Most transformers today are cooled by mineral oil but this has some major flaws. Most notably, it is a flammable liquid so mineral oil transformers are prone to fires, which can have catastrophic consequences. These fires can threaten the lives of people in close surroundings and cause significant damage to nearby property and land. Companies have little choice but to let them burn out, which can take days, or extinguish them with nitrogen, before counting the cost to their business, the environment or – in the worst case – lives.
It’s not just the fire risk that’s an issue. If a mineral oil transformer leaks, it can create further environmental damage as the liquid itself is not biodegradable. Companies might be obligated to clear up any spillage but, nevertheless, it still comes at a high financial and reputational cost.
A transformer fire might never happen – but with a mineral oil transformer, there will always be the chance. When travelling in a car, the possibility of a crash is remote but seatbelts are commonplace to ensure safety. In a similar vein, rather than dismissing the possibility of a fire or leak, businesses need to evaluate the risks and do their best to safeguard against them.
With transformers, the first risk factor is its location. Its proximity to people, combustible materials or environments such as water or woodlands will determine just how destructive a fire or leak could be. A typical utilities firm might run several thousand transformers and as much as 15% of these could be in high-risk locations.
The second factor is what the transformer is powering.