Two buses operated by biogas in Skellefteå, Sweden. From left to right: Solaris Urbino 12 LE CNG (#65, built 2007) and Solaris Urbino 12 LE CNG (#68, built 2008). Skelleftebuss AB from Skellefteå operator.
<a href="//commons.wikimedia.org/wiki/User:Jlundqvi" title="User:Jlundqvi">Jlundqvi</a>
CC BY 3.0
<span class="int-own-work" lang="en">Own work</span>