Solar Panels vs Heat Pumps: Which Should You Install First?
This article contains affiliate links. If you request a quote through our links, we may earn a commission at no extra cost to you. This helps keep Eco Home Check free. How we earn
If you can only afford one major energy upgrade right now, the choice usually comes down to solar panels or a heat pump. Both cut your carbon footprint and reduce energy bills, but they work in fundamentally different ways. The right answer depends on your current heating system, your roof, and how much you can spend upfront.
How Each Technology Works
Solar photovoltaic (PV) panels convert sunlight into electricity. A typical UK home installs a 3–4 kWp system on a south-facing roof, generating around 3,000–4,000 kWh per year. You use the electricity directly, store it in a battery, or export the surplus to the grid under the Smart Export Guarantee.
A heat pump extracts warmth from the outside air or ground and transfers it into your home at a ratio of roughly 3:1. For every 1 kWh of electricity consumed, you get about 3 kWh of heat. This makes them far more efficient than a gas or oil boiler. For a deeper explanation, see our guide on how heat pumps work.
Head-to-Head Comparison
Upfront Cost
A 4 kWp solar panel system typically costs £5,500–£8,000 installed, depending on panel quality and roof complexity. An air source heat pump costs £8,000–£15,000 before grants, while ground source systems range from £15,000–£35,000. After the Boiler Upgrade Scheme grant of up to £7,500, a typical air source heat pump comes down to £4,000–£8,000, comparable to solar.
Annual Savings
Solar panels save the average UK household £500–£700 per year by offsetting electricity purchases and earning SEG payments. A heat pump replacing a gas boiler saves roughly £200–£500 per year on heating bills, though savings are significantly higher (£800–£1,400) when replacing oil or LPG.
Payback Period
Solar panels typically pay for themselves in 6–10 years, with a system lifespan of 25–30 years. Heat pumps have a payback of 10–15 years when replacing gas, but as little as 6–9 years when replacing oil. Heat pump systems last around 20–25 years with proper maintenance.
Available Grants
Heat pumps have a clear advantage here. The Boiler Upgrade Scheme provides up to £7,500 towards installation in England and Wales. There is no equivalent grant for solar panels, though both technologies benefit from 0% VAT on domestic installations. Some local authorities run additional schemes. Check your council's website for area-specific support.
Home Suitability
Solar panels need a roof with reasonable south, east, or west exposure and minimal shading. Flat roofs work too with angled mounting frames. Heat pumps need outdoor space for the unit (air source) or garden area for ground loops (ground source). Homes with good insulation and larger radiators or underfloor heating get the best performance from heat pumps. Poorly insulated homes may need fabric upgrades first.
Installation Disruption
Solar panels are one of the least disruptive upgrades. Installation takes 1–2 days with most work on the roof and minimal interior disruption. Heat pump installation takes 3–5 days and involves pipework changes, a new hot water cylinder, and potentially upgrading radiators. Ground source systems require excavation, adding another 1–2 weeks.
Which Should You Install First?
You Have a Gas Boiler
Start with solar panels. Your gas boiler still has useful life, and solar gives you immediate electricity savings with minimal disruption. When your boiler eventually needs replacing, you can switch to a heat pump, and the solar panels will help power it, cutting running costs further.
You Have an Oil or LPG Boiler
Prioritise a heat pump. Oil and LPG are expensive fuels, so the savings from switching to a heat pump are substantial, often £800 or more per year. The £7,500 BUS grant makes the economics even more compelling. You can explore the best heat pump brands in the UK to find a reliable system for your home.
You Want Maximum Long-Term Savings
Install both, ideally solar first. A solar-and-heat-pump combination is the gold standard for UK home decarbonisation. The solar panels generate free electricity that powers the heat pump during the day, and a battery can extend that benefit into the evening. Together, they can cut your energy bills by 60–80% compared to a gas boiler with grid electricity.
The Bottom Line
There is no single correct answer. The best first step depends on your heating fuel, your home, and your budget. Solar panels are cheaper, less disruptive, and deliver reliable returns for almost any home. Heat pumps offer deeper decarbonisation and bigger savings for homes on oil or LPG, especially with the Boiler Upgrade Scheme grant.
Whichever route you choose, both technologies are proven, well-supported by UK policy, and will add value to your property. Energy prices remain high, grants are available, and every month you delay is money left on the table.
Frequently asked questions
- Can I install both solar panels and a heat pump?
- Yes, and the combination works exceptionally well. Solar panels can generate free electricity during the day to power your heat pump, dramatically reducing running costs. Many homeowners install solar first and add a heat pump later, or vice versa. If budget allows, installing both together can save on scaffolding and electrical work.
- Which has a better payback period in the UK?
- Solar panels typically pay back in 6–10 years, while heat pumps take 10–15 years depending on the fuel they replace. If you currently heat with oil or LPG, a heat pump can pay back faster because those fuels are more expensive per kWh than mains gas. Solar payback is more predictable because it depends mainly on electricity prices and your self-consumption rate.
- Do I need planning permission for either?
- Most domestic solar panel installations fall under permitted development and do not need planning permission, unless your home is listed or in a conservation area. Air source heat pumps also benefit from permitted development rights in England, provided they meet noise limits and are placed at least one metre from the property boundary. Ground source heat pumps rarely need permission as the equipment is underground.
- What grants are available for solar panels and heat pumps in 2026?
- Heat pumps benefit from the Boiler Upgrade Scheme, which provides up to £7,500 off the installation cost in England and Wales. Solar panels currently have no direct government grant for most homeowners, though the SEG (Smart Export Guarantee) pays you for surplus electricity exported to the grid. Both technologies benefit from the reduced 0% VAT rate on domestic installations.