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4 Alternative Fuel Types: The Inside Track

Get the basics on 4 types of alternative fuel, via SustainableBabySteps.com

Alternative fuel types can seem overwhelming, but are the only environmentally realistic way forward as their use replaces both our usage and also removes our dependence on fossil fuels.

If you ever wondered why we need to use alternatives, consider this. Each gallon of alternative fuel burned means a gallon of petrol is not. Each gallon saved can result in up to 20lbs of carbon dioxide not being released in to the atmosphere alongside other harmful gases. So, let's have a look at positives and negatives of some of the alternatives.


One of the most broadly used alternative fuel types and an alternative energy made generally from corn, Ethanol provides up to 30% fewer emissions than carbon monoxide, according to the US EPA. According to the Argonne National Lab the drop in greenhouse gases when ethanol is used is between 35-46%.

However, there are a number of problems associated with its use. Ethanol environmental costs usually fail to take into account the energy used in growing, feeding and harvesting. There are also concerns over the use of foodstuffs, such as corn in its production, which could be used for human consumption.

Ethanol has been credited with keeping petrol prices between 17-40% lower according to the USDA. Without the fuel it is thought there would be an annual shortage of 7.2bn gallons of fuel in the US - this figure is around half of the capacity for ethanol production in the US. In addition to this it is estimated that Renewable Fuels Standards will generate $2bn-$4bn in net agricultural income in 2012.


Biodiesel, as you may already know, is a substitute fuel created from vegetable or animal fats and is formulated for diesel engines. Biodiesel can be between 1-99% biodiesel mixed with petroleum diesel. This is measured in B plus the percentage of the fuel that is constituted of biodiesel (B5 fuel is 5% diesel; B20 is 20% diesel; B99 is 99% diesel).

Biodiesel provides a number of benefits over the traditional fossil fuel as it reduces carbon monoxide, dioxide and also particle matter emissions, among others. It also provides farmer's income, is a natural oil, and degrades between 4-5 times faster than traditional diesel.

Unfortunately, it has a lower energy content level than diesel or other alternative fuel types, and may damage non-synthetic and natural rubber fuel hoses and seals in engines over time.

Editor's Note: We've been running on waste veggie oil for over 3 years and haven't found the MPG to be lower, nor any engine damage. (Most issues result from improper use.) In fact, we found our engines ran better with vegetable oil. It's also much more sustainable than processing biodiesel. Read more about our experience with vegetable oil as an alternative diesel fuel here.


Obviously, the question is whether or not electricity can be considered among alternative fuel types when used in cars, as electricity has to be created through power generation. However, when you factor in all stations, including coal, gas and nuclear among others, an electric car is still 10% more efficient than the standard internal combustion vehicle. In addition, the creation of more wind power and solar powered stations each year increases the efficiency of electric vehicles and offers a great green deal still.

Electricity and the greenness of the electric car are dependent on these clean energy creating technologies. However, with such breakthroughs more and more prevalent, it's looking good for electricity in powering future means of transport.


LPG, or liquid petroleum gas, has had popularity in the past due to its low cost at the pump and reduced tax status. The fuel made from a mixture of propane and butane gas generally and its very simple chemical makeup is known to be easier on engines workings. This make up creates far fewer particles than traditional fuels and it is also free of additives and tetraethyl lead - a lead based toxin added to fossil to fuel to increase power and economy - even compared to other alternative fuel types. However, there are a number of problems with this source of fuel.

LPG may produce fewer emissions than its fossil fuel equivalents, but it is less dense than fossil fuels and so provides less miles to the gallon. This increases pollution levels over a distance as more LPG is used. There is also the added issue that LPG doesn't come as standard in any new car currently. The lack of manufacturer support also means that there are far fewer fuel stops that stock this fuel. That said, there are still over 13m cars using LPG according to 2008 estimates and over 7bn gallons are used annually for auto fuel.

LPG however has benefitted the environment outside of the auto sphere and has replaced CFCs in appliances and as an aerosol propellant, making this one of the more versatile alternative fuel types.

Cormac Reynolds works for Green Deal Upgrade, a company who offer a great green deal on domestic green energy solutions in the UK.
