Reading’s 'greenwave' biomethane bus service (United Kingdom)

By News Editor / Updated: 23 Jul 2015

Reading Borough Council seeks to establish Reading as the capital of the Thames Valley region and to encourage economic development to provide jobs, stimulate housing provision in an environmentally responsible way. The Council has established a corridor bus service to encourage development in a situation where a commercial bus service would not be provided.

After a period where two contract bus services existed, the Council decided to award a single bus contract that could be expanded and modified as developments took place. A key consideration was to make the bus service as high quality as possible including its environmental credentials.


Reading has a highly successful bus network, mostly run commercially by the company Reading Transport Ltd, trading as Reading Buses. Unusually for the UK, the bus company is owned by Reading Borough Council as a subsidiary. Passenger journeys have increased significantly to around 18m per year and the residents of Reading make the fourth-highest number of bus trips; 111 trips per head per year, in England (outside of London). At the heart of Reading’s transport network is one of the busiest railway stations with 16m journeys per year. Reading Station has been rebuilt in a £ 850m (€ 1.22bn) scheme to radically improve train operations through Reading, removing flat junctions and adding track and platform capacity.

While Reading does not have Sustainable Urban Mobility Plan it is very active in encouraging sustainable travel.  The modal split for journeys into the centre is; walking 33 per cent, bus 25 per cent, train 20 per cent, car 19 per cent cycle 3 per cent. The greenwave bus route is highly visible, running along a main corridor and thus needs to be both an efficient transport service and a clear indication of how to make public transport environmentally sustainable.  

In action 

With the expiry of two previous separate bus contracts, Reading Borough Council conducted an EU procurement for a consolidated bus contract. The contract was awarded from November 2012 with the winning bid coming from Reading Transport Ltd. The bid was awarded on the basis of the most economically advantageous tender, and a key part of the bid was the commitment to introduce a fleet of buses powered by compressed natural gas (CNG), which consists mostly of methane. The CNG buses commenced service in July 2013.

Reading Transport Ltd took the commercial decision to install a gas-compressing plant at the bus depot and in addition to the 11 buses purchased for the greenwave contract has purchased a further 15 buses for its own commercial bus services. The process is as follows:

Farm waste is processed using bio-digesters to produce methane - this is then fed into the national gas grid - Reading Buses takes gas from the grid at its depot - the natural gas is then compressed and dried and stored under pressure - buses come in from service and are refuelled with the CNG at one of the bus fuelling lanes.

It was important that the CNG buses could be refuelled at any fuelling lane so multiple gas lines were installed at the fuelling station. Staff can fuel a CNG bus then a diesel bus with no special rearrangements needed. The company pays for the gas it has used, and gas used is replaced in the grid from the certified bio source. The overall bus service is thus carbon neutral as it takes carbon already existing in the form of grass, that is processed by cows and left as waste. This is then converted to gas which is then used to fuel buses which then exhaust to atmosphere, from where it can be converted to vegetation again.


The CNG buses give a high quality feel to the greenwave service with dedicated branding supporting the Business Park and Park-and-ride services offered. Buses have a high-quality interior and offer on board Wi-Fi, next-stop visual displays with announcements, a welcome at the bus door stating where the bus is going, and for commuters heading for the station the on-board screens show the status of the next train departures when the bus is a couple of stops from the station.  The CNG buses are smoother and quieter than diesel equivalents.

Since the greenwave contract started, services have been increased to help support the developments along the corridor which, in turn, have led to more passengers being carried and more service being offered, a virtuous spiral. greenwave now offers up to 13 departures an hour at peak times, and carries around 60 000 passengers per four-week period.

At the start of the greenwave contract the annual total of passengers journeys was  465 171 and it is anticipated to be 725 000 this year, a growth of 55 per cent in three years. A majority is commuter travel, so the greenwave service remains non-commercial  (fares cover around 60 per cent of costs), requiring Reading Borough Council to take the financial risk, (with support from the business parks served).

In terms of air quality, the existence of 11 environmentally friendly, carbon neutral, buses on one bus route which runs along a busy dual carriageway, does not in itself make a significant improvement. The buses do help reduce pollution in the residential areas they serve (Kennet Island eco-village), and the town centre and demonstrate how solutions to the problems of transport pollution can be found. Reading Buses said that its gas buses produce almost no particulates or hydrocarbons, almost zero carbon and 55 per cent less nitrogen oxide. 

Challenges, opportunities and transferability 

The use of CNG-powered buses is not uncommon worldwide, but this was the first example in the UK. The use of certified biomethane to replace the CNG used at the depot makes the use of natural gas a carbon neutral, non-fossil fuel. This could be replicated anywhere and indeed the Gas Alliance, a group of UK independent companies specialising in natural gas and biomethane infrastructure, is seeking to interest other UK bus operators in this idea.

For the bus company there was significant development time and cost to design and install the compressing and fuelling arrangements as well as some investment in the workshop so that the gas buses could be worked on without causing a risk to the depot if there was a gas leak. As one of only two UK gas bus fleets, the 34 buses in Reading have successfully proved that these work in a busy UK bus environment.

For Reading Borough Council the use of an environmentally friendly fuel in a highly visible bus service is a clear indicator that there are some simple solutions to help with the problems of air pollution caused by transport. This is just one aspect of the various strategies employed by the Council to reduce its environmental impact.

In Depth 

Photo: Stephen Wise

Collective passenger transport
Clean and energy-efficient vehicles
United Kingdom
Stephen Wise
Stephen Wise
16 Jul 2015
23 Jul 2015