Beyond diesel; gas and electric leading the charge

Beyond diesel; gas and electric leading the charge

If you are going to run vehicles powered by alternative fuels then you need the infrastructure to support them. The upgraded facilities Reading Buses will require to power its growing compressed natural gas (CNG) fleet will cost up to £2million, says chief engineer John Bickerton; but he is certain the exercise is worth it.

Reading has 34 CNG buses in service at present but will boost the total during the coming months with the addition of five Scania N280UD chassis with ADL Enviro400 MMC bodywork at a cost of £1.3million. They will be the first CNG-powered Scania double-decks to go into service worldwide and can run on biomethane, CNG's close cousin; renewable gas generated by landfills.

"Our target is to have the first one in service by the end of November," Bickerton says.

It is interesting to note that when Reading announced the deal for the five Scanias back in April it stressed that the acquisition of the vehicles was not supported by public subsidy. The 16 CNG double-deckers that look set to follow them will be however, thanks to Reading's successful bid for some £1.7million of funding from the government's Low Emission Bus Scheme. 

The funding will also help pay for the aforementioned infrastructure improvement.

Nottingham City Transport was awarded £4.4million for 53 biomethane buses, including £1.5million for the associated refuelling infrastructure, in the same funding round.

The environmental credentials of CNG and LNG - liquefied natural gas - are stressed, perhaps not surprisingly, by Gasrec, which supplies gaseous road fuels. 

In its 'Driving change to low emission transport' report published last year, it pointed out that gas-powered Euro 6 vehicles emit up to 96 per cent fewer particulates and up to 78 per cent less NOx than their Euro 6 diesel counterparts. CO2 emissions are down substantially too, it adds.

Furthermore, although they are clearly not as quiet as electric buses, they emit fewer decibels. "They make 50 per cent less noise than their diesel equivalents," says the report.

They have another advantage too, says Bickerton; modern CNG buses are turning out to be twice as reliable as diesel Euro 6 models, he states. "Remember that you've got no AdBlue or particulate filters to worry about," he says. 

It is an advantage that helps justify the price premium, he believes.

So is Reading likely to switch completely to CNG? 

"I think there will always be a place for diesel in the fleet because you need three times the volume of gas to cover the same distance," Bickerton replies. That is a problem so far as some of Reading's longer routes are concerned, he says, because of the need to remove up to four seats to accommodate the additional cylinders.

In some cases it may be a penalty worth paying however, he suggests, given CNG's other advantages.

Gas power represents an alternative to the hybrid and electric route favoured by Transport for London, with 81-passenger, battery-powered BYD 10.2m double-decks with a claimed range of up to 190 miles between recharges now on trial with Metroline. Recharging is said to take no more than four hours and the vehicles will clearly comply with the ever-tightening requirements of the capital's Ultra Low Emission Zone.

The ULEZ is due to come into force in 2020, but bus operators will feel its impact rather earlier with the introduction of Low Emission Bus Zones.

They will make buses that meet or better Euro 6 mandatory along some of London's most-polluted routes. Next February, Putney High Street - a notorious pollution hotspot - will become the first to be affected with the route between Streatham and Brixton to follow in October.

Furthermore, all 3,100 double-decks operating in the central ULEZ will have to meet Euro 6 by 2019 and the ULEZ may expand. Earlier this year, mayor of London Sadiq Khan, launched a consultation which addressed the possibility of extending it to the North and South Circular roads and introducing it earlier than 2020.

Five other cities – Birmingham, Leeds, Nottingham, Derby and Southampton – will introduce Clean Air Zones by 2020. Both Birmingham and London are investigating the advantages of hydrogen fuel cell buses; Aberdeen now boasts the largest number of such vehicles in service in Europe.

Many operators UK-wide do not want to replace their existing, older, Euro 4 and Euro 5 diesel buses yet awhile, however, and may prefer to clean up their emissions and bring them up to Euro 6 standards instead. 

That is where retrofit packages such as the SCRT system available from Eminox comes in. It combines Selective Catalytic Reduction with Continuously Regenerating Trap technology.

"It has been independently tested and shown to cut NOx by 95 per cent and particulate matter by 98.8 per cent," says Eminox head of retrofit engineering Steve Rawson.

One way of cutting emissions is of course to consume less fuel. That is why Eminox is working with Controlled Power Technologies to combine its SCRT with CPT's electric supercharger with the aim of burning less diesel.

It assists rather than replaces the engine's own turbocharger, continually delivering air so that the fuel burns more efficiently. Better combustion means fewer pollutants.

Says CPT senior manager Andy Dickinson: "Electric supercharging provides a cost-effective technology for controlling emissions without increasing fuel consumption. Black smoke in particular, which is simply the result of too much fuel and insufficient air, can be significantly reduced or even completely eradicated."

Driver behaviour has a major impact on fuel usage. Onboard monitoring systems are increasingly being fitted with the aim of discouraging brutal acceleration, speeding and other practices likely to increase fuel bills and the risk of a collision.

Companies supplying such packages include 21st Century Technology, with EcoManager. It delivers instant feedback to drivers which will hopefully prompt them to modify their behaviour and is married to a web-based reporting system that provides feedback to management.

Instances of poor driving can then be discussed with the individual concerned, possibly with remedial training in mind. Another option is to set up a league table that will result in drivers that are fuel-efficient and accident-free being rewarded.

Actia offers a similar system, with driverAID mounted on the dashboard and Eco-Fleet generating the reports. It has an OE package for Optare called Eco Drive which is integrated with the dashboard and designed to achieve the same goals when used in concert with Eco-Fleet.

Returning to Reading Buses, the Berkshire operator has had MiX Fleet Manager driver behaviour monitoring systems installed in all 181 of its buses by MiX Telematics; and they have turned out to be a success, according to the operator.

By last December - nine months after they were first introduced - Reading reported a 27 per cent cut in harsh braking and a 44 per cent fall in harsh acceleration. Overall fuel consumption was down by 2 per cent - a modest decline, admittedly, but still worth having.

"One thing we were able to do was identify that there could be a difference of as much as 40 per cent in fuel consumption between our best and our worst drivers," says Bickerton.

Known as RIBAS, the MiX Telematics onboard display highlights over-revving, excessive idling, harsh braking, harsh acceleration and over-speeding. Lights illuminate that advise drivers about their behaviour at the wheel; red is poor, amber is neutral yet at the same time alerts whoever is at the wheel that they may be at risk of drifting into the undesirable red zone and green is good. 

"We've been extremely pleased to see a 35 per cent increase in drivers who meet green driving standards," says Reading operations manager, Dan Bassett.

Any such system can only function properly if drivers support it and do not fear that it will be used as a basis for disciplinary action. One way in which Reading has promoted engagement with its employees is through the use of MyMix, an app designed to give drivers direct access to their driving data.

The argument goes that if they can see what the boss sees, then there is less scope for suspicion and misunderstanding.

Apparent rises in fuel consumption can of course be due to unexplained losses from the operator's bulk tank. That is why close monitoring is vitally important, a point appreciated by Folkestone, Kent-based Crosskeys Coaches.

It runs some 20 minibuses and coaches on private hire and European and UK tour work including excursions for holidaymakers arriving at the Dover cruise ship terminal.

Earlier this year it decided to upgrade its diesel storage facilities with the installation of a Merridale Auditor GS integral pump and fuel management system. All fuelling transactions are polled using GPRS telemetry for processing by the web-based Merridale FuelWorks service.

"We like the idea of fuel management as a service because it means that as the key equipment supplier, Merridale has a commercial interest in the ongoing reliability of our depot facilities," says Crosskeys operations manager Nigel Matcham.

Operators can also benefit from software to help oversee fuel management systems. EP Morris supplies a Vehicle: Fuel and Miles (VFM) module as part of its Engineering Management System (EMS), a suite of tools designed to save time, prevent breakdowns, and maintain high reliability and quality of services.

VFM has been used by the industry for many years to provide accurate and reliable fuel consumption data for operators in order to measure the efficiency of their fleet and provide the necessary output for BSOG claims and tyre leasing returns.

The system can accept data from all of the industry fuel equipment suppliers and fuel card providers as well as manual input. It also caters for different fuel types such as ULSD, biodiesel and CNG. VFM is designed to manage fuel from delivery, through stock control to fuelling vehicles, and ensures that all fuel is accounted for. 

Vehicle mileages can be corroborated through analysis of consumption rates using a number of exception reports within the system, including correction tools for mis-recorded fuel or broken odometers. EP Morris says that these controls ensure that BSOG revenues are maximised, tyre leasing costs are managed and KPI /environmental reporting is accurate.