Introduction of gas powered buses in Ljubljana. Slovenia

By News Editor / Updated: 29 Aug 2014

Aiming at reducing noise levels, energy consumption and improvements of air quality, LPP the public transport provider for Ljubljana have recently begun replacing their old diesel bus fleet with natural gas powered buses.

Background & Objectives

LPP (Ljubljana Public Transport) is responsible for public transport in the entire Municipality of Ljubljana area and 16 suburban municipalities.


Currently 28 bus lines with a total length of 460 kilometres are in operation. The bus service covers 97% of the urban area of Ljubljana Municipality, which means that 97% of all households in Ljubljana have a bus stop situated less than 500 meters away from their homes.


211 urban buses operate in the inner-city bus network with an average age of 9 years and 3 months. This includes 5 midi buses, 53 single buses and 153 articulated buses. Single buses are low-floor 12 meter buses. Older articulated buses are high-floor 16.5 meter buses and newer are low-floor 18 meter buses.


The average fleet age implies a number of old, exhausted diesel buses which do not even match EURO 0 emission standards. These buses caused high emission levels and produce significant negative environmental and health effects.



To address this issue a study on the most suitable energy sources for inner city transport was conduced in 2006, and identified methane as the most suitable fuel source. Accordingly a program of vehicle replacement and public procurement process was introduced to replace the old buses with modern gas-powered buses.


The decision process involved individual departments within the Municipality of Ljubljana, the Federal Ministry of the Environment and Spatial Planning and two private companies from Ljubljana. Beneficiaries of the action are all citizens, tourist and users of public transport in Ljubljana. Energy Ljubljana in cooperation with subcontractors and LPP introduced a new gas charging station. The state financed the purchase of 20 Iveco 12m CNG low-floor the buses.


Some obstacles during the preparation phase of the measure regarded:

  • Difficulties in obtaining the various required consents and permissions to allow the initiative to proceed;
  • Technical difficulties while building the charging station, namely significant delays in delivery of certain elements.


Additionally the LPP service centre needed a upgrade to the specifics of gas vehicles.


Relevant costs for implementation and operation are as follows:

  • Purchase of 20 buses = 4,400.000 EUR;
  • Charging station including necessary documents = 1,250.000 EUR;
  • Upgrade of the service centre = 100,000 EUR;
  • Study in 2006 = 25,000 EUR.



All parties involved in the bus fleet upgrade assessed their experiences from the preparation and implementation process to be positive. Similar projects would easily be repeated, as the transfer of experiences and results from this to similar projects is is likely to be relatively easy. Based on the success in Ljubljana several surrounding towns have expressed their interest to implement the same measure.


The gas station currently provides charging for up to 100 vehicles. If the number of gas-powered buses exceeds 100 an upgrade to higher capacity will have to be made. For the future the purchase of 100 buses has been planned, which would reduce dependence on a single source (diesel fuel).


One key factor to make measure possible was the positive and constructive co-operation of all involved parties.



Picture by Vita Konti?

Clean and energy-efficient vehicles
Annie Kortsari
Annie Kortsari
fuel (energy) reduction
fuels – gaseous non regenerative
reduction – air pollutants - ICE internal measures
reduction – greenhouse gases
reduction - noise
18 Dec 2012
29 Aug 2014