Causes and Estimates of Photovoltaic System Losses: PVGIS 24 vs PVGIS 5.3

Photovoltaic system losses refer to the difference between the theoretical energy produced by solar panels and the actual energy injected into the grid. These losses are caused by various technical and environmental factors that impact the overall system efficiency.

Photovoltaic System Losses with PVGIS 24

PVGIS 24 provides a precise estimate of photovoltaic system losses for the first year of operation. According to international studies, system losses increase by 0.5% per year due to the natural degradation of solar panels. This estimation model is more accurate and better suited to real-world operating conditions, allowing for long-term performance monitoring.

Photovoltaic System Losses with PVGIS 5.3

In contrast, PVGIS 5.3 estimates photovoltaic system losses over 20 years, using a default value of 14% for total losses. This simplified approach provides a general overview of energy loss trends over an extended period but does not allow for annual adjustments.

Main Causes of Losses in a Photovoltaic System

Photovoltaic system losses can be attributed to several factors, including:

Cable losses: Electrical resistance in cables and connections causes energy dissipation.
Inverter losses: The efficiency of converting direct current (DC) to alternating current (AC) depends on the inverter's quality.
Soiling on modules: Dust, snow, and other debris reduce the amount of sunlight captured, lowering efficiency.
Module degradation over time: Solar panels experience a slight efficiency decline each year, impacting long-term energy production.

Detailed Breakdown of Losses in PVGIS 24

1. Cable Losses

Default estimation: 1%
Adjustable values:
0.5% for high-quality cables.
1.5% if the distance between panels and the inverter exceeds 30 meters.

2. Inverter Losses

Default estimation: 2%
Adjustable values:
1% for a high-efficiency inverter (>98% conversion efficiency).
3-4% for an inverter with a conversion efficiency of 96%.

3. Photovoltaic Module Losses

Default estimation: 0.5% per year
Adjustable values:
0.2% for premium-quality panels.
0.8-1% for average-quality panels.

Conclusion

Photovoltaic system losses depend on various technical and environmental factors.
With PVGIS 24, you can obtain more precise and adjustable loss estimates, allowing you to optimize your photovoltaic system's performance. By considering cable, inverter, and module losses, you can better anticipate long-term energy yields and improve overall system efficiency.