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 disadvantage 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
These factors contribute to the continued use of fossil fuels despite their drawbacks.
What are some environmental disadvantages of fossil fuels?
- Habitat destruction
- Emissions of CO2, NOx, SO2, and particulates
- Water competition and impact on aquatic ecosystems
- Thermal pollution
These factors negatively impact both the environment and human health.
What are the main characteristics of coal?
- Hard solid
- Contains carbon, hydrogen, oxygen, nitrogen, and sulfur compounds
- Most abundant fossil fuel
- Found in many regions, with largest reserves in China, USA, Russia, and India
Coal mining can be hazardous and has significant environmental impacts.
What are some health risks associated with coal mining?
- Industrial bronchitis
- Coal workers’ pneumoconiosis (black lung disease)
- Mining accidents
Thousands of deaths occur each year due to mining accidents.
What are the main features of oil?
- Pumped from underground reservoirs
- Offshore extraction can cause spills
- Largest reserves in Saudi Arabia, Venezuela, Canada, Iran, and Alaska
Oil production has environmental risks, including pollution and spills.
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 main components of natural gas?
Mostly methane, but also ethane, butane, propane, and pentane
Natural gas has a lower environmental impact compared to oil and coal.
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.
Fill in the blank: The combustion of fossil fuels produces ______.
CO2, NOx, SO2, and particulates
These emissions contribute to air pollution and climate change.
How is nuclear energy produced?
- Uranium ore is processed and purified before being used as nuclear fuel.
- Fuel elements are formed and placed in a nuclear reactor.
- Neutrons initiate a chain reaction, causing uranium atoms to split (nuclear fission).
- Energy is released from fission, generating heat.
- The heat converts water into steam.
- Steam is directed through a pipe to a steam turbine.
- The steam rotates the turbine blades.
- The spinning turbine generates electricity.
Nuclear power advantages
- high amount of carbon saved
- technology is available
- construction is expensive BUT cost of running plants and cost through buyers is low
- little inputs needed -> efficient (1kg uranium = 20000x 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
- serious risks related to radiation (eg. Chernobyl + Fukushima)
- potential that countries cover up the build of nuclear weapons through power plants is possible
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
- low relability (not always windy conditions)
Solar energy advantages
- low running cost
- high carbon saved
- can be used in remote areas
- renewable energy source
Solar energy disadvantages
- low cost efficiency
- low energy density
- low reliability (insolation rates differ)
Hydro energy advantages
- high amount of carbon saved
- low running costs
- resovoirs can provide ecosystems for fisheries and opportunities for recreation
Hydro energy disadvantages
- high building costs
- dam construction:
displacement
habitat loss
species diversity loss
disruption of migration routes for other organisms - low reliability
