Description
Need to solve question 2.
Unformatted Attachment Preview
MEGR4092/4094/5092/8892 – Intro to Electric Vehicles and Batteries
Spring Quarter 2024 Professor: Anthony Bombik
Homework 1 (60 points)
Due January 24th, 2024 at 11:59 PM (Electronic pdf copy in CANVAS)
Problem 1 (20 points)
Using the general chemical formula for burning of a hydrocarbon fuel:
+ ( + ) → +
a) Calculate the emissions for diesel fuel ( ) in g 2 /kWh. Use a specific energy of
12kWh/kg.
b) Calculate the emissions for natural gas ( ) in g 2 /kWh. Use a specific energy of
13kWh/kg.
c) Calculate the emissions of a diesel vehicle operating with 20% efficiency from tank to wheel
(g 2 /kWhtrac).
d) Compare the answer in part c to the emissions value we calculated for a gasoline car: 1565
g 2 /kWhtrac. Which car creates less 2 emissions?
Problem 2 (40 points)
As we discussed in class, the emissions of an EV depend heavily upon the cleanliness of the grid
system being used to charge it. We’re going to investigate the influence that some parameters
have on the breakeven point of hybrid gasoline (HEV) and electric (EV) cars. Using the table of
values below:
Source
Gasoline
FL grid
Emissions
266 g 2 /kWh
411.1 g 2 /kWh
Vehicle
HEV
EV
Refueling eff.
0.90
0.85
Powertrain eff.
0.285
0.80
Production
11*106 g 2
13.7*106 g 2
a) Calculate the breakeven point (in km driven) for an EV against an HEV in Florida. Use a
drive cycle conversion of 0.1 kWh/km.
b) For many years, Toyota has fought the transition to full EV by investing money in
improving the powertrain efficiency of their HEVs. (There is some merit in this strategy,
considering the base emissions from burning gasoline are less than the national average
grid emissions.) How efficient would the powertrain of the HEV in this example have to
be to break even with an EV in Florida after 150,000 miles of service (240,000 km)?
c) Is it plausible to achieve the answer from part b, considering the maximum theoretical
efficiency of the Carnot cycle is 50% and there are additional losses of the transmission:
~90% efficiency?
d) What do you conclude is the leading factor in why EVs are less emissive than ICEs?
MEGR4092/4094/5092/8892
Spring 2024
Purchase answer to see full
attachment
