current electricity 1. history 2. methods for generating current electricity

CURRENT ELECTRICITY

1. History2. Methods for generating

current electricity

Luigi Galvani’s Experiments (1780-6)

Discovered bioelectricity in animal cells.from The Day the Universe Changed by J. Burke

Mary Shelley’s Frankenstein concept was a result of Galvani’s discovery of bioelectricity.

Defibrillator:An example of

Galvani’s idea in modern use

Count Alessandro Volta (1799)from The Day the Universe Changed by J. Burke

A battery with negative and positive terminals and electric

current.

Faraday’s Induction Machine (1832)

from The Day the Universe Changed by J. Burke

Oersted Discovers Electromagnetism (1820)from The Day the Universe Changed by J. Burke

The First Motors and Electricity Generators are

Developed in the early 1800’s

MotorsElectrical

Generators

A generator converts motion energy to electrical energy.A motor converts some form of energy to motion energy.

Electricity Generation• Today we use vast amounts of electrical

energy.• According to the First Law of

Thermodynamics, energy can be converted from one form to another, but cannot be created or destroyed.

• How is the First Law of Thermodynamics used to generate electricity?

Current Electricity Generation

Hoover Dam

Generators and Turbines

In a turbine, the input energy, like flowing water, pushes blades. The blades turn a shaft connected to a generator. The generator converts the kinetic energy into electrical energy.

Energy Sources• Moving water, wind, sunshine energy,

nuclear energy and heat energy from burning fossil fuels like oil, coal and gas are all energy sources for generating electrical energy.

• These are divided into renewable and non-renewable energy sources.

Huron Wind Farm

PhotovoltaicCells

RENEWABLE – can be replaced within a human lifetime.

Burning Fossil Fuels: coal, oil or

natural gas

Nuclear Power: uranium

NON-RENEWABLE - can only be used

once

Advantages and Disadvantages• There are advantages and disadvantages

for all these forms of generating electrical energy. Consider these three factors:

• 1. Economic Factors – costs to build, operate, to shut down? Amount of electricity 24 hours a day, 7 days a week?

• 2. Environmental Factors – is the environment still healthy and clean?

• 3. Social Issues – are there any health care costs or other hazards?

What are some advantages and disadvantages?Wind Turbines

Ontario Place

Ontario PlacePickering

What are some advantages and disadvantages?Oil and gas from the Alberta Tar Sands

Ontario Place

Ontario PlacePickering

What are some advantages and disadvantages?Hydroelectricity – La Grande, a small part of the James

Bay power project in northern Quebec

SustainabilityIn summary we must consider if the electricity generation source is sustainable.

Sustainability means considering the social, economic and environmental effects of producing and using electricity now and in the future. The decisions we make about generating and using electricity have many consequences and we must make good social choices.

Sustainable?