The challenge of high temperatures

Traditional photovoltaic panels in hot weather can heat up to 70-80°C. This leads to a significant decrease in their performance - any degree above the standard test temperature (25°C) means a loss of about 0.35% of power. It is easy to calculate that at a panel temperature of 75° C we lose up to 17.5% of the potential energy production. It's like turning off every fifth photovoltaic panel in the middle of a sunny day!

The problem is even more serious in the case of BIPV systems (Building Integrated Photovoltaics), that is, panels integrated into the building. In traditional installations, the panels are mounted above the roof, which, at least theoretically, provides them with natural ventilation. On the other hand, in integrated systems, where photovoltaic modules are also the roof covering, the challenge of adequate cooling becomes crucial.

Let me give you a real-life example: a typical 10kW photovoltaic system under standard test conditions (25°C) should produce about 8kW of power on a sunny day. However, in reality, when the temperature of the panels rises to 70°C, the same installation only generates about 6.6 kW. This means a loss of energy worth up to several hundred zlotys per month at the height of the summer season.

Worse, high temperatures not only reduce current performance, but can also accelerate the aging of panels. Prolonged exposure to high temperatures can lead to microcracks in the cells, degradation of the encapsulation material, and ultimately - to a permanent decrease in system performance.

Investors are increasingly paying attention to this issue. After all, photovoltaic installation is a serious investment that should serve for 25-30 years. No one wants a system to lose efficiency just when it could produce the most energy. Especially that the summer months are the period when the demand for energy increases due to the operation of air conditioning.

It was these challenges that led us to develop CoolFlow Technology, an active cooling system that radically changes the way solar roofs cope with high temperatures. In the next section, we'll look at exactly how this innovative solution works and what makes it so effective.

CoolFlow Technology Mechanism

Now that we understand how serious the challenge is to overheat photovoltaic panels, let's take a closer look at how CoolFlow Technology works. This is a solution that completely changes the way we think about cooling solar systems integrated into the roof.

At the heart of the CoolFlow system is the use of a natural physical phenomenon known as the chimney effect. Imagine how a traditional chimney works - warm air rises upwards, creating a natural draft. We have used the exact same principle in our solar roofs, but in a much more advanced way.

In the eTILE system, each photovoltaic panel is equipped with specially designed ventilation ducts. Between the glass panel and the sheet, we create a space through which air can flow freely. However, this is only the beginning. The key element is the use of higher mounting patches - a minimum of 40mm instead of the standard 25mm. This seemingly minor difference creates a much larger ventilation space under the entire roof.

The system acts as a precisely designed network of air ducts. Cool air enters from the bottom of the roof through a specially designed ventilation shaft near the eaves. Then, when the photovoltaic cells heat up from the sun, the air under them also heats up and begins to float. This creates a natural draft of air that flows through the entire surface of the roof, up to the ridge (that is, the highest point of the roof), where the exhaust holes are located.

Importantly, this airflow is constant and independent of the wind. In traditional photovoltaic installations, the panels are mainly cooled by random gusts of wind, which is highly inefficient. In the CoolFlow Technology system, the air flow works continuously, as long as the sun shines - the more intense the insolation and the higher the temperature of the panels, the stronger the chimney effect becomes.

We have carried out a number of tests that confirm the effectiveness of this solution. Under identical weather conditions, with an air temperature of 30°C, standard panels integrated into the roof reached temperatures of up to 75°C, while panels equipped with CoolFlow Technology maintained temperatures 15-20°C lower. This is a huge difference that directly translates into the performance of the entire system.

The system is designed to operate reliably throughout the life of the roof. The ventilation ducts are protected from the access of insects and other contaminants, and their design prevents the accumulation of moisture or condensation of water vapor. This ensures that the system remains fully functional for many years without requiring any special maintenance.

In the next section, we will look at exactly what practical benefits the use of CoolFlow Technology brings and why it is so important for anyone considering installing a solar roof.

Practical benefits

After understanding how CoolFlow Technology works, let's take a look at the specific benefits this solution brings to solar roof users. The numbers and facts best show why you should invest in this technology.

Let's start with what interests investors most - real savings. Thanks to efficient cooling, the eTile system with CoolFlow Technology loses only 3-5% of efficiency on hot days, while traditional installations lose up to 15-20%. In practice, this means that from a 10kW installation we get about 1-1.5kW more power in summer during peak hours of sunshine. On a yearly basis, this translates into additional energy production worth up to several thousand zlotys.

Let's take a concrete example: a typical household with a 10kW installation. On a summer day, when the temperature of the panels in a normal installation reaches 70°C, the system with CoolFlow Technology maintains the temperature around 50-55°C. This difference of 15-20°C translates into an additional 5-7% of energy production exactly when it is most valuable - during the hours of greatest demand for air conditioning.

But that's not all. Efficient cooling has a huge impact on the long-term durability of the entire system. High temperature accelerates the aging of photovoltaic cells - every 10°C above the test temperature shortens their lifespan by about 1-2%. This means that the system with CoolFlow Technology not only produces more energy on an ongoing basis, but also retains its performance for a much longer time.

Moreover, a more stable operating temperature translates into lower thermal stresses throughout the structure. Traditional panels can heat up to 70-80°C during the day and cool down to a few degrees at night. Such sharp temperature changes cause microdamages, which over time can lead to more serious breakdowns. CoolFlow Technology significantly reduces these temperature fluctuations, which translates into a longer service life not only of the cells, but of the entire roofing.

It is also worth mentioning the additional advantages of the ventilation system. The air flow under the roof effectively wicks away moisture that could accumulate under the roof surface. This is a natural protection against condensation of water vapor and the potential development of mold or fungi in the roof structure. The system works completely passively, does not consume energy and does not require any maintenance.

Importantly, we get all these benefits without compromising on the aesthetics or functionality of the roof. CoolFlow Technology is fully integrated into the eTile system, does not affect its appearance or require additional elements visible on the roof surface. This is an example of a technology that works effectively while remaining completely invisible to the eye.

In summary, CoolFlow Technology is not only an innovative technical solution, but above all a system that brings tangible financial and practical benefits. Higher performance, longer service life and better protection of the roof structure - all this makes the investment in an eTILE solar roof even more profitable in the long term.

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