The orders comprise six bays, including circuit-breakers for 72.5kV and 145kV as well as 145kV instrument transformers.

The equipment is to be delivered by the middle of 2020.

These products of the ‘blue portfolio’ of Siemens are aimed at supporting E.ON Sweden’s goal towards a sustainable F-gas free power transmission.

They deliver high-performance operation at temperatures as low as -55° Celsius without a heating system.

The Fårhult substation in the local power grid operates at voltage levels of 20, 50, and up to 130kV and supplies electricity to more than 4,000 customers.

The high-voltage circuit-breakers and instrument transformers from Siemens will be deployed in Sweden for the first time.

E.ON Sweden regional grid director Mats Andersson said: “Using no SF6 is one way to support our goal of using less greenhouse gases in grid operation. With Siemens we have a competent and trusted partner on board for realizing this first CO2-neutral high-voltage project in Sweden.”

The orders consist of five 145kV bays with five ‘blue’ 145kV circuit-breakers, nine ‘blue’ 145kV current transformers (CT), and similar number of 145kV voltage transformers (VT).

One 72.5kV bay with another ‘blue’ circuit-breaker will also be installed. The circuit-breakers use vacuum-switching technology combined with ‘clean air’ to replace sulfur hexafluoride (SF6) as the insulating medium.

A vacuum-interrupter unit switches and extinguishes the arc. Purified air in a ratio of 80% nitrogen to 20% oxygen (clean air) provides the insulation for the current-carrying conductors inside the housing.

The insulation will also be used in the current and voltage transformers.

The ‘blue portfolio’ products feature insulating media that does not contain fluorine gases and therefore meet all safety and environmental standards.

The benefits of this technology over conventional SF6 insulation include operation at lower temperatures without heating systems, and easier handling during shipping, installation, operation, maintenance, and recycling.

Moreover, they do not require F-gas reporting during operation and have the same lifespan as their SF6 counterparts.