Supercritical CO2 Circuit Breaker: A Green Alternative to SF6

Researchers at Georgia Tech are testing a novel high-voltage circuit breaker that uses supercritical carbon dioxide fluid to replace the environmentally damaging sulfur hexafluoride (SF6). SF6 is nearly 25,000 times more potent as a greenhouse gas than carbon dioxide, and this new breaker promises to significantly reduce greenhouse gas emissions in power systems. The team overcame challenges in maintaining supercritical CO2 under high pressure, developing crucial components independently. If successful, this could provide a strong solution for the eco-friendly upgrade of millions of high-voltage circuit breakers globally, although it requires some auxiliary equipment like heat pumps. Meanwhile, GE Vernova has also developed circuit breakers using alternative gas mixtures, which, while still containing a small amount of fluorinated gas, have significantly reduced greenhouse effects. Ultimately, solid-state semiconductor circuit breakers promise faster and greener switching, but are still in early development.