Thanks to solar panels and an energy storage system, Spedition Lutter in Bönen is almost entirely energy self-sufficient. Together, a photovoltaic installation on the roof with a peak output of 80 kilowatts and a battery storage system with a capacity of 50 kilowatt-hours cover practically all the energy requirements of this company, which has 52 employees and transports goods throughout Germany. The entire installation, including the battery storage system, will have paid for itself in just eight years.

Electric vehicles with clean power

“As a shipping company, we inevitably emit a certain amount of CO₂ into the air. We wanted to change that, and we’re now gradually switching to electric vehicles,” explains Martin Gerold, who runs Spedition Lutter along with Thomas Gerold. The company currently has twelve electric fork-lift trucks and four electric cranes. Charging them from the public power grid would be expensive, as it would result in peak current loads during the charging process. Energy suppliers would have to be prepared for these and would apply correspondingly high charges.

Martin Gerold also has green plans for the future. As soon as battery technology reliably provides appropriate ranges, he intends to start replacing vehicles from his fleet of 26 diesel lorries with electric models. An on-site solar-powered recharging station will also be built at that point.

Battery storage for independence

The solar installation on the company building has an east-west alignment. The aim is to keep the amount of solar power generated as uniform as possible throughout the day rather than having a high yield around noon, as is the case with south-facing installations. The battery, which is installed in a VX25 enclosure system from Rittal, stores surplus solar energy from the roof. This is used to supply the site’s servers, IT systems, lorry workshop and lorry wash facility with clean power, overnight and early in the morning.

If the company fed this surplus solar power into the grid, it would currently be paid just 6 cents per kilowatt-hour. Without the storage system and the solar installation, on the other hand, each kilowatt-hour would cost the company 30 cents, and this figure continues to rise. The next step will be to make the necessary additions for the storage system to also serve as a back-up power supply solution. “We had a power cut just recently. That, too, costs an industrial company a great deal of money,” says Martin Gerold. In the future, the storage system will supply power when the public grid is down.

The lithium battery was supplied by TESVOLT, which is headquartered in the German town of Wittenberg and specialises in battery storage systems for commercial and industrial companies. TESVOLT has become a global technology leader and has already won a number of awards. Sophisticated technology makes its batteries particularly durable and cost-effective. The energy storage system specialist considers safety to be extremely important, so it uses industry-tested VX25 enclosure technology from Rittal.

“Energy storage systems for commercial and industrial use need to meet high requirements. We therefore use only industry-proven components,” says TESVOLT’s co-founder and CTO, Simon Schandert. “Rittal adapted the enclosure perfectly to our needs and has been supplying us with very high-quality, robust storage system enclosures for many years,” he adds.