Biofuel producer and boiler manufacturer Passat Energy has successfully commissioned a 220 kWp rooftop solar power plant of 880 solar panels of 250 W each at laser and profile cutting company TW Profile Services, in Boksburg, and expects a significant reduction in electricity consumption.

“Owing to our high electricity consumption, we needed to look at possible solutions and selected photovoltaic (PV) panels are the most viable. “We anticipate about a 25% saving in our monthly electricity bill,” says TW Profile Services MD Joost Smuts.

He notes that the panels are installed in four arrays, giving an output of 55 kW each. This feeds into two 100 kW inverters in parallel, tied to the grid. The pay-back period will be five to six years. The total voltage is 750 v direct current, which is converted into three-phase alternating current.

Passat Energy has partnered with solar panel manufacturer 3M for advice on attaching the solar installation to existing roof structures, minimising roof penetrations.

“3M has assisted with the installation of the solar panels by providing a unique solution for attaching the solar panels to the roof of the factory,” says Passat Energy director Pierre Lombard.
“The panels are not secured using the traditional method of mechanical fasteners, where holes are drilled into the roof to secure the panels. Mechanical fasteners tend to rust after a few years and the process is time consuming and labour intensive. Mechanical fasteners are also prone to creating water leaks,” he says.
The solution provided by 3M consists of a very high bonding double- sided, adhesive-rolled acrylic tape, initially used for high-speed trains in Japan.
“The adhesive is stronger than a mechanical fastener and will last longer – up to 15 years – and bonds immediately,” he notes.
He explains that the adhesive is also viscoelastic, which means it has no thermal expansion caused by changes in temperature and, therefore, ensures zero fatigue on the roof or panel.

“The installation took four weeks, whereas using mechanical fasteners would have taken six to eight weeks. Recent hail and high winds had no effect on the panels and they remained secure,” he concludes.