Using less energy is one way to manage household costs.

But there is another part of the picture that is becoming increasingly important.

When you use electricity can matter too.

Electricity demand changes throughout the day.

Solar panels generate more electricity at certain times.

Some electricity tariffs charge different prices depending on when electricity is used.

Battery storage can allow electricity to be stored at one time and used later.

And if your home uses a heat pump, heating can become one of the largest parts of your electricity demand.

This creates an opportunity to think about home energy differently.

Instead of looking only at how much electricity you use, you can also consider when you generate it, when you buy it and when you use it.

This is often known as load shifting.

When it is planned properly, load shifting can help homeowners make greater use of solar electricity, reduce exposure to expensive electricity periods and give them more control over how energy moves through the home.

Load shifting means moving some electricity consumption from one time of day to another.

The aim is not necessarily to use less electricity.

It is to use more of it at times when electricity is either available from your own renewable generation or cheaper to buy from the grid.

For example, you might have solar panels producing electricity during the day.

Rather than exporting all of the surplus electricity immediately, some could be stored in a battery.

That stored electricity may then be used in the evening when solar generation has fallen.

Alternatively, if you are on a suitable smart time of use tariff, a battery might charge from the grid during a cheaper period and provide electricity later when grid prices are higher.

The Energy Saving Trust describes battery storage in exactly this way. Batteries can store surplus solar generation, but they can also be charged during cheaper tariff periods and used later.

The principle is straightforward:

Use electricity when it is most useful or economical for your home rather than assuming every kilowatt hour has the same value at every time of day.

Electricity demand across the grid is not constant.

There are periods when large numbers of households are using electricity at the same time.

Early evening is a common example.

People arrive home, prepare food, use appliances and increase heating demand.

These higher demand periods are often referred to as peak periods.

Some smart electricity tariffs reflect this by charging different rates at different times.

Electricity may be less expensive during lower demand periods and more expensive when demand is high.

The Energy Saving Trust explains that smart time of use tariffs are designed around this principle and can offer households greater savings when they are able to move some electricity consumption away from more expensive periods.

This can become particularly relevant for homes with:

• Heat pumps
• Battery storage
• Solar PV
• Electric vehicles
• Smart appliances

These technologies can create more flexibility in when electricity is purchased or used.

Solar PV gives your home its own source of electricity.

During daylight hours, the panels generate electricity that can be used by the property.

The first opportunity is normally to use that electricity directly.

For example, solar generation might contribute towards:

• Household appliances
• Lighting
• Heat pump electricity demand
• Hot water heating
• Battery charging
• Electric vehicle charging where appropriate

Using electricity while your solar panels are generating can reduce the amount you need to import from the grid at that moment.

However, solar generation and household demand do not always happen at the same time.

You might generate more electricity around midday when nobody is home.

Then electricity demand increases in the evening after solar generation has dropped.

Battery storage can help move some of that electricity from one part of the day to another.

Using electricity directly when your solar panels are generating it is usually the simplest option.

The electricity moves from your solar system into your home and is used immediately.

There is no need to store it first.

This avoids the small energy losses that naturally occur when electricity is charged into and discharged from a battery.

That does not mean battery storage is unnecessary.

It means batteries are particularly useful for electricity that cannot be used at the moment it is generated.

For example, if your solar panels are producing more electricity than the home currently needs, a battery may allow some of that surplus to be used later rather than exported immediately.

Battery storage gives the home more flexibility.

Without a battery, solar electricity generally needs to be used when it is generated or exported to the grid.

With a battery, some of that electricity can be stored.

The Energy Saving Trust explains that home batteries are commonly used with solar panels, smart time of use tariffs or both.

This means the battery can potentially be charged in two ways.

From Solar PV

Surplus solar electricity is stored instead of being exported immediately.

From the Grid

Electricity is purchased during a cheaper tariff period and stored for later use.

The battery can then provide electricity when:

• Solar generation is low
• Electricity prices are higher
• Household demand increases
• The heat pump is operating
• Other electrical appliances are being used

Battery storage therefore does not simply increase the amount of renewable technology in the house.

Its main value is flexibility.

Yes.

This is an important point because batteries are often discussed only in relation to solar PV.

The Energy Saving Trust confirms that a battery can be useful even without solar panels.

If the household uses a smart time of use tariff, electricity can potentially be purchased during cheaper periods, stored and used later.

This can be particularly relevant for a home with a heat pump because heating can create substantial electricity demand.

The usefulness of this strategy depends on:

• The tariff
• Battery capacity
• Household electricity demand
• Heat pump consumption
• Charging and discharging settings
• Battery cost
• How long the battery is expected to last

A battery should therefore be designed around the home rather than installed simply because the property has a heat pump.

A time of use tariff charges different electricity prices at different times.

There are different types.

Some provide fixed cheaper periods every day.

Others use smart meters and can offer prices that vary more frequently.

The Energy Saving Trust describes two broad categories.

Static Time of Use Tariffs

These provide defined lower cost periods, often overnight.

Smart Time of Use Tariffs

These can offer different rates across the day, sometimes reflecting changes in electricity supply and demand more closely.

The exact tariffs available change frequently.

That is why Renewable Heat would not recommend designing a home energy system around the assumption that one particular tariff will always exist.

Instead, the system should provide flexibility so homeowners can consider suitable tariffs as the market changes

A heat pump can be one of the largest electrical loads in an all electric home.

That makes it an important part of the energy strategy.

However, load shifting with a heat pump needs to be approached differently from shifting something simple such as a washing machine cycle.

A heat pump is responsible for maintaining comfort in your home.

You should not switch the heating off for long periods simply to avoid an electricity price if doing so causes the property to cool significantly and forces the heat pump to work hard later.

Heat pumps generally perform well when maintaining relatively steady temperatures.

The Energy Saving Trust currently advises that keeping a heat pump operating for longer periods and using appropriate heating water temperatures can support efficient operation.

This means the goal is not simply:

Run the heat pump only when electricity is cheapest.

A better question is:

How can the heat pump, battery, solar PV and tariff work together while still allowing the heating system to operate properly?

Yes, where the battery system has been designed to support that demand.

The battery can provide electricity to the home, and the heat pump is one of the electrical loads it may supply.

For example:

The battery charges using surplus solar electricity during the day.

Later, solar generation falls.

The heat pump continues operating.

Stored electricity from the battery helps supply the home.

When the battery reaches its lower charge limit, the property returns to drawing more electricity from the grid.

Another strategy can involve charging the battery from the grid during a lower cost period.

Stored electricity can then contribute towards heat pump demand later.

Energy Saving Trust guidance specifically identifies running a heat pump as one of the potential uses of stored electricity.

Preheating can sometimes form part of an energy shifting strategy.

The idea is to allow the home to reach a comfortable temperature before a more expensive electricity period.

The building then retains some of that heat.

However, this needs to be done carefully.

The objective is not to overheat the property simply because electricity happens to be cheaper.

Comfort still matters.

The efficiency of the heat pump matters too.

If preheating requires the system to operate at unnecessarily high temperatures, the financial benefit may be reduced.

The most appropriate strategy depends on:

• Property heat loss
• Thermal mass
• Heating controls
• Heat pump design
• Electricity tariff
• Household routine
• Desired room temperatures

This is where good controls and proper system configuration become important.

Energy storage does not only mean batteries.

A home can also store thermal energy.

For example, a hot water cylinder stores heat for domestic hot water.

The building itself also retains heat for a period after the heating system has supplied it.

The Energy Saving Trust describes several forms of energy storage, including electrical batteries, hot water cylinders and other forms of thermal storage.

This means load shifting can sometimes involve both electricity and heat.

For example, domestic hot water may be heated at a particular time when electricity conditions are favourable, provided the system is designed and controlled appropriately.

The best strategy depends on the heating system and household requirements.

A battery has a limited storage capacity.

Once it reaches that capacity, it cannot continue storing additional electricity.

If solar panels are still generating more electricity than the home is using, surplus electricity can normally be exported to the grid where appropriate arrangements are in place.

The Energy Saving Trust explains that this can happen through an export tariff such as the Smart Export Guarantee, depending on the household and supplier.

This is another reason battery sizing matters.

A battery that is too small may regularly fill before the end of useful solar generation.

A battery that is much larger than the household needs may not provide enough additional value to justify its cost.

The appropriate size depends on actual energy patterns.

A home battery is not designed to discharge completely to zero.

The system normally retains a minimum level of charge to protect the battery.

Once the usable stored electricity has been consumed, the home continues to operate normally.

The grid supplies the additional electricity required, together with any solar generation available at that time.

This means battery storage should not be viewed as replacing the electricity grid.

It works alongside it.

No.

Load shifting can create opportunities to reduce electricity costs, but savings depend on several factors.

These include:

• Electricity tariff
• Peak and lower price periods
• Household consumption
• Solar generation
• Battery capacity
• Heat pump performance
• Battery efficiency
• Controls
• Seasonal weather
• Equipment cost

The Energy Saving Trust currently advises that battery storage can produce significant savings in some circumstances, particularly alongside a heat pump and a suitable smart tariff.

However, it also points out that those savings may not always be sufficient on their own to recover the cost of the battery.

That is an important distinction.

A battery should not be sold solely on an exaggerated payback claim.

It can provide several benefits, including greater energy flexibility and the ability to make better use of solar generation.

Whether the financial case works for your home needs to be assessed individually.

Battery storage is not completely loss free.
A small amount of electricity is lost during the process of charging and discharging.
This means electricity used directly from solar PV is generally more efficient than storing that electricity first and using it later.
But direct solar use is only possible when generation and electricity demand happen at the same time.
The value of the battery comes from allowing some electricity to be moved across time.
For example:
Use solar directly when possible
Then:
Store surplus electricity that would otherwise be exported
Then:
Use stored electricity later when it has greater value to the household
That is a more useful way to think about battery storage than assuming every unit of solar electricity should automatically pass through the battery.

Before changing when you use electricity, it helps to understand your current habits.

A smart meter can provide useful information about how electricity consumption changes throughout the day.

Some energy suppliers allow customers to download electricity use data in short time intervals.

The Energy Saving Trust recommends reviewing this data before choosing a time of use tariff.

Look for patterns.

When is your electricity use highest?

How much energy do you use in the evening?

Does the heat pump create significant overnight demand?

How much solar electricity are you exporting?

How often does the battery fill?

How much stored electricity remains in the morning?

These answers can help determine whether your system and tariff are working as intended.

A heat pump installer could design the heating system.

A solar installer could size the solar array.

A battery installer could recommend a battery.

But these systems increasingly interact.

That is why Renewable Heat takes a whole home approach.

Our Home Assessment considers the property and household energy use before recommending equipment.

Renewable Heat currently uses this process to consider factors including:

• Property heat loss
• Room heating requirements
• Existing heating system
• Energy usage patterns
• Solar PV potential
• Battery requirements
• Tariff considerations
• Future plans

The aim is not to install the largest battery or the maximum number of solar panels simply because space exists.

It is to create a system that suits the household.

Renewable Heat’s Heating Systems service brings heat pumps, solar PV and battery storage together as parts of one wider home energy system.

You can.

But you do not have to.

Installing the technologies together can make it easier to consider the complete energy system from the beginning.

However, many homeowners take a staged approach.

You may already have solar panels.

You might install a heat pump first and add battery storage later.

Or perhaps the battery is the next step because you already generate more solar electricity than you use during the day.

Renewable Heat’s current product approach explicitly allows homeowners to design the complete system from the outset or build it gradually.

Internal link: Renewable Heat Home Energy Technologies

Existing solar panels can still form part of a wider energy strategy.

Before adding a battery or heat pump, look at how the existing system currently performs.

Useful questions include:

How much electricity does the solar system generate?

How much do you use directly?

How much is exported?

When does household demand peak?

What size is the solar array?

Is the existing inverter compatible with the proposed battery approach?

Adding a heat pump will increase electricity demand.

That does not automatically mean you need more solar panels.

It simply means the existing generation should be considered when designing the wider system.

A battery may create additional options for a home already using a heat pump.

For example, it may allow you to take advantage of a suitable time of use tariff.

Electricity can potentially be purchased during a cheaper period and stored.

The battery can then supply part of the home’s electricity demand later.

Energy Saving Trust guidance specifically notes that batteries can provide particularly useful savings when combined with heat pumps and smart tariffs.

But the appropriate battery capacity still depends on your actual consumption.

Start with data.

Understand how much electricity the heat pump uses and when it uses it.

Then consider what a battery could realistically shift.

If battery storage is already installed, adding a heat pump may change the way the battery is used.

A battery that previously supplied evening appliance demand may now also be contributing towards heating.

That can change:

• How quickly the battery empties
• When it needs to charge
• Whether solar generation fills it
• How useful lower price tariff periods become

The battery may still be entirely suitable.

But its control strategy may need to be reviewed once the household’s electricity demand changes.

An electric vehicle can become another significant source of electricity demand.

If you already own one or plan to buy one, include it in the wider energy discussion.

The vehicle might be charging at the same time as:

• The heat pump is operating
• The battery is charging
• Household demand is high

Smart charging can create additional flexibility.

Future vehicle to home technology may eventually allow some electric vehicles to provide stored electricity back to the property, although Energy Saving Trust notes that this is not yet widely available.

Planning for future electricity demand can prevent a home energy system from being designed only around today’s consumption.

There is no single strategy that works for every home.

The best approach depends on:

• Property heat loss
• Heat pump size and performance
• Solar PV system
• Battery capacity
• Electricity tariff
• Smart meter
• Household routine
• Hot water demand
• Electric vehicle use
• Seasonal conditions

One household may benefit from charging the battery overnight.

Another might generate enough surplus solar electricity that grid charging rarely makes sense.

A third might use most electricity during the day and have little need to shift demand.

That is why energy management should be based on real data rather than a generic schedule.

Load shifting is not a replacement for energy efficiency.

The first objective should still be avoiding unnecessary energy use.

A home that loses large amounts of heat will still require more heating energy.

A poorly designed heat pump will still consume more electricity than a properly designed system might need.

Battery storage cannot correct those underlying problems.

The stronger approach is:

Reduce unnecessary demand

Then:

Generate renewable electricity where appropriate

Then:

Store useful surplus

Then:

Shift flexible demand where it makes sense

This puts load shifting into the wider home energy picture rather than treating it as a trick for reducing bills.

Managing energy more intelligently does not mean spending every evening watching electricity prices.

The aim is for the system to do much of the work in the background.

But good automation starts with good design.

You need to understand:

How much heat your home requires

How much electricity you use

When you use it

How much solar electricity you can generate

How much battery storage is useful

Which tariffs suit your household

Renewable Heat has more than 20 years of experience designing, installing and commissioning home energy systems.

Our current approach combines Home Assessment, heating system design and home energy technologies to help homeowners understand which combination of heat pumps, solar PV and battery storage makes sense for their property.

You do not need to know exactly which products you need before getting in touch.

Start with what you want to achieve.

That might be reducing peak electricity costs, making better use of your solar generation, adding a battery, replacing fossil fuel heating or bringing several technologies together as one home energy system.

Call 0330 022 0480 or email sales@renewableheat.com to arrange a home assessment and discuss how your property could generate, store and use energy more intelligently