Degradation over the years

Backed by two decades of continous operation

At BISOL^®, durability is not a marketing promise. It is a measurable fact.

One of the very first BISOL power plants, installed on the rooftop of BISOL’s headquarters in Slovenia, is still producing clean energy today, 20 years later. More than a landmark, this system is a living testament to long-term performance and manufacturing excellence.

Over the course of two decades, BISOL modules on this rooftop have endured summer heat, winter snow, heavy rainfall, and thousands of thermal cycles. Despite these conditions, they continue to outperform expectations, with degradation far lower than predicted.

These results are not projections or simulations. They are real measurements from a real system proving that BISOL modules are built to last.

Why degradation matters?

For solar investors, the key metric is not only how much energy a system produces on day one but how much it will still produce after 10, 20, or 30 years.

Degradation defines the true lifetime value of any photovoltaic system. With conventional modules, power loss over time can lead to hidden costs. Clients pay once for the system and again for the energy they no longer receive.

With BISOL, you pay once and get reliable energy for decades. BISOL modules are designed to maintain peak performance throughout the warranty period and beyond.

Real-world data confirmation

After 20 years of continuous operation, the average measured degradation of BISOL modules is just 0.01%.

Compared to an industry average of up to 5%, this is not just impressive, it is game-changing.

How BISOL achieves exceptional durability?

This level of performance is the result of intentional engineering, rigorous testing, and continuous process improvement:

• Specialized production equipment, custom-modified by BISOL engineers for optimal consistency.

• High-grade materials, tested to the point of failure to eliminate weak links.

• Advanced lamination processes and precision soldering for long-term weather resistance.

• Detailed quality control, verifying each of more than 25,000 solder joints, encapsulation layers, and mechanical stability with 3.2 mm glass thickness.

In addition, BISOL modules undergo accelerated stress testing in our in-house Climate Control Chamber:

• Damp Heat Test

Industry standard: 1,000 hours at 85°C and 85% humidity.

BISOL standard: 7,000 hours at 85°C and 85% humidity, simulating decades of real-world exposure.

• Thermal Cycling Test (TC200)

Modules are cycled repeatedly between +85°C and –45°C to replicate years of expansion and contraction.

BISOL pushes materials to the edge so that clients never experience failure in the field.

A European leades, trusted worldwide

Choose modules proven in the field, not just in theory.

BISOL is the largest European manufacturer of solar modules, with systems installed in over 120 countries. From Japan through Europe to Hawaii, from the Arctic to Antarctica.

With above-average energy yields, robust mechanical integrity, and a complaint rate of less than 0.01%, BISOL is trusted by engineers, developers, and investors worldwide.

Choose modules proven in the field, not just in theory

When you choose BISOL, you choose modules that are built, tested, and trusted to perform in real-world conditions for decades to come.

Quality without compromise. Reliability without risk.