Going ‘Off Grid’ with a Solar Energy System
Can you go off grid with a solar energy system?
Yep, you sure can – but not with all systems and certainly not if it’s a basic, panels and inverter system.
What does going ‘off grid’ mean?
The concept of off-grid is not something that the UK has been fascinated by, but we are starting to find the idea of energy independence very appealing.
Traditionally, any solar systems installed in the UK were to enhance the energy supply to the home – and occasionally sell back to the grid.
However, with the rises in oil prices, the energy cris and the uncertainty of our world, people are starting to look at stand alone systems.
That means they want a solar system that will take care of their home’s entire energy usage, without troubling their electricity provider.
How do you go off grid?
In the UK, that’s not an easy ask, but it’s not impossible.
The first thing you have to have is an energy storage method, as there is no way you can utilise solar power after the sun goes down.
You also need a way to isolate from the grid.
Why?
Well, all domestic solar energy installations have to be approved by your grid provider if you are connected to the national supply.
This is for a number of reasons, the most important being the grid can only handle so much power and if we are all pumping 100s of kilowatts into the system, it’s going to fail.
There’s also a safety issue, if there is a power cut and people are working on the problem, the lines must be dead or else someone could get badly hurt.
Gateways
One way of ensuring you solar system is fit for purpose and easy to disconnect from the grid is by fitting a 'Gateway’.
This is a device that speaks to all the different parts of your solar system to ensure all the electricity is flowing to the right places at the right time.
Sort of a belt and braces approach in conjunction with your inverter, optimisers and battery.
This extra safety feature means the electricity can be stopped from going to the grid if there is a power cut.
But it also means you can take your system ‘off-line’ any time you feel like it.
Harvesting energy from the sun
So, to go off grid you’re going to have make sure you have enough solar panels to power your home and fill your batteries.
This is an easy ask when the days are longer, domestic systems constantly power whole households between April and October.
However, in the winter, when the sun is weaker and lower in the sky, it can be much more difficult to generate huge amounts of energy with only a few panels.
To put it into context, a typical July in London sees approximately 4.74 kilowatt-hours per square meter (kWh/m²) of solar energy hitting people panels.
The panels are around 22% efficient so we can harvest about ??? per square meter – which, if you have 10 plus panels is plenty of power per hour.
In winter that irradiation can drop to a lackluster 0.54 kilowatt-hours per square meter (kWh/m²) – so a significant drop in energy production but not a total; write off.
If you are connected to the grid, it’s easy to fill your batteries with the power from the sun and by using SEGs to take advantage of night-time tariffs.
However, a standalone system would need to have significantly more panels to keep up with demand.
How many panels would I need to go 'off-grid'
So, if you are only getting the 0.54 per square meter, and your panels are 22% efficient, how much do you need to power your home?
A high use home uses about 11 kWh a day – which may be slightly more in winter.
To produce that much, you are going to need 93 square meters of solar panels – which sounds a lot … because it is!
That’s around 9 meters by 10 – with panels being 1.5 metres long by about 3 quarters of a meter wide that makes it 12 panels by 6.
So 72 panels.
Which is absolutely doable if you have the space, but not something you could do on a new-build estate in Doncaster.
Extra precautions for going ‘off grid’
While going off grid with solar is achievable, it’s not very practical.
In fact, it’s unwise to rely on a single source of power for your home, just like it’s unwise for national energy providers to do the same.
The power comes from coal, gas, nuclear, wind, solar, bio-fuel, burning rubbish, hydro and, on occasion, countries in the EU.
Now, while you can’t take advantage of the grid if you are ‘off-grid’, you can add other energy generation equipment to your property.
The first, and most simple, would be a wind turbine.
These are not huge, windmill-like generators and are becoming much more popular in the UK.
Domestic wind turbines look a bit like little helter skelters on poles, they are a bit of a nightmare to get past planning but are very practical if you have the room for them.
The next best thing is a diesel generator.
Larger inverters will a facility to switch to a generation when the solar isn’t generating and the batteries are flat.
Conclusion
If you needed or wanted to, you can certainly move towards going off grid, even her in the UK.
You wouldn’t be able to do purely with solar unless you had the land or space to install a large number of panels plus a good amount of storage for the evenings.
You’d also have to keep an eye on the energy you used, which we presume anyone looking to go off grid would do anyway.
In a normal, domestic situation, we’d recommend not trying to go ‘off-grid as the average home in the UK would not have the land or roof space to fit enough panels.
You can, however, reduce your bills, gain energy independence and do your bit for the planet by fitting a solar energy system on your property.
