A window of opportunity for natural gas vehicles

A Westport powered truck re-fuels in Vancouver Canada.

A Westport powered truck re-fuels in Vancouver Canada.

Two of Australia’s top experts in natural gas vehicle technology and policy, Westport Innovations (Australia) Managing Director Bruce Hodgins and ABMARC Principal Engineering Consultant Natalie Roberts put their heads together to advocate the use of natural gas vehicles.

With abundant natural gas resources available and a pressing social need to cut greenhouse gas emissions, there has never been a better time for Australia to harness the clean burning power of gas, and to apply its use domestically in as many sectors as possible.

The transition from oil and coal however has meant that many industries, including the transport and vehicle manufacturing industries, have to think creatively and act quickly to adapt technology and infrastructure to support this growing shift in energy. Westport Innovations Australia Managing Director Bruce Hodgins and ABMARC Principal Engineering Consultant Natalie Roberts share their insights with Gas Today.

What technological barriers does the natural gas vehicle (NGV) industry face?

Bruce: Most of the barriers facing the increased use of natural gas for transport are commercial rather than technological. Primary among these are the constraints on capital deployment by both fleet customers to purchase new trucks with more expensive natural gas engines, and of fuel providers to establish new natural gas fuelling stations to allow more thorough adoption of natural gas in the transportation fleets. While this is often described as a “chicken-and-egg” situation, a solution could be the initial development of transport corridors (Sydney to Melbourne for example), with sufficient natural gas refuelling locations to enable significant fleet operations along these corridors.

An additional barrier is the lack of flexibility in the vehicle length and weight restrictions that are based on diesel trucks. Small allowances on vehicle length and weight are necessary to cater for NGVs, which have a lower volumetric energy density than diesel, and thus require bigger and heavier fuel tanks.

Bruce, can you please explain the technology behind the LNG truck engines manufactured by Westport in simple terms?

Bruce: The Westport HD engine offered in Australia uses high-pressure direct injection (HPDITM) technology. With direct injection, the combustion process is identical to the diesel-cycle combustion, with fuel injected directly into the combustion chamber at the end of the compression stroke.

The Westport HPDI technology injects a small quantity (about 5 per cent on average) of diesel fuel at the beginning of the power stroke to provide sufficient energy to auto-ignite the natural gas injection that immediately follows the diesel injection. This method eliminates the possibility of pre-ignition or detonation that can occur with pre-mixing of air and fuel on the intake stroke.

The Westport HD system includes an LNG pump installed in the LNG fuel tank to efficiently pressurise the natural gas fuel to enable the high-pressure injection of natural gas.

From the general public’s perspective, what are the driving forces behind LPG/CNG conversions?

Natalie: Definitely cost. As part of ABMARC’s LPG report, we conducted an LPG user survey and the number one reason respondents chose to buy or convert to an LPG vehicle was to lower their running costs. The survey identified the socio-economic benefits of LPG in providing mobility to families, pensioners and low income earners. The results showed that LPG owners typically drove SUVs or large passenger vehicles, lived in the outer suburbs, and had lower incomes than the reference group. It was clear that LPG was used to help balance household budgets or enable family activities such as caravanning or horse riding.

Significantly, 72 per cent of respondents believed that if they didn’t have the option of LPG, they could not afford to operate their vehicle or would have to reduce their vehicle use or activities.

In your opinion do you think the use of CNG/LPG vehicles will in any way benefit the public perception of natural gas and the LNG industry for the better?

Natalie: Yes. A positive experience with an alternative fuel system such as LPG makes people much more likely to consider purchasing a natural gas vehicle – which is of benefit to the gas industry as a whole. If NGVs were adopted in greater numbers, this would result in an increase in gas demand that may have the benefit of increasing investment in transmission and reticulation pipeline infrastructure, and could also result in the expansion of the distribution network. The ABMARC LPG survey asked respondents about future engine purchase considerations. The results showed that 20 per cent of LPG vehicle owners would definitely consider a CNG vehicle in the future, which was more than three times greater than the reference group.

What message would you like to pass onto exploration and production companies operating in Australia about supporting the use of gas domestically?

Natalie: Supporting the use of gas domestically should ultimately result in good public relations for exploration and production companies. If Australians, particularly those living in the highly visible CSG-producing regions, can see direct benefits from its production, they may be more supportive.

What message would you like to pass onto government in order to encourage greater take up of CNG/LNG vehicles?

Natalie: The use of CNG and LNG in transport is beneficial in achieving three key outcomes including: enhancing energy security; enabling mobility to all sectors of the community and advancing economic opportunity; and, offering improved environmental outcomes when using the latest engine technologies – both to reduce CO2, which assists in the long-term goal of limiting the effects of climate change and to reduce particulates, which has the immediate benefit of improving air quality.

Natural gas is an abundant and indigenous resource for which known economic resources tripled in the 16 years to 2009. It is widely available in Australia – in fact, ABMARC estimates that nearly 48 per cent of premises, residential and commercial have a gas connection an important detail that could facilitate the rapid roll out of CNG and LNG refuelling infrastructure.

Bruce: The greenhouse gas benefits of HPDI technology and energy security benefits offered by high-substitution natural gas vehicles are significant and support the Australian Government’s introduction of a carbon tax. However, to encourage fleets to adopt this beneficial technology, the government must develop performance-based incentives to enhance the economics and reduce risk for the users.

There are several examples of workable incentives used by Canadian and US governments to initiate deployment of natural gas vehicles and refuelling stations. Unfortunately in Australia the current rebate to fleets on diesel fuel and introduction of excise tax on natural gas are completely opposite to the incentives needed to encourage intended behaviour change associated with the introduction of a carbon tax.

What lessons can Australia learn from the rest of the world in terms of LNG/CNG vehicles?

Natalie: Many global governments actively ‘push’ for the uptake of NGVs and provide a range of policy incentives. The US promotes gaseous fuels for ‘energy independence’; Europe encourages natural gas for its ability to reduce CO2 and noxious emissions; Pakistan, Thailand, India and other developing nations see it as a way to improve air quality, while at the same time promoting economic opportunity through lower vehicle operating costs. The Australian Government need to replicate this ‘push’, to receive the flow-on benefits.

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