ECO4 is the supplier-funded Energy Company Obligation. It is aimed at low-income and vulnerable households and is delivered by energy suppliers, not an open grant you can apply to directly. It is often mentioned alongside batteries, so here is exactly what it does and does not cover.
Status
ECO4 applies to measures installed up to 31 December 2026 after a nine-month extension. The Great British Insulation Scheme did not get that extension: it closed to new installations on 31 March 2026.
Solar panels: sometimes
Ofgem's guidance treats solar PV as a heating measure. It can be funded where the home has, or receives in the same project, a hydronic heat pump, electric storage heaters or another electric heating system, and some of the electricity generated is used for heating. There is a 10 kWp cap per home including any existing system, and minimum insulation pre-conditions apply.
Batteries: not funded
The guidance (paragraph 5.220) says a battery can be installed during an ECO4 retrofit, but it will not be added as a new measure type and will not contribute to ECO scoring because it does not improve the home's SAP rating. In practice, do not expect ECO4 to pay for a battery. If an installer says it will, ask for it in writing and check it against this page.
Who ECO4 is for
Eligibility is household-based, through qualifying benefits or local-authority flexible eligibility. A supplier or installer assesses the whole home and decides which measures to install.
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Check your eligibilityFrequently asked questions
Does ECO4 pay for a solar battery?
No. Ofgem's delivery guidance says a battery can be installed during an ECO4 retrofit but is not a measure type, does not count towards scoring and need not be notified to Ofgem.
When does ECO4 end?
ECO4 was extended by nine months and applies to measures installed up to 31 December 2026.
Did ECO4 end in March 2026?
No. The original term ended on 31 March 2026 but was extended to 31 December 2026. The Great British Insulation Scheme (single insulation measures) did close on 31 March 2026.
Can ECO4 fund solar panels?
In some homes. Ofgem's guidance allows solar PV where the home has or gets, in the same project, a hydronic heat pump, electric storage heaters or electric heating, and some of the generated electricity is used for heating.