Compared to a heat pump, underfloor heating, or even wood heating like wood logs, solar heating installation offers several fascinating advantages. It is no surprise that this system is gaining popularity.
More and more households are using devices that operate using solar energy. Ecological, clean, and free, it allows homes to enjoy optimal thermal comfort.
Recently, the solar radiator has become popular. It is an interesting solution to green the main heating system. Moreover, it helps you save money. To learn more about this solar heating system, this article provides important details to remember.
Overview from my point of view: In my opinion, the solar radiator represents the logical culmination of an autonomous and responsible home. I find it fascinating to be able to transform a free and inexhaustible resource into constant thermal comfort without resorting to complex systems. My editorial focus is on simplicity: far from technological gas factories, the direct coupling between photovoltaic panels and inertia emitters drastically reduces your energy bill while enhancing your real estate assets in the long term.
How does a solar radiator work?
Photovoltaic solar panels, solar thermal collectors, solar thermal panels, combined solar system (SSC), or individual solar water heaters (CESI), many technical terms may seem a bit strange to you during your search for the solar electric radiator.
To help you see more clearly, know that the latter works by capturing the calories from the sun’s rays and transmitting them to the water in the central heating system. It is necessary to use solar panels installed on the roof to receive solar radiation and their calories.
These raise the temperature of an antifreeze heat transfer fluid which is transmitted to a heat exchanger. This then ensures the diffusion of calories to the water in the central heating system or to the domestic hot water storage tank. Thus, solar panel radiators are powered without resorting to another auxiliary boiler.
To determine the performance of the solar heating installation, it largely depends on the sunshine rate of the area and especially the orientation of the solar thermal panels or photovoltaic solar panels. Almost all south-facing homes benefit from the efficiency of a solar electric radiator. With a glazed surface, windows offer you an energy gain of up to 200 kWh per year.
At some point, it is possible that the sunlight on these panels is not sufficient to meet heating or domestic hot water production needs. In this case, know that solar heating is often equipped with a solar storage tank for storage purposes. It serves to accumulate the calories captured throughout the sunny day, delaying the use of an auxiliary boiler. This allows you to save even more.
I was long skeptical about the real effectiveness of solar heating in the middle of winter, especially during gray days. My awareness happened during a visit to a friend who had installed forced-air solar heaters on his south-facing facade: despite an outside temperature close to zero, the air blown inside was pleasantly warm and, above all, completely free. I realized that day that solar energy was not just a backup solution for hot water, but a real lever to stabilize the indoor climate passively. Since then, I consider every watt recovered directly from the sun a victory against energy poverty.
What is the difference between a thermal solar heater and a photovoltaic one?
The solar heater uses the sun’s heat to generate domestic hot water or to heat a house. Captured by the solar panel installation, this energy is both free, non-polluting, and unlimited. These are major advantages of solar heating.
For the heater to work, it must be coupled with solar panels. There are two main categories, including photovoltaic solar panels and thermal solar panels. Although both use the sun’s heat, their operation and technology differ.
The first produces electricity which powers the solar electric heater. The second captures the sun’s rays to heat the heat-transfer fluid. This fluid transfers its heat to the water which is then used for heating a building or for domestic hot water production.
Simply put, photovoltaic solar panels exploit solar radiation to directly produce electricity. For thermal solar panels, they use solar energy to heat homes or domestic hot water.
The solar heater therefore operates on electricity from photovoltaic panels or by heating from thermal solar panels. There are two types of solar heating systems: the individual solar water heater (CESI) and the combined solar system (SSC).
With thermal solar collectors, the first focuses on producing domestic hot water in a single-family home. As for the second, it can also provide domestic hot water. Additionally, it can supply supplementary heat for heating.
Comparative table of solar heating systems
| System | Energy source | Type of distribution | Installation complexity |
| Thermal Solar | Heat-transfer fluid | Water radiators / Floor heating | High |
| Photovoltaic Solar | Direct electricity | Inertia radiators | Medium |
| Air Solar | Air heated on facade | Supply vents | Low |
What surface area of solar panels is needed for a solar heater?
Their surface area can vary depending on the number of solar panels used as well as the required power. For example, if you need 3 kWc, you should plan a solar heating installation with about ten solar panels, which can represent an area of approximately 15 m2.
If you plan to use photovoltaic solar panels, it is advisable to favor a solar radiator with a double heating core or with inertia. These models are capable of storing heat to distribute it evenly.
For those who prefer to use thermal solar panels, choose models with a surface area of about 10m2 for a 100 m2 home. This depends more specifically on their thermal performance.
For the solar heating system to be complete, you can accompany the solar panels with a hot water tank, circulators ensuring the distribution of hot water, and of course water radiators or other heat emitters.
Electric radiators are powered by the heat transfer fluid heated by the solar panels of your choice. To accumulate heat during the sunny period, using a buffer tank is an excellent idea. It ensures the transmission of heat to the heat emitters during the absence of sunny weather.
Can a solar radiator heat the entire house?
It is possible to heat a house with a solar electric radiator under one condition. It is imperative that the solar heating installation is sufficiently efficient to cover the majority of energy needs, especially in winter.
Whether you use thermal solar panels, hybrid solar panels, or photovoltaic panels, the solar energy produced provides high thermal comfort in the house economically and ecologically.
It can be used to ensure home solar heating, to guarantee domestic hot water production, and even to heat a swimming pool. Whether it is the combined solar system SSC or the individual solar water heater CESI, using solar energy allows households to save up to 70 % on their heating bill.
However, it must be said that the performance of solar heating can be limited when clouds cover the sky hiding the sun. In this case, you can use an electric, oil, or gas boiler. The device takes over, keeping the house comfortable.
Moreover, using a hot water tank coupled with the solar heating system delays the use of these backup solutions. Since it accumulates solar energy during sunny hours, it can ensure the temperature rise of the central heating. Generally, a solar radiator can cover about 65 % of heating needs and 50 % of domestic hot water production.
How much does the installation of a solar radiator cost?
The price of solar heating installation including the solar electric radiator depends on countless factors. It can especially vary depending on the size of the house, the geographical area, the orientation of the solar panels, and their mounting system. It should be noted that they can be installed directly on the roof. The professional also has the possibility to integrate them into the roofs, depending on the models.
If we consider the living area to be 70 m2, you need to install thermal solar panels of 10 m2. This requires a budget of about 13,000 euros. Generally, you need to prepare approximately 160 euros per square meter to be heated. This price range includes equipment and installation.
It must be admitted that the home solar heating system, whether with the combined solar system SSC or the individual solar water heater CESI, seems expensive. Fortunately, there are many financial aids related to the use of renewable, inexhaustible, and natural energy such as solar energy.
MaPrimeRénov’ is one of the most popular subsidies. This scheme is dedicated to landlords as well as owner-occupiers. For very low-income households, it offers up to 10,000 euros. As for those with standard incomes, this state aid offers them a sum of 4,000 euros.
Besides MaPrimeRénov’, there is also the CEE Energy Bonus reserved for the combined solar system SSC, the zero-interest eco-loan or Eco-PTZ, the reduced VAT rate of 5.5 %, and the energy voucher. The latter is mainly used to pay energy bills. For modest households, they can receive an amount between 48 and 277 euros.
Does a solar radiator work in winter?
Despite the many misconceptions circulating, any solar heating installation for homes can operate throughout the year, including during the cold season. The sun’s laziness generally poses no problem for solar panel radiators. Of course, their performance is reduced compared to that recorded during the summer season. Yet, they continue to heat the house by producing electricity even in winter.
With global warming, the cold season also benefits from sunshine. As we all know, this can be necessary for the profitability of your hybrid solar panels or photovoltaic solar panels.
No one can deny that there is a decrease in their solar energy production during winter, but this does not mean an absolute absence of their productivity. It is also possible to intensify their electricity production. To do this, you can adjust the tilt of the solar panel.
If it is generally oriented at 30 to 35 degrees during installation, please adjust it to 40 to 45 degrees in winter. During this bad season, the sun may appear lower. It is therefore advisable to call on an expert to change its inclination.
Take advantage of their intervention to remove leaves, snow, or debris that settle on the surface of the solar panels. They risk blocking photons, preventing solar energy production.
If you want to enjoy more thermal comfort, you can always use other supplementary heating solutions such as a gas condensing boiler. Many sources also state that a water-to-water heat pump combined with a solar home heating system shows increased performance.
What is the lifespan of a solar radiator?
Whether it is the cost of solar home heating installation or the purchase price of the equipment, the whole requires a large budget. The issue of the system’s durability is therefore crucial. It is not surprising that every buyer needs more information on the subject.
A solar electric radiator can last from 10 to 15 years. Other high-quality models can last up to 20 years provided they are well maintained. In any case, the longevity of the device depends on many factors such as manufacturing quality, frequency of use, installation environment, and regular maintenance.
When it exceeds more than 10 years, it is important to check its operation from time to time. Like any heating equipment, solar panel radiators can wear out over time. When they start consuming more energy, it is time to replace them.
Regarding solar panel installation, their lifespan varies depending on the model and frequency of use. In most cases, they are likely to last for about 20 years. Some units even have a lifespan of 30 years. To increase their longevity and fully enjoy their performance, be sure to take care of them regularly.
What are the ecological advantages of a solar radiator?
Compared to most electric radiators, there are many solar heating advantages. Many people choose to use a solar radiator because it can offer them increased thermal comfort. Thanks to the solar thermal collectors, it allows the diffusion of heat that is both homogeneous and gentle. During its operation, it makes no noise.
That’s not all, this device is perfect for making a home more ecological. If you plan to put it on the market, using a home solar heating system is an excellent idea to enhance its value. Thus, during the diagnostics to be carried out before a sale, your property can attract potential buyers.
Additionally, one can mention the simplicity of maintaining solar heating advantages. Since the solar electric radiator is designed to be durable, it requires little maintenance. In any case, make sure to take care of it to fully and longly enjoy it. It is recommended to entrust this operation to a professional.
Among the solar heating advantages, the solar electric radiator outperforms its competitors thanks to its significant energy savings. Since it does not need to consume more fuel to operate, it considerably reduces the heating bill. Moreover, it is able to meet quality requirements, making it a durable and reliable equipment.
How to maintain a solar radiator?
As we mentioned in the solar heating advantages, its maintenance is very easy. Nevertheless, please give it importance even if this operation is not mandatory. It is advised to carry out a first maintenance within months after installing the solar radiator. This helps you check its operation to use it safely.
Regarding its maintenance, you can perform it every 2 to 3 years depending on its age. And do not forget to do an annual cleaning. If you follow these measures, you manage to limit potential breakdown risks. Even better, you can extend its lifespan and increase its efficiency.
Photovoltaic panels, solar thermal panels, or hybrid solar panels, they all demonstrate great durability. Still, try to rinse them once or twice a year. As for the rest of the solar heating installation, namely the level of the heat transfer fluid, the solar thermal collectors, and the hot water tank, it is imperative to carry out an annual check by a specialist.
If you combine your solar panel radiators with oil and gas boilers, you must go through a certified expert to perform an annual check. This is part of the obligations to be strictly respected.
Can a solar radiator be used in addition to another heating system?
The use of supplementary heating mainly depends on the heating needs of each household, but also on the geographical location. Generally, you do not need it if your home is small and also perfectly insulated.
The solar gains may seem sufficient for domestic hot water production and for heating the home. You can similarly use a hot water tank to compensate for any shortfall.
However, if you live in an area with low solar input, you are forced to use a backup solution. The same applies to larger dwellings.
The use of a combined solar system with a device responsible for domestic hot water production may seem inevitable. And most of the time, households choose a gas and oil boiler. Additionally, a heat pump also combines performance and ease of use.
Frequently Asked Questions about Solar Radiators: Operation and Installation
The solar radiator itself does not produce heat at night, but it relies on the principle of inertia or storage. In a photovoltaic system, the energy produced during the day can be stored in batteries or used to heat a massive heat storage body (lava stone, refractory brick) which will slowly release heat during the evening. For total autonomy, these radiators are often hybrid and can switch to the conventional grid if the energy stock is depleted.
The thermal panel captures the sun’s heat to warm a liquid that then circulates through your water radiators. The photovoltaic panel, on the other hand, converts light into electricity to power a conventional or inertia electric radiator. The photovoltaic system is generally simpler to install and maintain, as it does not require complex piping nor the risk of heat transfer fluid leakage.
The installation of solar panels and radiators requires specific skills in electricity and sometimes roofing. While there are “plug-and-play” kits for small surfaces, a complete installation to heat a house requires the intervention of a certified RGE (Recognized Environmental Guarantor) professional. This not only guarantees the safety and efficiency of the installation but also allows you to benefit from state financial aids for the energy transition.
