World's largest charging park

12.12.2023

Merklingen charging park: Lighthouse project sets standards with integrative charging solution

The world's largest charging park is now located in the Swabian Alb: in October 2023, 259 covered charging points for electric cars went into operation at the park-and-ride area of the Merklingen ICE train station. The project in the Alb-Donau district is record-breaking on several levels. Not only the size, but also the short construction time and close cooperation between the project partners are unparalleled. For the first time, a charging and billing solution was implemented that complies with the German calibration law and also meets the requirements of the upcoming charging station ordinance.

There were just 20 months between the start of planning and commissioning. There were not only bureaucratic and construction challenges to overcome, but also the energy distribution to plan and the charging management to set up. Should the vehicle be charged with alternating or direct current, or both? Is bidirectional charging required, is plug-and-charge technology needed and how can both ad-hoc charging and charging roaming be made possible? How can a photovoltaic system be integrated for sustainable power generation, where should the transformer stations be located and what metering concept should be used? Urgent questions that needed to be answered.

The planners developed a forward-looking overall concept: a solar carport generates around 990,000 kilowatt hours of electricity per year for the 259 charging points and feeds the surplus into the grid. There are already plans to retrofit the remaining 171 regular parking spaces at the station with charging points and to integrate a battery storage system as soon as demand increases. The Zweckverband Region Schwäbische Alb is also in talks with providers to make e-cars and e-bikes available for hire at the charging park - a particularly interesting offer for holidaymakers or commuters from the region who board the ICE train to Ulm or Stuttgart in Merklingen.

The challenge of compliance with calibration law and girocard payment

The expertise of the project partners was essential for the charging setup. Here too, the operators opted for a future-proof and user-friendly concept that not only meets current regulatory requirements, but also those of the future. Measuring and billing the electricity consumed in accordance with calibration law was therefore mandatory: every charging process is shown exactly in kilowatt hours - for maximum transparency for consumers. They can authorize their charging conveniently and completely independently via central payment terminals. All charging stations and payment terminals are networked with each other via fiber optic cables, ensuring fast and constant data exchange. All charging points are also connected to the internet via this network structure, which simplifies payment as well as control and maintenance.

In Merklingen, payment can be made not only with the usual roaming cards or apps, where users can conclude individual charging tariffs with e-mobility providers. Other payment methods that consumers are accustomed to using in retail are also offered, above all the girocard, debit and credit cards or digital options such as Apple Pay and Google Wallet. These so-called open payment systems are widespread and correspondingly easy to use without registration or additional applications. According to current legislation, however, their integration is not yet mandatory - all new public charging stations will only have to support card payments from summer 2024. In Merklingen, we are anticipating this in the interests of consumers.

The comprehensive payment offering is made possible by Hectronic. The medium-sized company has many years of experience in outdoor payment and can look back on numerous projects realized together with VR Payment. The know-how gained and the shared project experience from the areas of parking space and filling station management are now being transferred to electromobility. In addition to a non-discriminatory payment system, the Hectronic HecPay terminal offers flexible integration into existing charging infrastructures and a high level of compatibility with charging stations. Open interfaces also enable simple connection to backend systems - such as the Smartlab backend system used in Merklingen. The problem-free connection was also ensured here, as Hectronic and Smartlab have also maintained close technical cooperation for many years.

Sven Stottmeier, Director BU e-Mobility, Fleet Cards & Mobile Payment at Hectronic GmbH:
"The mobility transition can only succeed if there is a reliable charging infrastructure. Transparency in electricity metering and billing creates trust on the consumer side, while the ease of use of the individual charging points promotes acceptance. In Merklingen, we have succeeded in doing just that with a modern charging setup."

E-mobility network guarantees success

The interaction between billing in compliance with calibration law, payment with roaming options and card payment, including the necessary pre-verification with a PIN pad, presented the experts with enormous challenges. They had to integrate various hardware components and software from different manufacturers and ensure compatibility. A task that could only be accomplished in the short time available thanks to extensive experience in the subject matter and close cooperation.

The success of the project speaks for itself. At the opening ceremony, Baden-Württemberg's State Secretary for Transport, Elke Zimmer, praised the regional implementation of the state government's environmental and transport goals. "Even if projects seem utopian or unrealistic at the beginning, they can be implemented if everyone pulls together and if you dare to think unconventionally. The charging park and the entire station are a good example of this," says Zimmer.[1] The response from the public has been just as positive. Acceptance and utilization are growing. The charging park is a real flagship project for the region and the mobility transition in Germany.