The public transport operator in Bratislava DPB has signed a contract to purchase four Solaris Urbino 12 hydrogen buses. They will be the first ever hydrogen buses not only in Bratislava, but also in Slovakia. According to a framework agreement concluded by DPB with the bus maker, the Slovakian carrier may eventually order up to 40 hydrogen buses. The first four Urbino 12 hydrogen vehicles will be delivered in July next year.The heart of the Urbino 12 hydrogen bus is a 70 kW fuel cell pack that acts as a miniature hydrogen power plant aboard the vehicle. The hydrogen system also features auxiliary devices, for instance to supply hydrogen and air at an adequate pressure, to recirculate hydrogen that has not been used up, and also to maintain a proper and stable temperature of the fuel cells during operation. Electricity generated during operation of the vehicle in the fuel cell is passed on directly to the driveline. The hydrogen is stored in gaseous form in cutting-edge composite tanks placed on the bus roof. The hydrogen tanks themselves are rigorously tested, and have been designed to ensure maximum safety for the driver, passengers and pedestrians.