Volcanic ash risk to systems studied
Future volcanic eruptions could threaten New Zealand's power supply, a researcher says.
University of Canterbury student Johnny Wardman has been looking into the effects of volcanic ash on electric-power systems.
Wardman said several problems were caused by volcanic ash contamination on power equipment, especially insulator flashover - large short-circuits.
After Mt Ruapehu erupted in 1995, ash fell on 220kV-plus power lines, which caused voltage fluctuations and problems for electrical equipment throughout the North Island, including at Wellington Hospital, he said.
Wardman, whose research is being funded by Transpower New Zealand, has been running laboratory tests in a high-voltage lab to see how high-voltage insulators performed when subjected to varying degrees of volcanic ash contamination.
He has been trying to identify the physical, environmental and electrical conditions that contribute most to the flashover mechanism.
Results from these tests will strengthen knowledge on the vulnerability of electricity supply to volcanic-ash fall hazards.
Wardman said there were no solutions to ash-fall contamination, but there were mitigating strategies, including shutting down critical parts of the system until ash was removed, efficient monitoring and operational readiness.
Wardman's supervising lecturer, Tom Wilson, said the research was highly relevant because all of the national grid was close to active volcanoes.