Fuel developments respond to climate change campaigns

The countless thousands of young people who demonstrated worldwide demanding that governments take radical steps to combat climate change have delivered a wake-up call to politicians. The same wake-up call is being delivered to bus and coach producers and fleets that operate their products, many of which have in fact been taking action to reduce their environmental impact for some time.

Electric vehicles and fuel cell technology are among the options being pursued by manufacturers. Steve Banner reports

Among those manufacturers energetically promoting environmentally-friendly vehicles is Van Hool. This year’s Busworld Europe show (18-23 October), to be held in Brussels, will see the Belgian manufacturer exhibit two zero-emission products.

One is an electric CX45E coach designed for the American market using battery technology sourced from US manufacturer Proterra. The 648kWh battery pack is said to deliver a range of almost 190 miles, which should make it suitable for commuter work.

Van Hool is a significant player in the North American market, with over 11,000 of its buses and coaches on the continent’s highways.

The other product is a 18m, single-articulated, 125-passenger Exqui.City18 FC powered by a hydrogen fuel cell which only produces harmless water vapour. Any unused energy is stored in lithium batteries and can be called on when the tram-bus, as Van Hool describes it, needs a bit more impetus; when it is accelerating away from a stop, for example.

Eight of these vehicles are going into service in the French city of Pau and will be deployed on a Bus Rapid Transit system. Each one can be refuelled in ten minutes, says Van Hool, and has the same range as the CX45E.

Van Hool has developed considerable expertise in fuel cell buses in recent years, supplying vehicles for use in Aberdeen and London and winning an order to deliver 40 12m single-decks to operators in Cologne and Wuppertal in Germany.

It is not the only manufacturer involved with the technology however. ADL has been developing a fuel cell Enviro400 double-deck, while Transport for London ordered 20 fuel-cell double-decks from Wrightbus for delivery in 2020, albeit that the Ballymena company’s recent collapse will impact on this development.

Fuel cell buses have their drawbacks.

A lot of electricity is required to produce the hydrogen they consume – and needs to come from renewable sources to make the environmental argument stack up – and they remain eye-wateringly expensive. A 12m single-deck fitted with a fuel cell will set you back well over £500,000, and is unaffordable without government support.

Such vehicles also need a suitable refuelling infrastructure.

The cost of electricity generated by renewable energy sources is falling steeply however.

The price of energy produced by offshore wind farms has tumbled by 30 per cent over the past two years to a new record low, says the government, and the next generation of wind farms due to be constructed will not require subsidies from the taxpayer.

Wind power is now cheaper than coal power. It is also considerably cheaper than the price the government will pay for electricity generated by the Hinkley Point C nuclear power station scheduled to open in 2025; remarkable developments which ought to gladden the hearts of climate change protesters.

Fuel cell vehicles should come down in price as the volumes sold increase. Refuelling sites are being set up, although the total remains small.

A plan to put up to 25 hydrogen-fuelled buses onto Liverpool’s streets drawn up by a consortium that includes Liverpool City Region Combined Authority, gas producer BOC, Arcola Energy and ADL embraces a refuelling station. It will be constructed at the BOC hydrogen plant in St Helens.

The entire scheme is being supported by £6.4million from the Office for Low Emission Vehicles.

Hydrogen is of course not the only gaseous fuel available. Compressed natural gas (CNG) and liquefied natural gas (LNG) both have their advocates.

Gasrec, which runs natural gas refuelling stations, says that natural gas is around 40 per cent less expensive than diesel and produces 70 per cent less NOx and 90 per cent fewer particulates. CO2 emissions are reduced by 15 per cent, the company adds, and by 90 per cent if you opt for biomethane.

Switch from diesel to gas and your engine’s average noise output will go down by around 3dB; good news if you operate services at night.

Well-known operators who run gas buses include Nottingham City Transport. This year it is acquiring 67 more biogas-powered ADL Enviro400 City double-decks based on Scania platforms, which means it will have a total of 120 in service.

Bear in mind that CNG and LNG have a lower energy content than diesel, making engines powered by them 10 per cent less efficient. Bear in mind too that installing an in-house gas refuelling station with significant capacity can cost anywhere from £300,000 to £1.2million, depending on how large it is.

Although diesel engines have been demonised, their environmental impact can be reduced if you run them on gas-to-liquid fuels such as Shell GTL instead.

Modern engines do not have to be modified in order to burn it and it can reduce particulate emissions by up to 50 per cent says Rebecca Swann, product manager for fuels and services at Certas Energy. It markets Shell GTL in the UK.

“Trials have shown that it can reduce NOx output by up to 37 per cent,” she observes. “The fuel also produces less odour, smoke and engine noise than conventional diesel to create a pleasanter journey for passengers.”

Nor does it require specially-designed storage and dispensing facilities. “It offers high energy density, ease of use, and safe handling, supported by security of supply,” Swann says.

Worth considering too is replacing mainstream diesel with HVO – Hydrotreated Vegetable Oil – says Richard Hutchinson, research and development manager at Crown Oil, which supplies the fuel. “It’s made from renewable and sustainable raw materials and its key environmental advantage is that greenhouse gas emissions are reduced by up to 90 per cent compared with mineral diesel,” he states.

Such fuels are more expensive than standard diesel – several pence per litre more in the case of Shell GTL – but may deliver fuel economy as well as environmental benefits.

One fleet which has switched 80 of its vehicles to Shell GTL is enjoying a fuel economy improvement of 0.4mpg, says Certas. None of the vehicles has required a diesel particulate filter regeneration, it adds.

“In some cases Shell GTL can elongate the regeneration cycle of particulate filters compared with regular diesel by up to 70 per cent,” Swann contends. “Furthermore, thanks to its high cetane number and good cold flow properties it offers better starting performance in cold conditions compared to running on conventional diesel.”

Diesel’s cetane number is an indication of its combustion speed and the compression needed for its ignition. The higher the number, the more efficiently the engine will operate.

Fuels marketed as an alternative to ordinary diesel can be easier to store.

“HVO has a storage life of up to ten years compared with standard diesel’s one to two years assuming it is stored in a well-maintained tank,” says Hutchinson. “This is a result of the hydrotreatment process used to create the fuel, which leaves HVO clear of particulates and far less susceptible to bacterial attack.”

Older diesel buses can be made cleaner through the use of retrofit emission control equipment. NCT is fitting aftertreatment equipment to its remaining diesel buses, a move which it says should ensure that the overall emissions of its fleet tumble by 90 per cent by next year.

Eminox has now equipped over 5,000 buses with its SCRT system. It represents a combination of CRT (Continuously Regenerating Trap) and SCR (Selective Catalytic Reduction) technology.

It can cut particulates by as much as 95 per cent and NOx by up to 99 per cent, says the company.

Earlier this year Eminox opened a new retrofit service and support centre in Stoke-on-Trent. As well as three fitting and three welding bays, it includes an operation which provides businesses which distribute Eminox’s replacement Euro VI particulate filters with a next-day service.

Eminox is not the only one that can offer aftertreatment packages. No less than 306 of TfL’s Euro V hybrid double-decks, so-called Borismasters, have been equipped with NOxBuster City technology from Finland’s Proventia by Excalibre. The Mitcheldean, Gloucestershire firm is Proventia’s UK partner.

No matter whether you run on CNG, LNG, GTL, HVO or mainstream diesel, the less of it you consume, the fewer the pollutants you emit; and one way of cutting fuel usage is to pay regular attention to wheel alignment.

It is a point made by Automotive Equipment Solutions, which supplies Josam alignment equipment. Align your wheels correctly and you can reduce fuel consumption by 2.5 per cent it says, rising to up to 15 per cent if closer examination also reveals that the tyre pressures are incorrect and the wrong tyres have been fitted.

Correct alignment also leads to longer tyre life and more accurate steering; a safety benefit which no sensible operator will wish to ignore.

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