Using An Air Source Heat Pump With Solar Panels

In Summary: Using An Air Source Heat Pump With Solar Panels

The installation of a heat pump with solar panels could save you up to £1,300 per annum, according to the Energy Saving Trust.

Obviously, there’s a huge cost involved; typically £20,000 for an average UK property. 

However, with government grants available (such as the Boiler Upgrade Scheme) the total average cost sits at around £7,500 per installation. 

Solar panels will work with an air source heat pump, as well as all of your other electrical household appliances. However, to get the most out of a solar panel / heat pump installation, you’ll need to have: 

• A relatively good EPC rating
• Quality insulation
• Larger radiators fitted in comparison to those used with gas, LPG and oil boilers (heat pumps work at their most efficient with large radiators)

Size wise, taking a 3-bedroom semi-detached property as an example, a suitable setup would be: 

• 5-10kW air source heat pump
• 12-15 solar panels
• 4-8kWh storage battery, if you want to be completely self-sufficient when it comes to electricity

These are estimates based on the average UK property. To spec your system accurately, you’ll need to use this heat pump sizing tool. 

Click “Add a solar panel system” once you’ve chosen your heat pump…our tool will suggest the exact solar panel and heat pump setup that you need!

Deciding If Solar Panels & A Heat Pump Are Worth It

Upgrading your property to include both solar panels and a heat pump is a huge decision. 

Below we’ll explain if this is a viable upgrade by exploring potential energy savings, how solar panels work with heat pumps and if your property is suitable.

Energy Savings

Starting with heat pumps, you’d expect to save somewhere in the region of £800 per year on your energy bills. This assumes a 3-bedroom semi detached property using an old G-rated boiler and converting it to a heat pump.

Similar stats from the Energy Saving Trust show average savings of approximately £500 per year for households using solar panels to produce electricity.

So, you’d be looking at a saving of £800 in energy bills utilising an air source heat pump and a further £500 by utilising solar panels, so £1,300 per year in total. 

We detail below, the average heat pump and solar panel installation costs £12,500 (after the Boiler Upgrade Scheme grant is applied). So, you’d be looking at about 10-years to pay off the full system; a solid investment!

Get your quote on a solar / heat pump installation here.

Installation Cost For A Heat Pump And Solar Panels

The average total cost for solar panels fitted alongside an air source heat pump is £20,000. This assumes a 3-bed semi-detached property with reasonable hot water and heat demand, fitted with a 5kW air source heat pump, and 12-15 solar panels.

Taking some rough figures here, expect a solar panel system for a 3-bedroom semi-detached property to sit in the £7,000-£10,000 range. 

You’d be looking at a system that’s uses at least a 5kW heat pump and approximately 12-15 solar panels, with reasonable electricity usage being approximately 3,700kWh for this type of property.

A typical air source heat pump installation for the same property would be somewhere in the region of £10,000. 

A 5-7Kw air source heat pump would be suitable in this case, depending on your exact hot water and heat demand. An example of a suitable pump would be the Vaillant aroTHERM Plus 5kW.

But, the majority of households in the UK would benefit from the Boiler Upgrade Scheme (BUS). This is a government grant for those looking to upgrade their old gas, LPG or oil boiler for an eco-friendly heat pump. 

If you qualify, you’d be able to get a government grant of up to £7,500, slashing the price of your heat pump and solar panel installation by nearly 50%.

Other grants are available such as: ECO4, Nest Wales and Warmer Homes Scotland. To check your eligibility, jump over to our page covering heat pump grants here. 

Or, use our clickable tool that takes into account all of the important details related to your property. It will then determine the most suitable heat pump and solar panel setup, as well as giving you fixed prices on-screen.

Will Solar Panels Work With A Heat Pump?

Solar panels will work with an air source heat pump. Correctly installed solar panels can be used to power all electrical appliances in your household, including your pump. 

There are plenty of variables when it comes to how much electricity you’ll need to generate, and how much your air source heat pump draws, including: 

• How energy efficient your property is thanks to insulation
• The kW output of your heat pump, as well as your heating and hot water demand
• The average temperature you keep your central heating at throughout the year
• The size of your radiators; larger radiators allow air source heat pumps to work at higher efficiency levels
• How many people live in your property, and their demand for hot water

So, whilst a heat pump with solar panels will work, it’s worth ensuring you get the right sized system. You can do that by using this clickable tool here. 

Is My Property Suitable For This Heating Setup?

Property suitability is something that’s massively overlooked. Low efficiency homes (those with a high EPC rating, G for instance) don’t work well with an ASHP. 

Instead, air source heat pumps work best with energy efficient homes. Typically, you’d want quality cavity wall and loft insulation as a minimum. 

And to work alongside your heat pump, you’ll want oversized radiators. Gas, oil and LPG boilers work at much higher flow temperatures than heat pumps. To achieve the same level of heat in your property, you’ll need radiators that on average, have an output of 2.5x in comparison to your current ones.

Improving the energy efficiency of your home means your air source heat pump doesn’t have to work as hard. Naturally, this is going to mean its energy consumption drops substantially. 

If you’re still unsure whether your property is suited to a heat pump and solar panel installation, speak to one of our experts here…they’ll be happy to help!

Or, if you’re ready to get your heat pump and solar panel installation quote, use our clickable form here. Remember to click the option to “Add a solar panel system” once you see heat pump prices on-screen.

Solar Panel & Heat Pump Sizing

What Size Heat Pump Do I Need?

For the average UK property (3-bedroomed semi-detached), heat pumps in the 5kW-10kW range will be suitable. The exact size you need will be determined by your hot water and heating demand. 

We’ve written a guide to heat pump sizing here. However, our sizing tool here takes out all the confusion, and will suggest the most suitably sized heat pumps for your property.

How Many Solar Panels Are Needed To Run A Heat Pump?

Taking the average UK property (3-bedroom semi-detached), you’d need around 12-15 solar panels to run a heat pump, as well as other household electrical appliances. 

Properties in the UK on average use 2,700kWh of electricity per annum, according to ofgem:

Of course, this doesn’t account for the additional electricity used by a heat pump. 

A 3-bedroom semi-detached property that doesn’t use an air source heat pump would easily generate enough electricity from a solar panel system using just 10 panels.

What Size Solar Battery Do I Need?

Depending on your electricity usage and the kW output of your heat pump, expect to need a 4-8kWh solar storage battery. 

Battery sizing for a solar panel and heat pump setup certainly isn’t a one size fits all approach. And the cost of solar batteries goes into the thousands; picking one that’s big enough (but not too big) is incredibly important. 

What you’ll likely see is that on evenings, there’s a deficit that needs to be made up (you’re consuming more electricity than the solar panels can generate) due to using your air source heat pump. This will be emphasised even further in winter.

With the improvements in technology, it’s reasonably simple to determine exactly what size battery you need: 

1. Use a smart meter to determine how much electricity you use, and at what times of the day
2. Compare this to exactly how much electricity your solar panels generate during the same time periods
3. Calculate the difference between the two (electricity used - electricity generated = a rough estimate of what size battery you need)

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