Show:
Efficiency Problems
Cogeneration
Efficiency and the Environment
Efficiency and the Environment Cont.
Output vs. Input Energies
100
A TV uses 4.0x10^3 J of electrical energy. If the TV emits 2500 J of light energy, what is the efficiency?
What is 63%?
100
Cogeneration is this:
What is combining two or more processes from one energy source?
100
These devices are about 20% efficient.
What is a car?
100
These must match their job in order to have maximum efficiency.
What is an electric motor?
100
A projector has these input and useful output energies
What is electrical and light energy, respectively?
200
A lawnmower uses 8000 J of chemical energy. If it is 60% efficient, what is the useful output energy?
What is 4.8x10^3 J?
200
A natural gas plant in Joffre, Canada does this in cooperation with a chemical plant:
What is producing electricity from two generators, where electricity is used in the plant and excess electricity is sold, and excess heat from the natural gas plant is used to heat the buildings?
200
Plants are only this percent efficient in photosynthesis.
What is 1-8%?
200
A city uses this to keep their buildings cool and reduce costs.
What is water from deep in Lake Ontario?
200
The common different forms of energy
What are mechanical, electrical, thermal and potential?
300
A space heater has an output energy of 2503 J. If the space heater is 90.2% efficient, what is the input energy?
What is 2.77x10^3 J?
300
The efficiency of a coal-plant can be increased in this way:
What is directing waste heat to heat water, which is later used to produce steam?
300
Most of the electricity in Canada is generated in these three ways.
What are hydro-electric, fossil fuel and nuclear energy?
300
This form of electricity is more efficient than alternate types because there is no water being boiled.
What is hydro-electric power?
300
A car has these useful energy conversions.
What are chemical → mechanical, and mechanical → electrical?