How can heat pump owners make the most of their solar panels? With the right smart controls, these two low-carbon technologies can work in perfect harmony to deliver super low bills and perfect comfort. In this Insight, we explore how the Passiv Smart Thermostat automatically optimises a heat pump to rooftop solar generation, reducing hot water bills by 48% without the need for any additional monitoring equipment and without any ongoing subscription fees.
Heat pumps are powered by electricity. Aside from being better for the environment, using electricity opens up new opportunities for heat pump owners to heat their homes for less. One option is to sign up to a time-of-use tariff with your energy supplier. These smart tariffs have different prices at different times of day and can work well with a heat pump if you’ve got the right controls. Check out our Insight on how the Passiv Smart Thermostat automatically optimises a heat pump to smart electricity tariffs to find out more!
Another way for heat pump owners to reduce their heating bills is with solar power. In the UK, solar panels are getting more and more popular, with growth of over 10% year-on-year since 2022. There are now over 1.5 million homes generating their own power with solar PV! By utilising heat pumps and solar panels, homeowners can heat their hot water and home during the day without spending a penny.
How can heat pumps and solar panels work together?
Traditionally, some solar panels have been installed with a solar diverter. Solar diverters redirect electricity generated by solar panels to an immersion heater in a hot water tank. This allows you to maximise the use of your solar generation by producing free hot water without using your boiler. This is a cost effective way of utilising solar generation, but it has a number of disadvantages for homes with heat pumps.
Heat pumps are super efficient, using ambient heat to achieve efficiencies of over 100%. On the other hand, an immersion heater has a maximum efficiency of 100%, so can never be as efficient as a heat pump. Using a solar diverter and an immersion heater instead of a heat pump means much less efficient hot water heating.
Sending solar generation straight to an immersion heater also means it cannot be used for heating the home. In late autumn and early spring there are plenty of days where the sun is shining but it’s chilly outside. By combining solar panels and heat pumps, homes can be kept warm even during the winter months using free electricity from the sun.
How can a heat pump make the most of solar generation?
The Passiv Smart Thermostat automatically optimises a heat pump to run when the sun is shining and solar panels are at their most effective. In the summer, this means hot water tanks are heated for free, while in the winter, both hot water and heating can use free electricity from solar panels. All you have to do is input some details about your solar installation in the Passiv app and the Passiv Smart Thermostat takes care of the rest!
By optimising to solar, a hot water bill can be reduced by up to 48% in comparison to heating hot water during standard morning and evening periods. With the Passiv Smart Thermostat this is done without the need for any additional hardware, including solar diverters or monitoring equipment. Not only that, all optimisation features in the Passiv Smart Thermostat are available without any subscription fee, so every penny of that 48% saving goes straight to the homeowner.
How does the Passiv Smart Thermostat optimise a heat pump to solar generation?
By using specific details about a solar installation, the Passiv Smart Thermostat forecasts the amount of solar generation a home will produce at any given time for any day of the year. Then the Passiv Smart Thermostat estimates the amount of that generation that isn’t being used elsewhere in the home and shifts heat pump operation accordingly. While this prediction won’t be as accurate as a solar diverter which is monitoring live generation, any additional electricity usage is more than offset by the increased efficiency of using the heat pump rather than the immersion element to heat the hot water tank.
Passiv is also the UK’s leading provider of domestic solar monitoring services, with 150,000 homes connected to our solar monitoring platform. This has provided one of the largest records of domestic solar generation across the UK.
The Passiv Smart Thermostat has been helping heat pump owners make the most of their rooftop solar generation for almost a year. With a whole host of cost saving benefits and an exciting roadmap of new features, there’s never been a better time to take your heat pump installations to the next level by installing the UK’s leading heat pump optimiser. Contact us today to find out more or book a demo of the Passiv Smart Thermostat.
