Estimation of Energy Consumption for Different Driving Scenarios
1. Consider the Toyota Camry 2020 L Sedan (203-HP 2.5-L 4-Cylinder 8-Speed Automatic). You can obtain detailed specifications at http://www.toyota.com/camry/ (The theory is described in the book “Sustainable Energy without the hot air”)
a. Estimate this vehicle’s energy consumption for 100 miles of (i) city driving, (ii) highway driving and (iii) aggressive driving. You may use the Environmental Protection Agency’s test schedules as a reference or guide while making assumptions of driving speeds and timings. Detailed information can be obtained at https://www.epa.gov/vehicle-and-fuel-emissions-testing/dynamometer-drive-schedules
b. Assuming that this vehicle burns gasoline, estimate the ideal miles per gallon (assuming no losses). Now, from the published miles per gallon available through the EPA or Toyota, estimate the efficiency of conversion of gasoline to energy.
c. Explore the contribution of energy required for acceleration/braking vs. energy required to overcome drag vs. energy required to overcome rolling friction as well as the total energy consumed as a function of
i. Mass of the car (the mass of car can change if you add passengers)
ii. Rolling friction coefficient (this can change depending on the choice of tire and
the inflation of the tire)
iii. Speed of the car as it varies from 0 – 35 mph
iv. Speed of the car as it varies from 35-65 mph
v. Speed of the car as it varies from 65-90 mph.
d. You are now exploring whether you can make the car electric. Assume that the mass of the car common to both electric and gasoline vehicles is about 40%. Furthermore, assume that the final mass of the electric car (with the motor and batteries) is about the same as the gasoline vehicle. What size of electric motor would you need (i.e. how much power)? You can assume a motor efficiency of 90%.
e. Estimate the size of Lithium-ion battery you would need to power this vehicle for 200 miles of 25% city driving and 75% highway driving.
f. Assuming that the above battery is fully drained, estimate the time it would take to charge the battery with a 440 V supply and about 20A. What supply current would you need if you want to charge the battery within 1 hour.
g. Explore the size of the battery and the time to recharge as a function of the range of the car (i.e. number of miles driven before recharge).
2. We want to compute the total heating and cooling load for a grocery store located in Las Vegas, Nevada. The store is 100 m long and 50 m wide. Its walls are 5 m high. Assume that the wall is made of a sandwich where the outer layer (exposed to the outside) is a 8” concrete blocks, the middle layer is a 6 ½ “ Fiberglass batt insulator, the layer inside that is a ¼” plywood layer and the innermost layer (exposed to the inside of the house) is a ½” drywall. The floor has a linoleum tiling over a particle board underlayer bolted to a 6” poured concrete layer. You can get the Rvalues (1/U) from http://www.coloradoenergy.org/procorner/stuff/r-values.htm. The roof is also a multi-layer sandwich that has a