5 Reasons to Transition from SF6 to Pure Air in MV Switchgear
Executive summary
As electrification increases and renewable penetration grows, so too does the need for more medium voltage switchgear. This equipment commonly uses sulphur hexafluoride (SF6), a man-made gas with a very high global warming potential. As the electricity industry invests in a more sustainable and digital future, it seeks green alternatives to SF6. Compared to other alternative gases for MV switchgear, pure air is quickly emerging as the superior choice. by Christophe Prévé Schneider Electric 2
What’s SF6?
Sulphur hexafluoride (SF6) is a man-made gas that for decades has been widely used in high and medium voltage electrical equipment, like switchgear, as an insulating and breaking medium. The gas owes its popularity to its insulating and current breaking properties, thermal capacity, and stability. It’s also inert, nonflammable, and completely non-toxic in its pure form. And crucially for the many tight spaces into which switchgear must be squeezed, SF6’s high insulating property made it possible to significantly reduce the size of switchgear. And although you may not see them, switchgear are everywhere. They are essential electrical equipment for the grid, for industrial applications, and for large buildings. Over 30 million units of medium-voltage switchgear installed worldwide use SF6, a highly trusted technology. Sounds great, right? Well, not exactly. There are some strong motivations for transitioning away from SF6 to an innovative new alternative that uses only pure air.
Reason #1
Pure Air is Superior to a Strong Greenhouse
Gas SF6 has a global warming potential (GWP) 23,500 times greater than that of CO2. The GWP metric was developed to compare the global warming impacts of different gases. It is a relative measure of how much heat a greenhouse gas traps in the atmosphere. Specifically, it is a measure of how much energy the emissions of 1 ton of gas will absorb over a given period of time, relative to the emissions of 1 ton of carbon dioxide (GWP=1). The larger its GWP, the more the gas in question warms the Earth compared to CO2 over that time period. SF6 is one of six types of greenhouse gases targeted by the Kyoto Protocol and European Directive 2003/87 (Greenhouse Emission allowance trading). Each typical load break switch, part of a unit of switchgear, has an average of 1 kg of SF6 inside it. If 1kg were to be mistakenly released into the atmostphere, it would have the same potential environmental impact as driving a car about 200,000 kilometers (a typical vehicle emits around 120g of CO2 per kilometer). Multiply that times 30 million switchgear units and it is becomes clear why choosing the best alternative to SF6 is necessary. Pure air is the ultimate replacement of the greenhouse gas. It makes the concerns around GWP obsolete, as it has none. But more than that, its environmental safety is fully transparent.
Reason #2
Pure Air Requires No Recycling
The pure air we breathe every day requires no recycling, naturally. The same cannot be said of SF6 or other man-made gases. When an SF6 switchgear unit reaches the end of its operational life, the gas is ideally recaptured, reprocessed, and reused. If it is handled within a closed system until the end of its lifecycle, the amount of leakage can be dramatically reduced, thus reducing its environmental impact. With pure air, no such concern exists. What’s SF6? Reason #1 Reason #2 Schneider Electric 3 5 Reasons to Transition from SF6 to Pure Air in MV Switchgear Unfortunately, SF6 end-of-life procedure is not always completed, and rules – when and where they exist – are often not properly enforced. SF6, after use, is considered hazardous waste because of the toxic byproducts that result from current breaking operations. Additionally, end-of-life treatment of SF6, or other man-made gases, can be costly – about 20% of the price of the equipment itself. It involves numerous steps, including collection, recovery, and neutralization before recycling or destroying the gas. Only authorized hazardous waste managers can handle, transport, recycle, or destroy gases according to some national or regional regulations and standards. Using a pure air solution helps eliminate the need to produce SF6, drastically reduces switchgear’s environmental impact, and avoids the end-of-life recycling process.
Reason #3
Pure Air is a Win-Win Alternative to SF6
New medium voltage switchgear technology from Schneider Electric using pure air is a groundbreaking alternative to SF6. It replaces SF6 in switchgear by using an innovative combination of vacuum interruption and pure air insulation, each a proven and trusted technology. And new SF6-free switchgear using pure air is able to achieve something more: It keeps the small physical footprint for which traditional SF6-based equipment is so valued, and it is operated in the same way as before so technicians require no retraining. Green MV switchgear technology is already up and running in pilot projects around the world, including at E.ON, the largest electrical distribution grid operator in Sweden, EEC Engie, the electrical distribution operator in New Caledonia, and at GreenAlp, a French electric distribution network. Key advantages of pure air in MV switchgear: environmental friendliness safety for people ease of operation same footprint as SF6 interchangeability with the currently used SF6 switchgear units no need for end-of-life gas recovery long-life expectancy Furthermore, switchgear manufacturers can obtain pure air by simply filtering ambient air, so they don’t have to rely on costly proprietary gases linked to specific vendors. For users, that translates to less likelihood of increasing equipment prices linked to a gas.
Reason #4
Pure Air is Green and Improves Safety
Health and safety are chief concerns when considering SF6 alternatives because medium-voltage switchgear is used in public areas. Pure air is a responsible alternative for protecting the public from potential health and safety risks. It is completely free from toxins, so in the event of a leak, there is no harm to either people or the environment. It also does not pose a health risk for Reason #3 Reason #4 Schneider Electric 4 5 Reasons to Transition from SF6 to Pure Air in MV Switchgear those responsible for installation and end-of-life recycling and does not require strict equipment disposal regulations to protect people. Pure air is also free from any potential health and safety risks associated with unproven proprietary gases.
Reason #5
Pure Air is Free from Regulatory Concerns
Many companies are taking great measures to dramatically reduce greenhouse gas emissions. These strategic efforts are motivated not only by the desire to improve sustainability, but also by strong regulatory pressure that can come from several levels of policy: country, regional, and international. In Europe, for example, SF6 use is already subject to stringent regulatory procedures, including its use, handling, decommissioning, monitoring, and inventory record maintenance. In 2014, SF6 was banned in the EU for most applications except the electrical industry because at that time there was no alternative for SF6. With that regulation due to be reviewed this year, further restrictions could be around the corner. That is in addition to other potentially expensive regulations including additional taxes and carbon pricing initiatives. It is prudent to future-proof operations by adopting an environmentally friendly alternative that’s immune to potential regulation. The pure air and vacuum technology provides reliable breaking and insulating performance without the risk of being subject to environmental regulations or carbon taxes
Conclusion
For a future dominated by electricity, today’s decisions matter Globally, electricity consumption is predicted to increase by 48% by 2040. 87% percent of that increase is expected to take place in countries that often have less stringent environmental regulations. More MV switchgear is essential to satisfy this rapid growth and support industrialization, especially in developing nations, which are increasing their investment in transmission and distribution. Over the next decade electric utilities are anticipated to invest around $3.2 trillion in new and replacement transmission and distribution infrastructure. Against this background, making a green switchgear choice is especially important as the demand for MV switchgear rises – not only for utilities, but for private installations, too (such as commercial and industrial installations). And as the popularity of renewables continues to grow, it’s important that their new MV infrastructure also be green. New green MV switchgear contains an additional benefit – it’s natively digital and connected. So in addition to being environmentally sound, its users can leverage the power of data for managing their infrastructure. By choosing SF6-free switchgear that uses pure air and vacuum interruption in these new installations, companies not only benefit from reliable breaking and insulating performance with a proven safety record, they prepare themselves for growth, contribute to energy decarbonization, and free themselves from regulatory considerations. Conclusion Reason #5 Schneider Electric 5 5 Reasons to Transition from SF6 to Pure Air in MV Switchgear
About the author
Christophe Prévé is the Chief Technology officer of MV Switchgear Activity at Schneider Electric. He graduated from the Ecole Supérieure d'Electricité (SUPELEC) in 1988. He began his career at a Grenoble, France utility as an Electrical Network Operator and then as an Electrical Studies Manager. He joined Schneider Electric in 1994 in the Protection Relay Department as an Electrical Network Expert. He had the opportunity to write a book on "Protection of Electrical Networks" in Edition Hermès. In 1998, he moved to MV Switchgear Activity where he took different responsibilities in R&D. He is now responsible for new product development and new technology integration. He is also a lecturer at the ENSE3 Engineering School in Grenoble
Source : https://download.schneider-electric.com/files?p_enDocType=White+Paper&p_File_Name=998-2095-07-10-20AR0-EN.pdf&p_Doc_Ref=998-2095-07-10-20AR0-EN&mkt_t
Source : https://download.schneider-electric.com/files?p_enDocType=White+Paper&p_File_Name=998-2095-07-10-20AR0-EN.pdf&p_Doc_Ref=998-2095-07-10-20AR0-EN
.png)
