A team from Chongqing, China, discovered that using a lot of renewable energy like wind and solar could make power transformers age nearly a quarter faster. Transformers control voltage in electricity grids. The study showed that more wind and solar power causes electricity to flow in both directions more often. This two-way flow stresses transformers more than current standards expect. This extra strain could worsen problems in places like the United States and Europe, where grids are already old and facing transformer shortages. The researchers tested a new model and found transformers age 23% faster due to frequent two-way power switching. Published on January 16 in the Chinese-language journal Power System Technology, the paper said, "This paper focuses, for the first time, on the impact of frequent bidirectional power flow switching caused by high‐penetration wind and solar integration on the operational characteristics and insulation lifespan of power transformers." With growing energy use from electrification and AI data centers, the study highlights fresh challenges for sustaining power grids with rising renewable energy share.