Why homeowners worldwide are using solar-powered heat pumps to cut energy bills


Key takeaways

  • Heat pumps draw energy from the air or the ground outside into your home, making them an efficient and sustainable way to heat your property.
  • Using solar energy to power your heat pumps can make them even more sustainable.
  • If you want to use solar energy to power your heat pump, you’ll need to make sure your solar system has a battery energy storage system, so that you can power your heat pump at night.
  • Depending on whether you’re starting a solar system from scratch or converting an existing solar system for battery storage, you will need to choose between two different types of inverters: a battery inverter or a hybrid inverter.
  • Benefits of combining solar power with a heat pump include reducing your carbon footprint, saving on energy costs, and taking advantage of government incentives.

Table of Contents

Nowadays, there is a huge range of options on offer for anyone wanting to cut their carbon footprint.

And more and more homeowners are thinking about investing in more than one kind of sustainable technology – and using them together to help them cut their energy use, emissions and spending even further.

Heat pumps and solar panels seem like a natural fit for this sort of approach. But is it possible to use heat pumps and solar panels together? And, if so, how

can you make sure you maximize the potential of both kinds of technology – and still keep your home snug and warm all through the winter?

What are heat pumps?

You might remember from your science lessons that heat naturally flows from warmer places into cooler places. A heat pump’s job is to move warm air from one place to another. That might mean drawing warm air into your home from outside, a bit like a reverse air conditioner. Or it might mean pushing warm air out of your home to keep it cooler in the summer. This is much more sustainable than most traditional, fossil fuel-based methods of heating homes: heat pumps use energy to move heat into your home, but they don’t use much energy to create heat the way an old-fashioned central heating system does. That means that heat pumps can create  two to three times more heat compared to the electricity they consume. Heat pumps come in a few different forms:
  • Air source heat pumps draw heat from the air outside your home. If the air isn’t warm enough, it will use a little bit of energy to boost it to a higher temperature, so that it can warm up your home efficiently. Air source heat pumps can be divided into two sub-types: air-to-water heat pumps move heat into the water that runs through your radiators or underfloor heating systems. Air-to-air heat pumps work more like air conditioning, pushing warm air directly into your home.
Air source heat pumps
  • Ground source heat pumps draw heat from the ground by circulating liquid underground, using the earth’s natural warmth to heat it. This makes installing a ground source heat pump a little more complicated, which means they’re generally much more expensive.
  • Hybrid heat pump systems combine either type of heat pump with a traditional boiler or gas-based heating system. The system monitors the temperature outside and, if it’s too cold to use the heat pump efficiently, switches to the traditional heating system to warm up your home.

How can you use solar energy to power your heat pump?

Heat pumps use much less energy than traditional heating methods, but they do need to use some electricity – which means there’s still room for improvement when it comes to sustainability. But by using solar panels to power your heat pump, you may be able to cut your carbon footprint further. And, even better, you might be able to reduce your costs, too. Here’s how you can start hooking your heat pump up to your solar system. Start by calculating your energy needs – as a rough guide, the average European household consumes around 3.7 MWh per year, and heating accounts for about 8.63% of that figure. You might find that your solar panels can’t produce all the electricity you need to run your pump – if that’s the case, you might need to rely on grid power every now and then. Once you’ve confirmed how much energy you need, you can start installing your solar system or upgrading your existing system. You’ll need to choose the right solar panels, of course. But you’ll also need to pick the right inverters, which convert DC solar energy into AC electricity that’s usable in your home. When you’re powering something as important as a heat pump, you’ll need to choose inverters that are as reliable and efficient as possible. That’s why lots of homeowners choose Hoymiles inverters, which:
  • Have high efficiency ratings
  • Offer an extended warranty and technical support
  • Use built-in monitoring to keep an eye on how your solar system is performing
You can find out more about how to set up your solar system here.

How Hoymiles energy storage helps you stay warm all day (and night) long

There’s one big challenge with using solar energy to power your heat pump: solar panels can’t generate energy at night when you’re most likely to need to be using your heat pump.

That’s why many people who combine heat pumps with solar power choose to add some form of energy storage to their system. This means that your solar system can generate ‘extra’ energy during the day and then store it in a battery, to be used at night once the sun has gone down and the temperature has dropped.

SG Ready


If you’re based in Germany or a German-speaking country, you can even use your energy storage system to add an extra layer of efficiency In these regions, heat pumps that come with an ‘SG ready’ label are compatible with smart grid technology. If you have the right kind of inverter (such as a Hoymiles battery or hybrid inverter), you can set your heat pump to automatically start up whenever your solar system produces excess energy. This allows you to use as much of your solar energy as possible, as efficiently as possible. Here’s how to go about integrating energy storage into your solar system:

Adding energy storage to an existing solar system

As we mentioned above, a microinverter converts DC solar energy into AC power that can be safely used in your outlets and home appliances. But AC energy can’t be stored. This means that, if you want to save excess energy in a battery, you’ll need a way to convert AC power back into DC power. And for that, you need a battery inverter. That’s why we created the Hoymiles HAS series battery inverter; it’s designed specifically to retrofit solar systems for battery storage, which means it can efficiently and safely convert AC electricity into DC electricity. And, once you’re ready to use the power, your inverter can convert the DC electricity in your battery back into AC power that’s safe for use in your home. It’s also very flexible, which makes it perfect for systems that use a heat pump. The HAS series allows you to integrate solar, battery and grid power, so you can switch between energy sources to keep your pump running while minimizing your carbon footprint. The diagram below shows how the Hoymiles HAS series battery inverters fit into your existing solar system.
Diagram to show how Hoymiles HAS battery inverters in a wider retrofitted solar system.

Building a solar system with energy storage from scratch

If you’re building a solar system from scratch, you won’t need to install two inverters. Instead, you can use a hybrid inverter like the Hoymiles HYS series, which can handle both operations: converting DC to AC, and converting AC to DC for battery storage. This smart technology makes your solar setup much simpler, and allows you to switch easily between converting energy for use in your home, and converting it for storage in your batteries. The diagram below shows how this works in practice.
Diagram to show how a Hoymiles HYS inverter fits into and simplifies a solar system with battery storage.

What are the benefits of powering your heat pump with solar energy?

We’ve already touched on a few of the benefits of combining a heat pump with a solar system, but let’s explore them in more detail:
  • Reduce your environmental impact
Heat pumps certainly use less energy than traditional heating methods, but they do still require some electricity to run; by switching to renewable energy, you can ensure that the entire cycle of heat generation is completely sustainable.
  • Save on fuel costs
With fuel costs on the rise, it’s hardly surprising that many people are combining heat pumps with solar panels with another goal in mind: saving money. One study estimates that European households using a combination of solar power and heat pumps saved up to 84% on their household bills. That’s a huge difference for any household. The chance to save such a huge chunk of energy costs is driving the popularity of heat pump/solar power systems around the world.
  • Take advantage of government incentives
By combining a heat pump with a solar system, you can benefit from some impressive government incentives: in Poland, for example, you can now get a government rebate when they buy a heat pump, as part of the same scheme that reimburses homeowners for investing in solar panels. The UK has a similar scheme called the Home Upgrade Grant, which gives low-income off-grid households grants for insulation, solar panels, heat pumps and other measures that make homes more energy efficient and sustainable. In 2023 the US announced similar measures, providing grants to both businesses and private homeowners to cover the cost of measures that improve energy efficiency – including heat pumps.

Choosing Hoymiles solar solutions for your solar-powered heat pump

Heat pumps and solar power really are better together: by combining them, you can take control of your energy costs and your carbon footprint. The key is to combine them in the right way, with the right battery setup and the right inverters. So that you can always get the energy you need to keep your home cozy without draining energy from your lights or appliances. Whether you’re trying out a solar-powered heat pump for your home or your business, we’ll be there to make sure you reap all the benefits of your technology. All of the Hoymiles inverters we’ve covered in this blog come with real-time monitoring via S-Miles Cloud – your complete toolkit for monitoring, managing and troubleshooting your solar system’s performance. Ready to take your energy savings to the next level? We’re here to help – just get in touch to see how we can help you get more from your solar power/heat pump system.