The Effects of Geomagnetic Storms on Power Systems Mary Holleboom Justin Voogt ENGR W82 January 22, 2002

Outline 1. Space weather background 2. Effects on power systems 3. Case studies 4. Prediction 5. Impact reduction 6. Conclusions

Definitions n Space Weather –Geomagnetic storms, substorms, and auroras produced by ionized particles captured in the earth’s magnetic field n Solar Wind –Motion of interplanetary ionized particles away from the sun and towards the earth n Magnetosphere –Magnetic field produced by the earth that extends into space n Geomagnetically Induced Currents (GIC) –Currents produced by sudden fluctuations in the earth’s magnetic field during a geomagnetic storm Background

What is a Geomagnetic Storm? n Sudden production of intense GICs n Ability to create instability in earth’s magnetic field n 11-year cycles n Variations –Duration (10s – several days) –Daytime v. Nighttime –Size –Frequency Background

Coronal Mass Ejection (CME) n Mass up to one billion metric tons n Temperature greater than one million K n Millions of km wide n Cause storms on earth several days after leaving the sun Background

Impact on Power Systems n Disrupts power grids n GICs enter through thousands of grounding points n Transformer saturation n Blackouts n Satellite malfunction n Radio transmission disruption n High altitude aircraft damage n Costs of transformers and additional power purchase Effects

Transformer Saturation / Blackouts n GICs resemble slowly varying DC currents n Saturation of transformer core n Harmonic levels increased n Over 100A measured in grounding connections of affected areas n Voltage regulation capabilities overwhelmed n Multiple power systems affected simultaneously n Permanent damage to network equipment n Up to 600% of normal load drawn upon power restoration Effects

NOAA Weather Scales n National Oceanic and Atmospheric Administration n G scale of 1-5 n Kp values 5-9 n Frequency based on 11-year cycles Effects

March 13, 1989 n Entire Hydro Quebec power system collapsed due to G5 geomagnetic storm n 6 million customers lost power n Entire system collapsed in 90 seconds n Restoration took 9 hours n Total cost to Quebec: $13.2 million Case Studies

March 13, 1989, cont. n Utilities throughout North America felt storm n Several transformer heating problems n 1,200 MVA transformer in New Jersey destroyed Case Studies

July 15, 2000 n G5 Class geomagnetic storm n Kp of 9 for over nine hours n No significant power system damage Case Studies

Satellite Forecasting n 1998: Advanced Composition Explorer (ACE) launched n Real-time solar wind monitoring n Up to 1 hour warning Prediction

Numerical Modeling n Inputs from satellite –Magnetic field magnitude –Solar wind velocity –Solar wind density n Models can predict geomagnetic activity n Goal: give client- specific impact assessments n Problems –Modeling GICs is very difficult –False alarms are costly Prediction

Reducing the Effects n Problems –Immense volume of space –Massive size of power grid –Devices to block GIC flow would cost billions for entire system n Contingency Strategy –Reduce imported power –Disconnect links between grids –Delay system maintenance –Put satellites to “sleep” Impact Reduction

Conclusions n Current methods of predicting geomagnetic storms are becoming more accurate n No feasible way of preventing effects n Low frequency of threats, but high potential for damage n More research is necessary