Energy and Electricity

ES 303

The lifetime of a resource depends on…

1. How much we have2. How fast we use it

What resources does the US have?

• Fossil fuels = – Oil– Coal– Natural Gas

• Why are we depleting our resources (running out)?– http://www.npr.org/news/specials/climate/video/

Energy is…

– The ability to do work.

IMPORTANT ENERGY CONCEPTS1. Energy is neither created or destroyed.2. Energy is lost as heat as it gets transferred

or changes form.

Energy Resources

• Renewable Energy

– Hydroelectric– Wind – Solar– Biofuels– Hydrogen fuel cell– Geothermal

• Nonrenewable Energy

– Oil– Coal– Natural gas

What is energy used for?

Transportation

Manufacturing

Heating Electricity

Can you make it work?

• What is causing the ball to light up?

• Where is the power coming from?

Can you light the lightbulb?

• Make a circuit = energy CIRCLE

Electricity

• The movement of electrons.

• Created by moving wires

(electrons) through a magnetic field.

Energy is needed to make electricity

• Where does the supply of electrons come from?

http://www.youtube.com/watch?v=AbUjieMLFSo• Can you list the steps to create electricity?

Electricity Production

• Coal/oil/natural gas fired power plants

1. Burn fossil fuel to make heat.

2. Heat boils water to make steam.

3. High pressured steam turns a turbine.

4. Moving turbine turns the generator (magnets and wires).

5. The magnet creates a flow of electrons = Electricity!

6. Moving electrons sent through wires to houses, schools, etc.

•Can you order the pictures correctly?

Turbine and Generator

What is a watt?

• 1 watt = energy to lift 100 g (or 1 Newton) in 1.0 seconds.

• It is a measure of energy over time

• 1 kWh = one kilowatt of electricity over 1 hour

Energy Efficiency

• Amount of energy that gets converted to useful energy.

What’s the difference?

Light bulb or heat bulb?

Two sides to everything.

http://www.mnn.com/earth-matters/translating-uncle-sam/stories/cfl-vs-incandescent-battle-of-the-bulb

Byproducts of electrical generation

• Burning coal Air: Mercury, CO2, SO2, NO2, fly ash

Water: thermal pollution, acid rain

Ground: bottom ash

Do you have any vampires in your house?

What if I left my computer on every night…

How much energy would it consume? Assume 14 hours

• In “sleep” mode, the computer draws 4 watts/hour

How much would it cost the district per day? Per year?• 1 kWh costs $0.15

What if all computers at the school were left on? Energy consumed? Cost to district?

• Around 200 computers at UDHS

How can changing a light bulb reduce

greenhouse gases?

2nd Energy Concept

• When energy changes form, some useful energy is always lost as heat.

• EX: Only 5-10% of the electricity flowing through an incandescent light bulb is converted to light energy (the rest is heat).

Example of the Matter and Energy LawsExample of the Matter and Energy Laws

Global WarmingGlobal Warming

Acid RainAcid Rain SmogSmog

Burning Coal = CO2 + SO + H20 + Ash +(CxHxSxOx) Light + Noise + Heat

Cartoon: http://www.youtube.com/watch?v=OqVyRa1iuMc

What processes involve the transfer of carbon?

Carbon Cycle Drawing

• Make your own, UNIQUE, drawing of the carbon cycle. Include the following:– Photosynthesis, decomposition,

respiration, combustion (LABEL ALL)– Include yourself somewhere in the

cycle– Point out where humans

interfere/alter the carbon cycle

What does this sticker mean?

What can you do?

What is your guess?

Fossil fuel power Wind / solar powerNuclear power Hydroelectric power

1. Out of the energy sources above, which is used the most worldwide? Least?

2. Guess what percentage each source contributes to the world’s energy supply.

3. Create a graph.

Worldwide energy sources

84%

7%7% 2%

fossil fuel

nuclear power

hydroelectricpower

wind and solarpower

Energy In ≠ Energy Out

It takes energy to get energy

Before it’s useful…

Oil must be 1. Found2. Pumped3. Transported4. Refined5. Transported6. burned

Net energy

• DEFINITION: Total useful energy available from the resource over its lifetime minus the amount of energy used and wasted

• Example: – 10 units of energy in oil in ground– Use 8 units to find, extract, process, transport– 2 units of net energy available