Right, here’s the question loads of people are asking – should I get solar panels or a heat pump? Or both? And if I can only afford one, which gives me the best bang for my buck?
The short answer is: they do completely different things, so it’s a bit like asking “should I get a car or a washing machine?” But I get why people ask. You’ve got limited budget, you want to go greener, and you need to pick where to spend your money.
Let’s break this down properly so you can make the right choice for your situation.
The Fundamental Difference
Before we compare them, you need to understand what each one actually does.
Solar panels generate electricity. They take sunlight and turn it into power you can use for everything in your house – lights, telly, kettle, phone charging, the lot.
Heat pumps are a heating system. They replace your gas boiler. They take heat from outside air (or ground) and move it inside to warm your house and provide hot water.
So one makes electricity, the other provides heating. Different jobs entirely.
The confusion comes because heat pumps run on electricity. So if you have solar panels, they can power your heat pump. Which is brilliant, but it doesn’t mean you have to choose between them.
What Each One Costs
Solar Panels
For a typical three-bedroom house, you’re looking at around £7,860 for solar panels (or £12,360 if you add battery storage).
That’s for a 4kW system which is standard for most homes. Without the government grants of yesteryear, you’re paying for this yourself (though there’s 0% VAT which helps).
Installation takes 1-2 days typically. Pretty straightforward.
Heat Pumps
Heat pumps cost between £10,000 and £18,000 for supply and installation, but here’s the thing – the Boiler Upgrade Scheme can save households in England and Wales £7,500 on the price of a heat pump.
So your actual cost after the grant is more like £2,500 to £10,500.
But wait, there’s more costs potentially. Many homes need upgrades first:
- Better insulation (£1,000-£5,000+)
- Larger radiators (£500-£2,000)
- Hot water cylinder if you’ve got a combi boiler (£500-£1,000)
These aren’t always necessary, but they often are. So factor that in.
Installation takes 2-4 days usually, sometimes longer if you’re getting ground source.
Upfront Cost Winner?
Heat pump (with the grant) is cheaper upfront. But only if your home doesn’t need major upgrades. If you need new insulation, bigger radiators, and all that, solar panels might actually work out cheaper.
What You Actually Save
This is where it gets interesting.
Solar Panels Savings
Solar panels could reduce your annual energy bill by 70% or £520 a year on average.
Plus you can sell excess electricity back to the grid. Through the Smart Export Guarantee (SEG), you can earn around £159 per year, making your total annual benefit about £679.
Over 20 years, that’s £13,580 in total savings.
If you add battery storage, the savings increase further because you use more of what you generate instead of exporting it cheaply.
Heat Pump Savings
Heat pumps are trickier to calculate because they’re replacing gas heating, not electricity.
The average household can expect to save around £217 per year on their gas bill by switching from a gas boiler to a heat pump – that’s £4,340 over 20 years.
Now, that sounds worse than solar. But remember – you’re not paying for gas anymore. You’re using electricity instead, which heat pumps use very efficiently.
A heat pump will use around 3,200kWh of electricity to heat the average household, assuming the heat pump has an average efficiency rating of around 350%.
That’s about £823 per year at current prices. So you’re swapping a gas bill for a smaller electricity bill, hence the £217 annual saving.
The savings get much better if you pair a heat pump with solar panels (we’ll get to that).
Savings Winner?
Solar panels save you way more money. Around £462 extra per year compared to heat pumps, or £9,240 over 20 years.
Payback Periods
Solar Panels
With current prices and savings, you’re looking at 10-12 years payback typically. After that, it’s basically free electricity for another 15-20 years.
Total profit over the system’s lifetime? Around £7,800 with an efficient system, potentially £12,300 if you add battery storage.
Heat Pumps
Payback is longer, around 15-20 years if you include all the upgrade costs.
The problem is, heat pumps typically last 20-25 years. So you might just about break even by the time it needs replacing.
However, if gas prices continue rising faster than electricity prices (which they might), the payback period could be shorter.
Payback Winner?
Solar panels, no contest. You’ll see returns much faster and the total profit is significantly higher.
Efficiency and Performance
Solar Panels
Modern solar panels have increased efficiency to about 20-23%, which means they convert roughly a quarter of the sunlight hitting them into electricity.
They work all year round, even on cloudy days (just less effectively). No moving parts, very low maintenance, last 25-30 years.
Performance varies by location – south of England generates more than Scotland – but the difference isn’t massive.
Heat Pumps
Ground source heat pumps can achieve efficiency levels of up to 400%, meaning they produce four units of heat for every unit of electricity used.
Air source heat pumps are typically around 300-350% efficient.
That’s insanely efficient compared to gas boilers (which max out at about 90-95% efficiency).
However, heat pumps work best with:
- Good insulation
- Larger radiators or underfloor heating
- Consistent heating (they don’t like being turned on/off constantly)
- Homes that aren’t freezing cold to start with
In really cold weather, efficiency drops a bit, but they still work fine.
Efficiency Winner?
Heat pumps are technically more efficient at what they do (converting energy into heat), but solar panels are more universally effective without needing home upgrades.
Home Suitability
Who Can Get Solar Panels?
Pretty much anyone with a roof. You need:
- Roof space (about 20-30 square metres for a typical system)
- Ideally south-facing (but east/west work too)
- Not too much shading from trees or buildings
- Roof in decent condition
That covers most UK homes. Maybe 85-90% of properties can have solar.
Who Can Get Heat Pumps?
This is more complicated. It has been estimated that 54% of UK homes aren’t suitable for heat pumps.
Why? You need:
- Outdoor space for the unit (and it’s quite big)
- Indoor space for hot water cylinder (if you don’t have one)
- Decent insulation (or willingness to upgrade it)
- Larger radiators ideally (or underfloor heating)
- Homes that don’t get absolutely freezing
Heat pumps can be installed in all property types – from flats to detached houses – and in homes from any architectural era, according to the government-funded Electrification of Heat project. But that doesn’t mean they’ll work well without upgrades.
Older homes with poor insulation and small radiators? You’ll struggle without spending serious money on improvements first.
Suitability Winner?
Solar panels work for way more homes without requiring other improvements.
Environmental Impact
Both are brilliant for the environment compared to what they replace.
Solar Panels
Zero emissions once installed. Every kWh generated is one less kWh from the grid (which still uses some fossil fuels).
Using solar panels can reduce your household’s carbon emissions significantly.
Manufacturing solar panels does have an environmental cost, but it’s offset within 2-3 years of use.
Heat Pumps
Heat pumps produce no direct carbon dioxide, particulates, or nitrogen dioxide emissions.
Replacing a gas boiler with a heat pump is one of the biggest carbon reductions you can make at home.
The electricity they use still has a carbon footprint (unless it’s from your solar panels), but it’s much lower than burning gas.
Environmental Winner?
Both are excellent. Heat pumps probably edge it for total carbon reduction because heating is such a big part of home emissions.
The Magic Combination: Solar + Heat Pump
Here’s where it gets really good. If you can afford both, they work together beautifully.
The average household with a 8.2kWp solar & battery system can cut its heat pump bills by £592 per year.
How it works:
- Solar panels generate electricity during the day
- That electricity powers your heat pump for free
- Excess electricity charges your battery
- Battery powers the heat pump in the evening
- You buy much less electricity from the grid
A 3.5kW solar system produces around 2,650 kWh per year, or 220kWh per month, which almost covers the 246kWh of electricity used monthly by the average domestic air source heat pump.
But the average home uses about 200kWh per month for other stuff too (kettle, washing machine, etc.). To cover everything completely, you would need a 5-7kW solar PV system.
Using a heat pump with solar panels can reduce your household’s carbon emissions by a total of 2.6 tonnes of CO2 per year, which would wipe out the great majority of your home’s carbon footprint – 74%, on average.
The combined cost is steep though – you’re looking at £15,000-£25,000 total even with the heat pump grant. But the savings and environmental benefits are massive.
Installation Hassle
Solar Panels
Pretty straightforward. Most installers can do the job in 1-2 days.
Minimal disruption. Some scaffolding, people on your roof, bit of electrical work inside, done.
No planning permission needed for most homes (unless listed building or conservation area).
Heat Pumps
More involved. 2-4 days installation typically.
Disruption includes:
- Digging/mounting outside unit
- Installing hot water cylinder inside
- Connecting to your heating system
- Possibly upgrading radiators
- Definitely some upheaval
You might need planning permission depending on location and type (ground source is more likely to need it).
Installation Winner?
Solar panels are much less hassle.
Maintenance and Lifespan
Solar Panels
- Maintenance: Basically none. Maybe clean them once a year.
- Lifespan: 25-30 years for panels, 10-15 years for inverter (which needs replacing once)
- Degradation: Lose about 0.5% efficiency per year
- Running costs: Virtually zero
Heat Pumps
- Maintenance: Annual service recommended (£100-£200)
- Lifespan: 20-25 years typically
- Repairs: More components that can go wrong than solar
- Running costs: Electricity to run it (though much less than gas boiler costs)
Maintenance Winner?
Solar panels. Fit and forget basically.
Noise
Solar Panels
Silent. They just sit there doing their thing.
Heat Pumps
Air source heat pumps have a fan that makes noise. It’s not super loud (about 40-60 decibels, similar to a fridge), but it’s noticeable.
Your neighbours might complain if it’s close to their bedroom window.
Ground source heat pumps are quieter but cost way more.
Noise Winner?
Solar panels obviously.
What About Flats and Apartments?
Solar Panels
Tricky for flats unless you own the whole building or can convince all the other residents. Shared roof space is complicated.
Some housing associations are installing communal solar systems, but it’s not common yet.
Heat Pumps
Even harder. You need outside space for the unit and inside space for the cylinder. Most flats don’t have suitable outdoor space, and you can’t just stick a noisy unit on a shared balcony.
Some new-build flats are being designed with heat pumps, but retrofitting existing flats is tough.
Flat-Dweller Winner?
Neither is great, but solar might be possible in some situations.
The Verdict: Which Should You Get?
Right, decision time. Here’s my honest take:
Get Solar Panels If:
✅ You want the best financial return ✅ Your home’s suitable (decent roof, not too much shading) ✅ You want something low-maintenance ✅ You’re looking to reduce electricity bills ✅ Your gas boiler’s still working fine
Get a Heat Pump If:
✅ Your gas boiler needs replacing anyway ✅ You can get the £7,500 grant ✅ You care more about carbon reduction than financial returns ✅ Your home’s well-insulated (or you’re willing to upgrade) ✅ You’ve got the space needed
Get Both If:
✅ You can afford the upfront cost (£15k-£25k total) ✅ You want maximum carbon reduction ✅ You’re planning to stay in your home long-term ✅ You want energy independence ✅ You’re willing to make a big commitment
Don’t Get Either Yet If:
❌ You’re moving in the next 5 years ❌ Your home needs major repairs first ❌ You can’t afford it without going into serious debt ❌ Your property’s unsuitable for both
My Personal Recommendation
For most people reading this in 2025, I’d say: Get solar panels first.
Here’s why:
- Better financial returns
- Works for more homes
- Less hassle to install
- No prerequisites needed
- Lower maintenance
- You can always add a heat pump later
Then, when your gas boiler eventually gives up the ghost, replace it with a heat pump. By then, you’ll have solar panels already generating electricity to help power it.
This staged approach means you’re not dropping £20k+ all at once, and you start seeing savings from the solar panels immediately.
The exception? If your boiler’s dying right now and you need to replace it anyway, get the heat pump and take advantage of that £7,500 grant. Then add solar panels in a year or two when you’ve recovered financially.
What About Just Getting a Heat Pump?
If you can only afford a heat pump (especially with the grant bringing costs down), it’s still worth doing. Especially if:
- Your gas boiler’s knackered
- You care about reducing your carbon footprint
- You expect gas prices to keep rising
- You might add solar panels later
Just be realistic about the savings. They’re not as good as solar panels alone, but you’re future-proofing your heating system and dramatically cutting your carbon emissions.
Final Thoughts
Solar panels and heat pumps aren’t really competitors – they do different jobs. But if budget forces you to choose, solar panels give better financial returns for most homes.
The dream scenario is getting both. Solar panels and air source heat pumps are a perfect match, and pairing them can slash pounds off your UK energy bill cost.
But if you’re doing it in stages, solar first makes more sense for most people. It pays for itself faster, requires less upheaval, and works for more homes.
Then when your boiler needs replacing (or when you’ve saved up more cash), add the heat pump and suddenly you’ve got a home powered almost entirely by renewable energy.
That’s the proper way to do it. Not necessarily the quickest way, but the most sensible financially.