Thinking of installing both solar panels and a heat pump on the same house, but not sure if that’s a good idea? Then this is the guide for you.
Can Heat Pumps and PV Solar Panels Work Together?
Yes, heat pumps and PV solar panels can work in total harmony, without conflict. Here’s why:
Different tasks: A heat pump heats your home, while solar panels provide electricity
Different systems: A heat pump is part of the central heating system, while solar panels are part of the electrical system
Separate locations: Solar panels go on the roof, while a heat pump goes on the ground outside
Is it Worth Having Both A Heat Pump And Solar PV Panels?
Heat pumps and PV solar panels compliment each other very well. Indeed, there’s no cheaper way to power a heat pump than with your very own electricity harvested on your roof! So it certainly can be worthwhile having both.
On the other hand, it’s unrealistic to expect 100% of the electricity for your heat pump to come from solar panels. This is because heat pumps are generally designed to run continuously – and solar panels can’t power them through the night. So there’s one more ingredient to add to this mix – a smart electricity tariff. This will let you compliment daytime solar energy with night-rate electricity to power your heat pump at the lowest overall cost.
Besides, with solar feed-in tariffs now live in Ireland, you can offset the cost of electricity you consume with electricity you sell to the grid. So, with a heat pump and plenty of solar panels, your energy bills can be ultra-low. Think about it: No oil bill, no gas bill – only one small electricity bill every two months.
One important side note: A heat pump is not suitable for every home. In particular, your home needs to be well-enough insulated for a heat pump to work efficiently. If you have doubts, then read: Is a Heat Pump Worth it in Ireland?
What About Solar Panel Power Diverters and Heat Pumps?
A solar panel power diverter is a device that heats water using surplus electricity from PV solar panels. It does this by sending the surplus electricity to your immersion heater. Many heat pump units also use an immersion heater for back-up and to Pasteurise Legionella bacteria in hot water tanks. Unfortunately, you generally can’t connect a power diverter and a heat pump to the same immersion element.
There are several possible solutions to this dilemma:
- Use a hot water tank with multiple immersion heaters. Connect the heat pump to the bottom immersion heater and the power diverter to the top immersion heater
- Get a custom-made immersion heater with two electrically separate elements. Or in other words, two side-by-side immersion heaters that fit into the same hole in a hot water tank. Connect the heat pump to one and the power diverter to the other.
- Just don’t use a power diverter. With export payments for surplus solar electricity now live in Ireland, this is currently the most economically attractive option for most people with solar PV and a heat pump.
Can Heat Pumps and Solar Thermal Panels Work Together
Solar thermal panels (plates or tubes) heat water using solar energy. Meanwhile, a heat pump heats water using electricity and warmth from the ambient environment. So there’s some overlap in what these two technologies do.
There are two main scenarios to consider when both solar thermal panels and a heat pump are installed in the same house.
First is the case where the heat pump provides space heating only (not hot water for taps and showers). This case is very simple – there will be no interaction between the heat pump and the solar thermal systems. And therefore, the solar thermal panels and the heat pump can work fine side by side.
Second is the case where the heat pump provides both space heating and hot water for taps and showers. In this case, it’s likely that the heat pump and solar panels will be supplying heat to the same hot water cylinder. In this case, you’ll need a cylinder with two heat exchange coils – one for the heat pump and one for the solar thermal panels.
Is it Worth Having Both Solar Thermal Panels and a Heat Pump?
Households with solar thermal panels but no heat pump could have a lot to gain by adding a heat pump. This is because adding a heat pump could allow them to slash their space heating costs. They could also reduce their winter-time water heating costs.
On the other hand, households that already have a heat pump (one that also supplies hot water) have less to gain by adding solar thermal panels. This is because the heat pump will already provide low-cost hot water for taps and showers. So solar thermal panels would be largely redundant. On the other hand, solar thermal panels could extend the life of a heat pump by eliminating the need for it to run during the summer months. And they will provide some additional energy savings. But probably not enough to justify the cost of the panels. And in the case where the heat pump only provides space heating, solar thermal will perform just like they would in a house without a heat pump.
In practice, if you already have a heat pump, there’s usually not much point in adding solar thermal panels. Better to add solar PV instead.
SEAI Grants for Heat Pumps and Solar Panels
You can get a heat pump grant and a solar panel grant on the same house.
Specifically, the SEAI provides grants up to €12,500 for heat pumps in Ireland (from February 2026). And €2,100 for solar PV.
These grants won’t be around forever. So consider upgrading now, before carbon taxes increase again!
