ECO4 Scheme for Solar Panels

ECO4 is the fourth phase of the Energy Company Obligation, a government scheme that compels larger energy suppliers to fund energy-saving improvements in lower-income and less efficient homes. Crucially, ECO4 has no published flat cash cap handed to each household. Instead, it funds the suitable measures identified for your specific property — which for many eligible homes means solar PV is installed at no cost to you when it forms part of an approved retrofit package.

Because funding is measure-based rather than a fixed grant, the value you receive depends on what your home needs. ECO4 takes a 'whole-house' approach: a solar PV array is typically paired with insulation, heating upgrades or controls so your property reaches a meaningful EPC improvement. That matters for context — a standalone 3–4kW domestic solar system would usually cost roughly £5,000 to £9,000 before any grant, so a fully-funded installation under ECO4 represents a substantial saving for a qualifying household.

What ECO4 does not do is pay you cash, top up a system you have already bought privately, or guarantee solar specifically — the surveyor recommends measures based on your home's energy profile. The scheme is currently set to run until around March 2026, so eligible households are best checking availability sooner rather than later. A free eligibility check is the quickest way to find out what your property could qualify for.

ECO4 solar installations are sized to the property, not to a fixed product. For a typical UK home the surveyor will usually specify a system in the region of 3kW to 4kW — broadly 8 to 12 panels depending on roof space, orientation and shading. Larger detached homes with suitable south or east/west-facing roofs may be specified higher; smaller properties or constrained roofs, lower. The goal is a meaningful contribution to your electricity use and a genuine EPC improvement, not the biggest possible array.

On timescales, the journey from first enquiry to a working system generally runs in stages over several weeks: an initial eligibility check, then a property survey and (where needed) an EPC assessment, followed by the funding application your installer submits to an energy supplier, and finally installation once approved. Demand, supplier processing and seasonal workload all affect the calendar, so treat any timescale as indicative rather than guaranteed.

After installation you should receive an updated EPC certificate, your MCS certificate and warranty paperwork — the MCS certificate also being what licensed suppliers require before you can be paid for exported electricity under the Smart Export Guarantee. Keeping that documentation safe matters, because it underpins both any future property sale and your export earnings.