C H A P T E R

N ° 14

Space Weather and The Energy Sector

On the 24’th of March 1940, the first space weather event that had a noticeable effect on power systems occurred and got discovered by American scientists such as Albertson V.D. and Thorson J.M.. 18 years later, in February 1958, another space weather event occurred that similarly had an effect on the power systems in the United States of America. Despite these two events, it was not until 1967 that detailed investigations began on the relation between space weather and power systems. In the following years, an extensive investigation was made showing the relation between space weather and geomagnetically induced currents (GIC), and the range of effects they could have on power systems. During a space weather event that occurred on the 4’th of August 1972, some of the investigators’ recording systems were still deployed, which lead to the best documented event of geomagnetically induced currents (GIC).

After the discoveries made in the United States of America, the Sun went into Solar Cycle 21 (1976-1986). During this time, no major effects were made on power systems. However, a number of studies were made in different countries that informed about the processes that occurred during the interaction between space weather and power systems, and how to model them. For example: In Finland, a long series of recorded geomagnetically induced currents (GIC) lead to the development of techniques for calculating the electric fields and geomagnetically induced currents (GIC) produced in a power system during geomagnetic disturbances. In North America, scientists such as Leonard Bolduc and Jacques Aubin showed how to estimate the transformer saturation produced by geomagnetically induced currents (GIC). Additionally, they discovered how geomagnetic effects influences power system operation.

However, despite the research done on the impact of space weather on power systems, scientists worldwide were not ready for what was to come. In March 1989, Earth-directed solar activity created a geomagnetic storm that showed to be the largest recorded space weather event since observations began in the 1840’s. This event is often referred to by scientists today when discussing space weather impact on society, as it produced widespread technological effects that became the absolute wake-up call for the power industry. The most significant effect of the 1989 space weather event was a blackout of the Hydro-Québec power system. Independently from this, other places such as North America and Europe, likewise experienced issues with their power systems. Here, they experienced relay trips (a safety measure detecting faults and isolates them), voltage drops, and transformer heating.

However, the 1989 space weather event was only the beginning. In 2003 the space weather event referred to as the ‘Halloween storm’ occurred, causing blackout in Sweden and damage to several transformers in South Africa.

- Read more about the 1989 and 2003 space weather events and their consequences on SR Hoplon’s blog –

What happens inside the power grid system?

Space weather can affect power systems because geomagnetic field variations induce electric currents that can get into the power transmission lines. These geomagnetically induced currents (GIC) can then flow to and from the ground through the windings of power transformers, and cause partial saturation of the transformer core. As a consequence of the saturation, it can disrupt the ac operation of the transformer, consequently causing added heating that can damage winding insulation.

The consequence of having issues with the cooling system within the transformer is that it will demand the transformer to increase reactive power. This will lead to a drop in system voltage, and higher levels of ac harmonics which can trigger tripping of protective relays.

In an extreme case, the combination of all these stresses to the transformer can have serious effects on its systems stability. A lack of stability within a power system can lead to a blackout of the power grid. This is what happened to the Hydro-Québec power system. Once a power grid experiences a blackout or a complete collapse, it increases the risk of cascading effects (i.e., a ripple effect) leading to impact on sectors dependent on electricity, such as food, water, conservation, fuel, distribution, and transportation.

**Image Credit:** NEED.org Electricity: *Cartoon illustrating a power grid system.*

Satellites and power systems

No system or society has ever been as dependent on satellites as the society we live in today. This dependency will only increase with increasing development of new technologies. Satellites offer multiple services that help different sectors - especially sectors within critical infrastructure - to provide their services in order for the well-functioning of society. The energy sector is no exception.

The modern-day power grid system gets increasingly more dependent on satellites in order to function as efficiently as it currently does. Power system owners and operators for example use the Global Positioning System (GPS) that is a part of the Global Navigation Satellite Systems (GNSS) for navigation, position, and timing. This service is used in order to monitor local grid conditions down to the microsecond, and for system protection measures such as to activate control operations for line trips (i.e., shutdown/closes down/isolation).

Additionally, power systems use a lot of telecommunications which is a service provided by Telecommunication satellites. Furthermore, they additionally use IT Network, which rely on timing delivery services. If issues or a loss of any of the mentioned services were to occur, it would complicate grid operations. Space weather can, thus, impact power systems directly through its capability of inducing electric currents, or indirectly through complications with satellites that the power system depends on in order to function properly or efficiently.

**Image Credit:** ESA: *Showing the ESA Solar Orbiter Probe.*

How to make power grid systems resilient?

Although no system has shown to be 100% resilient to space weather impact, there are some preventive measures that can be taken to insure a more robust and resilient power system. According to the British scientist David H. Boteler, some transformers like the 3-phased 3-legged core type are to be less susceptible to saturation from geomagnetically induced currents (GIC). However, Boteler also clearly states that changing existing transformers to a 3-phased core type is not necessarily feasible for every country due to the high expenses and its size.

**Image Credit:** MBT: *Cartoon illustrating a 3-phase and single phase core type transformer.*

Alternatively, one can try to block the flow of the geomagnetically induced currents (GIC) by placing blocking capacitors in the power transmission lines as done in Hydro-Québec. However, the mentioned mitigation measures are not economically friendly nor do they insure 100% resilience.

An assessment of the potential space weather risks to for example the United Kingdoms transmission grid conducted by the European Commission suggests that only a Carrington-type of space weather event could cause a disruption to the grid. An event at the size of the Carrington event has a ~50-100-year return period. However, widespread transformer damage and a total power grid collapse is estimated to be highly unlikely. Estimations suggest that only 20 transformers would be affected by extreme space weather, which constitutes to only ~1% of all transformers in the United Kingdom. According to the 2016 European Commission’s report on space weather and critical infrastructures, only local blackouts are to be expected. However, the United Kingdoms national grid relies on mitigation measures such as geomagnetically induced current (GIC)-resistant transformer design, voltages lower than 400 kV, and backup transformers.

Furthermore, their national grid relies on operation mitigation measures such as return to service of items out for maintenance and switching in of all circuits, and connection of all Supergrid Transformers. Supergrid transformers are vital high voltage devices that boost substations’ capacity and resilience. Additionally, they work closely with the Met Office (United Kingdoms’ national meteorological service) which offers advanced space weather forecasting and warnings, and with others in order to create operating and emergency strategies.

As presented, even with a strong power grid system, power system operators cannot only rely on one mitigation measure. The system demands the creation and implementation of multiple mitigation measures in order to be close to resilient. Depending on the country, it may be the same as in the United Kingdom, or it might be different and demand more. As the Earth’s magnetic field is weaker at its equator and strongest at its poles, one should always be aware of a countries location when discussing the potential of space weather impact on infrastructures, as the impact of an event may be different depending on its location on the planet.

Source

Advancing Earth and space sciences (AGU) (2015): “Equatorial regions are prone to disruptive space weather, new study finds”. https://news.agu.org/press-release/equatorial-regions-are-prone-to-disruptive-space-weather-new-study-finds/

Albertson, V.D. et al. (1973): ”Solar induced-currents in power systems: cause and effects”. IEEE Trans. Power App. & Sys.. Vol. PAS-22. Pp 471.

Albertson, V.D.; Thorson, J.M. (1974): “Power system disturbances during a K-8 geomagnetic storm: August 4, 1972”. IEEE Trans. Power App. & Sys.. Vol. PAS-93. Pp. 1025.

Albertson, V.D. et al. (1974): ”The effects of geomagnetic storms on electrical power systems”. IEEE Trans. Power App. & Sys.. Vol. PAS-93. Pp 1031.

Albertson, V.D. et al. (1981): ”Load-flow studies in the presence of geomagnetically induced currents”. IEEE Trans. Power App. & Sys.. Vol. PAS-100. Pp. 594.

Allen, J. et al. (1989): “Effects of the March 1989 solar activity”. EOS Trans. AGU. Vol. 70. Pp. 1479.

Boteler, D.H. et al. (1989): ”Effects of geomagnetically induced currents in the B.C. Hydro 500 kV system”. IEEE Trans. Power Delivery. Vol. 4. Pp. 818.

Davidson, W.F (1940): “The magnetic storm of March 24,1940 – effects in the power system”. Edison Electric Institute Bulletin.

Kappenman, J.G. et al. (1981): ”Current transformer and relay performance in the presence of geomagnetically induced currents”. IEEE. Trans. Power App. & Sys.. Vol. PAS-100. Pp. 1078.

Krausmann, Elisabeth et al. (2016): “Space weather and critical infrastructures: Findings and Outlook”.European Commission, JRC Science For Policy Report. DOI: 10.2788/152877

Lehtinen, M.; Pirjola, R. (1985): “Currents produced in earthed conductor networks by geomagnetically induced electric fields”. Annales Geophysicae. No. 3. Pp 476.

Pirjola, R. (1985): “On currents induced in power transmission systems during geomagnetic variations”. IEEE Trans. Power App. & Sys.. Vol. PAS-104. Pp. 2825.

Pirjola, R.; Lehtinen, M. (1985): “Currents produced in the Finnish 400 kV power transmission grid and in the Finnish natural gas pipeline by geomagnetically induced electric fields”. Annales Geophysicae. No. 3. Pp 485.

Silverstain, A. (2016): “Electric Power Systems and GPS”. Civil GPS Service Interface Committee.https://www.gps.gov/cgsic/meetings/2016/silverstein.pdf

Slothower, J.C; Albertson, V.D. (1967): “The effects of solar magnetic activity on electric power systems”. J. Minn. Academy of Science 34, 94.