Lot's Wife Edition 6 2015

34
SCIENCE & ENGINEERING
By Farah Ibrahim
Renewable Energy
A Sector
in Research
and Development
Because carbon emissions are causing climate change...
Because we need to wean ourselves off foreign oil...
Because fossil fuels are going to run out in the next hundred years...
Because drilling for oil sometimes causes spills...
What do the four statements have in common? They’re
reasons for investing in renewable energy.
On June 29th, Bill Gates announced he is going to invest $2
billion over the next five years in renewable energy.
Last year, worldwide investment in renewables increased
17 per cent, according to the Frankfurt School-UNEP
Collaborating Centre for Climate and Sustainable Energy
Finance.
The hunt for the energy of the future is on.
Solar Energy
"Solar Energy is most attractive because the sun will
never disappear", says Professor Yibing Cheng from Monash
University. He has been researching solar panels for the past
10 years and believes that solar is the energy source of the
future.
It is abundant and can be used in land-locked countries.
Solar energy is synonymous with silicon solar cells.
However, the iconic, black panels we see atop rooftops and in
solar power plants, are "not commercially competitive", says
Professor Cheng.
The production of silicon wafers and silica sand used
in these panels are expensive. So is their installation and
maintenance.
The challenge of the solar energy sector is to make solar
panels more economical. For Professor Cheng, this means a
new type of solar energy - the printed thin film solar cells.
Based on wet solvents and ink, these solar cells can be
printed.
Professor Cheng hopes this new technology will do for solar
energy what the printing press did for newspapers: make
them so cheap and easy to produce that solar panels would
be as common place and accessible as your daily newspaper.
Currently, silicon based solar cells dominate ninety per cent
of the market. In order to compete with that, the new thin
film solar cells would need to be more than three times more
efficient.
These new solar cells are not in their infant stages of
development. Flexible, polymer solar cells are out in the
market, but have the same problem- too expensive for mass
production and not very efficient. Plus they’re not printed
and would not bring about the revolution that Professor
Cheng envisions.
To make solar energy the powerhouse energy of the future
that Professor Cheng has in mind, there would have to be
a flurry of new technologies of printing, capsulation, solar
panel materials and solar cell structures.
Biofuels
Biofuels, since they come in liquid form, are seen as an
easier a substitute for fossil fuels.
Bioethanol can be substituted for petrol and biodiesel for
petroleum diesel.
Biodiesel is available in blends, according to the Biofuel
Association of Australia. B100 is biofuel on its own. B5 is five
per cent biodiesel mixed with petrodiesel. It does not need
to be labelled as a biofuel when sold. A blend of 20 per cent
biodiesel with petrol diesel is not available for commercial
use.
However, biofuels have been criticised for taking resources
away from agriculture. Land and water that could be used for
food crops or for feedstock are diverted for biofuels.
Algae-based biofuels remedy this, explains RMIT University
professor Aidyn Mouradov. Algae grow in saline, brackish or
wastewater. Thus, it doesn’t need agricultural land.
It can also be produced quickly. Algae are fast growing and
take eight to twelve hours to double their biomass.
EADS Airbus has tested algae-based biofuels for jet-fuel.
However, it is not yet currently available for commercial use.
Commercially and practically, fossil fuels dominate the
markets.
In 2012-2013, about 72% of Australia’s electricity was
produced by black and brown coal, according to the Energy
Supply Association of Australia. Meanwhile, the renewable
energy from wind and hydro sources took up 11 per cent.
Despite this unfortunate fact, the future looks brighter, with
investment in renewable energy overtaking investment in
fossil fuels in that same period.
Image Courtesy of:
https://www.flickr.com/photos/basf/4837267013/