Power Industry Questions to Space Weather Researchers: Reflections on discussions with the system operator for business planning

Abstract:

Geomagnetically induced currents (GIC) in ground systems are one of the better recognised hazards that can result from large geomagnetic storms, appearing in many national risk registers. Coupling via processes in the ionosphere, an example of GIC is the hazard to electrical transmission networks as a consequence of damage to power network transformers at high, mid, and even comparatively low geomagnetic latitudes. This is a research area where there is growing interest and activity across multiple parts of society, including industry, researchers, and regulators. Mitigation requires a clear understanding of the user needs; it is also important to recognise that needs may vary from nation to nation due to geophysical, regulatory, and organisational differences across the world.

In this presentation I will particularly focus on discussions with Transpower New Zealand Limited who are responsible for electric power transmission in New Zealand. Having lost a transformer during a geomagnetic disturbance in November 2001, Transpower subsequently enacted operational protocols to decrease the risk. However, improved scientific understanding and international focus on the GIC-produced Space Weather hazard to power grids have led to a recent re-examination of those plans.

Transpower have archived near-continuous measurements of GIC at multiple South Island locations for nearly two decades. At the same time, Total Harmonic Distortion observations across the entire power network has been available for some years. These experimental observations have allowed researchers to help answer some of Transpower's questions around the risk of extreme geomagnetic disturbances. In this presentation I will discuss the research, and the questions posed by the national system grid operation as they develop a business case to respond to the Space Weather hazard through operational mitigation practises and equipment changes.