Does ECO4 Include a Solar Battery? UK Guide 2026
If you are considering ECO4 support and have heard that solar panels can be combined with battery storage, you may be wondering: does ECO4 include a solar battery?
The short answer is no — a solar battery is not an ECO4-funded measure and does not receive an ECO4 score. However, Ofgem’s current ECO4 Delivery Guidance confirms that battery storage can be installed during an ECO4 retrofit in certain circumstances. The important distinction is that the battery itself does not count towards the supplier’s ECO4 obligation.
ECO4 is designed primarily around improving the energy efficiency of eligible homes. The scheme supports qualifying measures that reduce energy consumption and improve the property’s energy performance. Solar PV can form part of an eligible project where the relevant ECO4 requirements are satisfied, but homeowners should not assume that adding a battery means the battery will be paid for through ECO4.
This guide explains exactly how solar batteries interact with ECO4, whether solar panels can be included, who may qualify, what happens if you already have solar panels and what you should ask an installer before agreeing to an ECO4 installation.
Quick Answer: Does ECO4 Include a Solar Battery?
No, ECO4 does not directly fund a solar battery as an eligible scored ECO4 measure. Ofgem’s current guidance allows battery storage to be installed during an ECO4 retrofit, but the battery does not contribute to the ECO4 score or count as a qualifying ECO4 measure in its own right.
This means there is an important difference between being installed alongside an ECO4 project and being funded by ECO4. Solar PV may be eligible where the project meets ECO4 rules, while a battery would generally need to be funded separately or through another available arrangement.
ECO4 currently runs until 31 December 2026, following a nine-month extension confirmed by the Government and reflected in Ofgem’s latest guidance.
ECO4 and Solar Batteries: What Is Covered?
| Measure or component | ECO4 position | What homeowners should know |
|---|---|---|
| Solar PV | Potentially eligible | Must meet the relevant ECO4 requirements |
| Solar battery | Not an ECO4 scored measure | Can potentially be installed alongside an ECO4 retrofit |
| Existing solar panels | Can be relevant to project assessment | System condition and project requirements matter |
| Battery added separately | Not funded by ECO4 itself | Separate funding/payment may be required |
| Insulation and heating measures | Core ECO4 measures | Eligibility depends on the property and household |
The exact measures available depend on the property, household circumstances and the ECO4 project design. Eligibility does not automatically mean that an energy supplier or installer is required to install a particular measure.
What Is ECO4?
The Energy Company Obligation 4 (ECO4) is a government energy-efficiency scheme administered by Ofgem.
It places obligations on larger energy suppliers to support qualifying energy-efficiency improvements in homes across Great Britain. ECO4 takes a more whole-house approach than earlier versions of ECO, with projects assessed according to the property’s needs rather than simply installing one isolated improvement.
ECO4 can support different types of energy-efficiency work depending on the property and eligibility route.
The scheme is currently scheduled to run until 31 December 2026.
Does ECO4 Pay for a Solar Battery?
No. A solar battery is not itself an ECO4-funded measure.
This is the most important point for homeowners.
A battery stores electricity generated by solar panels so that it can potentially be used later. Although this can improve how much solar-generated electricity a household uses, battery storage is not treated as a qualifying scored measure under ECO4.
Ofgem’s Delivery Guidance specifically addresses battery storage and allows it to be installed during an ECO4 retrofit, but it does not become a new ECO4 measure or contribute towards the ECO4 score.
Therefore, a quotation describing a battery as being “included with ECO4” should be examined carefully.
Ask the installer:
- Is the battery actually being funded by ECO4?
- Is it being installed alongside another eligible measure?
- Is there a separate customer contribution?
- Is another funding mechanism being used?
- Which parts of the installation are being claimed under ECO4?
This distinction helps prevent homeowners from misunderstanding what their ECO4 support actually covers.
Can a Solar Battery Be Installed Alongside ECO4?
Potentially, yes.
The fact that a battery is not an ECO4-scored measure does not necessarily mean it cannot be physically installed as part of an ECO4 project.
Ofgem’s current guidance recognises battery storage in the context of ECO4 delivery. However, the battery does not generate an ECO4 score or become an eligible measure simply because it is installed at the same time.
For example, a project could potentially involve eligible ECO4 measures together with battery storage, subject to the project’s technical and funding arrangements.
The important question is therefore not simply:
“Can ECO4 have a battery?”
It is:
“How is the battery being funded, and is it separate from the ECO4-supported measures?”
Can ECO4 Fund Solar Panels?
Solar PV needs to be considered separately from battery storage.
A solar PV installation may be eligible under ECO4 where the relevant scheme requirements are met. However, eligibility depends on the property, project design, technical requirements and how the measure is being delivered.
ECO4 is not simply a general solar panel grant available to every homeowner.
The property and household must satisfy the relevant eligibility requirements, and the energy supplier or delivery organisation must agree to support the project. Ofgem explicitly warns that ECO eligibility does not guarantee that a supplier or installer will decide to install energy-efficiency measures.
Solar PV vs Solar Battery: What Is the Difference?
Solar panels and batteries perform completely different jobs.
Solar panels generate electricity.
They convert sunlight into electricity that can be used by the property.
A battery stores electricity.
Instead of using all generated electricity immediately, surplus electricity can be stored and used later.
For example, solar panels may generate significant electricity during the middle of the day when a household is empty. A battery can store some of that electricity for use later in the afternoon or evening.
This can be particularly useful for households whose electricity consumption is concentrated outside daylight hours.
However, installing a battery does not automatically make solar PV financially worthwhile. The economics depend on electricity consumption, system size, battery capacity, tariffs, export arrangements and installation costs.
Can You Add a Battery to Existing Solar Panels?
Yes, in many cases.
Homeowners who already have solar panels may be able to add battery storage later.
However, compatibility needs to be checked before choosing a battery.
An installer should consider:
- Existing inverter type
- Solar PV capacity
- Battery capacity
- Available installation space
- Electrical characteristics
- Existing monitoring equipment
- Whether the system is AC- or DC-coupled
- Warranty implications
- Export arrangements
- Household electricity consumption
A battery should be sized according to the property’s actual energy use rather than simply choosing the largest battery available.
Who Can Qualify for ECO4?
ECO4 eligibility depends on both the household and the property.
One important route is the Help to Heat Group, which includes households receiving certain qualifying benefits subject to the applicable requirements. Ofgem lists benefits including Universal Credit, Pension Credit Guarantee Credit, Income Support, income-based Jobseeker’s Allowance, income-related Employment and Support Allowance and certain Child Benefit circumstances.
There is also ECO4 Flex, which allows participating local authorities and devolved administrations to identify certain households that may be vulnerable, fuel-poor or on a low income.
Meeting an eligibility criterion does not guarantee that a particular measure will be installed.
A property’s existing heating system, insulation, EPC, construction and wider energy performance can all influence the project.
What Happens During an ECO4 Assessment?
A proper assessment should look at the property as a whole.
Depending on the project, this can involve assessing:
- Existing heating system
- Insulation
- Property construction
- EPC information
- Existing renewable technology
- Energy efficiency opportunities
- Potential ECO4 measures
- Technical suitability
- Household eligibility
- Required improvement to the property’s energy performance
ECO4 follows a whole-house approach and uses the domestic retrofit process associated with PAS 2035:2019 for projects involving relevant measures.
This is why a reputable installer should not promise a particular ECO4 measure before properly assessing the property.
Is a Solar Battery Worth Adding?
Whether a battery is worthwhile depends on the household.
A battery may be attractive if:
- You already have solar PV
- Your daytime electricity consumption is relatively low
- You use more electricity in the evening
- You want to increase your use of your own solar generation
- You have a suitable electricity tariff
- Your existing solar system is compatible
- You expect to remain in the property for several years
It may be less attractive where:
- Electricity consumption is already concentrated during daylight
- The solar system is very small
- The battery is expensive relative to expected savings
- The system requires substantial additional electrical work
- The household is likely to move shortly
A proper calculation should consider expected savings rather than assuming that every battery installation provides the same return.
How to Choose a Solar Battery
If you decide to install battery storage alongside an ECO4 project, compare systems on more than capacity.
Look at:
- Usable battery capacity
- Round-trip efficiency
- Warranty period
- Warranty throughput
- Maximum charge/discharge rate
- Inverter compatibility
- Monitoring and controls
- Installation requirements
- Manufacturer support
- Expected lifespan
- Total installed cost
A larger battery is not automatically a better battery.
The objective should be to select a system that matches your solar generation and household electricity demand.
What Should You Ask an ECO4 Installer?
Before agreeing to an installation, ask for a clear written explanation of the funding.
Useful questions include:
1. Which measures are being funded by ECO4?
Ask the installer to identify each measure individually.
2. Is the battery ECO4-funded?
The answer should be clear. A battery being installed alongside ECO4 does not mean ECO4 is paying for it.
3. Is there a customer contribution?
If a battery or other component is being funded separately, ask exactly how much you are expected to pay.
4. What happens if I do not want the battery?
You should understand whether the battery is optional or an integral part of another installation.
5. What warranties apply?
Ask for separate warranty information for solar panels, inverter and battery.
6. Who is responsible for maintenance?
Make sure you know who to contact if the system develops a fault.
Why Installer Transparency Matters
ECO4 is a regulated scheme, so homeowners should be cautious about claims that make funding sound broader than it actually is.
Ofgem publishes guidance covering eligible homes, measures, project notification, scoring, technical monitoring and auditing.
A trustworthy installer should therefore be able to explain:
- Which measures qualify
- Which components are outside ECO4
- How the project is funded
- What the customer pays
- What warranties apply
- What work will actually be completed
Do not rely solely on phrases such as “fully funded solar and battery” without asking for a detailed written breakdown.
Frequently asked questions (FAQs)
Clear answers about ECO4, solar batteries, battery storage, solar PV and how battery systems can be installed alongside eligible ECO4 retrofit projects. Speak to Simple Green Energy .
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Check my optionsFinal Thoughts
So, does ECO4 include a solar battery?
No — a solar battery is not an ECO4-funded or ECO4-scored measure. However, Ofgem’s current guidance allows battery storage to be installed during an ECO4 retrofit, provided the wider project complies with the scheme’s requirements. The battery itself does not contribute to the ECO4 score.
Solar PV and battery storage should therefore be treated as two separate technologies with different roles.
If solar PV is being proposed as part of an ECO4 project, ask the installer to explain exactly how it qualifies. If a battery is also being offered, ask how that component is being funded and whether you need to make a separate payment.
ECO4 currently runs until 31 December 2026, so anyone considering support should check their eligibility and project options while the scheme remains open.
The best approach is to obtain a property-specific assessment and a transparent written quotation showing exactly what is funded, what is optional and what, if anything, the homeowner needs to contribute.
