Stuttgart is the capital of the region of Baden-Wurttemberg in South-West Germany and faces the same challenges as any large urban area: CO2 emissions, local air pollutants, congestion, noise. A long sustainable mobility action plan (“Nachhaltig mobil in Stuttgart”) has been developed to tackle those issues and enable a better quality of life for all in the region. The plan builds on previous measures such as the introduction of the Low Emission Zone in 2008 or the cycling policy. In the action plan, the purchase of low emissions and non-polluting vehicles in the public transport sector is one the measures foreseen.
The Stuttgarter Straßenbahnen AG (SSB) is the company operating the buses. Created more than 145 years ago, the SSB operates some 260 buses and 184 light rail trains on 70 lines in Stuttgart and its suburbs. SSB lines are used daily by above 500,000 people. Sustainability has been a priority for SSB for over a decade: The company signed the UITP-Charta for sustainable development in 2007. The SSB has been a pioneer in the demonstration of ultra-low carbon vehicles, with the trial of 3 fuel cell buses as part of the CUTE Project (2003-2005). Today, in addition to the four fuel cell hybrid buses, SSB operates 12 hybrid buses (articulated buses).
Four 12 m fuel cell hybrid buses (EvoBus) are in operation since 2014, as part of the project “S-Presso” (“Stuttgarter Praxiserprobung von wasserstoffbetriebenen Omnibussen”). The buses have a full tank capacity of 35 kg of hydrogen. The buses are operated on two lines:
Line 79: the 11 km long line goes from Plieningen to Stuttgart airport and serves 6 stops. The fuel cell buses are in service during up to 17 hours, and cover some 280 km daily.
Line 67: the 14 km long line operates in the area of Fellbach and serves 14 bus stops. The buses travel 193 km daily. On this line, the operation of the buses is carried out by the bus company Schlienz on behalf of SSB.
Two hydrogen refuelling stations are used to refuel the buses: The refuelling station at the airport, operated by OMV, has a daily capacity of 125 kg hydrogen/day. Hydrogen is delivered in gaseous form.
The refuelling station in the city centre (Talstrasse) is operated by EnBW. Hydrogen is produced on-site per electrolysis. As a back-up solution, the use of trucked-in hydrogen is possible as well. More information here.
Both are public refuelling station, offering both a refuelling at 350 bar (buses) and 700bar. The buses are refuelled within 10 minutes in average.
The S-presso project received 3,2 million € co-funding support from the National Innovation Programme (NIP), a programme developed by the NOW GmbH (National Organisation Hydrogen and Fuel Cell Technology).
The co-funding is planned until mid-2016. The SSB foresees a continuation of the buses operation after this date. The SSB is considering fuel cell and hydrogen technologies as one of the solutions to clean its bus fleet. This is why on 23 June 2015, at the occasion of the TEN-T days, the SSB signed a Letter of Understanding along with some 30 cities/operators, stating its readiness and willingness to integrate fuel cell buses in its bus fleet.
A leaflet presenting the project is available in DE for download.
Pictures © SSB