Electrical grid
Verlo siempre en Español
What Is a solar storm?
Solar storms are a rare and largely unknown phenomenon. What Are They and How Do They Affect Us?
A solar or geomagnetic storm is a disturbance of the Earth's magnetic field caused by a sudden increase in the particles emitted during solar flares. These particles reach our planet's magnetosphere and can disrupt the Earth's magnetic field for hours or even days.
The intensity of these storms varies depending on the latitude. They are usually stronger in areas closer to the poles.
According to the Spanish National Geographic Institute, "geomagnetic storms are typically of lesser magnitude and cause no harm." Their most pleasant effect are the northern lights, visible at high latitudes, which result from the interaction of solar particles with gases in the atmosphere.
In rarer instances where storms are more intense, they can interfere with certain infrastructures, including satellites, telecommunications services, and power grids.
How do solar storms affect the power grid?
More intense solar or geomagnetic storms can cause disruptions in power grids. Here are some facts about the earliest recorded phenomena of this kind worldwide.
- In 1859, the Earth faced the negative effects of solar activity for the first time through the so-called "Carrington Event." This solar storm, observed by astronomer Richard Carrington, is the most powerful recorded to date. The "Carrington Event" mainly affected telegraph lines, disabling much of the 200,000 km of lines worldwide for 8 hours, according to the U.S. National Center for Biotechnology Information. At that time, modern electrical grids had not yet been developed. This solar storm was so intense that it caused northern lights in unusual latitudes, even reaching Spain.
- In March 1940, a solar storm forced several transformers of the Philadelphia Electric Company (USA) to shut down. Telephone and telegraph services were also affected.
- On February 10, 1958, Toronto (Canada) experienced power outages, and abnormal power flows were recorded in Minnesota (USA). Two years later, on November 13, 1960, a solar storm disrupted transoceanic cable services, especially those connecting North America with Europe.
- One of the most recent and impactful on the power grid occurred on March 13, 1989. A solar storm collapsed the Hydro Quebec (Canada) grid in just two minutes, shutting down 21,500 MW of generation capacity and leaving the transmission grid inactive for nine hours.
These events are examples of the impact of solar storms on electrical infrastructure. But why do these phenomena affect the grid?
Why do solar storms affect the grid?
Solar storms generate low-frequency geomagnetically induced currents (GICs) (0.0001 to 0.1 Hz), which can affect the operation of the power grid. If these currents reach transformers and spread through the grid, they can cause overloads, saturation, and fluctuations in power quality.
Factors such as latitude, soil resistivity (the ground's ability to conduct electrical currents), proximity to the coast, and specific characteristics of the grid influence the impact of GICs. Regions with high resistivity and latitudes between 55° and 70° are the most vulnerable. Additionally, when storms are more intense and protracted, the risk of damage to the grid increases.
Solar storms can potentially impact electrical infrastructure. Its potential effects include:
- Transformer incidents: Transformers can overheat and sustain damage, leading to prolonged outages and the need to repair or replace the transformers.
- Electric overloads. Solar storms can generate geomagnetic currents that overload transmission lines, which may cause lines to fail or activate protection systems, resulting in power outages.
- Disruptions in control systems. Geomagnetic currents can cause malfunctions in the power grid control and protection systems, affecting their operation and stability.
- Degradation of equipment insulation. Prolonged exposure to geomagnetically induced currents can degrade the insulating material of cables and other electrical components, increasing the risk of failure and reducing the equipment's lifespan.
- Impacts on the communications sector. Solar storms can interfere with communication systems, such as radio signals and GPS, hindering the coordination and management of power grids.
Could Spain experience a solar storm?
A major solar storm is unlikely to occur in Spain given our location at a lower latitude, where such events are less common.
Spain lies between latitudes 36° and 43° north, while solar storms tend to affect regions closer to the poles, above 55° latitude. This is because charged particles from solar winds are directed toward the Earth's magnetic poles.
Despite this low probability, several solar storms have been recorded in Spain since 1941 until today. Though we may not have experienced a disturbance like the 1859 Carrington Event, the Spanish National Geographic Institute has documented the largest solar storms through various observatories.
Over the years, several solar storms have been recorded from different points in Spain, such as the observatories in Toledo, Almería, Logroño, and Tenerife, among others. These observations span from 1941 to 2005, including significant events like those in 1982, 1989, and 2003. These records have allowed scientists to monitor solar activity and assess its potential impact on the power grid and other systems.
In May 2024, Spain witnessed a geomagnetic storm, considered the most intense in recent years. The storm resulted in spectacular northern lights visible across much of the country.
This phenomenon highlighted the importance of implementing preventive measures against more intense solar storms. This leads us to ask, are there any preventive strategies for this type of events?
Can the effects of a solar storm be mitigated?
Spain has research centres dedicated to studying and monitoring solar activity. These include the observatories at the Spanish National Geographic Institute, which conduct constant monitoring to anticipate potential solar events.
The University of Alcalá and the Institute of Astrophysics of the Canary Islands, which collaborates with NASA, are also crucial in predicting disturbances in the Earth's magnetic field. Globally, the European Space Agency (ESA) and the U.S. National Oceanic and Atmospheric Administration (NOAA) lead efforts in monitoring and predicting solar activity, providing critical data to mitigate its effects on ground infrastructure.
Are there protective measures focused on transmission grids? To prevent severe issues caused by solar storms in the power grid, research must be conducted to identify potential weak spots in the system through simulations and enable the development of necessary improvements.
For new power lines, specific transformer and grid designs can be implemented to help reduce the impact of geomagnetically induced currents. This includes adjusting certain technical features, such as the transformers' ability to withstand these currents and the configuration of electrical connections, to divert these currents and minimise damage.
For existing power lines, systems can be installed to limit the presence of geomagnetically induced currents. These systems, consisting of sensors and electronic components, detect anomalies and prevent these currents from entering through the neutral conductor, which is the return path of electric current in a circuit, thus protecting the power grid from potential damage.
In a world dependent on electricity to function, solar storms remind us of our vulnerability. While these events can cause disruptions in power grids, it is important to note that significant impacts are unlikely due to the increasing implementation of preventive measures and the strengthening of our infrastructure, which minimises risks and ensures greater resilience against such eventualities.
