How much can solar panels reduce your reliance on the grid?

Saving money on electricity bills is the main driver for many customers looking to add photovoltaic (PV) solar panels to their home. 

But just how much can a PV system save you? How much can it reduce your reliance on the grid? Here’s what our customer, Matt, had to say about his solar panel system, and the impact it’s had on family life.

Saving power and saving pennies 

Matt and his family live in a three-bedroom, semi-detached home in Leeds which would typically use around 4,600kWh of electricity per year. 

After installing a solar PV system in his home in 2011, Matt was so impressed with the amount of power generated and savings on his electricity bill that he upgraded to an even bigger, more efficient system in 2015.

In his patch of the UK, Matt could expect his panels to generate around 3,800kWh a year. For context, this is around the figure the Department for Business, Energy and Industrial Strategy uses as the average annual electricity consumption of a UK household. 

Although the amount of energy generated by solar systems will change through the year, on a particularly sunny day in June, Matt’s solar panels generated 29kWh of energy in just 24 hours. 

What happens to the excess energy? 

On this specific sunny day, 29kWh was more than enough energy for Matt and his family. They only ended up using around 12.5kWh. 

But where does all that excess solar energy go? 

During the day, Matt’s home was powered with 8.9kWh of electricity generated by his solar panels. This meant he didn’t have to buy any electricity from the grid whilst the sun was shining. Winner. 

The remaining 20.1kWh of energy would normally have been exported back to the grid, because it wasn’t needed in Matt’s home that day. A solar PV system generates more energy when the sun is at its highest and brightest, peaking between 12-2pm. But in most cases, this pattern doesn’t match the demand of electricity in an average home. 

When you’re singing in the shower before work and brewing that first cup of coffee, like most UK households, your home is probably experiencing a surge in the amount of energy you’re using. It’ll probably happen again later in the day, when you’re cooking dinner and binge-watching the latest box set.

And here’s where battery storage really comes into its own. You’ll be able to store any excess energy generated and use it in the evening when you need it. 

Imagine using your solar energy after the sun sets, and still benefiting from solar during winter's shorter daylight hours.

Life is better with a battery

The benefits of a battery are mighty. Without a battery, Matt’s home would only use the energy from his solar panels as it was being generated. He wouldn’t be able to store any of the ‘excess’ power. During the night – when the solar panels weren’t generating – Matt would need to buy 3.6kWh of electricity from the grid. (You can see where we’re going with this, right?)

Fortunately for Matt, he installed a 13.5kWh Tesla Powerwall. And this was what made all the difference.

“We decided to add a battery to our home last year. Both my wife and I work during the day, meaning that a lot of the electricity our solar panels are generating isn’t actually being used by us. So we decided that the ability to store that energy for use when we get home would be the logical thing to do.”

Because his battery is able to store ‘excess’ energy generated by his solar panels, Matt stores up his renewable electricity for use at a later time – when the sun isn’t shining, or when his household demand is particularly high. 

During the periods when his solar panels weren’t generating energy and when his household usage peaked during the day, Matt was able to use the electricity stored in his Tesla Powerwall rather than buying electricity from the grid. 

So, just how much electricity did Matt buy from the grid? Almost none – a mere 0.01kWh. Matt’s home is almost entirely energy independent.

On a typically cloudy and drizzly British summer day, Matt’s solar panels might not have the same level of performance as they do in mid-June. However, across five months from May to September, with solar panels and battery storage installed, the amount of energy Matt’s household imported from the grid fell from 1619kWh to just 18kWh. That’s less than two days’ worth of average energy consumption, spread across five months.

Want to learn more about battery storage? Find all the answers you need in our guide on battery storage benefits.

A more independent, sustainable energy source

“Since having the Tesla Powerwall installed, our electricity savings have risen from around 30% to around 80%. On sunny days we are able to power our home 100% from our solar and battery system, meaning that some days we don’t buy any electricity from the grid at all. It’s a great feeling!”

“The ability to generate and use our own dedicated renewable electricity gives us a sense of independence and pride that we’re doing our bit to help the shift away from fossil fuels.”

Not only has Matt’s solar and battery system dramatically reduced his carbon footprint, his increased independence from the grid means he’s saving a huge amount on his bills, too. That’s a happy tale for Matt’s household, his wallet and the planet.

To find out how Egg can help you find the right solar PV solution for your home.