The idea of running vehicles on methane obtained from sewage and waste is nothing new, although it seems to have taken a while for it to find actual use in the UK. There, the first bus running on biogas just went into service, taking passengers from Bath to Bristol Airport and back.
What are the advantages of running buses in this way? Well, firstly as far as renewable sources go, there will always be a never ending stream of raw matter, plus the fact that the resulting methane can be burnt in a conventional internal combustion engine.
However, it only emits 30 percent less carbon than conventional diesel vehicles, because the methane undergoes a chemical process which removes carbon dioxide and adds propane into the mix.
The bus that’s currently in use has a range of 186 miles or 300 km and can seat 40 people. Aside from the suggestive stickers, the main telltale sign that it’s not a usual bus is the humped roof which hides the pressurized tanks that hold the fuel.