Alexandre Golisano of Schneider Electric assesses how switching your switchgear to a ‘SF6-free’ option can help to combat the fight against climate change

Today, there are over 30 million units of medium-voltage switchgear installed w orldwide using sulfur hexafluoride (SF6)

TIME TO SWITCH YOUR SWITCHGEAR?

Alexandre Golisano, Strategy Director – Power Systems at SchneiderElectric, assesses how switching your switchgear to a ‘SF6-free’ option can help to combat the fight against climate change.

From forest fires in Australia to climate activist Greta Thunberg, the world is finally listening and working to reduce our greenhouse gas emissions and slow down climate change.

Concerns in the electrical industry revolve around the commonly used SF6 or sulphur hexafluoride gas. While it can vastly reduce the switchgear footprint and is easy and cost effective to use, it also has the highest global warming potential of any known substance. Clearly, the need to replace technology using SF6 to SF6-free, has become more attractive.

Distribution network operations (DNOs) in the UK are increasingly expected to provide a trajectory of the amount of SF6 emissions emitted and phase it out of their infrastructure altogether. Due to the durable design of components in our electrical infrastructure, it can take many years or even decades until all the old components are replaced, and the new technology becomes the norm.

However, the industry is expecting the introduction of new legislation and regulation around the use of SF6 gas, especially in medium voltage applications, to be introduced over the next few years – meaning that DNOs need to begin rethinking their approach to substation insulation now in order to be ahead of the curve.

That’s exactly what’s behind the development and adoption of new switchgear technology, which allows electricity companies and building managers to wage war on global heating and slash their carbon footprint.

Control & Automation

ISOLATORS

• Switch Disconnectors

• Manual Changeover Switches • 20A -125A

There’s more to SF6 than meets the eye Electrical power systems use switchgear, which are circuit interruption devices that control the flow of electrical current by stopping or starting the current between points A and B. Every piece of switchgear must be able to break electrical currents and must insulate itself and ensure safe operation of the network.

Today, there are over 30 million units of medium-voltage switchgear installed worldwide using sulfur hexafluoride (SF6). SF6 has been trusted and used extensively since the mid-1950s as a highly reliable replacement of oil as an insulator in electric equipment. However, SF6 is a greenhouse gas and contributes to the climate challenges we face today.

Thinking about reverting back to oil insulated electrical equipment as opposed to innovative alternative solutions? The case against moving back to oil insulated equipment is strong too. The main reasons why there was a shift towards SF6 is that oil required more maintenance work because it could quickly become a safety issue, with the possibility of the inflamed oil exploding. It was therefore wise to move towards an alternative as a precautionary measure.

The impact? Think of a typical load break switch, part of a unit of switchgear. On average, it contains 1kg of SF6. That 1kg of SF6 equals the same impact as 23,500kg of CO2. That’s the same as driving a car about 200,000 kilometres (your typical vehicle emits around 120g of CO2 per kilometre). Switching to sustainable solutions Sustainable medium voltage switchgear reduces greenhouse gas emissions by eliminating the need to create a new gas to replace SF6 and avoids the problems with end-of-life recapture, recycling and leakage.

The utilities industry represents 80% of the SF6 global market, so it is logical that they lead the charge for reducing the use of SF6 by adopting more environmentallyfriendly products. UK DNOs are also very aware of the impact that the energy industry has by using SF6 gas, and it’s clear that proactively searching for an alternative solution which meets network requirements and is environmentally sustainable is imperative.

Pursuing SF6-free alternatives is a priority because overall energy consumption continues to grow, with an anticipated 48% growth by 2040. New medium-voltage switchgear technology that uses vacuum interruption and pressurised air insulation allows us to avoid SF6. And while ambient air-insulated switchgear for medium voltage applications above 24kV has long had a reputation of being too large compared to SF6 technology, this is not the case with pressurised air which is able to keep SF6 dimensions at 24 kV with a pressure of 2.5 bar absolute.

Today’s alternatives to SF6 switchgear are as compact as SF6 versions, and costeffective. They offer all functions, including fuse-switch, which can meet requirements of varied customer applications and deliver the most sought-after transformer methods. It’s the ideal alternative to the status quo. • Switch Disconnectors • Switchfuses

New mediumvoltage switchgear technology that uses vacuum interruption and pressurised air insulation allows us to avoid SF6, says Alexandre

Staying ahead of the game With a growing appetite from businesses and individuals alike to reduce their carbon footprint, it’s clear that sustainability and climate change is at the top of the global agenda.

As such, looking towards adopting SF6-free switching technology, such as vacuum interruption technology with pure air insulation, combines the best of both worlds of retaining the benefits of a sealed pressure system like compactness, safety, longevity and sustainability without the use of SF6 gas. As regulators look towards imposing more restrictions to encourage environmentally friendly solutions, stakeholders in the energy supply chain should be taking this opportunity to get ahead of the game before the rules change. After all, the best gas is air.

Sustainable medium voltage switchgear reduces greenhouse gas emissions by eliminating the need to create a new gas to replace SF6

Schneider Electric, se.com/uk

Control & Automation