The process by which drilling is used to collect natural gas
Rock is cracked using pressurized water, and the natural gas is then released and collected
Shale rock
A common type of rock that is drilled into for fracking purposes
Tar sands or oil sands
These sands can also be harvested for crude oil
The bitumen that is deposited in tar sands can be separated out and turned into crude oil
Bitumen is a black, viscous mixture of hydrocarbons
Natural gas and oil are nonrenewable energy sources because the rate at which they are currently depleted far exceeds the rate at which they can be formed
One common way to use resources to generate power is to burn a fuel to generate heat, which then turns water into steam
The steam that is released turns a turbine, which generates electricity
6.6 Nuclear Power
Nuclear fission
When a neutron is fired into the nucleus of an unstable radioactive element, the nucleus breaks apart, and these fragments can also further break apart
This reaction releases massive amounts of heat and energy
Nuclear power is similar to other sources of power in how it generates electricity
The heat that nuclear fission produces is used to generate steam, which is similar to how to heat that burning other fuels produces is used to generate steam
Radioactive half-life
The amount of time it takes for half of the atoms in a radioactive substance to decay
These absorb neutrons and prevent the nuclear plant from exploding
Fuel rods that have been used need to be stored safely in nuclear plant sites
Cooling tower
Cools down the steam that was generated during the nuclear process
Nuclear energy
A nonrenewable source of energy
Because radioactive elements exist in finite amounts, nuclear energy is not renewable
No air pollutants are released during the nuclear energy generation process, but the practice of mining resources used in nuclear generation can result in increased pollution
Hot water that is released from nuclear plants can cause thermal pollution
Nuclear meltdowns that result from accidents at nuclear plants can cause genetic mutation and cancerous effects
6.7 Energy from Biomass
Ethanol
An organic compound/biofuel made from biomass such as corn and sugar cane
Can be used as a substitute for gasoline
Burning ethanol doesn’t introduce additional carbon into the atmosphere from combustion, but the energy return on ethanol is relatively low
Burning biomass doesn’t introduce additional carbon because the plants that are planted to produce the fuel take carbon out of the atmosphere
These systems absorb heat directly from the sun without mechanical/electrical equipment, but the energy cannot be collected or stored
For example, greenhouses might use windows with large glass panes to absorb solar radiation, which can be used as temperature regulation (as opposed to using an additional powered heating system)
Obtained by using the heat stored in the Earth’s interior to heat up water
This heated-up water is brought back to the surface as steam
The steam turns a turbine, which generates electricity
Unlike some other sources of energy, geothermal energy is not powered by the sun
Ground source heat pump
Because the ground about 10 feet down holds heat from the sun, fluids that are piped down through the ground can absorb heat from the ground during winter or can release heat into the ground during summer
This is not technically a geothermal process because it is not powered by heat from magma
Geothermal heating
Water is piped deep into the ground to reach a heated water reservoir, which is heated by magma (geothermal process)
The water is then carried back up, and its heat is transferred to manmade buildings
Break hydrogen and oxygen bonds in water to form hydrogen gas
The hydrogen can be used to generate electricity through a chemical reaction
Water is the product/emission of a fuel cell
Hydrogen fuel cells have a low environmental impact and do not produce carbon dioxide (which is good)
However, the technology is expensive, and energy is still needed to create the hydrogen gas used in the fuel cell.
In cars, hydrogen fuel cells can replace the need for gasoline
Water vapor emissions from these cars are much less damaging than gasoline emissions
Electrolysis
Process where an electrical current is applied to water, breaking it into oxygen and hydrogen
Steam reforming, which is a different process used to obtain pure hydrogen gas (which doesn’t exist naturally), involves burning natural gas and using steam to separate the hydrogen gas from the methane
