APES Nonrenewable Energy

Nonrenewable energy

Fossil fuels and nuclear fuels that can not be replenished once used up. (Ex. Coal, oil, natural gas, nuclear fuels)

2 categories of Nonrenewable energy

Fossil Fuels-derived from biological material that became fossilized millions of years ago (coal, oil, natural gas) that are combusted. Nuclear Fuels are derived from readies give materials that give off energy (heat transfer)

Why do developed countries demand more energy than developing countries?

As energy demand increases, societies change types of fuels they use. Examples- people who own automobiles, gasoline and diesel demand increases, factories demand electricity

Commercial Energy

Those that are bought and sold such as coal, oil and natural gas

Subsistence Energy

Gathered by individual for own individual needs

What is EROEI

Energy return on energy investment. How much energy we get out of an energy source for every unit of energy expended on its production (Energy obtained from the fuel/Energy invested to obtain the fuel)

As Americans move from cars to light trucks (pickup, SUV, minivan) what happens to energy efficiency?

Lower energy efficiency

Turbine

Large device that resembles a fan of a jet engine that generates electricity from energy

Electrical Grid and its limitations

A network of interconnected transmission lines that connect power plants together and links them with end users of electricity. Distributed to homes and other places for energy. High water consumption and slightly less reliable energy=limitations

How do natural gas power plants use a combined cycle to get a higher efficiency?

Two turbines and generators. Natural gas is combusted and products turn gas turbine. The waste heat boils water and turns a conventional steam turbine. (Efficiencies up to 60%)

Capacity

Maximum electrical output

What is the capacity factor of a plant?

Fraction that a plant is operating. Most are .9 or greater. Power plants using some renewable energy are around .25

Why do coal and nuclear power plants usually remain operational constantly?

Because of the time it takes for them to start up and become operational

4 sub-bituminous types of coal and how they're formed

Peat-vegetation dies and is buried under anaerobic conditions.

Lignite-peat is compressed between sediment layers

Sub-bituminous-compressed even more

Anthracite-very compressed and completely dried up

Advantages and Disadvantages of Coal

Advantages-energy dense and plentiful, relatively easy to mine, technological and economic demands are low, little refining and can be easily transported

Disadvantages- contains impurities like sulfur that are harmful to atmosphere, toxins are found in it, polluted air.

Consequence of ash/slurry spill

Mixtures of ash and water go to holding ponds and can get into well water. Homes can be destroyed and land becomes filthy. Increases co2 concentration in atmosphere

Petroleum and method of formation

Fluid mixture of hydrocarbons, water, and sulfur that occurs in underground deposits. Formed from remains of ocean dwelling phytoplankton Capped by nonpourous rocks.

Why are natural gas and oil usually found together?

Petroleum contains natural gas. Some of the gas separates out naturally. (Cause of gas flares)

What are the products of oil refining?

Tar, asphalt, gasoline, diesel, kerosene

Advantages and Disadvantages of Petroleum

Advantages-extremely convenient to transport and use. Relatively energy-sense and cleaner-burning than coal. Disadvantages-releases co2, contains toxins, leakage and spills, extraction destroys homes and habitats

2 largest uses of natural gas

Electricity generation and Industrial Processes

Advantages and disadvantages of natural gas

Advantages- cleaner of the fossil fuels (less co2 and pollutants, high energy yield, low cost, easily transported by pipelines, good for turbines, low land use

Disadvantages- Nonrenewable, methane leaks, can't be exported internationally, easily wasted, requires building of pipelines

Electric generation from coal vs. electric generation using nuclear energy

Coal emits lots of co2, whereas nuclear releases v little and is better for the environment but radioactivity accidents are a high risk

What is fission?

Nuclear reaction in which a neutron strikes a relatively large atomic nuclear then splits into multiple parts and release energy in form of heat.

How is electricity produced from nuclear energy

Steam turns turbine that turns a generator that generates electricity. Nuclear power plant uses a radioactive isotope as its fuel source.

Fuel Rods

Cylindrical tubes that enclose nuclear fuel.

Control Rods

Cylindrical devices that are between fuel rods to absorb excess neutrons, slowing down fission.

Why are control rods critical to a nuclear reactor?

Nuclear rods that are uncontrolled will overheat and melt leading to a catastrophic nuclear accident

Advantages and disadvantages of nuclear energy

Advantages-large fuel supply, low environmental impacts, lower co2 emission than coal, moderate land use

Disadvantages-need huge gov't subsidies, low net energy yield,catastrophic accidents can occur, high environmental impacts, terrorist attack hotspot

Radioactive waste

Nuclear fuel that isn't useful anymore but continued to emit radioactivity

High level vs. low level of radioactive waste.

High level waste (form of fuel rods), low level waste (form of contaminated protective clothing, tools, rags, etc.

How is radioactive waste disposed?

Very carefully. Anywhere where there isn't groundwater or can easily escape to environment. Far from habitation.

Half-life

The time it takes for one-half of its radioactive atoms to decay.

Major disadvantages of nuclear waste storage

There will never be a safe enough place to store high-level radioactive waste.

Nuclear fusion. Why is it not an energy source currently?

Reaction that powers the sun and stars. Occurs when lighter nuclei are forced together to produce heavier nuclei. Lots of heat generated.

Hubert Curve

Graph projecting the point at which world oil production will reach a maximum and the point when we will run out of oil.

Major considerations for the continued use of fossil fuels

Sustainability factor and capacity. Environmental effects. Economic too.

How is energy produced in a coal fired power plant?

Energy from coal combustion converts water into steam, which turns a turbine. The turbine turns a generator which produces electricity.