Using solar power during outage

[Runor]

I have solar panels, but if the mains electricity goes off, then they don’t run. I understand why that is - so that electricians working in the area know that when the grid is down, there aren’t any other power sources, so they can work safely.

Of course this doesn’t really fit a prepping model, so is there any safe & legal way to circumvent this - effectively shifting the house off-grid in the event of a power cut?

Your solar panels would be unlikely to power your house during a power cut. You could however get batteries that charge from your panels, however this will be dependent on exactly what deal you signed up to when you got solar panels.

I don’t expect to keep the whole house going, but it would be nice to keep the food in the freezer safe!

We have solar panels, they supply our power and they also charge to the grid and charge up 2 big batteries. When the power goes out we have to isolate our house and they switch to the batteries. They don't automatically switch on when the grid goes down.

Like @Nellieinthebarn we have a switch that we have to turn on that allows a limited supply from the batteries

Yes it is limited, it keeps the lights on, and the freezers ticking over, but it wouldn't run the cooker for long or the heating. You still need an alternative for cooking and heating, we have a wood burner and a couple of primus stoves. I have managed to make quite nice dinners, usually a stew type thing and rice or spuds. I can just about do soup on the top of the wood burner.

That sounds like exactly what I want - how did you get it in place? I did ask one electrician, but he was concerned about whether it could be done legally

I had them installed at the same time as the solar panels and air source heat pump. It was a specialist company, its all legal and above board, we had to get a certificate to get the grants and the feed in tariff.

Thankyou Nellie and tailor, I’m going to look for a different electrician to sort that out.

When we got solar, there was a much more expensive option of off grid, which would keep working if the power is down. It is definitely possible, but you pay. It wasn't worth the extra for us, but everyone has different budgets and priority.

Most fridges/freezers now last for a certain amount of time - our freezer it's 18hours.
We do have a generator which we rarely use, and we also have an inverter in my husband's van - so can throw leads in, charge phones, and pop the freezer on to cool, back down. Nowadays the electricity company tend to get the generators out relatively quickly, in most cases you're back on within 6-12 hours - there is a maximum otherwise they have to pay you.
For cooking we have a small camping stove and for heat a log fire.

You can get a solar installer to installer a retrospective battery to your system. You will need to tell the electricity network operator, and they will tell you if you need to upgrade your supply in order to have the battery, you may need to upgrade to three phase supply but it is looked at on an individual basis, depending on the demands on the network in your area.

A generator switch will fully isolate the mains supply allowing you to safely power your house from batteries or a generator.

You can get ones which will switch over automatically in the event of a power cut but they are expensive.

We have a backup gateway system in the case of a power outage. Had it installed retrospectively because they forgot to add it when they installed the solar panels and battery. It is a manual changeover switch which makes your home an island so that engineers working on the grid cannot get electrocuted. Some systems have them as part of the package like GivEnergy I think, but it took half a day to fit one into our system. You need an inverter that has it as an option though and not all do. Ours can run the fridge for several days off the battery. Not so worried about the freezer as you can run it intermittently to keep it frozen. You can get batteries for camping/home backup use not linked to solar such as Bluetti or Ecoflow that you could charge from the solar and leave charged in case of a power outage.

We have a couple of camping batteries with fold up solar panels to charge (we have Jackery). We can also charge the batteries from mains electric or a car. In the summer we manage to run electronics (internet, laptops, phone chargers etc), slow cooker and lights in the evening off the batteries. I also charge AA/AAA batteries off the jackerys, and use these as much as possible. In the winter, we keep the big batteries topped up for power cuts. In a poweroutage we can periodically plug the freezer in to keep things frozen and can run a slow cooker off one battery. The other we keep for anything else. I'm gradually adding to our array when funds allow and there is a good deal. The fold up solar panels are great because I can move them easily to maximise intake. It's amazing the difference a couple of inches makes. Our roof is not much use for fixed solar, and this bodged solution is cheaper as well. I dream of telling the electric company to bugger off.