Energy – Where does it come from?

ES 302

Objectives• What is energy?• What forms does it come in &

how do we use it?• Understand that ALL sources of

energy have costs and benefits

What is Energy?

• Energy “The ability to do work”.

• Remember: The amount of energy in the universe is constant, but it flows in a one way path

What are the 2 major laws???- 1st and 2nd Law of thermodynamics

What are the 6 major forms?- light, chemical, nuclear, mechanical, electrical, heat

Energy Resources

• Renewable Energy

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

• Nonrenewable Energy

– Oil– Coal– Natural gas– Nuclear

What was the US’s principal energy source…

in 1875?

In 1910?

In 1960?

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

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

What is 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=HBu9LZa8Yrk

• 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 spins a magnet within wires (generator).

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

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

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

Other Units of Energy• 1 calorie

• 1 Btu (British thermal unit)

• 1 Q (quad) = 1 quadrillion Btu (very large!) – The U.S. uses ~ 1 quad of energy about every 3.7

days

• 1 kWh = one kilowatt of electricity over 1 hour

Can you make 2 observations regarding energy and electricity generation?

Extra Resources

2nd set of notes on Energy:Usage & Quality

Net EnergyEnergy Quality

Energy Efficiency

Energy in = Energy OutBut the quality is always lower

It takes energy to get energy

• Before it’s useful…

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

Net energy

• 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– How much net energy available?

• 2 units

Energy Quality

• Second Law: In any energy conversion, you will end up with lower quality (less usable) energy than you started with.

• QUALITY = The measure of the energy’s ability to be used to produce mechanical or electrical energy

• Low temperature heat has the LOWEST quality

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

Take old bulbs to Lowe’s or Home Depot!

How can changing a light bulb reduce

greenhouse gases?

Example of the Laws of Conservation of Matter and ThermodynamicsExample of the Laws of Conservation of Matter and Thermodynamics

Global WarmingGlobal Warming

Acid RainAcid Rain SmogSmog

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

Matter Cycles, Energy Flows

Matter Cycles, Energy Flows

Cartoon: https://www.youtube.com/watch?v=OqVyRa1iuMcMini-FBL lesson

Discuss the following questions…1. What is global warming?...climate change? Are

they the same?

2. What have you heard about it?

3. Do you think it’s “real?”

Climate change vs. Global warming

• Climate change - major changes in climate (temperature, rainfall, snow, or wind patterns) lasting for decades or longer.

• Global warming - average increase in temperatures near the Earth’s surface and in the lowest layer of the atmosphere. – One form of climate change

Global warming

• In specific terms, an increase of 1 or more Celsius degrees in a period of 100 – 200 years would be considered global warming.

• Over the course of a single century, an increase of even 0.4 degrees Celsius would be significant.

Byproducts of electrical generation

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

Water: thermal pollution, acid rain

Ground: bottom ash

Simple Solutions…

What processes involve the transfer of carbon?

Carbon Cycle Drawing

• Make your own, UNIQUE, drawing of the carbon cycle (both land and ocean). Include the following:– Photosynthesis, decomposition,

respiration, combustion, diffusion, (LABEL ALL)

– Include yourself somewhere in the cycle

– Point out where humans interfere/alter the carbon cycle

How Fossil Fuels Are Formed

How Fossil Fuels Are Formed

Did you beat Mrs. Loch?• You analyzed your (presumed) usage of electricity

– That energy is secondary

• Primary Energy Resources: The fossil fuels(oil, gas, and coal), nuclear energy, falling water, geothermal, and solar energy.

• Secondary Energy Resources: Those sources which are derived from primary resources such as electricity, fuels from coal, (synthetic natural gas and synthetic gasoline), as well as alcohol fuels.

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

• Sources of electricity

http://www.ted.com/initiatives/aws/soccket.html

Matter cycles, energy flows

What is our best immediate energy option?

1. Cut out unnecessary energy waste by improving energy efficiency

2. Transition to a renewable or solar age– Sun, wind, flowing water, biomass, geothermal,

hydrogen gas

3. Burn more coal & synthetic gas/liquids4. Natural gas5. Nuclear power

No matter what our decision…

Ask:

• How much will be available in the next 15 years? the next 30 years? longterm?

• What is the source’s net energy yield?

• How much will it cost to develop, phase in, and use this energy resource?

• How will extracting, transporting, and using the energy resource affect the environment?

• Can this energy source help us sustain the earth?

• http://www.youtube.com/watch?v=1xPjES-sHwg&feature=related– Very slow explanation of current & voltage. Nice

analogy to water (river, lake)

• http://www.youtube.com/watch?v=k7Sz8oT8ou0– Cardboard generator constrxn (7:44)