We live in such times – we should be prepared for the worst and take adequate precautions. We should wear helmets and knee braces when riding bikes if our feet can no longer support our weight. In winter, we must salt the pavements and preferably wear scarves.
Northern Lights – Aurora Borealis, Norway Ringvassøya Tromsø. Image credit: Svein-Magne Tunli – tunliweb.no via Wikimedia, CC-BY-SA-4.0
And to think that there are people in the world interested in things happening as far as 400,000 kilometres away! Kristian Solheim Thinn is one of them. He is a research scientist at SINTEF Energy Research working with electrical power components.
“The only real protection from solar storms is to switch off the electricity. Is that tabloid enough for you?”, he asks, before adding:
“If a major storm occurs, we must either live with it and hope that our distribution grids will not be severely damaged, or simply prepare for the fact that we will all be without electricity”, he says. These are the two extremes.
Vulnerable transformers
Solheim Thinn has been talking for some time and explaining the situation slowly and very patiently. He tells us how in 2019 he installed sensors in a transformer in Ogndal in Trøndelag county. The intention was, and still is, to measure and analyse what happens when solar storms collide with the Earth’s magnetic field, creating problems for all of us – not least in northern latitudes where the field protects us far less than at the equator. As Solheim Thinn puts it, the problems caused by solar storms are the result of what he calls geo-magnetically inducted currents (GICs).
It was, of course, no coincidence that the transformer at Ogndal was chosen. Since the distance between neighbouring transformers is so great, it is easier for the solar storms to create problems.
“We are currently as well prepared as we can be”, says Solheim Thinn. “Overhead cables are resilient in the face of solar storms, but we have to consider the transformers because they represent the weak link in the chain. In Norway, our transformers are connected to the main distribution grid, operated for the most part by Statnett, and it is these that are the problem.
– Why is this?
“They are connected to earth, which means that any current induced in the cables passes through the transformers and onward to ground. This creates no problems at lower voltages. However, things are very different during solar storms.
Solheim Thinn explains that our transformers are designed for alternating current. So, when direct current is geomagnetically induced during solar storms, they may start to generate internal heat. This results in increased, or so-called reactive, power consumption that disrupts the distribution grid. This then causes high frequency noise that may result in problems for the control system. Eventually, the transformer cores may become what is known as ‘saturated’.
This in turn causes safety mechanisms to cut in, hopefully disconnecting the transformer before it is badly damaged.
But it doesn’t end there. If one transformer is in trouble, the next in line has to take over. But this means that the second transformer must carry twice the load. This may be more than enough to cause it to throw in the towel as well – and in this way a domino effect will develop.
“In the worst case, we’re talking about a total blackout”, says Solheim Thinn.
First of all, it will start to get cold
This is why the grid operates under a number of precautions. In 2019, the Directorate for Civil Protection and Emergency Planning (DSB) compiled a list of ‘things that can go wrong’ here in Norway. The list includes issues such as the impacts of extreme weather events, flooding, pandemics, cyberattacks, and not forgetting the mother of all catastrophes – solar storms, which were classified as a real threat.
It’s patently obvious that there isn’t a lot we can do about solar storms. When they arrive, we have anything from between 18 and 72 hours to prepare ourselves for something that cannot be stopped. Let me explain. We will only find out how big a solar storm is one or two hours before it strikes the Earth. They can arrive very suddenly.
A recent SINTEF report reveals that there is currently no Norwegian system for solar storm warnings.
“The upside is that during the most intense storms we will get to see some fantastic displays of the northern lights, even as far south as Florida”, explains Solheim Thinn.
The downside is that the impact will be felt for many long months afterwards, and the researcher has no shortage of issues on his list. Disruptions to satellite navigation systems will make things very difficult, even for ordinary vehicle traffic. The vessels that we rely on to maintain oil and gas production in the North Sea will not be able to operate as they should. Excavators that depend on GPS guidance systems will grind to a halt. Both high and low frequency radio transmissions will cease, and you will not be able to fill your car with fuel.
“Petrol pumps also rely on electricity”, says Solheim Thinn.
“After two hours, the batteries at the base stations supporting the mobile network will run out. We will then lose mobile coverage and things will really begin to go downhill”, he says.
First of all, it will start to get cold.
And when this happens, it will be up to us ordinary folk to have done our homework in advance. The DSB has compiled a contingency list for households. Nine litres of water, two packets of crispbread, a packet of porridge oats, three packets of dried foods, or tins, per person, as well as warm clothes, blankets, sleeping bags and a battery-powered DAB radio.
The solar storm of 1859
One of the most famous solar storms in recorded history was the Carrington event of 1859, named after the British astronomer Richard Carrington, who was observing some intense sunspots.
“The event occurred during one of the famous Californian gold rushes, and one urban myth suggested that the light was so intense that miners were able to pan for gold at night”, says Solheim Thinn. “The telegraph lines glowed red in the dark and the terminals caught fire”, he says.
In 1921, we saw evidence that solar storms could create problems even when technological infrastructure was in its infancy. For the three days during which this storm continued, electrical fires were started all across the world. The worst examples were in New York. Trains were brought to a standstill, so the storm became known as the ‘New York Railroad Storm’.
In 1972, a solar storm detonated several thousand sea mines along the coast of Vietnam.
“This was the first occasion on which problems were reported with satellites”, says Solheim Thinn.
In 1982, problems with as many as four transformers and 15 power lines were recorded in Sweden. This event also caused disruptions in Norway, but no blackouts occurred.
In 1989 a solar storm caused a nine-hour outage in Quebec.
“We also experienced solar storms in 2003, 2017 and most recently in 2022, when the company Space X lost 40 of its satellites”, says Solheim Thinn.
According to the New York Times, the storm cost Elon Musk more than one billion kroner.
Things could have been much worse. In 2012 the planet experienced a near miss. It is calculated that if this storm had struck the USA, it would have caused in the region of 20 trillion dollars of damage. This is equivalent to twice the Norwegian Government Pension Fund Global, and would have been as catastrophic, in financial terms, as a large asteroid colliding with the planet, less the social and human costs and loss of life.
But enough of these horror stories. Let’s get back to Ogndal in Trøndelag, and what has been discovered there.
The unpredictability of space
“If you can’t measure it, you can’t prove that it exists”, says Solheim Thinn.
“We’ve installed sensors in the transformer at Ogndal in order to take measurements and calibrate our data models”, he says.
Several factors have to be considered, one of which is solar activity, which is not too difficult to monitor. The US Space Weather Prediction Center (SWPC) is a mine of information, but there is one problem – the difficulty of making reliable long-term predictions.
The Tromsø Geophysical Observatory has deployed several magnetometers with the aim of measuring the strength of the Earth’s magnetic field. One of them is in Røyrvik, which is between 150 and 160 kilometres away. The magnetometers measure both the natural geomagnetic field and the magnetic perturbations generated by solar storms.
Naturally, these measurements are in real time, but they can also help us to understand how the geomagnetic field is influenced by events in space, including the solar storms that induce currents in our distribution grids and transformers.
“We also have to know about the electrical conductivity at depths of several hundred kilometres below the Earth’s surface”, says Solheim Thinn. This is because the geo-magnetically inducted currents also penetrate deep into the Earth’s crust, and in turn impact on the inducted currents flowing through the transformers”, he says.
Solheim Thinn explains that it is difficult to construct reliable predictive models because electrical conductivity in the different geological layers within the crust is very variable. It is especially difficult to assess electrical conductivity at the transition between the sea and land. The ocean exhibits relatively high conductivity, while the opposite is true for land areas.
“On the other hand, it is not difficult to identify correlations between magnetic field measurements and actual geo-magnetically inducted currents in our distribution grids, provided that both are being measured at the same time”, says Solheim Thinn. It is possible to calculate a ratio that describes their inter-relationship”, he says.
Long seabed cables installed on the continental shelf are very vulnerable to solar storms. One of the studies cited in the SINTEF report focused on the influence of the conductivity of shallow offshore continental shelves, similar to the situation in the North Sea. It demonstrated that the geo-magnetically inducted current would be three times as strong if the ocean had not been there.
Solheim Thinn has also made a couple of other finds. The ionospheric electrojets that circle the Earth’s magnetic poles travel for the most part in an east-west direction. Researchers have believed for some time that solar storms impact on electrical power lines in different ways, depending on the direction from which the current is travelling. But this has now been shown to be untrue.
“It makes no difference at all whether power lines are oriented in a northerly, southerly, easterly or westerly direction”, says Solheim Thinn. They still remain just as vulnerable”, he says.
Solheim Thinn also believes that there are differences in resilience between different transformers. In recent years, transformers have been purchased that are resilient to solar storms for a given period because they are designed not to overheat too quickly. It has been shown that three-phase transformers installed with five-limbed iron cores become saturated more quickly than the three-limbed type.
“For this reason, it is now recommended to install three-limbed three-phase transformers in the most important and most vulnerable substation facilities.
Approaching a solar maximum
Most people are aware that the sun exhibits periods of greater and lesser activity, defined within an 11-year cycle. Solheim Thinn explains that during the first two years after the sensors were installed at Ogndal, only very low levels of activity were recorded. However, starting in 2021, and during the remainder of that year, six measurements were made indicating so-called moderate effect activity.
“During moderate effect activity, our transformers will remain resilient, but this may not necessarily apply to the grid”, says Solheim Thinn.
On 4 November 2021, a transformer went down at a neighbouring substation in Namsos, about 70 kilometres from Ogndal.
“The safety mechanism was tripped, and this disconnected the transformer”, says Solheim Thinn. “Our findings indicate that there is a connection between reactive power consumption, geo-magnetically inducted current, and changes in the magnetic field as recorded by space meteorology instruments. In other words, when we measure strong currents, we observe a simultaneous and major peak in reactive power consumption. If we exceed the safety mechanism threshold value, this trips the transformer’s circuit breaker”, he says.
However, even if a transformer takes a time-out and goes down, as happened in Namsos on that late autumn day, this was hardly noticeable to electricity consumers. This was because other transformers stepped in to do the job. The electricity grid operates with a so-called ‘buffer’, or reserve capacity, which in this case kicked in to avert a crisis.
“However, it was a close call and a stroke of luck that the Ogndal transformer remained in operation”, says Solheim Thinn.
“In 2024 we will be entering a period in the cycle when solar activity is at its highest. Solar storms are classified on the basis of their intensity. A G1 storm is a small one, while the most intense is classified as G5.
“We expect to see four G5 solar storm events during every 11-year cycle”, says Solheim Thinn. “The current cycle is expected to display its highest levels of activity in 2024 and 2025”, he says.
– What will this mean?
“We will most likely experience control and safety issues in the electricity grid”, says Solheim Thinn. “We may experience a collapse or blackout of the grid, and some transformers may be damaged. We will also experience problems with satellite navigation”, he says.
We can in fact only hope that the worst doesn’t really come to the worst.
Source: Sintef
