Hybrid solar panels combine the technology of PV and thermal panels to produce both heat and electricity. Here’s what you need to know before considering them for your home
A replacement dwelling, the roof of this stunning house, designed by Hawkes Architecture, was designed to harness solar energy via roof mounted photovoltaics(Image credit: Hawkes Architecture)
Hybrid solar panels, or PVT solar panels, are a combination of solar photovoltaic panel and solar thermal panels in one module. A hybrid solar PVT module can therefore produce both electricity and heat simultaneously
While combining these systems may sound like a no-brainer, the technology does have limitations in comparison to separate PV and thermal solar panels.
This includes specialist installation with increased costs and a reliance on a primary heating system when using hybrid solar panels.
However, there are some instances where hybrid panels are the perfect choice for supplementing your home’s energy supply. We explore the technology in more detail.
How Do Hybrid Solar Panels Work?
Hybrid solar panels are effectively a solar PV panel that also has pipes that are built into the collector with a fluid circulating between them and a water cylinder.
As the sun shines on the panel the light is absorbed by the PV cells and the heat is absorbed by the solar thermal element.
This has two advantages:
The fluid warms up and can be used as useful heat
The fluid cools the PV cells which makes them more efficient.
Pros and Cons of Hybrid Solar Panels
Hybrid solar panels take up less space on a roof because the solar PV and the solar thermal panels are combined. This could be ideal on homes that have smaller roofs, such as three-storey properties.
However, solar PVT panels can be expensive. They are not a mainstream product yet so the installers and materials could be harder to source and therefore more costly. There are a few different solar PVT manufacturers but the products are very similar.
The combined nature of the way these panels work is a good concept and optimises the PV. If production increases then we may see economies of scale that means the panels could then be financially competitive and more widely specified.
Solar PVT panels were installed on this self build house, designed by Hawkes Architecture.(Image credit: Hawkes Architecture)
Further, the thermal element of the PVT panel will also not get to the same high temperatures reached by standard solar thermal panels. This makes the heat more difficult to use as it requires additional heating.
This means that PVT panels are a complimentary system and you will still need a primary heating system.
Given the cost of the solar PVT panels and the relatively small number of installers, the general consensus is that if you have enough room on the roof then going for separate solar PV and solar thermal systems could be the best option.
The solar PV and the solar thermal panel systems can then be sized properly and the energy use optimised.
How Much Do Hybrid Solar Panels Cost?
The cost of solar PVT systems ranges depending on the manufacturer, capacity of the system, components included and the installer. As there are not a lot of approved and experienced installers of these systems, the price could also be affected quite significantly by travel costs.
A 4kWp system could cost around £10,000 installed.
This compares to around £5,000 - £8,000 each for PV and solar thermal panels.
How Much Energy do Hybrid Solar Panels Generate?
According to manufacturers, a solar PVT system can generate around 1500kWh of energy per kWp installed per year. That would be around 1000kWh of electricity and around 500Wh of heat.
The hybrid solar PVT panels can produce more heat than this but that could then be too hot for the PV cells. The crucial design details would be to make sure that you can use all the generated energy but also not overheat the PV cells.
Most manufacturers will have software that can give you a reasonable indication of your annual energy generation and you can then use this to evaluate the return on investment.
How is a Hybrid Solar Panel Installed?
Hybrid solar panels are installed in the same way that regular solar panels are.
Roof hooks are fixed to the roof trusses or rafters, depending on where the panels will sit in relation to the roof cladding, to which aluminium rails are then fixed horizontally. The panels are bolted to these rails.
Solar PVT panels will require the wires from the PV function to lead back to an inverter to turn it into usable energy, as well as pipes connecting to the home's hot water storage for its solar thermal component.
As PVT systems are more specialist at present, the best way to find the right installer is to ask the manufacturer of your product for a list of approved installers.
Hybrid Solar Panels vs Other Solar Hybrid Technology
Don't confuse hybrid solar panels with Hybrid Solar air systems also referred to as aerovoltaic. This is where ducts are built into the photovoltaic panel, through which air is drawn across the panel. This is delivered to the home to cool the PV panel but also preheat the fresh air entering the home.
Thermodynamic panels are also often confused with solar PVT. These technologies have collectors that are mounted on a roof or a wall and have refrigerant in them that absorb the sun’s energy.
They do not generate electricity and effectively a type of heat pump system.
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David is a renewables and ventilation installer, with over 35 years experience, and is a long-standing contributor to Homebuilding and Renovating magazine. He is a member of the Gas Safe Register, has a Masters degree in Sustainable Architecture, and is an authority in sustainable building and energy efficiency, with extensive knowledge in building fabrics, heat recovery ventilation, renewables, and also conventional heating systems. He is also a speaker at the Homebuilding & Renovating Show.
Passionate about healthy, efficient homes, he is director of Heat and Energy Ltd. He works with architects, builders, self builders and renovators, and designs and project manages the installation of ventilation and heating systems to achieve the most energy efficient and cost effective outcome for every home.
