Mauritius makes a green leap: public buses to use compressed biogas

The tiny Indian Ocean island state of Mauritius is giving us a great example of what 'energy leapfrogging' is all about. The island has only one large public transport service, namely the autobuses which carry some 200,000 people around each day.

The Mauritian State Trading Corporation (CNT), which operates 525 buses, is launching a project [*French] to convert its vehicles in such a way that they can operate on compressed biogas (CBG). Currently, only in Europe, and most notably in Sweden, France (see below), Germany and Austria, biogas is being used on a large scale as a transport fuel (earlier post). Many developing countries can benefit from the paradigm and the technologies that make this possible.

Biogas is the cleanest and most efficient of all biofuels, second-generation biofuels included (earlier post) and when produced from municipal or industrial waste, it can be carbon negative. For the renewable gas to be used as compressed biogas in transport - in a way similar to how compressed natural gas (CNG) is used -, it must be purified first. New technologies allow biogas to be scrubbed and cleaned in such a way that the methane content approaches natural gas standards (around 96%) (earlier post).

Some developing countries have succeeded in converting diesel and gasoline fleets into CNG-fleets in an impressive way: in Pakistan, 1 million CNG-vehicles hit the road in a program that lasted two years (earlier post). Likewise in the Indian capital Delhi, all public transport vehicles (94,000 buses and taxis) now use CNG; in Mumbai, 154,000 public vehicles do the same, the consequence of a law aimed at reducing air pollution. Once a CNG-fleet and a gas distribution infrastructure is in place, it should be possible to feed biogas into it (earlier post). And indeed, following in Europe's footsteps, India has already expressed interest in feeding biogas into the natural gas grid, and ultimately into the CNG-infrastructure to get a fleet of biogas vehicles on the road soon (earlier post).

For Mauritius, a switch from fossil fuels and inefficient first-generation biofuels to CBG would be a green leap forward. It would allow the country to manage its industrial, municipal and agricultural waste-streams more efficiently, and to diversify away from expensive fossil fuels, which are a heavy burden on its economy. The state's buses spend some €460,000/US$600,000 per month on diesel fuel - not much to Western standards, but for a tiny island state that has to import all its fossil fuels, savings on these expenditures are more than welcome. The biogas project is expected to deliver:
bioenergy :: biofuels :: energy :: sustainability :: waste management :: biogas :: biomethane :: compressed biogas :: CBG :: CNG :: climate change :: energy independence :: Mauritius ::

The project requires interventions on several fronts: the CNT will convert the engines of its diesel-fleet, and coordinate the construction of filling stations that are coupled to industrial-scale biogas digesters. The biogas stations will deliver compressed biogas in large high-pressure canisters that are then picked up by the buses.

Besides converting the existing diesel-fleet, the CNT will import 80 new vehicles capable of using CBG. (In the French city of Lille, to which the Mauritian government refers as a prime example, the European BiogasMax project has been running for several years, involving the use of compressed biogas in 100 buses, in this case vehicles developed by Renault. The project extends to Stockholm, where buses have been running on CBG for years too.)

The Mauritian government expects that once the current project is successful and the infrastructure in place, all other bus operators will step in and start using biogas.

More information:
European Union: BioGASMAX project [*.pdf].
Novethic: Lille Metropole carbure au biogaz - March 27, 2006
L'Express (Port Louis, Maurice), via AllAfrica: Ile Maurice: La CNT roulera au biogaz, Dec. 19, 2007