Unit 22: Materials Science
D: Examine materials used in applications in order to reduce carbon emissions for a sustainable future.
Managing our ‘Carbon Footprint’
What are global emissions and what causes them
Emissions are substances such as pollutants, for example – carbon dioxide – which are
discharged into the environments. The amount of carbon emissions that get released and
trapped into the atmosphere cause global warming and therefore causing climate change.
Amongst many negative effects of emissions, some include the melting of polar ice caps,
sea levels rising, and natural animal habitats being disturbed. Things that produce carbon
emissions can include burning fossil fuels for electricity, construction, heat and
transportation.
Materials used to reduce carbon emissions
Glass fibres
The glass fibres used as alternative for wind turbines are E-glass fibres. E-glass fibres are
inexpensive and combine high strength from 1500 to 2500 MPa and stiffness, 72 to 76 GPa.
However, as the trend goes towards longer blades, the weight and the stiffness of the blade
become an issue. When combined with a resin matrix, glass fibre composites become
strong, lightweight, corrosion-resistant and dimensionally stable, therefore making it ideal
for wind turbines and resistant to weathering. Unlike metal, plastic, and
wood; fiberglass has the least expansion and contraction with heat, cold and/or stress. GRP
dominates the market due to the fact that provides the necessary properties at a low cost.
The important characteristics of GRP are good mechanical properties, high temperature
tolerance, ease of manufacturing and favourable cost. The glass fibres are also light,
durable, and have a long-life span. Their recyclable properties mean that they are good for
the environment, this also means that they can be reused and won’t end up in landfills
which not only would affect the environment but would also be very expensive.
Glass fibres are composite materials, using composites for wind turbines not only makes
them more lightweight but the use of them also contributes to reducing the CO2 footprints,
especially with the use of glass fibres in airliners and vehicles.
Silicon wafer
Silicon wafer semiconductor devices can withstand a wide range of current and voltage.
Crystalline silicon cells are made up of silicon atoms which are each connected to each other
to form a crystal lattice. This lattice has an organised structure therefore making the
conversion of light into electricity more efficient. Silicon wafer is also relatively low in cost,
this is due to the use of well-established processing techniques. There is a large market for
crystalline silicon due to the high efficiency. Its hardness means that large wafers can be