Analysis: Australia’s future fuel
Posted by Car Geek on July 5, 2007
If you’ll indulge me for a moment, I’d like to take the opportunity to step back from each individual step that we’ve been focusing on here to take a look at the broader perspective.
In 2005, Australia consumed:
- – 18,712 million litres of petrol (15,856 ML of which was used in passenger vehicles)
- 8690 million litres of diesel fuel (5,636 ML of which was used in rigid or articulated trucks)
- 1564 million litres of LPG/CNG fuel
Current indicators are that fossil fuel use has increased in the 18 months since this data was recorded; alternative fuel use in transport was not significant enough to appear with these statistics at the time. In terms of fuel production:
- – Non-renewable fuel production has increased 446% in the last 30 years
- Renewable fuel has increased 28% in the same period
Clearly these are not the markers of a country that has embraced alternative and renewable fuels, as much of the world is doing. This is both a weakness and an opportunity for us: although we have so far given up the chance to be a world leader in the reduction of greenhouse gas emissions, we have been able to observe a very rapidly maturing field of fossil fuel replacements and make a sensible decision about which is best for the Australian environment. If you’re interested in knowing who the primary contenders are, read on.
Easily the largest and possibly the most controversial of the alternative fuels available today, biofuels have seen explosive global growth over the last decade as fuel prices rise and consumers become increasingly aware of the effect that their everyday activities may have on the environment. Simply put, biofuels are any type of liquid or gaseous fuel that is derived from an organic, renewable source. The most popular example of this is ethanol, which is largely derived from corn or sugar cane, but the field also includes biodiesel, biobutanol and other organic fuels. The process for extracting useful product from these organic materials varies widely between fuel types and material used, as does their effectiveness and efficiency. The Federal government has set a target of 350 million litres of biofuels produced annually by 2010.
Ethanol is the most common biofuel in Australia, with an estimated 23 million litres produced in the 2004-05 year. It is generally combined with petrol in a 10/90 blend, commonly sold as “E10″ fuel. E10 is certified for use in 60 per cent of Australian vehicles (of which most are post-1986 models). Ethanol has a lower energy content than unleaded petrol (about 34% lower by volume), resulting in higher fuel consumption depending on the ethanol concentration, however it also has a higher octane number which is comparable to premium unleaded petrol. In Australia, ethanol is mostly produced from molasses (a sugar cane byproduct), which has a positive net energy balance as high as 8 according to the IEA (that is, for each unit of fossil fuel used to create sugar cane ethanol, eight units of ethanol can be produced). The next generation of ethanol production, known as cellulosic ethanol, promises to be even more efficient as it derives its product from unused portions of the crops, such as stalks.
Biodiesel varies slightly from ethanol in that it can be produced not only from crops (primarily canola and soybean in Australia), but also from animal fat or cooking oil. Its energy content is comparable to that of mineral diesel (around 90 per cent), and use in diesel-powered vehicles requires no modifications, though some manufacturers will not endorse using pure biodiesel in their engines. Approximately 4 million litres of biodiesel was produced in the 2004-05 year. Biodiesel is not yet widely available at retail outlets in many parts of Australia, where it is generally sold as “B20″. As with ethanol, biodiesel presents significant greenhouse gas emission reductions over its fossil fuel equivalents, but suffers some minor technical problems such as difficulty working at sub-zero temperatures. Blending with mineral diesel, such as in B20, assists in alleviating these problems.
There are a number of obstacles that remain before biofuels in Australia can gain widespread acceptance. As is currently being seen in the United States, significant production of biofuels from farm crops can affect the use of those crops as feedstock, both for domestic use and export. Upcoming technologies, such as cellulosic ethanol and algae biodiesel, may eliminate the need to use food crops entirely, but they are not expected to be put into widespread use for a number of years yet. Additionally, there remains some consumer concern about the use of ethanol in vehicles after some incidents in recent years where unmarked high-ethanol content fuels were used in vehicles that were not equipped for them, allegedly causing damage. Although a review and enforcement of ethanol classification standards can help resolve this, it will take time for consumer confidence to be fully restored.
There are a wide variety of vehicles that fall under the general category of “electricity powered” on the global market, ranging from hybrids that run intermittently on electric power generated from the car’s movement, to plug-in battery-powered vehicles that use no liquid fuel at all. Australia’s electric drive market for passenger vehicles is low when compared to other countries, with only a small number of “parallel” hybrids such as the Toyota Prius available and almost no plug-in models commercially available, mostly due to reasons which will be discussed shortly.
The fundamental premise of an electrically driven vehicle is simple – energy is stored in the vehicle, generally using batteries, which drives an electric motor in place of a standard internal combustion engine to provide movement. This energy can come from onboard sources such as regenerative braking, where kinetic energy is recovered and stored in batteries, or external sources such as a power outlet or solar panels. Electric drivetrains have a number of distinct advantages over traditional combustion engines – they are much more efficient (up to 90 per cent compared to an average of about 25 per cent); they produce no tailpipe emissions as there is no chemical reaction or combustion; they run far quieter than a standard vehicle; and they provide an impressive amount of torque for reduced weight. They excel in start-stop urban environments, where they are using almost zero energy when idling (as compared to ICE vehicles, which idle and use fuel when stationary).
For all these advantages, though, electric drive vehicles have some drawbacks which limit their usefulness in the Australian environment. Battery life is a well-known criticism of any electric vehicle, including hybrids; although battery technology is steadily improving, current lithium and nickel metal hydride batteries have a limited life span and need to be replaced after a certain number of recharge cycles, which can be an expensive proposition. The benefits of a plug-in vehicle in Australia are also questionable: assuming an average consumption of 0.25 kWh/km, a plug-in electric vehicle actually results in more carbon dioxide being released into the atmosphere via power generation than a standard four-cylinder car. This isn’t necessarily true in other parts of the world, where electric vehicles are gaining popularity, but Australia’s own power generation industry is undeniably its worst polluter. This is neglecting the fact that Australia’s power grid is not capable of handling a sizeable fraction of its transport drawing power from it. Zero-emissions home power generation, such as solar and wind power, is a feasible but expensive solution that provides truly pollution-free travel. Finally, the range of a battery powered vehicle and time to recharge are criticisms that eventually led to the concept of the plug-in hybrid vehicle (or PHEV), which combines a significant battery pack with a fuel-powered engine or fuel cell to drive the vehicle when the battery runs out of power. PHEVs are not yet available on the market, however some major auto manufacturers are currently working on production models due in the next couple of years.
Hydrogen is something of a dark horse in the alternative fuels race – everybody knows a little about it, enough to know that a number of people in government and industry are predicting it to be the Next Big Thing, but not a lot of people can tell you how the entirety of the “hydrogen economy” works. Hydrogen does not occur naturally as an immediately usable fuel in any large quantities, requiring it to be generated via other means. Currently the most common way to produce hydrogen is through steam methane reformation, in which methane (a greenhouse gas) is manipulated to produce hydrogen. The second method, and one that is generally promoted by hydrogen vehicle manufacturers, is electrolysis of water to “split” water molecules into hydrogen and oxygen gases. Vehicles then use this hydrogen, generally in a fuel cell which uses the hydrogen to generate electricity which drives an electric motor, with water vapour the only emission. Some vehicles such as BMW’s Hydrogen 7 instead use a combustion engine to burn hydrogen as one would with standard fuels; although a less expensive option, it is also less efficient than fuel cells and produces NOx as a result of the high combustion temperatures.
Hydrogen powered vehicles in Australia have a number of advantages over both conventional vehicles and rival alternative fuels. Australia has an abundant supply of natural gas which can be used in the short term as a hydrogen source to reduce the amount of imported fuel. Clean vehicle emissions can help to reduce smog levels in the city, as there are no particulates, ozones or VOCs being emitted as there are in hydrocarbon-based combustion engine vehicles. Hydrogen vehicles also have a much faster refilling time than electric vehicles, on a similar order of magnitude to standard fuel refilling.
There are various drawbacks to hydrogen vehicles, though, that also need to be considered. At present there is no hydrogen piping or transport infrastructure – either one would have to be created, or hydrogen would need to be generated on-site. Using natural gas to create hydrogen also creates carbon dioxide on a comparable per-kilometre level to a modern four-cylinder car, according to the CSIRO, reducing much of its environmental benefits. The other option, electrolysis of water, is less efficient than the equivalent energy path for battery-electric vehicles, essentially using more power for the same driving distance. Electrolysis on a large scale could also put a significant strain on Australia’s potable water supplies; unlikely to be a popular option in the midst of a serious drought. Future technologies such as sea-water electrolysis or high-temperature thermochemical production using waste heat from nuclear reactors are a possibility, but are not yet feasible. Additionally, fuel cell vehicles are the most expensive out of the types listed here, with even standard models in the hundreds of thousands of dollars.
The ideal fuel (or combination of fuels) depends largely on Australia’s focus. If we want to achieve energy independence above all other goals, a strong focus on biofuels with incentives for Australian car makers to produce biofuel-optimised cars will help to achieve that, especially when second-generation plants come online that take the strain off food production. Gas-to-liquids projects and a focus on Australia’s existing energy resources such as coal and nuclear power can assist in that goal. If the aim is emissions reduction, biofuels will still play an important part in the short term, but in the long term still result in some emissions (albeit far lower than their fossil fuel equivalents). Cleaner electricity is a necessary step for any emissions reduction scheme in Australia, and an expansion of grid capacity will allow for more efficient electric-drive vehicles to use less energy than with combustion engines. Hydrogen may become a feasible option if nuclear power is brought online in Australia, but that presents its own set of unique challenges.
Regardless of any future government’s focus, Australia will need a diverse portfolio of renewable fuels to tackle the potential threats of climate change and limited oil availability as it relies more and more on imported resources. One type on its own is unlikely to provide an increasingly energy-hungry country with the transportation it needs without significant drawbacks.
Australian Bureau of Statistics
“Biofuels Taskforce Report”, Dept of the Prime Minister and Cabinet
“Biofuels for Transport”, International Energy Agency (PDF)
“Comparison of Transport Fuels”, CSIRO/Australian Greenhouse Office