A large solar flare frying all of Earth’s electronic devices and sending us back to the stone age sounds like the plot of a bad science fiction movie—but it could happen. Luckily, protecting your electronics from solar flares and electromagnetic pulses (EMPs) is quite simple.
You don’t need to spend hundreds of dollars on high-tech equipment, and you may even have everything you need sitting in your kitchen. But, if you do want to get your wallet out there are cheap, reliable, EMP-proof containers on the market. In this article, we’re going to look at exactly how the sun could cook your favorite tech and the science behind stopping it.
Solar flares are explosions on the sun’s surface that throw out heat, light, and massive radiation. They also produce an electromagnetic pulse. More minor flares occur pretty often, and the largest ones, “X Class solar flares,” happen around ten times per year. The disruption caused by X class flares is usually limited to radio blackouts, but a particularly bad flare hitting at the right time could cause far-reaching damage.
The flares happen when parts of the Sun’s magnetic field cross and rapidly reorganize themselves. This reorganization can cause the sun to throw out large amounts of heat, light, and radiation. A coronal mass ejection, which is a huge outburst of solar wind plasma capable of throwing a billion tons of solar material into space at hundreds of kilometers per second, is also possible.
Scientists can predict solar flares before they happen, and when they do occur, it still takes time for the EMP to reach Earth. So if you pay attention to the news, you’ll probably receive some warning that a flare is on the way. Then you have to get your vulnerable, expensive tech somewhere safe.
A solar flare is also powerful enough to interfere with the Earth’s magnetic field. So compass readings may be off by up to 10 degrees, and auroras will be brighter and visible far further south than usual. During the Carrington event, auroras were visible as far south as Colombia and bright enough to read a newspaper under.
While most EMPs the sun produces are too minor to cause damage, a large flare could have a pulse large enough to destroy electronics on Earth. An EMP contains a bunch of charged particles; when those particles hit something conductive, they impart that charge on that conductive object, creating current in a part of a circuit that should not be active, or overloading a powered line.
Electronics are designed to work in a particular way, and an electrical charge being somewhere it shouldn’t is a major issue. Components can be fried, and wires can melt when they become overloaded.
A major solar flare has knocked out electronics around the world before. In 1859 the Carrington Event, which was the largest solar storm in recorded history, knocked out the world’s telegraph systems. There were widespread reports of wires sparking, telegraph operators receiving shocks, and electrical fires springing up. Due to the amount of power the solar flare put into the lines, some operators were also able to send messages through the telegraph system without hooking up batteries.
Electronics are far more widespread now than they were in the 1850s. Experts predict a modern-day Carrington event could cause trillions of dollars worth of damage and leave major population centers without power for weeks.
Although the Carrington Event is the most damaging storm on record, severe storms are quite common—occurring roughly once every three years. Six “superstorms” have also happened over the last 150 years, some of which have caused damage. The last storm to cause notable damage happened in 1989 and knocked out part of Quebec’s electricity grid for nine hours. In 2012, a coronal mass ejection powerful enough to count as a superstorm narrowly missed Earth.
Back in the 1800s, British scientist Michael Faraday did a lot of pioneering work around electromagnetism. One of his most notable achievements was establishing the concept of the electromagnetic field. He also invented a kind of enclosure that will shield whatever you place inside it from electromagnetic radiation. This enclosure is known as a Faraday cage.
A Faraday cage doesn’t just protect your stuff from EMPs and solar flares. It also counters electrical shocks, so you can use it to protect sensitive devices in a static-heavy environment. This works because electricity will always take the easiest route to the ground. It is easier for a surge of electricity to travel around the outside of the highly-conductive cage than it is to leap through the far less conductive air or insulated layer inside it.
You can see a Faraday cage at work in this video:
Whatever you decide to use as a Faraday cage, you should test it out before relying on it to protect something you value. Testing a Faraday cage is simple. Take something that requires a signal like a phone or a radio, place it inside the cage, then see if it still receives a signal. If you can’t call the phone, or the radio gets nothing but static, your cage works.
Although it may sound like a piece of high-end scientific equipment, Faraday cages are pretty easy to get hold of. Major retailers like Amazon and Walmart stock a wide variety of “Faraday bags,” with the cheapest examples selling for less than $10.
Most of the Faraday bags you’ll see are just simple pouches, but there are also backpacks, duffel bags, and laptop bags available if you want something you can use every day. Just remember, a Faraday cage will block a phone signal, too, so don’t put your cell phone in one when you’re expecting a call.
If mass-produced Faraday bags and cages don’t suit your fancy, it’s not too difficult to build your own from scratch or convert a household item into a Faraday cage. Making your own is as easy as constructing a frame from wood, or wire, or a discarded object like a birdcage, and surrounding it with a fine metal mesh. Copper and aluminum are the best metals for your mesh, but steel chicken wire will also work.
You can also buy Faraday fabric—a sheet of cloth with conductive mesh woven into it. Faraday fabric can be used to line a box, bag, or even a room and turn it into a Faraday cage. If you have a favorite laptop bag or backpack but wish it offered an extra degree of protection for your devices, consider sewing in a Faraday fabric lining. One thing to remember is that Faraday cages block radio signals too. So if you leave your phone in a bag, pocket, or pouch you’ve lined with Faraday fabric, don’t expect any calls or texts to come through.
Aluminum foil can be used to make a Faraday cage. For a single-use cage, you can place the device in an insulating layer, like a plastic sandwich bag, then wrap it directly in the foil. If you want multiple uses from your foil, you can use it to line an envelope or similar pouch, then place another envelope or bag inside it to form an insulating layer. The foil needs to surround the device with no holes or gaps in either case.
To some degree, any kind of metal box will function as a Faraday cage, so you may be tempted to shield your tech in a conventional oven or microwave. Unfortunately, this won’t always work. While an oven or microwave may offer some degree of shielding, they aren’t close to a perfect Faraday cage and are unlikely to give the level of protection you need.
While searching for a way to stop criminals remotely erasing data from phones seized as evidence, a Massachusetts police department turned to commercially-available microwave ovens. The department’s reasoning was if it blocks out microwaves, it should block a phone signal. They tested a couple of microwaves and found out they were wrong (and were also wrong about microwave ovens blocking their own microwaves).
You may still already have an effective Faraday cage in the house. Anything designed to block RFID signals will be using a Faraday cage. So if you bought a backpack, box, or wallet which offers RFID protection, you already have a functional Faraday cage in your possession. And if you haven’t got a Faraday bag handy and push comes to shove, you should go for the aluminum foil and sandwich bags.
Monitoring news websites and reports from agencies like the Space Weather Prediction Center, NASA, and the European Space Agency is a great place to start. Unless you plan on keeping your laptop and cellphone in a Faraday bag 24/7, you’ll need to know when a solar flare is coming. A solar flare can also increase the amount of electricity flowing through the power grid, so installing surge protectors may give you an extra line of defense, along with protection from more common occurrences like lightning strikes and grid malfunctions.
Even if you protect everything in your home, there is every chance the power grid may be knocked out for some time. Therefore it is probably a good idea to prepare for a long power outage by purchasing a backup generator and storing two weeks’ worth of water and canned or dried food. Power agencies do closely monitor solar forecasts and make adjustments to minimize damage where necessary, so while this is unlikely to be a major issue, it’s better to be safe than sorry.