For the purpose of one project, I have recently analysed publicly available data about transformer failures and their impact on the society. This was more of a qualitative analysis since the data was analysed for a specific season, so it is not representative of the whole year. Also, the input data was not available in the same format, and was sometimes incomplete and inconsistent. For example, while comprehensive information about transformer outages, including even the minor outages of distribution transformers, is readily available in the US and a few other countries, in most other countries only the information about major failures with bigger damages and fatal consequences is made publicly available.
During the observed period, there were thousands of transformer outages due to faults, failures and fires, which left millions of people without power, affecting their quality of life – not only in terms of comfort, but financially as well. When services become unavailable, this causes damage to both service providers and service receivers. The goods stored in conditioned spaces may get stale and their quality may be compromised; the energy spot prices in some regions may rise by an order of magnitude, and many other consequences may ensue.
The analysis showed that the major causes of failure, among others, include: overheating, lightning strike, physical destruction (careless or intentional actions), and short circuit (caused by birds, rodents, monkeys, etc.).