John Comer, Volvo Truck's product manager UK & Ireland, shares his thoughts with Freight in the City on carbon reduction and alternative fuels
Alternative fuels bring with them some very interesting challenges as not all fuel types suit all operations. Some offer a carbon reduction because they are sustainable and therefore close the carbon loop. Some offer a carbon reduction on the vehicle. When it comes to carbon and the climate change effect, the process has to be measured from ‘well to wheel’ and of course this needs to include the sustainability of the base feed stock and its source. However, the diesel cycle remains the key power cycle choice as there is no other energy convertor that can offer the same efficiency.
LNG and CNG
In terms of alternatives on regional haul, there are commercial paybacks with liquefied natural gas (LNG) dual-fuel. Gas currently does not carry any fuel duty with it, so the figures stack up. Using LNG the industry should get a 15%-20% reduction in tail pipe CO2. However, to get significant reductions on greenhouse gas emissions, a truck running on biomethane would see a CO2 reduction of 70% well to wheel. This gas is available from bio-digesters and it is easier to send that to the grid as there is currently only one unit that can cryogenically process biomethane. The change to dual fuel involves Volvo, the dealer, the operator and driver along with the gas supplier for successful buy in.
Long and regional haul
For the city we have the Volvo FE 18 or 26-tonner with a spark ignition gas engine with compressed natural gas (CNG)) tanks, which fit conveniently in the wheelbase. Based on natural gas we have a 15%-20% reduction in CO2 but the aim is to use biomethane. When operated as a city truck, we can refill overnight if needed and we can support the range by additional gas tanks. The gas truck is pure gas so there is no requirement for a diesel particulate filter (DPF) or selective catalytic reduction (SCR) system, just a three-way exhaust catalyser.
Another key city benefit is that the gas engine on this truck is 2dB quieter [than a diesel engine]. These technologies are available, or in the advanced development stage. But they require significant work on the vehicle and fuelling resource. Their current pay back potential is linked into the effect of national taxation levels of gas as a fuel.
Alternatives to diesel
In terms of technologies we understand, for vehicle engineering and infrastructure there are three fuels that are in contention. The first is biodiesel, which Volvo is able to use providing it is of the type known as FAME (Fatty Acid Methyl Esters) and it is produced to European Standard EN 14214. That is very important, with up to 100% blend being used on the FL240 from 10 to 16-tonne, FE320 at 18 and 26-tonne and now the 460 13 litre for FM, FMX and FH - providing the correct engine has been specified at the point of sale.
The maintenance regime has to be controlled and we work with the local dealer on the service plan to ensure maximum performance. The result is that the filter and oil change intervals are halved. However, a downside is that the exhaust after treatment system has a reduced service life.
The key issue in service is the fuel blend. It has to achieve the standard and the quality of storage. Interestingly, harvesting biomass and converting it to hydrotreated vegetable oil (HVO) makes a much better fuel than that produced by the process of esterification. HVO is not true to its name as 60% comes from slaughter house waste. HVO fuel has a good cetane rating and it can replace conventional diesel. It does not have the same aftermarket issues that one gets with biodiesel.
However, the availability of HVO fuel is limited. But, due to its potential, there is significant investment currently being made in the HVO process. HVO is definitely a front runner in the Gartner Hype Cycle of technology development, where early promise is weighed against performance in reality over time. In my opinion, the only real contender is synthetic diesel.
Electrification and hybrids
Hybrids and electrification work well for bus operation, where stop start gives a regenerative boost to the system when braking and road speeds are low. It has also delivered some success in certain refuse collection operations. The systems work in parallel. For trucks however, the density of the energy produced from the battery alone, is not, at this stage of development, ideal for emission free or everyday driving mode. To achieve that, external support is needed. This might come from the road or via a pantograph. Volvo is working on such a system for regional distribution.
Volvo Bus is working on plug-in hybrid and pure electric buses for emission free city operations so maybe an electric truck based on the bus design and using the bus conductive network is a possible solution for consolidated inner city shipments in London.
Modality and vehicle size
A key carbon advantage of the truck compared to other modes is that the load can be shipped directly from A to B, without the need for transhipment to another source or carbon production; the bigger the load the better in terms of CO2/kg. However the idea of delivering with a 16.5m-long artic in a city poses other issues; that one truck with a 28-tonne payload would require 14 3.5tonne vans for onward delivery of the goods, which puts massive pressure on road space, noise, safety and emissions in the city.
So a key question is what size truck is ideal for the city? Consolidation of loads into the city is the way forward – rather than replace the traditional 7.5 tonner with a van, it could be replaced by a 10-16 tonne truck which has a similar dimensional foot print with the advantage of a 5 to 9 tonne payload, (compared to 2 tonne for a van). The design is low and convenient for ease of unloading, avoiding penalty charge notices (PCNs) and ensuring good traffic flow. The other alternative in terms of consolidation is the flexibility and load capacity of the urban artic, a low tractor unit with a single axle trailer at 24t GVW offering a 10 tonne payload.
Consolidation centres at the edge of town could mean the employment of large trucks to supply on a green highway or even a mode switch to rail.
For maximum carbon reduction, safety and air quality the whole distribution structure has to be reviewed including infrastructure and a flexible working day to keep the traffic flowing in the city.
- For more on Volvo's involvement with alternative fuel technology click here
