Can I Run My House Entirely Off-Grid from Solar and Batteries?
It is easy to assume that if you have enough solar panels and a large battery, you should be able to disconnect from the electricity grid altogether.
For most homes in the UK, however, that is not really practical.
The main problem is not summer. During the brighter months, a well-sized solar PV system can generate plenty of electricity and may regularly produce more than the home can use.
The difficulty comes in winter.
Why is going completely off-grid difficult?
Solar generation varies enormously through the year.
During winter, the days are shorter, the sun is lower in the sky and there can be long periods of dull weather. At the same time, household electricity demand may be higher.
A battery can store surplus electricity generated during the day and make it available later, but it cannot create energy.
If there is very little solar generation for several days, eventually the battery will run down.
To operate completely off-grid throughout the year, a home would therefore need a much larger solar array and battery system than would normally be installed. Even then, some form of backup generation might still be needed during prolonged periods of poor weather.
For most households, keeping the grid connection is therefore the more practical and economical solution.
How close can solar and batteries get you?
A well-designed solar and battery system can greatly reduce the amount of electricity you need to buy from the grid.
For much of the year, some homes may operate largely from their own solar generation and stored energy, with grid electricity mainly needed during poorer winter periods.
Could I still achieve a zero electricity bill?
Possibly.
Being off-grid and having a zero annual electricity bill are not the same thing.
You may still import electricity at times, but income from exporting surplus solar could help offset those costs. In the right circumstances, annual electricity costs could potentially be reduced to zero or even result in a net credit.
System design is important
If your aim is to minimise grid use or annual electricity costs, the system needs to be sized around the property, available roof space, household consumption and battery requirements.
A larger system is not automatically better; the important thing is that the solar array and battery are properly matched to the household’s needs.
So, do I still need the grid?
For most UK homes, yes.
Trying to operate completely off-grid using only solar panels and batteries would normally require a disproportionately large and expensive system and may still require backup generation during poor winter weather.
A more practical goal is to use solar and battery storage to reduce reliance on the grid as far as reasonably possible.
Want to know what’s realistic for your home?
If you would like to reduce your reliance on the grid as far as possible, talk to our solar and battery experts. We can look at your property, electricity use and available roof space, and explain what level of self-sufficiency is realistically achievable.
