Renewable Energies plus Energy

The optimal operating conditions of a photovoltaic plant are directly associated with environmental variables and can have a significant impact on performance.

Photovoltaic plants are designed to efficiently convert solar energy into electricity, but their performance depends on several environmental factors. Among these, temperature is one of the most critical. Although solar panels need sunlight to generate energy, high temperatures are not always beneficial and can, in fact, significantly decrease their efficiency.

Temperature and performance of solar panels. Photovoltaic modules are calibrated to operate under Standard Test Conditions (STC): irradiance of 1000 W/m², cell temperature of 25 °C, and air mass of 1.5. This is not always the case; in real-world conditions, operating temperatures are often much higher, especially in warm climates or in installations with poor ventilation.

Each solar module has a  temperature coefficient  for maximum power (Pmpp), typically between -0.3% and -0.5% for each degree Celsius above 25°C. This means that if a panel has a coefficient of -0.4%/°C, and its operating temperature rises to 45°C, its performance will decrease by approximately 8%.

Ideal operating conditions. To maximize the production of a photovoltaic plant, the following conditions must be considered:

1. Good solar irradiance : Places with high annual solar radiation (greater than 1600 kWh/m²/year) are ideal.

2. Moderate temperatures : Climates with average annual temperatures closer to 25 °C reduce heat loss.

3. Good ventilation : The installation of the panels should allow airflow underneath the boards to dissipate heat.

4. Optimal orientation and angle : The modules should be oriented towards the equator (south in the northern hemisphere) and with an optimal inclination according to the latitude of the place.

5. Regular maintenance : Cleaning panels, checking connections, and monitoring the system ensure consistent performance.

Conclusion:

• The construction of photovoltaic plants requires experience in design and operation.

• Measuring and controlling the impact of temperature on solar modules is key to reducing performance losses and ensuring greater energy production over time.

• The selection of materials, the system design, and the climatic environment are factors that must be considered from the planning stage of a photovoltaic plant.