Solar assisted heat pumps

A solar assisted heat pump heats water by absorbing heat from direct sunlight and from the air. The hot water is then stored in a hot water cylinder, ready for when you need it. Solar assisted heat pumps can also work without direct sunlight. 

A solar assisted heat pump will reduce your hot water heating’s carbon emissions. This is because heat pump technology transfers energy from outside to heat your water. It uses electricity to do this, but it delivers more heat energy to your hot water than electrical energy it uses. 

You’re more likely to recover the costs of installing a solar assisted heat pump if your household uses a lot of hot water or pays higher energy costs for heating water (for example, if you use an electric immersion heater). This is because you’ll see more savings on your energy bills.  

When the sun shines on an object, some of that light is absorbed and changed into heat.  

A solar assisted heat pump has a large, flat evaporator panel that absorbs the heat from sunlight falling directly onto it and from the air around the panel. This heat is absorbed into a fluid that passes through a heat exchanger into the heat pump. This raises the temperature and transfers that heat to your hot water cylinder.  

Our in-depth guide to heat pumps explains how a heat pump works in more detail. 

Because a solar assisted heat pump continuously produces a low volume of hot water, it can take some time for the hot water cylinder to heat up again after you’ve used all the hot water that’s available. For example, if you fill multiple baths, you might have to wait a few hours to have enough hot water again. 

A typical solar assisted heat pump installation could cost around £6,000. The exact cost will vary depending on the model, the number of evaporator panels you need and whether you need a hot water cylinder, as well as if any additional work required like pipework and scaffolding. Costs may also vary depending on where in the country you live and what the local installer’s rates are. 

We recommend asking at least three installers to give you a quote for your heat pump system. This will give you the best idea of how much it might cost. 

The amount of money a solar assisted heat pump will save you on your fuel bills depends on how much hot water you use and what system you currently use to heat your hot water.  

You’ll likely save more if you use typically more expensive fuel, such as LPG or oil, to heat your hot water and if your current heating system is inefficient, which may be the case if your current boiler is old.  

The financial savings are also best when your hot water demand is higher than average. The more hot water you use from your cylinder, the more you may save by installing a solar assisted heat pump. This may be the case if you have a lot of people living in your home and they use a lot of hot water for bathing that isn’t heated a in another way, such as an electric shower. 

You can see the potential annual savings of installing a solar assisted heat pump in an average sized, three-bedroom semi-detached home below for a range of hot water heating systems and number of occupants.