The future of electric heating isn’t just about how much electricity you use – it’s when you use it

Energy prices are changing again this October. But as more of our homes and cars move away from fossil fuels, there’s another part of the energy conversation becoming increasingly important: not just how much electricity we use, but when we use it.

From 1 October 2026, the energy price cap for a typical dual-fuel household will increase by 4%. Much of that rise is being driven by higher wholesale gas prices, with Ofgem estimating that the gas portion of a typical capped household’s bill will rise by around 8%. Electricity costs, meanwhile, will remain broadly stable, helped by the temporary removal of VAT from domestic electricity bills between October 2026 and March 2027.

For households thinking about moving away from gas, oil or LPG, though, simply comparing the headline price of a unit of gas with a unit of electricity doesn’t tell the whole story.

Increasingly, when electricity is used matters too.

Electricity doesn’t have to cost the same all day

Many of us are used to thinking of electricity as having one price.

But with a smart meter and a time-of-use tariff, electricity can cost significantly less during certain periods of the day (sometimes even free!) – often overnight or at times when demand on the grid is lower.

This is already familiar to many electric vehicle owners. Rather than plugging the car in at 6pm and immediately charging it during one of the busiest periods on the grid, drivers can schedule charging for later in the night when their tariff offers cheaper electricity.

Heat battery boilers work in a similar way, storing electricity when it is cheaper and making it available to the home later.

And increasingly, home heating can become flexible too.

Read the Energy Saving Trust’s explainer on Smart time-of-use tariffs.

What does ‘smart electric heating’ actually mean?

Traditional heating tends to use energy at roughly the same time that you need the heat.

Turn your gas boiler on at 7am and it burns gas at 7am. Switch electric heating on at 6pm and it needs electricity at 6pm.

A heat battery works differently: instead of needing to use electricity at the exact moment your home needs heating, it can charge earlier, store that energy as heat, and release it later.

That creates a separation between when your home buys electricity and when your home actually needs heat.

It might sound like a small distinction, but as millions of homes and vehicles become electrified, being able to move electricity use away from the busiest times could become increasingly important.

How does a heat battery boiler work?

The tepeo ZEB is a heat battery boiler powered by electricity, designed to replace the fossil-fuel heat source in a home’s wet central heating system.

Instead of burning gas, oil or LPG, it uses electricity to heat up its thermal storage core. That energy is stored as heat until the home needs it, when it can be delivered through radiators or underfloor heating.

This means the ZEB can do most of its charging at a completely different time from when the heating is actually being used.

With a time-of-use electricity tariff, that could mean charging predominantly during cheaper off-peak periods and storing enough heat for later.

And this is where things get smarter

Of course, nobody wants to spend their evening checking tomorrow’s weather forecast, looking at their electricity tariff and trying to work out how much heat their house will need the next day.

That’s why the ZEB does that work automatically. Its Smart Charging technology considers factors including:

• your electricity tariff
• local weather forecasts
• how much heat your home has previously used
• predicted heating demand
• the carbon intensity of electricity

It then works out when to charge and how much energy to store for the heat it expects your home to need.

If a milder day is forecast, for example, the ZEB may determine that the home needs less stored heat. When colder weather is expected, it can adjust its charging plan accordingly.

The aim is simple: store the heat you need while making better use of the electricity available to you.

Why does this matter for energy bills?

From October, the average capped electricity unit rate for a UK household paying by Direct Debit will be 26.32p/kWh.

But that figure is an average rate for customers on standard variable tariffs. It doesn’t mean every household pays 26.32p for every unit of electricity it uses.

Time-of-use tariffs operate differently, offering different prices depending on when electricity is consumed.

For technologies capable of shifting their electricity consumption, that distinction is vital.

The ZEB works best with a time-of-use tariff offering a useful period of cheaper electricity. An empty ZEB takes around 4.5 hours to fully charge, so tariffs with several hours of lower-cost off-peak electricity can give it greater opportunity to move charging away from more expensive periods.

Of course, tariffs vary considerably, and switching away from a fossil-fuel heating system doesn’t automatically mean a household will have lower running costs. Property size, heat demand, insulation, tariff choice and how the heating system is used all matter.

That’s why it’s important to consider the whole home rather than comparing a single gas and electricity unit rate.

What about heat pumps?

Heat pumps will play a major role in moving UK homes away from fossil-fuel heating, and for many properties they’re an excellent option. But not every home is the same.

Some homeowners may not have suitable outdoor space, may want to retain a higher-temperature radiator system, or may simply have a property where a different approach to electrification makes more sense.

Heat batteries offer another option. The ZEB sits indoors and works with a traditional wet central heating system, providing homeowners with a different route away from fossil fuels while also bringing energy storage into the heating system.

The question increasingly shouldn’t be “heat pump or another gas boiler?”

It should be:

“What’s the right low-carbon heating solution for this particular home?”

Heat pump vs heat battery boiler: which low-carbon option is right for you? Read more.

A smarter electricity system needs flexible homes too

The UK’s energy system is changing. We’re generating more electricity from renewable sources. More of us are driving electric cars. More homes are installing batteries, solar panels and electric heating.

That means simply producing enough electricity isn’t the only challenge. We also need to think about when millions of homes are asking the grid for it.

Flexible technologies can be part of that picture. 

Your home may need to be warm at 6pm. But that doesn’t necessarily mean your heating system has to buy all of the energy to produce that warmth at 6pm.

And that is one of the big opportunities presented by heat batteries: making home heating part of a smarter, more flexible electricity system.

We’ve already seen this work in real homes. In the 18-month Neat Heat trial led by UK Power Networks in partnership with OVO and tepeo, heat batteries were able to shift peak heating demand to off-peak periods by up to 95% 

Thinking about moving away from fossil-fuel heating?

If you’re considering replacing your gas, oil or LPG boiler, there are now more options available than many homeowners realise.

The right solution will depend on your home, your heating requirements and how you use energy.

Complete our free ZEB Home Check to find out whether a heat battery boiler could be suitable for your home.