Charging an Electric Bus Fleet With Self-Generated Power

Part of the company philosophy of Salza Tours is to take advantage of technical innovations to benefit customers and the environment. As far back as 1993, the company was already using locally produced bio-diesel as fuel for some of its vehicles. When use of the rapeseed-based fuel became too expensive due to a tax increase, the Königs sought an alternative power concept. They weighed up the relative merits of hybrid and electric vehicles and in 2016 acquired their first electric buses with support from the Thuringian government. The company first bought two SILEO S10 city buses with a battery capacity of 200 kWh, and later added a SILEO S12 with 220 kWh for long-distance travel.

Initial procurement costs for electric vehicles, however, are roughly twice that of diesel vehicles. To ensure economical operation, Salza Tours had to negotiate a longterm rate agreement with the local energy supplier. But with rising electricity prices, in-house production of electricity became increasingly attractive, and the company ultimately opted to install a photovoltaic system. With top-up charging impractical in urban transport, Salza Tours generally uses the system to charge the buses overnight. But because the photovoltaic installation only produces electricity during the day, Salza Tours needs a way of storing the electricity.

The requirements for a storage solution:

• High storability with many guaranteed cycles for sustainable provision
• High output power with high C-rate to charge electric vehicles quickly