alternative energy sources

The latest Research Tuesdays presentation “Where will we source our energy?“ is now online. This was a special end of year event featuring five panellists, including Professor Barry Brook, Director of Climate Science at the Environment Institute.

The topic of this presentation is particularly pertinent after last weeks heatwave, during which blackouts were experienced across the country due to high demand for power. The cost of running air-conditioning in what are predicted to be more frequent heatwaves is an issue that will inevitably also focus our attention further to exactly where we will source our energy from in the future.

Other members of the expert panel included Professor Graham “Gus” Nathan, mechanical engineer and founding Director of the University of Adelaide’s Centre for Energy Technology as well as Associate Professor David Lewis (PhD CEng FIChemE), a chemical engineer in the University of Adelaide’s School of Chemical Engineering.

Flickr: Ralph Walker

There is the potential for biofuels, biodiesel and bioethanol produced from organic products, to provide all of our energy needs, but are they really a green alternative?

Traditionally biofuels are produced from farm crops like corn or soy, however biofuels from these products can have negative impacts on the environment and society the form of deforestation, and rising food prices. Using algae to produce biofuel does not have the same consequences for society or the environment. Algae are a high-yielding source of biofuels and do not compete for land or water like other biofuel sources.

However like traditional crops, algae requires fertilisation. A recent article in New Scientist and Environmental Science and Technology claim that due to the costs of fertilisation, biofuels produced from algae are not a truly green option. Researchers from the University of Virginia used models to determine the environmental impacts of algal farms. Their findings found that algal farms used far more energy than growing land plants and created significantly more greenhouse gases.

Researchers from the Centre of Energy Technology (CET) and Murdoch University have been examining the technical aspects of downstream algal processing to produce biodiesel. This team has achieved the best production rates of oil from algae grown in saline ponds in the world. The CET is currently collaborating with the CSIRO to undertake life cycle assessments of algae for the downstream processing developed by the CET.

In response to the findings from the University of Virginia, Peter K. Campbell from the CSIRO notes,

“They’re comparing the heat content of crops, which means the end use of everything is burning it in a boiler for heat production, which kind of misses the point of why we’re growing the crop – i.e. for a vehicular fuel. Obviously if you’re just looking at biomass to burn, you’re going to be hard-pressed to beat grasses/weeds like hemp, bamboo, duckweed and the like. If you’re just growing biomass for the purposes of heating up your house, then algae is not the way to go. On the other hand, if you want to produce a liquid fuel that is compatible with the majority of the engines in the world’s transport fleet (trucks, buses, ships), then algae can be quite favourable when compared to other forms of biomass.”

Despite the conclusions detailed in the Environmental Science and Technology article there is a bright future for algal derived biofuels. Peter K. Campbell says “production methods look like they will be able to produce algae biofuels at a price point competitive with conventional fossil-based diesel within a few years, and with much more energy being produced than utilised in its production.”