PROJECT DESCRIPTION
BACKGROUND
Sulphur hexafluoride (SF6), the worst gas in terms of global warming potential (GWP), was chosen for use from the 1960s onwards in medium-voltage electrical equipment because of its dielectric properties, which make it particularly suitable for electrical insulation and current interruption. However, each tonne of SF6 is the equivalent of 23,894 tonnes of CO2, which represents a well-identified threat to the global climate.
Until recently, the lack of a viable alternative has been a limiting factor in progressing towards a low-carbon policy for electric facilities. An effective solution with a GWP <10 threshold has been successfully demonstrated for 12 and 24 kV, but not yet for 36 kV. This voltage is required for current and future photovoltaic (PV) and onshore wind farms, and for the deployment of electric vehicle (EV) recharging installations. On average, one switching unit is required every 3MW, and with forecasts predicting that 100-150 GW will be deployed over the next 10 years to meet the transformational electrification of energy needs, 35-50,000 switching units will be required.
After more than 10 years of intensive R&D work, mature solutions are ready, including HFO1234zeE (HFO). But to reach a solution with a GWP <10, Schneider Electric is studying air-based alternatives more likely to meet the criteria of the F-Gas Regulation currently under revision. Despite their well-known advantages (safety, zero or low GWP, high availability), air-based alternatives have some weaknesses including low dielectric strength and low breaking capacity.
A pilot project, with prototypes operating on customer sites under real conditions, is needed to convince all stakeholders and target audiences that there are safe and reliable alternatives to SF6 or air-based alternative gases, even for 36 kV. Schneider Electric's solutions to compensate for these weaknesses for 36 kV need to be implemented and tested under 'real conditions' to be accepted by everyone.
OBJECTIVES
LIFE 36KV aims to demonstrate that despite technical challenges, air-based technology for 36 kV switch gears is a viable alternative in terms of safety, costs, energy efficiency and fit-for-purpose to replace SF6.
To do this the project aims to:
- Finalise the overall design of circuit breaker and disconnectors and test the new components using mock-ups.
- Develop prototypes and test them to strict International Electrotechnical Commission (IEC) test standards.
- Implement pilot projects with potential customers during an 18-month test under real conditions to monitor potential issues.
- Communicate widely with stakeholders (customers, authorities at national and European level, industry players and other stakeholders).
RESULTS
The purely quantitative result concerns the amount of SF6 not released into the atmosphere: 123,000 tonnes over the life of the project and 7.7 Mt/CO2eq over the average life of the devices implemented.
Three detailed results:
- The four prototypes installed by the project during the test period (18 months) and over the following five years will save a total of 15.2 kt/CO2eq. If the total lifespan of the installed products is considered, 483 Mt/CO2eq will be saved.
- Schneider Electric's sales of new equipment at the end of the project are expected to save 47 kt/CO2eq (project + five years) and 2.7 Mt/CO2eq (over the entire life of the product).
- The sale of new equipment by other market players, thanks to the stimulating effect of the project, is expected to save 123 kt/CO2eq (project + 5 years) and 7.7 Mt/CO2eq over the lifetime of the products installed.
