Net zero construction methods used in building the new facility will mean that 5229 tonnes of CO₂ emissions were saved.
The 400 kV substation is in Littlebrook, North Kent, UK, adjacent to the River Thames. It will enable 2 GW of low carbon and renewable energy to flow, sufficient to power around 1.5 million residences. The new substation replaces a 50-year-old facility on the same site, and indeed uses four of the old turbines, but replaces many of the systems with new, low-carbon equipment. Particularly important is the removal of potent greenhouse gas sulfur hexafluoride (SF₆), a gas commonly used in the electrical industry to prevent short circuits and to keep the network safe and reliable. The upgraded means plant engineers are able to use GE’s Grid Solutions’ g³ innovation, which ensures the newly installed gas-insulated bus-bar equipment is SF₆-free. A total of 5.6 tonnes of SF₆gas has been saved, forming part of National Grid’s plan to reduce its SF₆ emissions by 50% by 2030 and removing all SF₆ gas from electrical assets by 2050.
The three-year build included the installation of cabling, overhead line connections and switch-gear. Four existing transformers will be moved from the old substation to the new one, with one new transformer being delivered in July 2022.
The scheme used other net-zero construction methods to reduce any environmental impact of the works, including steel manufactured in the UK, solar powered electrics, EV charging points, and a biodiversity net gain plan for the local area, as well as an on-site biodigester to manage wastewater.
The project was a partnership between National Grid Electricity Transmission (NGET), construction giant Balfour Beatty and GE’s Grid Solutions. It is an important stage in the “greening” of NGET's network of substations and transmission facilities and will ensure continuity of power to the local community and businesses.