7.1 Energy choices and security Flashcards
What are the main sources of energy for electricity generation, transport, and heating globally?
Fossil fuels: coal, oil, and natural gas
Fossil fuels are the primary energy sources and their reliance is expected to continue due to rising energy demands.
How are fossil fuels formed?
dead animals and plants decompose in anoxic conditions, are covered by silt and mud, and are subjected to heat and pressure over tens and thousands of heat.
This process results in a finite source of energy.
What is a significant disadvantages of fossil fuels?
- main contributor to the build of co2 in atmosphere -> main cause of climate change
- unsustainable because it implies liquidation of a finite stock of a resource
- becoming increasingly difficult to extract + increasingly dangerous
Continued use will eventually lead to exhaustion of these resources.
What are some advantages of using fossil fuels?
- Infrastructure is already established
- High energy content
- Relatively cheap
- Currently abundant
- Oil + gas can be delivered over long distances through a pipeline
These factors contribute to the continued use of fossil fuels despite their drawbacks.
What are some environmental disadvantages of fossil fuels?
- biggest co2 contributor -> biggest contributor to global warming
- unsustainable
- oil spillages from tankers / burst pipelines can damage natural ecosystems
-> expensive to clear
How does oil’s emission profile compare to coal and natural gas?
Produces less emissions than coal but more than natural gas
This highlights the environmental impact of different fossil fuels.
What are the largest reserves and producers of natural gas?
- Largest reserves: Russia, Iran, Qatar, Turkmenistan
- Top producers: US, Russia, Iran
The distribution of natural gas resources impacts global energy dynamics.
How is nuclear energy produced?
When enough fissonable material (eg. uranium) is brought together, and the process is initiated, a slow moving neutron collides with the uranium atom, and this causes a chain reaction that continues to splits atoms releasing tremendous amounts of energy.
Nuclear power advantages
- doesnt emit co2 -> doesnt contribute to global warming
- large amount of electrical energy in a single plant
- very efficient (1kg uranium = 20,000x more energy than 1kg coal)
Nuclear power disadvantages
- time frame to plan and build nuclear power plant = 20-30 years
- uranium = scarce and non renewable source
- waste from power stations is very dangerous, stays for thousands of years (how to best dispose is an unresolved problem)
What happened in Chernobyl?
On 26 April 1986, Chernobyl reactor operators overrode a safety mechanism during a routine test, leading to an unexpected power surge, a fire, and an explosion that destroyed the reactor’s roof. This released a radioactive plume, which was carried westward by prevailing winds, contaminating Ukraine, Russia, Belarus, and parts of Europe, including Norway, Sweden, and the UK. Helicopters dropped materials to extinguish the fire, and tunnels were filled with concrete to prevent groundwater contamination. The army was deployed to clear radioactive debris. The official death toll was 31, but long-term effects include increased cancer rates, birth defects, and the relocation of over 350,000 people.
Wind energy advantages
- high amount of carbon saved
- abundant supply available
- high deployability
- low operational cost
- renewable energy source
Wind energy disadvantages
- noise pollution
- aesthetically unpleasing
- no wind, no energy created
Solar energy advantages
- low running cost
- high carbon saved
- can be used in remote areas
- (combined with insulation) cheaper for heating homes than fossil fuels
Solar energy disadvantages
- usefulness limited in Northern countries during winter months
- low energy density
- expensive to turn solar energy into high-power energy needed for manufacturing
Hydro-electrical power advantages
- reliable
- dams form artificial lakes > can be used for leisure, food, irrigation
- cheap to run
Hydro-electrical power disadvantages
- high building costs
- dam construction:
displacement
habitat loss
species diversity loss
disruption of migration routes for other organisms - vast areas may be flooded
-> loss of habitats
-> loss of farmlands
-> displacement of people - low reliability
- dams can affect sedimentary flow
-> affects ecosystem/farmlands downstream
Hydro-electrical power - how does it work?
uses a dam or diversion structure to power turbines that produce electricity, which can be switched on whenever needed
Geothermal energy advantages
- pipes can be arranged in various formations
- reliable
- small land footprint (less space needed compared to wind or solar)
Geothermal energy disadvantages
- location dependent
- high initial costs
What country uses mainly hydro-electric power?
Brazil
What country uses mainly solar power?
India / Brazil
What country uses mainly wind power?
Denmark
What country uses mainly geothermal energy?
Iceland
