What is Solar PV Power Generation? and Types of Losses

Solar PV power generation is an intricate process involving a plethora of parts and components that come together to create these systems. Every component integrated into the system has a specific role to play in ensuring a reliable supply of solar energy. These components are often subjected to various levels of stress from solar irradiation, wind, dust, and other hazardous elements in the environment. Additionally, the risk of human-induced damage and corrosion cannot be overlooked.

The design, manufacture, and installation of solar PV systems is a complex and extensive process. A failure is regarded as a loss of material integrity, resulting in the inability of the component or system to perform its normal functions. Understanding why solar systems and solar power plants fail is vital in delivering a secure supply of affordable renewable solar power to help decarbonize the global energy system.

Due to the difficulty of predicting exactly what will happen at a particular location or time, macroscopic models are needed to understand and predict the damage caused by a solar PV farm.

Failures in Solar Asset Management

Solar generation ensures the best results on sunny days, but hot summer conditions are a challenge in itself.

Effect of temperature on Solar PV module: With the increase in temperature the efficiency of solar panels decreases drastically. It is common practice to test photovoltaic modules at 25 °C (STC) – about 77 degrees F. The output voltage of a solar panel drops as the temperature rises, which results in less power being produced. The efficiency of a solar panel typically decreases by 0.3% to 0.5% for each degree Celsius above 25°C (77°F). As the panel’s temperature increases, its voltage output drops linearly, which can lead to the solar photovoltaic module system not performing as per expectations. In the presence of direct sunlight, solar panels can achieve temperatures of up to 66°C (150°F). High temperatures may hurt the effectiveness of solar panels, resulting in less energy produced.

When PV module losses are not addressed, they lead to higher maintenance costs, unpredicted downtime, and degradation of the modules. Such issues can be identified and predicted easily by using solar asset management software such as Futr OS. It uses digital twin technology which creates a digital replica of the PV module. Thus, helping the asset owners to compare the direct effects of overheating on PV modules.

Types of Losses:

Cable Losses:

Cables in solar PV systems are often prone to external environmental conditions. Thus, they should be capable enough to withstand harsh atmospheric conditions. Ohmic losses account for most cable losses, while ambient conditions determine the ampacity of power cables. The impact of temperature on a cable depends on whether the cable is buried in soil, installed in the air, or placed in ducts. An installation in free air, for example, will have a greater effect on potential ampacity because of solar radiation. When there is a large voltage loss, under certain circumstances, the cable is no longer able to function as desired due to the loss of voltage. According to a study, it was found that cable losses affect the system performance at 1.7%, 0.6%, and 0.2% for the cross-sectional areas of 1.5 mm², 4 mm², and 10 mm² respectively.

Therefore, a predictive tool that helps understand the effects of temperature on cables is always beneficial. To avoid failures that could occur anywhere along cable lines and keep operational costs to a minimum, extended monitoring of temperatures along cable lines is a necessity.

Soiling Loss:

One of the major roadblocks in the performance of solar PV modules is soiling. Any kind of deposition on the panels such as accumulation of dust, dirt, bird droppings, etc. that reduces the absorption capacity of the module comes under soiling loss. Dust does not accumulate all at once, it takes time for the dust to accumulate; in extremely dusty areas, it can reach rates of 0.5% per day. An NREL model that uses a steady soiling increase found that, for a system that would build up soil that blocks 1.9% of sunlight over the course of a year, having one annual cleaning would maintain the loss around 1.5%, two cleanings per year could drop the average loss to 1.3%, and three cleanings per year would reduce that further to 1.2% average annual loss3. Unlike any other losses, soiling losses are reversible.

Futr OS not only provides a periodic schedule for cleaning but also using AI technology estimates the cleaning cycle.  To generate a dynamic cleaning schedule and track the cleaning effectiveness for different sections of the plant, it considers soiling trends, meteorological events, cleaning costs, and electricity costs.

Inverter losses:

Inverters are the heart of the solar system. Solar projects have a central inverter and their typical efficiency rate is between 95% to 98%, but it can vary depending on other factors. Unlike any other semiconductor device, they are sensitive to overheating. Higher temperatures lead to power losses and cause damage to the inverter. While converting DC power to AC power, the inverter dissipates heat. This heat combined with atmospheric temperature increases the ambient temperature of the inverter. The heat needs to be controlled below a certain level. Otherwise, the insulations become brittle and capacitors start to degrade. The inverters should be replaced on average every 10 years5.

Futr OS continuously monitors solar PV systems on a real-time basis. Thus, keeping an eye on the overall performance of the system. Any kind of alert is detected instantly, thus reducing the downtime of the solar PV system. Also, the predictive maintenance feature helps the system run securely and predicts faults before they occur. Digitizing solar asset management will help you improve the performance of the entire solar PV system. Hence, you will be able to run your solar plant for many more years with great efficiency.