At Ecolinc last week we did several practical activities related to energy, including the following:
- demonstration of hydroelectric power using a model turbine
- demonstration of solar power using photovoltaic cells
- demonstration of hydrogen power using a model hydrogen car
- comparison of incandescent and fluorescent light globes
- energy transformations in household appliances
- variables in wind power (height of turbine, number of blades, length of blades, angle of blades)
During these experiments we discussed some of the advantages and disadvantages of different energy sources. In general, the advantages of fossil fuels (coal, oil and gas) are that they are relatively cheap, accessible and available on-demand. Fossil fuels are energy-dense and able to produce base-load power – power can be produced on demand. Thermal power stations using fossil fuels take up little space (compared to a wind farm, for example) and can be located almost anywhere. However, fossil fuels are non-renewable, because they take many millions of years to be formed and are a finite resource, which means they will eventually be used up. Experts predict that we have a few hundred years supply of fossil fuels, although as the price increases, more sources become economical to extract. The other disadvantage of fossil fuels is that they all release carbon dioxide and other greenhouse gases to the atmosphere, which contribute to the enhanced greenhouse effect.
Renewable energy sources (such as wind power and solar power) are generally very expensive to construct initially, but do not have ongoing fuel costs. They cannot usually provide base-load power, because they are intermittent or unreliable. Geothermal power and hydroelectricity are exceptions, because they can produce power on demand, but are location specific (you cannot build a hydroelectric plant or geothermal plant anywhere; you need specific geographical features). Although wind farms take up a large area, other industries can co-exist, such as grazing and cropping. So, the farmer who owns the land where a wind farm is built is able to have two income streams, from agriculture and electricity production.
Some people claim that wind farms are “ugly”, but these aesthetic concerns are subjective and would apply equally to fossil fuel power plants. There are also concerns about the impact on land prices on adjacent properties, noise from wind turbines and disturbance to flying birds, mammals and other wildlife. There are claims that wind power is inefficient and not viable without government subsidies.
The advantages of wind farms include that they are a renewable form of energy – there is an infinite supply of wind; it will not run out – and that no greenhouse gases are produced during operations, so there are no emissions that contribute to the enhanced greenhouse effect.
Today I sent out to my online students copies of the documentary “Switch”, together with question sheets. In this documentary, Professor Scott Tinker visits various locations across the globe where fuel is extracted or electricity is produced. He discusses the pros and cons of fossil fuels and renewable energy resources. For each energy source mentioned in the video, list the advantages and disadvantages.