1. Using Energy Efficiently
Energy & Transformations
Using Energy Efficiently

2. Efficiency of Technologies
Using new energy-efficient technologies are crucial to our future.
Fossil fuels are depleting causing increased costs.
Typically more expensive up-front, their maintenance costs and lifetime are typically longer than less-efficient technologies.

3. Efficiencies of Technologies
Technology
% Efficiency
Comments
NON-RENEWABLE ENERGY RESOURCES
Fossil Fuels
40%
Canada’s most common source of electrical energy.
Nuclear Fission
30%
Ontario has 4 nuclear reactors which provide a great deal of electrical energy.
RENEWABLE ENERGY RESOURCES
Solar Cells
10-15%
Experimental ones have been shown up to 35%
Hydraulic
95%
Canada has a wealth of hydroelectric potential
Wind
45-55%
Being used more frequently.
wind turbines = 1 fossil fuel plant.
Tidal
Large up-front cost, only suitable in certain areas.
Geothermal
15-20%
Biomass 5%
Nuclear Fusion
20%-50%
Energy source of the future.

4. Efficiencies of Technologies
Technology
% Efficiency
Comments
HOUSEHOLD TECHNOLOGIES
Gasoline
Automobile
10%-16%
Many energy transformations reduce efficiency, most losses from combustion process.
Electric Automobile
80%
Fluorescent Light
20%
Incandescent
Light 5%
Requires a lot of heat to light filament.
LED Lighting
15-20%
Large up-front cost, only suitable in certain areas.

5. Gasoline Automobile
Mechanical Energy

6. Electric Automobile
7x More efficient than Gasoline!!

7. Overall Efficiency
As seen in the automobile diagrams, every energy transformation results in energy losses.
Most processes involve more than one energy transformation which requires the calculation of overall efficiency.

8. Example #1
Running an electric hair dryer on hydroelectricity in Ontario has the following efficiencies:
95% efficient energy generation
95% efficient hair dryer
Draw an energy flow diagram for the situation.
Calculate the total efficiency of the hair dryer.

9. SOLUTION a) 5% 5%
100%
Eout
95%
95% b)

10. Example #2 A gasoline driven car has the following efficiencies:
97% efficient oil extraction process
Oil refined to gasoline with 95% efficiency
Transportation of gasoline with 94% efficiency
Engine is 24% efficient
Transmission is 76% efficient
Draw the energy flow diagram.
What is the overall efficiency of the car?

11. SOLUTION a) 3% 5%
76%
100%
97%
24%
95%
24%
Eout
76% b)