That is a basic question – but it’s an essential one. Solar panels, over time, can save you a bundle on electricity bills, but to all intents and purposes, most UK homes will not achieve year-round independence without some compromises.
A decently sized solar PV system can account for most, or potentially all of your daytime electricity use on sunny spring and summer days. If you are at home mid-day and able to run more appliances when the sun is shining, then all systems will benefit! For Solar Panel Installation Portishead, consider https://redbridgeandsons.co.uk/solar-pv-panels/solar-panel-installation-portishead/
However, solar output fluctuates every hour. It peaks around midday and decreases late afternoon again, and of course during the night.
The largest constraint: nights and winter
As solar panels can’t produce electricity in the dead of night, and Brits are averaging short winter days that tend to be cloudy, it’s a problem. That means:
You will still draw some power from the grid during night hours
You might have a massive amount of importing in the winter, opposite to what you do in the summer.
That last bit is important because when you say, “run my whole house,” this implies to never use the grid again.
What about a battery?
It allows the excess solar energy created during the day to be captured and stored for use later as you need it (eg, starting from evening/night). It helps you to consume more of your own solar.
However, a battery isn’t magic:
It cannot hoard weeks of energy to survive the winter.
How much ‘spare’ solar is there in winter to fully charge it?
It’s all about battery size, though: a puny cell might only carry you partway through your evening hours.
Your Lifestyle Is More Important Than You Think
Solar is an excellent pairing for those with energy use during generation. The results will be superior if you:
Limit using the washing machine/dishwasher to the day hours
Charge devices during daylight
Use timers for appliances
Because if you are out all day, your export to the grid will be higher, and in the evening, most of your consumption needs would be powered by the power supplied from the National Grid.
A modest goal: not off the grid, less on it. The only realistic expectation for most UK homes is:
Big savings in spring/summer
Smaller savings in winter
Fewer bills overall – and more energy independence
Receive a custom estimate
The next thing to do is ask installers for an estimate of your average annual generation, how much you will consume yourself, and what difference a battery would make.