHG emission is actually greater from electric vehicles. As the grid is becoming cleaner, thanks to the implementation of advanced coal-fired power plant technology as well as renewable energy, these emissions can be cut significantly in 2030. Electric vehicles will be a cleaner option when only CO2 emissions need to be considered in 2030, with similar performances from petrol hybrid electric vehicles. When switching to electric vehicles from ICEVs, a reduction in CO2 emissions of 18% to 31% can be achieved per kilometre travelled. In the case of NOx, the life cycle NOx emissions from electric vehicles will still be four to six times higher than those from vehicles using conventional liquid fuel. As the reduction in NOx emissions is not significant enough, electric vehicles are still the worst option when one considers the total GHG emissions. The worst case is that of SOx: although there is a projected 43% reduction in SOx emissions from the grid in 2030 compared to in 2010, the life cycle SOx emission from electric vehicles will be more than 1000 times higher than those from ICEVs and hybrid electric vehicles in 2030. Implementing electric vehicles in South Africa does not help to cut total GHG emissions, now (2010) or in the foreseeable future (2030), and would lead indirectly to higher SOx and NOx emissions. If electric vehicles are to play an important role on South Africa’s roads, new technologies have to be investigated and implemented to lower the SOx and NOx emissions for electricity generation further, in order to make electric vehicle emissions comparable to those of ICEVs and hybrid electric vehicles. 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