Solar vs Air Source Heat Pump for a Holiday Let

Quick answer

Solar panels and an air source heat pump are not competing purchases. Solar reduces what you pay per unit of electricity by generating your own. A heat pump reduces how many units your heating consumes by running at 300% or more efficiency. On an off-gas-grid holiday let, the strongest answer is usually both, because the pump’s daytime running lines up with peak solar generation, so the panels feed the pump directly.

Key takeaway: the real question is not “which one”, it is “which first, and do they work together”. For most self-catering owners the honest order is solar first if you have a hot tub and high electric load already, or the two designed together if you are replacing an oil or LPG boiler.

What each one actually does

Solar generates electricity on your roof. It cuts your import bill and, on a holiday let, self-consumption is high because your busy months are your sunny months. It does nothing directly about how efficient your heating is.

An air source heat pump is a heating appliance. It moves heat from the outside air into your hot water and radiators or underfloor system, delivering roughly 3 to 4 units of heat per unit of electricity it draws. It replaces an oil boiler, LPG boiler or old electric heating, but it adds electrical demand.

Put plainly: a heat pump makes your heating cheaper to run than oil or LPG; solar makes the electricity that runs it cheaper still. That is why they pair.

Side-by-side comparison

	Solar PV (plus battery)	Air source heat pump
What it does	Generates electricity	Provides efficient heating and hot water
Cuts	Cost per unit of electricity	Units of heat energy needed
Best replaces	Grid import	Oil, LPG or old electric heating
Holiday-let fit	Excellent, occupancy matches generation	Strong off the gas grid, adds electric load
Indicative cost (cottage)	£7,000 to £16,000	£8,000 to £16,000 (varies by heat demand)
Grant support	SEG export income; 0% VAT (residential)	Boiler Upgrade Scheme where eligible (see below)
Runs when	Daylight, peak in summer	Year-round, harder in winter
Together	Pump runs on daytime solar; battery covers evening re-heat	Cheaper to run when fed by solar

Why they work best together on a holiday let

The seasonal and daily timing is the whole reason to pair them. A holiday let’s heating and hot-water demand is concentrated in the occupied months and, at changeover, in the daytime, exactly when solar generates. A heat pump re-heating the hot-water cylinder for new arrivals at midday can draw much of that power straight from the roof. Add a battery and the evening re-heat, plus the hot tub top-up, runs from stored solar rather than peak-rate grid electricity.

Stat callout: An air source heat pump running at a seasonal efficiency (SCOP) of around 3.2 delivers roughly 3.2 kWh of heat per 1 kWh of electricity (Source: MCS heat pump performance data, mcscertified.com). Feed that 1 kWh from your own solar rather than the grid, and the heat is cheaper again.

Because many lets are off the gas grid on oil or LPG, replacing that fuel with a solar-fed heat pump attacks the biggest, most expensive part of the energy bill.

The hot-water and hot-tub interaction

On a holiday let the two big heat demands are the hot-water cylinder, re-heated hard at every changeover, and the hot tub. A heat pump can serve the cylinder efficiently, and where the pump is sized with that changeover peak in mind, it copes with the back-to-back turnover a busy let demands. The hot tub is usually a self-contained electric heater rather than something the pump serves directly, but it is exactly the kind of daytime and evening electrical load that a solar-and-battery system covers. So in practice the pump handles the space and water heating efficiently, and the solar array covers the tub and the pump’s own electrical draw, each doing the job it is best at.

A running-cost worked example (illustrative)

An illustrative comparison for an off-gas-grid cottage, not a quote. Assume the property currently heats on LPG.

• LPG boiler alone: you pay the full LPG unit rate for every unit of heat.
• Heat pump alone: the pump delivers roughly 3 units of heat per unit of electricity, so even at grid electricity prices the running cost per unit of heat falls sharply against LPG.
• Heat pump plus solar-and-battery: the pump’s daytime and battery-served running now draws largely on your own generation rather than grid import, cutting the cost of each of those electricity units again on top of the efficiency gain.

The exact figures depend on your heat demand, your tariff and your fuel price, which is why we model them from your consumption rather than quoting a headline saving.

When to prioritise one over the other

Fit solar first if: you already have a hot tub, guest EV charging and a high electric load, and your heating is staying as it is for now. Solar attacks the load you already have, with a strong holiday-let payback. See whether the numbers stack in our worth-it guide.

Design them together if: you are replacing an ageing oil or LPG boiler anyway. Sizing the solar and battery around the new pump load from the start avoids paying twice for scaffolding, electrical work and a second DNO application. A pump plus solar-plus-battery on a single G99 application is more efficient than two separate projects.

Heat pump first, solar later, if: your oil boiler has failed and heating is the urgent problem. You can size the array afterwards to cover the pump’s new demand.

The grant and tax picture

The Boiler Upgrade Scheme offers a grant toward an air source heat pump for eligible domestic properties in England and Wales, though eligibility for a property run as a commercial let is not automatic and must be confirmed, so take your own tax and grant advice. Solar earns export income under the Smart Export Guarantee and qualifies for 0% VAT on residential-scale installs to 31 March 2027, with the same commercial-let caveat we flag throughout.

On tax, the Furnished Holiday Lettings regime was abolished in April 2025, so the old capital-allowance route for personally-held lets has gone. Take your own tax advice and see our grants and funding page.

How it differs by property type

• A self-catering cottage off the gas grid is the classic pump-plus-solar candidate.
• A lodge or cabin may already run air-source heating and cooling, so solar to feed it is the obvious add.
• A glamping site off-grid may run heating from the same solar-and-battery system, covered in our off-grid glamping guide.
• A self-catering park can serve multiple buildings’ heating from a site-wide array.

Full sizing sits on the main solar panels for holiday lets page and the cost guide.

Frequently asked questions

Is a heat pump or solar the better first purchase for a holiday let?

It depends on your urgent problem. If your electric load is already high (hot tub, EV charging) and your heating is fine, fit solar first. If you are replacing a failing oil or LPG boiler, design the pump and solar together so you do not pay twice for the groundwork.

Does a heat pump make my electricity bill go up?

It raises electricity demand because it moves your heating onto electric, but it lowers your total energy cost by replacing more expensive oil or LPG and running at over 300% efficiency. Feeding it from solar cuts the cost of that new electricity further.

Can I run a heat pump entirely from solar?

Not entirely, especially in winter when heat demand is high and generation is low. Solar covers a meaningful share of the pump’s running in the occupied months and at changeover, and a battery extends that into the evening. The grid or a battery covers the winter shortfall.

Do heat pumps struggle with holiday-let changeover demand?

A pump sized with the changeover hot-water peak in mind copes well. The key is designing for that back-to-back re-heat, not fitting a domestic default, which is why sizing from your actual turnover pattern matters.

Off-gas-grid cottages, where solar and a heat pump pair best, are common in rural areas we cover such as Brecon in the Beacons and Betws-y-Coed in Eryri.

The verdict

Do not think of solar and a heat pump as a choice. Solar cuts the price of a unit of electricity; the heat pump cuts how many units your heating burns. On an off-gas-grid holiday let they compound, and the pump’s daytime running is a near-perfect match for solar generation. Fit solar first if your electric load is already high, or design both together if you are replacing an oil or LPG boiler.

Related reading: battery versus no battery and the cost of solar for a holiday cottage.

Request a free quote and we will model the solar, the battery and, where relevant, the heat-pump load together, so you see the combined running cost rather than two separate estimates.