Amann, G; Monizza, G; Ploger, S; Harnisch, J
ORMAZABAL; ABB; SIEMENS
SF6 has unique, and currently irreplaceable, properties that allow the optimised operation of electrical switchgear and electricity networks. Electric equipment based on SF6-technology is used in the generation,
transmission and distribution of electricity all over the world. The substance SF6 possesses a unique combination of properties such as nontoxicity, non-ozone-depletion, non-flammability and outstanding electrical properties. However, SF6 is one of the six greenhouse gases regulated under the Kyoto Protocol. Despite great research efforts, to date no equivalent alternative gas has been identified.
This paper addresses the relevance of SF6 electrical equipment in past, current and future greenhouse gas reduction efforts. The analysis was carried out by ECOFYS2 on request of CAPIEL3, the Co-ordinating Committee for the Associations of Manufacturers of Industrial Electrical Switchgear and Controlgear in the
European Union in co-operation with the Union of the Electricity Industry, EURELECTRIC4 representing the main utilities in the European Union.
The study came to the following conclusions:
In the EU-15 the contribution of SF6 from electrical equipment amounted to 0.05 % of the total greenhouse gas emissions in 2002. Total greenhouse gas emissions in the EU-15 in 2002 amounted to 4852 million tons of CO2- equivalent (EEA 2004). According to the most recent survey, at the same time the
manufacturing, use and decommissioning of SF6 electrical equipment contributed 2.4 million tons of CO2-equivalent to EU-15 emissions, respectively. Although the electricity industry is a major user of SF6, it is only a minor source of SF6 emissions.
Since 1995, voluntary actions by the European electricity industry have resulted in a reduction of 40 % of SF6 emissions. Most of the potential for emission reductions has already been realised. However there
remains some scope for further reductions. Accepting climate change as a major challenge, the electricity industry – including both manufacturers and users of electrical equipment – started around the year 1995 to
implement various measures to reduce SF6 emissions. These include enhanced tightness by design, gas recovery and re-use as well as training of personnel handling SF6. Specific reduction costs of the various measures voluntarily implemented by the sector since 1995 range up to 40 Euro per ton of avoided
CO2–equivalent, which is twice the current trading price of emission allowances in the mandatory EU emissions trading scheme. The electricity industry has managed the growing population of SF6 equipment in the EU-25+3 in order to reduce annual emissions from 4.8 million tons of CO2-equivalent to 2.9 million tons
– delivering a reduction of nearly 40 % in less than ten years. While the action already taken covers most of the potential reduction measures, full coverage of these measures throughout the electrical industry in the EU- 25+3 has not yet been achieved.
Life-cycle-assessments show that the use of SF6 in electrical equipment can reduce the overall CO2-emissions from the electricity systems due to reduced network losses. The use of SF6 technology permits a compact design of equipment and thus allows for an optimised layout of power networks. High voltage networks can be located closer to the consumers of electrical energy, which leads to lower transmission losses. Less energy lost means also less CO2-emissions from power generation from fossil fuels. In 2003 this effect is estimated to have avoided emissions of about 1.7 million tons of CO2 across the EU- 25+3. These savings therefore help to diminish the net-climate contribution of SF6-technology in any power generation system at least partly based on fossil fuels.
The study shows that the voluntary actions taken by the electricity industry have resulted in significant emission reductions and proposes how to access the remaining reduction potential through further voluntary action.
