How Off-Peak Tariffs Can Transform Your Battery Storage System

Laura Alliss
1 day ago
4 min read

As energy prices continue to fluctuate across the UK, more homeowners are turning to battery storage to take control of their usage and reduce their bills. But what many people don't realise is that the real savings don't just come from storing excess solar – they come from using the right tariff.

What are Off-Peak Tariffs?

Off-peak tariffs give you access to cheaper electricity during certain hours – usually overnight when the grid is quiet. And this is where it gets interesting. Pairing a home battery with one of these tariffs means you can top up your battery at the lowest possible price, then rely on that stored energy during the day when rates are at their highest. It's a simple shift, but one that can make a huge difference to your monthly bills.

Energy suppliers (e.g. Octopus Energy, British Gas) offer these cheaper periods to help balance demand on the grid. During the night, far fewer homes and businesses are using electricity, so prices drop to reflect that lower demand. Depending on your supplier, off-peak windows can range from a fixed block – for example, 11 pm to 5 am – to more flexible time-of-use tariffs that change rates throughout the day.

How Off-Peak Charging Works Day To Day

So, what does off-peak charging actually look like in everyday life? In simple terms, your battery automatically charges during the cheapest hours of the night, using low-cost electricity supplied by your off-peak tariff. As the day begins and your energy use ramps up, your home starts using the stored electricity from your battery first. You stay off the grid for longer, avoiding those higher daytime prices without lifting a finger.

Throughout the morning and early afternoon, your battery continues to support most of your household demand. It's only once the stored energy drops to a certain level that your system begins drawing from the grid again – by that point, you’ve already avoided the most expensive hours of the day.

Common Misconceptions About Off-Peak Tariffs

Even with these clear benefits, we still encounter numerous misconceptions about off-peak tariffs that can deter homeowners from exploring them.

“I need solar panels for off-peak charging to work.”

Not at all. Many households see great results simply by charging their battery on its own overnight and using that cheaper energy through the day. Solar adds another source of free energy in the mix.

“It’s too complicated to manage.”

Everything is automated. Once your system is set up, your battery knows exactly when to charge and discharge, so you don't have to worry about it.

“I’ll have to change when I use my appliances.”

In fact, your daily routines stay the same, and the battery handles the smart energy shifting in the background.

“The savings aren't worth the effort.”

For homes with higher usage, such as EVs, heat pumps and homeworking, the savings can be substantial. Shifting a larger portion of your consumption to cheaper hours can significantly reduce your electricity bills over the year.

Current Off-Peak Tariffs

To show how off-peak pricing typically works, here's a quick look at some of the most common off-peak tariffs available in the UK*. These give you an idea of the cheaper time windows and basic requirements you might expect when pairing a battery with a smart tariff. Some of these tariffs are designed specifically for EV owners, while others are available to any household with a smart meter.

*Available from July 2025

Tariff	Off-peak Rate (p/kWh)	Off-peak Window	Peak Rate (p/kWh)	Smart Meter Required	EV Required	Specific EV Charger Required
Octopus Go	8.50	00:30–05:30	up to 24.88	✓	✓	✗
Octopus Intelligent Go	7.00	23:30–05:30	up to 24.88	✓	✓	✓
British Gas Electric Driver v8	7.90	00:00–05:00	26.90	✓	✓	✗
EDF GoElectric Overnight	8.99	00:00–05:00	25.47	✓	✓	✗
EDF Evolve	12.36	00:00–05:00	22.36	✓	✓	✗
E.ON Next Drive	6.90	00:00–07:00	29.70	✓	✓	✗
Ecotricity One-year Fixed EV	8.00	00:00–05:00	30.78	✓	✓	✗
SO Energy: SO EV	6.50	00:00–05:00	26.30	✓	✓	✗

While each tariff works slightly differently, the pattern is the same: a block of low-cost electricity overnight that can fully charge your home battery and reduce your daytime energy costs. If you're unsure which tariff suits your home, we can help you choose a tariff that maximises the benefits of your system.

Why Off-Peak Charging Works So Well with EVs and Heat Pumps

These benefits become even more impactful if your home includes higher-demand technologies like an EV or a heat pump, as both naturally increase your home's electricity demand. Instead of paying peak prices to run these systems, off-peak charging allows your battery to handle much of the load using the cheaper energy it stored overnight.

For EV owners, this creates a very efficient setup. Your car charges on the lowest rate of electricity while your home battery does the same – and the next day, that stored energy helps you cover your general household use long before you need to draw anything from the grid.

Since heat pumps run steadily throughout the day, having a battery filled with cheap overnight electricity helps reduce the cost of that continuous demand. Electricity is drawn from your battery storage first, meaning more of your heating is powered by low-cost energy.

Make Your Home Work Smarter, Not Harder

If you're considering battery storage or want to make better use of your existing system, we can help you choose a setup that maximises off-peak charging and keeps your energy bills down.

At Green Flare, our team will review your home, usage and tariff options to design a solution that works for you.