You’re at home, snuggled on the sofa, in front of Britain’s Got Talent and suddenly you are plunged into darkness.
The electric oven goes off, halting the cooking of your pizza.
The room starts to get cold as the electric heater fades away. No kettle, no alarm clock, no charging of mobile phones, no laptop, the list is endless.
You’re in the middle of a blackout, back into the dark ages – your house is suffering from a power cut.
Without all the modern comforts, most of which rely on electricity, those minutes can seem like days.
While you are at home rummaging under the sink for a candle, a hub of activity is happening at the Scottish & Southern Electricity depot in Cosham.
The depot looks after the power network covering the south of England, delivering electricity to over 2.8 million customers.
Agents are waiting for phone calls 24 hours a day, while other members of staff are monitoring the power grid on a series of screens akin what you would imagine in an air traffic control tower.
Andy Brown, operations manager at the Cosham depot, says: ‘Our number one priority is keeping our customers on supply and keeping their lights on.
‘On the rare occasions when the power does go off, we will do everything we can to restore supply as quickly and as safely as we can, as well as keeping the customers updated.
‘It doesn’t happen that often but when it does, it is a massive inconvenience and we understand that so we work hard to try and get them connected again quickly.’
Call centre workers sit nearby while we talk, handling a trickle of calls from customers who are experiencing power cuts.
Tom Humphrey, 27, from Eastney, is one of the operators.
He tells me that the team is constantly checking for bad weather and when it’s predicted, his manager will draft in extra staff to handle the calls which could arise from overhead power lines being brought down.
Although, he says it doesn’t matter whether a whole street is plunged into darkness or it’s just your house – you’ll get the same treatment.
‘We treat all the customers as a priority. Whether it is a single call or whether we are receiving multiple calls in an hour, they receive an engineer within two hours who will investigate and work to fix the problem,’ he says.
The calls are logged on Tom’s computer, which is being monitored by another department who dispatch engineers working on the ground.
At the same time, another department is keeping watch for disruptions to the main power network which feeds into the smaller circuits supplying individual roads, ranging anything from one house up to several hundred.
It’s a massive operation, and one that operations director Andy knows well.
He talks me through some of the problems which lead to power cuts.
He says, ‘Our most common cause of interruptions is cable damage caused through excavation.
‘Sometimes it’s just people at home putting up fences, sometimes it’s contractors digging up the road.
‘These interruptions can affect anything from one person to thousands of customers.’
Andy says that SSE has a mapping service which shows all the potential problem points, which they send out for free if people are doing work and they request it.
‘We have thousands of kilometres of underground cable which are under every road and street, so it can be easy to damage them.
‘We would like that they are buried at least four and a half metres underground, but that’s not always the case.’
Andy says that while cable theft and overhead cable damage are big problems, the hardest to determine is cable damage, especially when it is not reported to them.
This is when a cable is partially damaged under the ground, making a break in the PVC plastic coating of the cable.
This allows water to seep in during periods of heavy rain.
Once the interior aluminium cable is wet, it causes small explosions, which knock out people’s power supply.
These small explosions cause heat, which eventually dries out the cable and restores the power, restoring the electricity to your house.
This can occur in a cycle and proves particularly annoying as once the engineer arrives at your home, the power is back on, making the fault hard to locate.
Andy says, ‘At three or four times, the customers are starting to get fed up.
‘That’s when we will section the network and try to isolate the supply until we find where the problem lies.
‘Then we know to replace the cable on that section of the network. It’s one of our biggest headaches.’
SSE runs a constant programme of investment and upgrade, making its cables more flexible and easier to work with.
Andy assures me that even the older cables stay sound, as long as they are not damaged.
‘There are cables that have been on our network for 70 years and they are still as good as they were on the day they were put there.’
How to cope with a power cut
Keep a torch with fresh batteries in a place where you can reach it easily.
Turn off your electrical appliances and lights, but leave one light switched on so you know when the power is back on.
Be careful if you use other forms of heating and lighting, such as paraffin heaters and candles.
Remember that the doorbell will probably not work, nor will an alarm system.
If you have been warned that the electricity will be turned off, boil some water and keep it in a thermos flask.
You can use it to make hot drinks or fill a hot water bottle if it gets cold
When your supply is back on, you may need to reset electric timers, alarm clocks and so on.
Food in the freezer should keep for about eight hours without power.
Do not open the freezer doors unless you have to.
Check the food when the power is back on to make sure it has not thawed. If it has, do not refreeze it.
You may be able to claim on your household contents insurance for any lost food. Check your policy to make sure.
Scottish & Southern Energy Power Distribution is responsible for maintaining the electricity networks which supply over 3.5m homes and businesses across central southern England and north of the central belt of Scotland.
But what should you do if you are suddenly without power?
Here’s the official advice from SSE.
Check with your neighbours if they have lost power. If they have, it’s likely that the fault is with the local network.
You might notice that the streetlights are still on but all the lights in the houses in your street are off, or that only every second or third house has power. This is because once the power leaves the local sub-station, it will sometimes be split across two or three circuits before it’s delivered to the homes in your street.
Usually if there’s a fault at the local sub-station, only one of the circuits will be affected. That’s why just some homes will lose power.
If everyone else has power and your home doesn’t, it’s likely to be an issue with your fuses or trip switches.
Check your fuses and trip switches to see if these have cut your power.
If they’ve tripped or blown, it’s likely that you have a faulty appliance or problems with your wiring.
Check your appliances.
If you think you have a fault with your appliances, fusebox or wiring you’ll need a qualified electrician and shouldn’t try to repair it yourself.
Phone SSE Home Services on 0845 712 5349 for advice on finding an electrician.
If you’ve checked your fuses or trip switches and your appliances and wiring are not faulty, you should report the power cut. Contact the emergency line on 08000 727282.
They will give you up to date information for your area and one of their specialist advisers should be able to let you know when your power will be back on.
Andy Brown is the operations manager based in Portsmouth.
He has worked for SSE for 25 years, starting as an overhead linesman in 1988.
During his time with SSE, Andy has worked in many aspects of the business including stints on the ground and in the office.
Before transferring back to Portsmouth in 2011, he was the operations manager at SSE’s depot in Aldershot.
Andy, who lives in Alton with wife and two children, says that he has never even thought about looking for another job as the possibilities for change all exist under the SSE umbrella.
Andy says: ‘I have spoken to friends who have jobs with other companies, who tell me that after three or fours years they start to get bored and want to move on.
‘With SSE you can move on, but in one organisation. I was a linesman, then moved into large power, then became a team manager and then ops director.
‘You are having that change of environment but in one company. It’s a very good company to work for and we employ about 20,000 members of staff.
‘These days, I have the pleasure of coming into Portsmouth. It’s a fantastic depot with a very, very strong team, which is great.’
The Cosham depot shares the site at Walton Park, Walton Road, with Scotia Gas Networks, who look after the south’s gas supply, although the two networks operate independently.
SSE employs around 700 staff who work from the Cosham depot.