PVT vs. PV: Differences Quickly Explained
What is better: PVT or conventional PV? What are the differences? Can a PV system simply be replaced with PVT? Are the systems even comparable, and to what extent are they compatible?
You can find all the answers in our FAQ section on PVT vs. PV. This section is updated and supplemented on an ongoing basis. We reserve the right to make changes accordingly. All information is without guarantee.
On the front side (PV surface), a PVT module resembles a conventional PV module. The main difference lies in its construction and thus in its range of functions. PVT modules have an additional heat exchanger on the back side, which absorbs the excess heat from the PV cells and transfers it to a heat transfer fluid. This fluid is a water-glycol mixture designed to lower the freezing point. Its composition is similar to the fluid used in standard car windshield washer systems. The heated fluid is transported via a hydraulic system to a brine heat pump, where it provides the necessary source heat.
PVT systems make use of not only the solar energy (which can be converted into electricity) but also of the heat from solar radiation and ambient temperature. This increases the overall efficiency to more than 80 percent (compared to around 20 percent for common PV modules). By removing excess heat, the PV cells are cooled and thus can operate within their optimal efficiency range. This increases the annual PV yield by 5 to 10 percent and extends the lifespan of the PV side.
Hybrid modules combine the best of both worlds: PV and solar thermal energy in one. Silent power and heat generation on the roof, direct energy supply for operating brine heat pumps. Silent, suitable for (almost) any application, attractive in cost, easy to install, and maximally efficient.
Switching from PV to PVT is easily possible. The substructure of the decommissioned PV modules can usually be used for PVT as well. Since the electrical side of a PVT module differs little from that of a standard PV module, there are no special considerations in this regard.
We recommend always using PVT in combination with a brine heat pump, as this allows the system to achieve maximum efficiency. In exceptional cases, operation without a heat pump is also possible, for example for heating a swimming pool. For optimal integration into your building’s heating system, you should consult a plumbing and heating installer. In our partner section, you will find a wide range of contacts for your region.
That depends on your heating system. If you have already invested in a (new) air-to-water heat pump, then PVT will not be worthwile for your project, as the systems are not compatible. However, it’s a different case with a brine heat pump. Instead of geothermal energy, the necessary source heat can also be provided by PVT modules, which additionally generate electricity. This is particularly worthwhile for single-family homes, as PVT is significantly more cost-effective than, for example, drilling one or more geothermal probes.
If your house was built a few years ago and you opted for geothermal energy at the time, installing a PVT system may still be worth considering: by combining hybrid modules with geothermal probes, ground collectors, or ice storage systems, the overall system efficiency can be significantly increased. This leads to long-term savings on electricity costs.
For all single-family home projects still in the planning phase, we generally recommend considering a brine heat pump in combination with PVT. Practical data show that this system is currently one of the most efficient heating solutions existing and often proves to be more economical, durable, and reliable than, for example, a combination of an air heat pump and PV.
Yes, a PVT module is at least as efficient on the electrical side as a conventional PV module. In fact, the annual electricity yield of a Sunmaxx PVT module is even 5 to 10 percent higher, approximately. This is a positive side effect of the active cooling of our modules: excess heat is simply extracted and transferred to the brine heat pump via a heat transfer fluid. As a result, the solar cells do not overheat and can operate in their optimal temperature range almost all year-round. This improves both their efficiency and lifespan.
Thanks to the full-surface heat exchanger mounted on the back of the PV side, we are able to extract excess heat from the PV cells and transfer it to the brine heat pump via a heat transfer fluid. This prevents the performance of the PV cells from dropping at higher temperatures. As a result, the annual electricity yield increases by 5 to 10 percent, and the lifespan of the PV cells is improved.
In Sunmaxx PVT modules, the surface area of the heat exchanger is slightly smaller than the PV surface. This is necessary to optimally mount the heat exchanger on the back side and thus ensure the best possible heat transfer.
Yes, that is possible. There are already plenty of successful systems with power optimizers implemented.
The investment costs of a PVT system are only partially comparable to those of a standard PV system. PVT should always be considered as part of the building’s heating system. A more realistic comparison is between PVT + brine-to-water heat pump and PV + air-to-water heat pump. In this case, the investment costs are roughly the same, since PVT – unlike PV – is eligible for subsidies.
Over the long term, the combination of PVT and a brine-to-water heat pump is a significantly more efficient system with higher annual performance factors, resulting in lower operating costs and a longer lifespan of the entire system. PVT modules enable a three times more efficient use of the roof surface and operate completely silent – an ideal solution, especially in densely built-up areas. This is a major advantage over air-to-water heat pumps, which are not only bulky but, in some locations, even are no longer permitted due to noise emissions.