Solar Heating in the UK: Costs, Benefits, and How It Works
When most people think of solar power, they picture solar PV panels generating electricity. But there’s another technology worth exploring: solar heating. Also known as solar thermal heating, this system uses the sun’s energy to heat water for your home, reducing reliance on gas or electricity.
In this guide, we’ll explain how solar heating works, what it costs, how much you can save, and whether it’s the right choice for your household.
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What is Solar Heating?
Solar heating systems use solar thermal collectors – panels installed on your roof that capture the sun’s heat rather than converting sunlight into electricity. This heat is transferred to a fluid, which circulates through a coil in your hot water cylinder, warming the water you use for showers, baths, and household needs.
Solar heating doesn’t usually provide 100% of your hot water. Instead, it works alongside your existing boiler or immersion heater, supplying 50–60% of your annual hot water demand.
How Does Solar Heating Work?
A solar heating system typically includes:
Solar Thermal Panels (Collectors): These are mounted on your roof. Two main types exist:
Flat-plate collectors – durable, cost-effective, and widely used in the UK.
Evacuated tube collectors – more efficient in colder climates, slightly more expensive.
Heat Transfer Fluid: A mixture of water and antifreeze circulates through the panels, absorbing heat.
Hot Water Cylinder: The heated fluid runs through a coil inside your water tank, transferring its heat to your domestic water supply.
Backup Heating: A boiler or immersion heater tops up water temperature when sunlight is insufficient.
Costs of Solar Heating in the UK
The average cost of installing a solar water heating system in the UK ranges from £3,000 to £6,000, depending on:
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System size and complexity
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Type of solar collector (flat-plate or evacuated tube)
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Whether a new hot water cylinder is required
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Roof type and accessibility
Maintenance costs are low. Most systems only require an annual service costing around £100–£150, plus fluid replacement every 3–7 years.
Savings from Solar Heating
Solar water heating can reduce your water heating bills significantly:
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A typical household can save £150–£300 per year depending on energy usage and fuel type.
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Households using electric immersion heaters benefit most, since electricity is more expensive than gas.
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Gas-heated homes see smaller savings but still benefit from reduced reliance on fossil fuels.
With an average lifespan of 20–25 years, solar heating systems provide long-term savings and protection against rising fuel costs.
Environmental Benefits
By using the sun’s energy instead of fossil fuels, solar heating can cut your household carbon footprint:
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Saves around 250–500 kg of CO₂ per year (depending on your fuel type).
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Reduces demand for gas and electricity during peak times.
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Works alongside solar PV if you already have panels, creating a more sustainable home.
Government Incentives and Support
In the past, UK homeowners could claim the Renewable Heat Incentive (RHI) for solar heating. This scheme ended in 2022. However, there is still financial support available:
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0% VAT on solar heating installations until 2027, cutting upfront costs by 20%.
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Some local authorities may offer grants through ECO4 or Home Upgrade Grant (HUG2) schemes if you meet eligibility criteria.
Although incentives are more limited than for solar PV, the VAT cut makes solar heating more affordable today than in previous years.
Is Solar Heating Right for You?
Solar heating works best for households that:
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Use large amounts of hot water (families, frequent baths/showers).
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Have a south-facing roof with minimal shading.
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Already use an immersion heater or expensive fuel for water heating.
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Are looking to lower bills and reduce carbon emissions.
It may be less suitable if:
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Your hot water demand is low.
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You don’t have a suitable roof space.
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You already have an ultra-efficient boiler.
Solar Heating vs. Solar PV
Both technologies use the sun’s energy, but they serve different purposes:
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Solar PV: Generates electricity for your home; can be stored with a battery.
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Solar Thermal (Heating): Produces hot water; cheaper upfront but only offsets water heating costs.
Some households choose to install both, maximising renewable energy use.
Installation Process
The installation process is straightforward:
- Survey: An installer assesses your roof, hot water system, and demand.
- Design & Quote: You’ll receive a system design with expected savings.
- Installation: Collectors are mounted on your roof, piping is connected to the hot water cylinder, and controls are installed.
- Commissioning: The system is tested and certified.
Most installations take 1–2 days.
Solar heating is a proven technology that can cut hot water bills, lower carbon emissions, and provide long-term energy savings. With installation costs of £3,000–£6,000 and annual savings of up to £300, it’s an affordable renewable energy solution for many UK households.
Although government incentives have reduced in recent years, the 0% VAT rate and long system lifespan still make solar water heating an attractive investment.
At SolarPanels.co.uk, we help homeowners explore their solar options, compare trusted installers, and find the right renewable system for their needs. If you’re ready to harness the sun for hot water, now is the perfect time to consider solar heating.