Quality for Photovoltaics: Calls for module transport improvement

Despite the current difficult market situation, the issue of quality still seems to be key, with 130 participants heading to Solarpraxis’ quality conference today. "We have massive price pressure and we have to, at the same time, improve quality," said Karl Heinz Remmers, CEO of Solarpraxis AG during his opening speech.

During the first conference session, Willi Vaaßen, business unit manager of renewable energy at TÜV Rheinland addressed the issue of module transport. "Products are transported across the length and breadth of the world," he stated. "But we have no documentation of what the stress is during transport." That has to change.

He went on to emphasize that high stresses can cause almost invisible microcracks in photovoltaic modules, which later lead to a loss of power. As such, the transport chain must be optimized, so that module damage is minimized. To achieve this, it must first be defined how much stress is allowed, and then the stress must be measured. A draft standard exists, but Vaaßen believes more must be done.

In the past, the manufacturer’s guarantee was often attacked if module damage occurred in an installed photovoltaic plant. However, with modern quality control methods, producers can increasingly prove that the modules left the factories intact. In the future, they will therefore assume less and less liability, meaning others will have to pay.

Other issues

Vaaßen added that module transport is not the only issue the solar industry faces. It is estimated that in every 5,000th plant, a "particular heating occurrence, an arc, or even a fire" can happen. And, according to investigations carried out by TÜV Rheinland, faulty installations are also often at fault. "If the plug is not properly connected, it is a problem. If the cable is not installed properly, it is a problem, which can later lead to arching," he explained.

A particular sticking point, Vaaßen believes that only certified contractors should be allowed to install photovoltaic plants, that a system should only be accepted by accredited companies, and that regular maintenance and inspections should be carried out. "I know that they are strict requirements and that I am here to create a business model for TÜV Rheinland," he said, "but please accept it as my honest opinion."

Unnecessary

In addition to discussing the aforementioned issues, the quality conference will also address the changes the solar industry is currently undergoing. Specifically, in response to cost pressures, it is important to not just focus on creating new quality standards, but to also look at where quality standards are perhaps not necessary.

Ground-mounted installations now fall under Germany’s general energy law and some criticize the industry, for example, for not adhering to lightning protection systems. "A ground-mounted plant is not a nuclear or coal-fired plant, but something independent," stated Karl Heinz Remmers, CEO of Solarpraxis AG.

As such, as long as people are not at risk, he objects to the fact that the same rules which apply to lightning protection on buildings, also apply to ground-mounted photovoltaic plants. He raised the question of what happens when, for example, a module falls over on the ground. Due to the funding, it should not fall within 20 years. But if it happens, it’s not so bad. "Then you just put it up again," said Remmers.

Likewise with solar cables. The requirements for ground mounted plants are the same as for rooftop systems. However, the components in ground-mounted systems could be cheaper, as there is less risk of them falling and injuring someone. "I call it controlled downgrading following an intensive risk assessment, and appeal for the insurance companies to also go along with it." Balance of system costs in Germany should also not be more than €0.50/kWh, he added.

Translated by Becky Beetz.