Car Efficiency and Energy Storage Project
Big Question #1: Are electric cars (EVs) more efficient in converting potential energy to kinetic energy than internal combustion engine cars (ICEs)?
Big Question #2: What is "regenerative braking" in hybrid and electric cars, and how much energy does it recover?
Big Question #3: Why is energy storage important as electric grids increase their percentage of renewable energy?
Big Question #1: Are electric cars (EVs) more efficient in converting potential energy to kinetic energy than internal combustion engine cars (ICEs)?
Table 1. Efficiencies of a variety of vehicles
Definitions
1. Efficiency
Ratio of work done by a machine to the energy supplied to it (in percent).
For example: 200 Joules input -> 60 Joules work and 140 Joules heat. 60 J/200 J is 30% efficient
2. Well to Tank Efficiency
Efficiency of fuel production and delivery of the fuel to the vehicle. For an electric car, this is the efficiency of the power plant used to generate electricity.
3. Tank to Wheel Efficiency
Efficiency of fuel usage in the vehicle
4. Well to Wheel Efficiency
Efficiency of the overall process from fuel production to usage. Can be found by multiplying the other two efficiencies together.
5. EV - electric vehicle ICE - internal combustion engine vehicle
1. Efficiency
Ratio of work done by a machine to the energy supplied to it (in percent).
For example: 200 Joules input -> 60 Joules work and 140 Joules heat. 60 J/200 J is 30% efficient
2. Well to Tank Efficiency
Efficiency of fuel production and delivery of the fuel to the vehicle. For an electric car, this is the efficiency of the power plant used to generate electricity.
3. Tank to Wheel Efficiency
Efficiency of fuel usage in the vehicle
4. Well to Wheel Efficiency
Efficiency of the overall process from fuel production to usage. Can be found by multiplying the other two efficiencies together.
5. EV - electric vehicle ICE - internal combustion engine vehicle
Part 1. Complete the google doc template on Canvas with the following:
- Make three observations about Table 1 above.
- Read both Union of Concerned Scientists articles and write ONE 3-2-1 Summary (3 key points, 2 interesting ideas, 1 question I have). Reference which article your points come from and make sure both articles are referenced at least once.
- Watch both videos and list 2 key ideas from each.
- Use the map below: select 3 states with small MPG equivalents. Find out the power profile (the % of each power generation source in that state) using the EPA power profiler (link below the map). Type in a zip code for that region. Total up the renewables (solar, biomass, wind, geothermal). Also include the percent that is nuclear, which doesn’t produce greenhouse gases. Repeat for 3 states with large MPG equivalents. Summarize your findings in 1-2 sentences.
- Reflection: What surprised you in today's lesson? 1 sentence.
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Part 2. Big Question #2: What is "regenerative braking" in hybrid and electric cars, and how much energy does it recover?
6. Write a paragraph to explain
a) how regenerative braking works and
b) how much energy it recovers: report quantitatively with units for hybrid and EVs (increase in range would be acceptable).
Give each fact a reference from the articles below. Use at least 2 of the articles. 5 facts required.
Example: A Prius operates in stealth mode when the engine isn't running (Article 3).
6. Write a paragraph to explain
a) how regenerative braking works and
b) how much energy it recovers: report quantitatively with units for hybrid and EVs (increase in range would be acceptable).
Give each fact a reference from the articles below. Use at least 2 of the articles. 5 facts required.
Example: A Prius operates in stealth mode when the engine isn't running (Article 3).
7. Explain what form of energy is converted into what form of energy in the process. Contrast with the energy conversion in regular braking. Address why cars with regenerative braking have brakes that last longer.
Part 3. Big Question #3: Why is energy storage important as electric grids increase their percentage of renewable energy?
8. Identify the Need for Energy Storage Methods Watch the background video about Compressed Air Energy Storage. It gives a good introduction to the need for energy storage within power plants. Answer two questions: a) What times of day can energy be stored by a power plant, and what times of day is that stored energy used to generate electricity? b) Why is it better to store that energy than to slow down the power plant? |
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9. Read pp. 1-4 of Renewable Energy Future article. Use it to help you explain why an electric grid that has more electricity generated by renewables needs energy storage. Give four key ideas from the article.
10. Describe 2 Energy Storage Methods on the list below. Put in your google doc and then paste on a google slide for easy sharing with the class.
Batteries - Electrochemical Capacitors (don't choose batteries)
Thermal
Mechanical - Flywheel
Mechanical - Compressed Air
Pumped Hydropower
Hydrogen Storage (fuel cells)
Find an image that represents each method. Give a reference for each image.
Explain three key facts about each method that you chose. Put it in your own words; don't copy and paste.
Bonus: Find an image and describe a third type.
Batteries - Electrochemical Capacitors (don't choose batteries)
Thermal
Mechanical - Flywheel
Mechanical - Compressed Air
Pumped Hydropower
Hydrogen Storage (fuel cells)
Find an image that represents each method. Give a reference for each image.
Explain three key facts about each method that you chose. Put it in your own words; don't copy and paste.
Bonus: Find an image and describe a third type.
Older Map Below. Link underneath is a great blog post about well-to-wheel for any gearheads out there.