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A recent study by Chinese researchers suggests that high levels of renewable energy integration could accelerate the ageing of power transformers, raising concerns for regions with ageing electricity infrastructure.

The research team from Chongqing University of Posts and Telecommunications and State Grid Chongqing Electric Power Company examined how increased use of wind energy and solar energy affects transformer performance. According to the study, higher renewable penetration leads to more frequent bidirectional power flows, in which electricity moves both into and out of the grid.

“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,” the researchers wrote in their paper, published in January in Power System Technology.

Using a newly developed modelling framework, the team found that transformers exposed to two-way power flow could age approximately 23 per cent faster than estimated under current industry standards. The researchers said existing assessment methods “do not fully account for the additional stress caused by bidirectional operation.”

The findings come amid growing concern over ageing grid infrastructure and global transformer shortages. The US Department of Energy has previously warned that “more than half of the transformers in this country are becoming too old to reliably function and can fail at any time.”

Supply constraints may further complicate replacement efforts. The International Energy Agency has reported that delivery times for large power transformers can extend up to four years due to manufacturing complexity and limited global capacity.

The researchers said their proposed lifetime-loss calculation framework could help utilities better assess transformer condition and plan maintenance as renewable energy deployment continues.

Source: scmp.com