Generating energy with the help of photovoltaics is very much on trend: according to various statistics, the capacity of all PV systems installed around the world has increased by an average of more than 30 percent per year over the past 20 years. Scientists expect around 10,000 gigawatts of solar power to be generated annually in 2030 – with the figures continuing to rise. An increasing number of companies, homeowners and operators of public buildings are turning to renewable energy to reduce their ecological footprint, cut costs and become more independent of the grid.
When constructing plants, it is not only the solar collectors themselves that are of central importance, but also the appropriate mounting systems. S:FLEX GmbH is a specialist in this area. Founded in 2009, the company develops and manufactures prefabricated and tailor-made frame technology for flat roof, pitched roof and ground-mounted plants and supplies wholesalers, project planners and installers worldwide. In addition to its headquarters in Germany, S:FLEX is now also represented in many other European countries, and in the Middle East and the USA.
The company serves its German customers from its headquarters in Hamburg and a further site in Bad Krozingen. Here, S:FLEX has also taken over an additional warehouse due to its strong growth. Five electrically driven forklift trucks take care of the fast, emission-free and low-noise transport of goods at the site. “As a company that is particularly concerned with sustainability, we also want to keep our ecological footprint as small as possible internally,” explains Managing Director Ralf Müller-Maerz. “That is why we have also configured our intralogistics processes to be as resource-conserving and energy-efficient as possible.”
The existing battery charging technology for the electric forklift trucks was a real thorn in the side of the S:FLEX managers. The trucks were being operated with outdated 50-Hertz transformer technology, which was causing high energy losses during charging and damaged the expensive traction batteries in the long term. “During this process, a considerable proportion of the energy used is converted into heat,” explains Logistics Manager Heico Dretke. “This increases power consumption and operating costs, and reduces the capacity and performance of the batteries.” More frequent opportunity charging and battery changes are the result. “We wanted a more modern technology that would eliminate these disadvantages.”
“In addition, as photovoltaic experts, we naturally rely on self-generated solar power at our own sites,” adds Müller-Maerz. “If possible, this should be used to supply the forklift fleet without any major detours.” At a trade fair in autumn 2019, the Managing Director therefore sought contact with Fronius: the international company from Pettenbach, Austria, is one of the innovation leaders in both battery charging technology and photovoltaics with its Perfect Charging and Solar Energy business units. “Furthermore, we offer the major advantage of being able to combine our products and expertise from both business units to create individually tailored complete solutions for our customers,” emphasises Andreas Horn, account manager at Fronius Germany.
As a first step, the Fronius experts took a close look at the conditions and requirements at S:FLEX. Using the Fronius I-SPoT Calculator, the possible savings potentials were determined and discussed with the customer. The new charging technology can reduce energy consumption by around 20 percent: “This not only met our sustainability requirements, but was also financially attractive, because the acquisition was expected to pay for itself within a short time,” summarises Müller-Maerz. Furthermore, Fronius also offered to equip the planned photovoltaic system on the roof of the hall with inverters and to connect it directly to the charging technology for the highest possible degree of self-consumption. “We were immediately impressed by this overall package,” adds the Managing Director.
The photovoltaic system generates around 100 kilowatts of power at peak times. A large part of this is fed directly to the Fronius Selectiva battery chargers via the electricity supply network on site. Six of these are available to forklift drivers in different power categories, depending on whether the forklift trucks have larger or smaller traction batteries. With their innovative Ri charging process, they flexibly charge the different types of batteries – and do so in a particularly gentle and energy-efficient manner: “The charging process adjusts itself individually to the age, capacity and condition of each battery, thus reducing harmful overcharging to a minimum,” says Fronius expert Horn. The result is significantly lower energy consumption and a longer battery service life.
S:FLEX is highly satisfied with the overall package from Fronius. “The battery chargers are easy to use. All our staff need to do is plug in the charging plug; no further adjustments on the device are necessary,” explains Dretke. Surplus energy from the photovoltaic system is fed into the public grid, and thanks to the Fronius system’s extensive analysis functions, S:FLEX is always up to date with all production and consumption data. “This combination of photovoltaic and battery charging technology is certainly unique on the market,” enthuses Müller-Maerz. “With Fronius, we have been able to significantly reduce our electricity requirements and operating costs, while at the same time making our intralogistics more sustainable.” The Austrian company is also a reliable partner when it comes to service requirements. “We are very happy to receive everything from a single source and to always know who to turn to when we need it,” sums up the Managing Director. “It makes the working relationship easier and much more pleasant.”