hydropower

• define

  • Derived from the energy of moving water, falling from high elevation 
  • To harness this power, mega-dams are built (although not all dams are built for this purpose alone)
  • Most hydropower plants generate energy through forcing water to flow from a reservoir downslope. Water can be used to turn the blades of a turbine
• example

  • Hydropower is the main source of electricity in some countries (eg. Australia, Brazil, Canada)
  • In 2021, hydropower accounted for 14.5% of total electricity generation in South and Southeast Asia, with a total hydropower installed capacity of 117 GW.
• economic advantages

  • Cost effective 
  • Cheapest source of renewable energy, at an average of $0.05 kWh
  • The financing can be undertaken by states or private firms 
  • From 2010 to 2020, in many developing regions such as Africa, the financing has been undertaken by Chinese firms
• environmental advantage

  Can be generated emission-free
• environmental disadvantage (emit greenhouse gas)

  • Manufacturing steel or concrete used in dams can cause environmental impacts, including carbon dioxide if fossil fuels are used to power the equipment 
• environmental disadvantage (kill fish)

  • turbines will kill and injure any fish that passes through them 
  • Dams also block the pathways taken by fish to reach their spawning grounds upstream 
  • Eg. US department of Energy has sponsored the research and development to turbines that could reduce fish deaths to lower than 2%, in comparison with fish kills of 5% to 10% for the best existing turbines
• environmental disadvantage (variable river flow downstream)

  • The Omo dam in Ethiopia threatens the livelihoods of many tribal people and add to water problems in downstream areas in the neighbouring Turkana area of northern kenya as river flow is regulated 
• economic disadvantage (depend on traditional fuels)

  • Many countries depend on traditional fuels for employment, and the generation of income 
  • Countries with a large deposit for fossil fuels are likely to tap on this resource as they can harness the energy source more cheaply 
  • The livelihoods of the people are tied to the coal industry, such as the transportation of the fly-ash of coal burning
• economic disadvantage (climate change)

  • Energy access varies due to climate change
  • With rising temperatures, extreme rainfall patterns, melting glaciers, and increasing occurrence of extreme weather events 
  • Eg. in 2022, a drought in Sichuan led to power cuts along the Yangtze River. This jeopardises the economic viability of these projects with increasing abnormal weather patterns, along with issues related to energy security that has further economic impacts
• socio-political disadvantage (displacement of people)

  • Displacement of people from their ancestral land 
  • 40 to 80 million people have been displaced by dams 
  • A 2012 survey found than more than 70% of people who had been resettled said they had become impoverished 
• socio-political disadvantages (funding)

  • There are political implications related to funding 
  • Many experts believed that Chinese companies now control at least half of the hydropower dam-building market worldwide, after funding from World Bank dropped (for a period of time) amidst controversies about dams 
  • Concerns are raised about the dependency on foreign nations for national electricity consumption. In fast-developing Southeast Asia, Chinese involvement in hydropower projects have reached 40% in 2021