Building a more sustainable power transmission network near Glasgow, UK Read more about Building a more sustainable power transmission network near Glasgow, UK At Windyhill, GE Vernova is supplying SF₆-free 420 kV gas-insulated switchgear for a new SP Energy Networks substation designed to support a stronger, more resilient and more sustainable transmission network.As more renewable power connects to the grid, transmission networks need to carry more electricity, manage changing power flows and maintain the reliability customers depend on every day.