APES Chapter 15 - Nonrenewable Energy [Net energy + Use, Fossil Fuels, Nuclear]

What is net energy and why is it important? NN

Net Energy:

The ration of energy produced to the energy used to produce it.

• Net energy rations for various energy systems differ widely

• As the ration increases, the net energy also rises.

• When the ratio is less than 1 - there is a net energy loss

• Also can be expressed as amount value (-) amount required and wasted to access/produce it

Space heating - passive solar has greatest net energy

High -Temp industrial heat - surface mined cola has highest net energy

Transportation - natural gas has greatest net energy

Does Hydrogen have a negative net energy ratio?

YES! Hydrogen has a negative net energy ration - it takes more energy to make this rule than we get by burning it.

• Can not compete in open market without financial support fro government, though it can be useful as a way to “store” energy like a battery.

How much of non renewable resources are left? + consequences

Natural gas - about 155 years. Consequences: CO2 emissions and CH4 leaks

Coal - about 400 years. Consequences: CO2 emissions, mining, heavy atmospheric pollution

Oil(including gas) - about 40 years. Consequences: CO2 emissions, drilling, atmospheric pollution

Uranium—200 years. Consequences: Mining, waste

What are the three fossil fuels?

1. Coal

2. Crude oil

3. natural gas

Measurements of energy: Electrical

*Not an energy source because it must be generated from other sources.

1kWh = 1000 Wh = 100 watt incandescent light bulbs lit for 1 hour = 40 fluorescent bulbs = 860 calories

Kilowatts measure electrical “power” - how fast energy is used.

Kilowatt-hours measure energy use itself.

1,000,000 kW = 1,000 MW = 1 GW

Measurements of energy: Natural Gas

• A fossil fuel found associated with crude or shale oil

• 1 Therm = 100,000 BTU = 29 kWh

Measurements of energy: Gasoline

• Derived from crude oil, a fossil fuel

• 1 gallon of gas = 30,000 calories

Describe energy in relation to KE and PE:

• Energy can be stored to do work (kinetic) — electrical energy, mechanical energy

• Energy can be stored (potential) — batteries, etc.

The burning of cola, oil, and gas was ________ by $5.9 trillion is 2020.

Subsidized

What are the advantages and disadvantages of fossil fuels? NN

Where does the world get most of it’s energy?

87% of energy comes from carbon-containing fossil fuels (oil, natural gas, and coal).

• Oil is especially important

• Renewable resources are starting to increase in the world and the US

• The US primary energy consumption also comes from unrenewable resources

Examples of the Formation of and Finding of Fossil Fuels:

Petroleum - Reserves found in underground “traps”

Coal “bands” in sedimentary rock

When crude oil is refined, many of its _________ are removed at various levels:

Components

Is oil/will it be in economic depletion?

YES! Geologists predict the know and projected global reserves of conventional crude oil will be 80% depleted between 2050-2100. The remains 20% will probably be to costly to remove = Economic Depletion

When was/will be the peak production of oil?

Between 2010-2030

Solution to the low availability for oil:

Because oil is a finite resource and non-renewable resource. We can…

• Look for more oil

• use less oil

• waste less oil

• use other energy resources

Advantages of Crude/Conventional Oil

1. Ample supply for several decades

2. Net energy ties is high but decreasing

3. low land disruption

4. efficient distribution system

Disadvantages of Crude/Conventional Oil

1. Water pollution from oil spills and leaks (Ex. BPP - Gulf Coast US - 2010)

2. Environmental costs not included in market price

3. Releases CO2 and air pollutants when burned

4. vulnerable to international supply interruptions

Who controls much of the world’s oil supply?

OPEC (made up of 15 countries) - hold 79% of the world’s proven crude oil reserves

• Currently the world largest producers of oil are Russia, Saudi Arabia (large reserves), and the U.S. (#1 daily producer since 2016)

• Venezuele is considered to have the largest reserves.

What are examples of Heavy Oils:

Shale Oil - can be extracted from oil shale rock

Tar Sand

Advantages of Heavy Oils (Oil Shale, Tar Sand):

1. Large potential supplies

2. Easily transported within and between countries

3. Efficient distribution system in place

Disadvantages of Heavy Oils (Oil Shale, Tar Sand):

1. Low net energy yield

2. Releases CO2 and air pollutants when produced and burned

3. Severe land disruption and high water use

What is natural gas?

Is a mixture of gases of which 50-90% is methane (CH4)

• Lies above most reservoirs of crude oil

• When a natural gas field is tapped, propane and butane gases are liquefied and removed as liquefied petroleum gas (LPG).

• Cleanest burning among fossil fuels

Advantages of conventional Natural Gas:

1. Ample supplies

2. High net energy yield

3. Emits less CO2 and air pollutants when burned than other fossil fuels

4. Versatile fuel

What is hydraulic fracturing or fracking?

Pumps water mixed with sand and some toxic chemicals underground to fracture deep rock and free up natural gas stored - the pressure causes the rock surrounding the pipe to crack and the natural gas is captured and flows up the well to be collected.

Risks of Fracking:

• Groundwater contamination

• Air quality degradation

Coal:

Different types of coal have formed over millions of years (rocks effected by heat and pressure — lead to cola)

• Cola burns dirty and requires mining

• 47% of worlds electricity (esp China, India, US)

Advantages of coal:

1. Ample supplies in many countries

2. High net energy yield

3. Low cost when environmental and health costs not included

4. Plentiful and Cheap

Disadvantages of coal:

1. Severe land disturbance and water pollution

2. Fine partial and toxic mercury emissions threaten human health

3. Emits large amounts of CO2, and air pollutants when produced and burned - among, acid rain

Alternatives for increased efficiency or reduced pollution:

1. Replace cola with another fuel - cleaner burning fossil fuels such as natural gas

2. Spin turbine with wind, water, solar thermal, or geothermal heat

3. Cogeneration

Cogeneration:

Use waste heat for heating

CO2 emissions ranking:

1. Coal-fired electricity

2. Synthetic oil and gas produced from cola

3. Coal

4. Tar sand

5. Oil

6. Natural Gas

7. Nuclear power fuel cycle

8. geothermal

Nuclear Power Plant

Water-cooled nuclear power plant: light water reactor (LWR)

• Controlled nuclear fission

• Only about 18% efficient when all inputs considered

• World slowest growing form of commercial energy

Advantages of conventional nuclear fuel cycle:

1. Low environmental impacts (without accidents)

2. Emits 1/6 as much as CO2 as coal

3. Low risk of accidents in modern plants

Disadvantages of conventional nuclear fuel cycle:

1. Very low net energy yield and high overall cost.

2. Produces long-lived harmful radioactive waste

3. promotes spread of nuclear weapons

Dealing with high-level radioactive wastes produced by nuclear power is a difficult problem…

• Deep burial

• Dismantle worn-out nuclear plants

• spend fuel rods can be processed to remove radioactive plutonium

Future Solutions to nuclear power + and its consequences:

1. Fusion reactors

2. New advanced light-water reactors

3. Thorium chapter and safer than Uranium