PROJECT DESCRIPTION
BACKGROUND
Growing concern in Europe and worldwide over the security of energy supply, climate change and health are driving a shift from fossil fuels to alternative fuels, and the development of new and more sustainable road vehicle propulsion systems. At present, urban traffic is responsible for 40% of CO2 emissions and 70% of emissions of other pollutants arising from road transport. Transport is especially vulnerable to oil supply disruption and price volatility. Despite considerable progress in reducing emissions of harmful pollutants, concern remains about air quality and noise, especially in urban areas.
OBJECTIVES
The main objective of the HYPER BUS project was to demonstrate an innovative public transport vehicle (hybrid bus) that combines outstanding performance with low-energy consumption. The aim was to introduce hybrid buses with a newly-developed plug-in technology on an existing public bus route, to show that it is possible to electrify a major part of a city’s bus lines. The project also aimed to demonstrate the optimisation of hybrid bus performance (e.g. drivability, durability and safety) and the implementation of a reliable and efficient fast-charging service for the hybrid bus fleet. The project aimed to demonstrate that this technology can contribute to reducing harmful emissions from European city public transport systems.
RESULTS
The HYPER BUS project demonstrated the viability of an innovative plug-in hybrid bus, and the effectiveness of a fast-charging service for the buses’ batteries. This system was demonstrated using three plug-in hybrid buses, purchased by the project and operated on an existing public transport route in the city of Gothenburg (Sweden). The project also purchased two fast-charging stations and installed them at bus stops at both ends of the bus line.
In Gothenburg, the 17 km-long Route 60 was chosen, because it included hills and narrow streets that passed through housing areas where traffic noise is a problem. The project achieved its target of driving the hybrid buses for at least 60% of the time in electric mode (with diesel usually cutting in for steep hills). The hybrid buses completed around 5.6 million passenger trips on the busy route, which they worked along with 18 existing diesel buses. The project team trained 8 drivers from the bus company Västtrafik to operate the hybrid vehicles.
The project demonstrated major possibilities for environmental improvements in terms of energy efficiency (up to 63%) and reduced pollutant emissions from a plug-in hybrid bus in comparison with a traditional Euro 5 diesel bus. Emissions of the greenhouse gas carbon dioxide (CO2) were reduced by some 80%, while tailpipe emissions comprising nitrogen oxides (NOx), particulate matter (PM), hydrocarbons (HC) and carbon monoxide (CO) were reduced by 79%. The outcomes obtained for energy efficiency, emissions reductions, and also noise reductions, exceeded the target numbers set before the project. Due to measurements failure, the level of emission reductions was estimated based on measured energy consumption and comparing to a regular diesel bus. Overall, the results point to the dramatic environmental benefits that could derive from replacing a fleet of diesel buses with the new hybrid bus technology.
Hybrid buses took 3-6 minutes to charge at the two charging stations. These were purchased from the Spanish company Opbrid, and costs were higher than expected. However, once investments for charging infrastructure have been made, there should be room for economical improvements and savings due to reduced fuel costs (some 81%). The charging process was identified as the most problematic issue, and further improvements are being made in this area. In addition, the project team estimated the lifetime of the battery cells to be 10 000 hours, which they suggested needs to be further improved before the hybrid bus technology is commercially viable. Further tests of the concept are being performed in the (non-LIFE) ELMOB project and a new public transport system is implemented in ElectriCity where the collaboration is extended to some 15 partners.
The project published its findings in a series of reports, including a power quality evaluation of the Opbrid charging stations and an evaluation of the business case for plug-in buses in Stockholm, in which it was concluded that plug-in hybrids would provide better reductions in noise, emissions and energy consumption than buses run on biogas. Vehicle manufacturer and project partner Volvo, whose head office is in Gothenburg, built the hybrid buses in its factory in Poland, in collaboration with the other project partners (research organisation, energy utility, transport company, public transport company, city authorities, charging station provider, bus operator). Volvo is one of the world's largest manufacturers of buses, so the potential for replicating and transferring the new technology is very good. The joint efforts of all the different partners ensured that the demonstration value to promote the technology was high. This adds value to both knowledge and experience about how to plan, implement and operate innovative public transport solutions.
Surveys and interviews showed that passengers and residents of narrow streets on the bus route were very happy with the reductions in vehicle noise. The bus drivers also preferred the quieter working conditions.
Major socio-economic benefits would emerge with widespread deployment of hybrid buses as replacements for fleets of diesel buses. In particular, these would relate to lower emissions of pollutants and greenhouse gases, and a quieter environment, reducing transport-related health concerns and increasing the quality of life for citizens.
Further information on the project can be found in the project's layman report and After-LIFE Communication Plan (see "Read more" section).
