Unit 6 & 7 Notes

Petroleum is formed from decaying organic matter, specifically fossilized remains compressed over time.
The process squeezes out non-carbonate elements, concentrating hydrocarbons.
Petroleum can be extracted by drilling and pumping.

Tar sands contain bitumen, a low-quality, viscous form of petroleum mixed with sand and clay.
Bitumen is similar to asphalt and can be used on roads.
Extracting petroleum from tar sands involves heating the bitumen with water (steam) to melt it down for extraction.
This method is used due to the depletion of conventional petroleum deposits.

The primary method for generating electricity globally involves burning fuel.
The fuel source varies by country; natural gas is increasingly used alongside coal.
Burning fuel generates heat, which converts water into steam.
The steam spins a turbine, which powers an electric generator.
Inside the generator, magnets spin to create an electric current.
The current is transmitted via transmission lines for consumption.
The heat-turbine-generator process is consistent across many forms of electricity generation.

The environmental consequences of nuclear energy are not limited to meltdowns.
Spent fuel rods require on-site storage due to radioactivity.
Mine tailings can contain radioactive elements.
Thermal pollution occurs when water used to cool the reactor is discharged back into the environment, potentially reducing dissolved oxygen levels.
Despite these drawbacks, nuclear energy produces no air pollution.
Nuclear energy can provide base load power, operating 24/7, unlike intermittent renewables.

Hydroelectric dams have drawbacks, including flooding, methane release, and habitat destruction.
Benefits include creating reservoirs for tourism and jobs, and producing non-emitting electricity.
Methane release occurs from the anaerobic breakdown of vegetation underwater.
Hydroelectric dams provide reliable base load power without air pollutants.
Their use is limited geographically to areas with steep slopes and abundant water.
In the U.S., only a small percentage of dams are for hydroelectricity; many are for flood control, reservoirs, irrigation, or recreation.

Methane is produced in reservoirs due to the anaerobic decomposition of flooded vegetation.
Lack of oxygen prevents aerobic decomposition that would produce $CO_2$ .

Coupling hydroelectric power with solar or wind energy can provide a more constant source of electricity.
Hydroelectric power can compensate for the intermittency of solar and wind power by providing power when these sources are unavailable.

Individuals can conserve energy by lowering thermostats or using programmable thermostats.
Conserving water by replacing lawns with native plants.
Using energy-efficient appliances to reduce electricity consumption.
Governments can improve corporate average fuel economy (CAFE) standards.
Subsidizing greener energy sources with tax credits for electric car purchases, solar panel installations, or switching to heat pumps.

Realistic government actions include offering tax cuts or incentives for using renewable energy sources like solar and wind.
Subsidizing projects that promote clean energy and reduce pollution helps to mitigate the impact of pollution.