20th January 2010
There are many ways we can cut down on the amount of fuel our cars use these days. As simple a thing as changing your heavy steel wheels for alloy wheels, upgrading you tyres to energy efficient tyres and keeping your vehicle well maintained with regular servicing can dramatically decrease your annual fuel costs however, can we cut down even further and in doing so even help cut down on our carbon footprint? Well, the answer is yes! And it's not nearly as difficult as you would think.
With rapidly increasing fuel costs across the UK and throughout the world most of us really are starting to feel the pinch when it comes to filling our cars up these days. This coupled with increasing pressure from the government and environmental agencies to combat Co2 emissions, could biofuels be the future for the automotive industry?
Let's take a quick peek at the advantages, disadvantages and cost of some of the alternative fuels available to us today. And hopefully answer a few burning questions about the viability of alternative fuels on a practical level as we head into the most green focussed decade in nearly 3 century's of the modern auto mobile.
NB: If you car runs on diesel then skip to part 1, Biodiesel.
What is bioethanol?
Bioethanol is liquid ethanol produced from various common crops including but not limited to sugar cane in Brazil, corn in the US and wheat and barley in Europe and the UK. It is produced by a process of conversion of feedstock crop into fermentable sugars through enzyme amylases. Yeast is then added to ferment the resulting sugars into alcohol and carbon dioxide.
Compatability
Although bioethanol is very similar in properties to petrol, if is often mixed with petrol as a low percentage blend; E10 contains 10% ethanol and 90% petrol, E15 contains 15% ethanol and 85% petrol etc. However, it is possible to run cars effectively with a far higher ratio blend of ethanol such as E85 (85% ethanol and 15% petrol) with a few small modifications to the vehicle, the fitting of a larger fuel tank and adjustment of the ignition timing.
It is also possible to run a vehicle of 100% ethanol however, most Bioethanol mixes retain at least a small amount of petrol. This is because ethanol is more difficult to vaporise than petrol, particularly in cold weather thus making it difficult to start a car with 100% ethanol in cold weather conditions.
Bioethanol is on the increase as a fuelling alternative in the form of flexible fuel vehicles (FFVs). FFVs are designed to run on straight petrol or an ethanol/petrol blend of up to 85%ethanol (E85). Except for a few engine and fuel system modifications they are identical to petrol-only counterparts.
FFVs have been produced since the 1980s, and dozens of models are currently available from a variety of manufacturers including Ford, Volvo and Saab.
FFVs experience no loss in performance when operating on E85 however, since a litre of ethanol contains less energy than a gallon of petrol, FFVs typically get about 20-30% fewer miles per gallon when fuelled with E85 and up to 50% fewer on 100% (E100) ethanol.
What are the advantages of bioethanol?
The biggest advantage of running your car on bioethanol is environmental with some studies suggesting that lifecycle greenhouse gas emissions can be reduced by up to 90% with bioethanol in comparison to petrol. This is of however best case scenario based on using sugar cane as the crop and the actual figures vary between crops used ranging from 7.5% to 70% for corn ethanol predominantly produced in the US.
Another advantage would be taxation, in the UK road tax payable on FFVs that can use high percentage blends is lower than for conventional petrol cars by around £10.
Due to economies of scale, commercially produced bioethanol tends to have higher production costs than petrol. These are partly offset by tax benefits as the UK government has reduced fuel duty on bioethanol for the next three years by 20p/litre (to stimulate production).
Despite this, the retail fuel price of bioethanol can be higher than conventional petrol - the exact price depending on whether the bioethanol is a pure or blended formulation.
What are the disadvantages of bioethanol?
There are some concerns over the use of bioethanol as a long-term alternative to petrol. These include:
- Biodiversity – The sheer amount of arable land required to grow bioethanol crops could see some natural habitats destroyed, including rainforests.
- The food versus fuel debate – Due to the lucrative prices of bioethanol there is concern that some farmers may sacrifice food crops in favour of biofuel production, which could potentially increase food prices around the world.
- Carbon emissions – There is also debate over the carbon neutrality of bioethanol when all elements in the production process are taken into account including the cost of changing the land use of an area, transportation and the burning of the crop, a process which usually requires large quantities of fossil fuels.
- Compatibility – Most older vehicles are limited to a maximum of around 5% bioethanol and 95% petrol.
- Fuel Economy - Huge decrease in fuel economy with bioethanol (typically around 20% but can be as much as 50% with 100% ethanol) compared to petrol.
Can I run my car on bioethanol?
Well, that depends on the rate of bioethanol you're after. A normal engine can handle up to 5% bioethanol and 95% petrol easily but for higher ratio ethanol mixes a specific flexi-fuel engine will be needed to cope with larger intakes of bioethanol.
This twinned with the fact that finding bioethanol is still difficult in the UK as there are very few filling stations that sell high percentage bioethanol makes it an even less viable option.
Final Thought
Our advice would be if you want a cheaper, greener, better smelling car buy a diesel and convert it to run on Waste Vegetable Oil, for now at least!
Further reading
Part 1, Biodiesel
Further information from HM Revenue & Customs can be found here
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