The Technology Context – B101
Itaipu Hydro- Electric Dam, Brazil/ Paraguay
Can the Itaipu Hydro- Electric Dam be considered sustainable?
People living on earth cannot exist without using the resources of the earth. When using these resources waste is nearly always produced. Being sustainable would mean using the resources, but without producing any waste. This could be by recycling or finding ways of harnessing the renewable resources. The problem with defining sustainable development is that different people have different requirements.
The Itaipu Dam uses a renewable source of energy, the flow of water as kinetic energy into electricity, which has now become an almost global requirement. Unsustainable resources like coal, oil and natural gas produce a lot of waste, which include greenhouse gases like carbon dioxide which contributes towards global warming. The power stations themselves are also very inefficient, 35% of the energy used is converted to electricity. About 4 billion tons of coal is used annually for producing electricity, which means in decades to come supplies will start to run out.
This is relevant to me and to everyone, as it is part of a global issue to stop using fossil fuels and use renewable sources of energy, to slow down climate change and improving the environment. Sustainable projects would then encourage future generations like me to choose it as an option for future energy needs. Now and in the future sustainable technology will become important and studying these projects will help to understand what they do and how they can be used.
The Itaipu dam is constructed across the Paraná River, the seventh longest in the world along the border of Brazil and Paraguay. The dam is capable of producing 14 Gigawatt's of electricity. It was constructed at the narrowest part, where the river flows fastest and therefore having more energy to convert to electricity. The generators convert 93.8% of the available power into electricity, making hydro-electric power the most efficient of all renewable sources.
This will be a good project to study, with a recent 32 year history. It provides 20% of Brazil’s energy and 93% of Paraguay’s energy, so is crucial in providing energy for both countries. If it was not used then 434,000 barrels of petroleum would have to be burned every day to replace it, a very unsustainable option producing lots of waste.
Sustainable Issues
Construction of the concrete dam only produced a small amount of waste, as carbon dioxide. The electricity production produces no harmful waste products, but the creation of the reservoir that made the worst impact, this flooding of 1,350 square kilometers meant that:
- Rare fruit trees, orchid species and other vegetation were destroyed.
- Only 50% of the species, many endangered, were saved by the governments.
- 10,000 people had to be relocated, creating ethical issues and compensation issues.
- This problem may occur again when new dams are built in the future.
An issue that came up a few years ago stated that hydro-electric dams are not environmentally friendly. Countries like Brazil who use mostly hydro-electricity have 7% more greenhouse emissions due to the dams, because the vegetation at the bottom of the reservoir will decompose aerobically and produce carbon and methane, which would contribute towards the greenhouse effect more that if the dam was not created. So far this is not proven to worsen the effect and further research will have to be carried out into this problem.
Cost/ Benefit Ratios
The amount of power from a dam depends on the size of the dam, volume of the river, the topography of the land, and other factors. Therefore to compare the effectiveness of dams, I can look at the cost of the dam and the amount of power it produces.
Itaipu Dam
Cost/ Power Ratio = £9,745,000,000 / 14,000,000,000 Watts =
0.696 (£/ Watt)
Aswan High Dam, Egypt
Cost/ Power Ratio= £487,300,000 / 2,100,000,000 Watts =
0.232 (£/ Watt)
Three Gorges Dam, China
Cost/ Power Ratio = £10,990,000,000 / 22,500,000,000 Watts =
0.488 (£/ Watt)
This shows compared to other dams the Itaipu dam is the most cost efficient, but I have compared it to a very old dam that has needed upgrades over about 100 years and a very modern dam not yet fully completed. I would have to compare it to more dams to get a better picture of how effective the dam is.
Having been used since 1984 with only the reservoirs creation as the biggest problem, I think it has more advantages than the problems and environmental issues it has created. If it is proven that hydro-electric dams do contribute towards the greenhouse effects in a significant way, then my view will be changed and I will have look into the effects of the greenhouse effects to see whether this will be an issue for the construction of hydro-electric dams in the future.
Further Research
To look further into the different advantages and disadvantages of the dam I could:
Visit the site of the dam. Look for myself at the impacts of the dam.
Survey the people around the site and the people that have been relocated.
Conduct a field study of the area, finding the environmental impacts on the area.
Look further into other hydro- electric dams compared to the Itaipu dam.
I can compare the different dams, looking at the advantages and disadvantages of the different dams.
Compare other sustainable development projects, such as solar power, tidal power (similar to using dams) and others.
I can investigate further into the article on how hydroelectric dams contribute more towards the greenhouse effect.
Look into non- sustainable development projects and compare the advantages and disadvantages.
Primary Sources
New Scientist Magazines
3rd June 2000 and 24th February 2005 “Hydroelectric power's dirty secret revealed”
Articles arguing that hydro electric dams are not sustainable.
Secondary Sources
