Alternative sources of energy

Nonrenewable energy, including fossil fuels and nuclear power, make up the vast majority of the U.S. energy portfolio.

In the long-term, there are two major issues with this reliance on nonrenewable energy: Dwindling supplies. Environmental

pollution. 2

Nonrenewable Energy

EdPuzzle

COAL, PETROLEUM, AND GAS

Coal, petroleum, and natural gas are

considered nonrenewable

because they can not be replenished in a

short period of time. These are called

fossil fuels.

Open ended question: How do we currently use fossil fuels?

What is an alternative source of energy?

An energy source that can be used instead of fossil fuels

It is usually a renewable source of energy that could be used should fossil fuels run out

Why is there a need for alternative sources of energy?

90% of the worlds energy supply’s come from fossil fuels

Fossil fuels are convenient and relatively cheap

How much longer can we depend on fossil fuels?

Because they are fossil fuels they DO have a life expectancy

“Oil has 40 – 50 years left” In 1960 they said this too! – what has

happened is that we have found new reserves of oil and new technology has made the oil we use last longer

Open ended question

What are some problems associated with fossil fuels?

Burning fossil fuels has increased atmospheric pollution.

Vehicle exhausts contribute to acid rain more so than power stations burning coal.

The carbon stored in fossil fuels is released as carbon dioxide when they are burned – this leads to the green house effect and global warming

Don’t get this confused with the hole in the ozone layer – this was caused by CFC’s

Coal has the longest life expectancy Environmentalists dislike the burning of this

fossil fuel the most as it gives off the most CO2

Unless cheap alternatives to burning coal are found there is likely to be an increase in its use – especially from Asia which has a lot!

Open-ended

What is an alternative fuel?

So what are the alternative energy sources to fossil fuels?

Once upon a time – nuclear power was seen as the answer. Huge amounts of power could be produced from a small amount of uranium

However, it was not well known that it produced radioactive waste

The waste is dangerous to health and life for hundreds of years There is no secure place for storage. Public confidence has also been shattered by the explosion at

Chernobyl in 1986

Chernobyl 1986

On April 26, 1986, a sudden surge of power during a reactor systems test destroyed Unit 4 of the nuclear power station at Chernobyl, Ukraine, in the former Soviet Union.

The accident and the fire that followed released massive amounts of radioactive material into the environment.

Open ended question:What events lead to the discovery of alternative use of nuclear energy?

Chernobyl

The Chernobyl accident’s severe radiation effects killed 28 of the site’s 600 workers in the first four months after the event.

Another 106 workers received high enough doses to cause acute radiation sickness.

Chernobyl

Two workers died within hours of the reactor explosion from non-radiological causes.

Another 200,000 cleanup workers in 1986 and 1987 received doses of between 1 and 100 rem (The average annual radiation dose for a U.S. citizen is about .6

REM a unit of effective absorbed dose of

ionizing radiation in human tissue. Simplified- Effective energy dose that

won’t cause health problems

Under normal operating conditions what is released in the atmosphere by nuclear plants

Other hopes?

Now that nuclear power is considered too risky hopes lie with things like sun, water, wind, waves and tides.

RENEWABLE RESOURCESRenewable resources are

natural resources that can be replenished in a short period of time.

● Solar ● Geothermal● Wind ● Biomass● Water

Geothermal Energy

Heat from the earth can be used as an energy source in many ways This heat energy, known as geothermal energy

Below the Earth's crust, there is a layer of hot and molten rock called magma.

Geothermal Energy

The amount of heat within 10,000 meters (about 33,000 feet) of Earth's surface contains 50,000 times more energy than all the oil and natural gas resources in the world. 

Geothermal Energy

Ground-source heat pumps. A much more conventional way to tap geothermal energy is by using geothermal heat pumps

These take advantage of the constant year-round temperature of about 50°F that is just a few feet below the ground’s surface.

3 types of Geothermal

Ed Puzzle

An enormous amount of energy (over 1,000 watts per square meter) hits the Earth every day.

Two separate technologies have been developed to convert solar energy into electricity.

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Solar Energy

Types of Solar Energy

Parabolic solar collection involves using curved reflective surfaces that collect light and focus it onto a concentrated point.

The heat is absorbed and used to boil water into steam, which spins a turbine.

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Types of Solar Energy Continued

Photovoltaic cells contain a semiconductor material (typically silicon-based) which converts sunlight into direct-current (DC) electricity

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An on-site inverter converts the DC power to 120-volt AC power, which can then be connected to a home or building’s power supply or directly to the electricity grid

Solar energy activity

Not available on overcast days or at night.

Hydroelectric power plants use running water to spin a turbine and generate electricity. Hydroelectricity is very economical, with costs per

kilowatt-hour similar to coal. No pollution is produced.

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Hydropower

The construction of the dam has major ecological impacts. Regular flooding downstream stops, preventing deposition of silt

and nutrients. The reservoir can experience sedimentation, where particles of soil

in the river settle to the bottom of the reservoir. The ecosystem immediately behind the dam becomes flooded. River water, when stopped, warms faster and begins to evaporate. Fish and other organisms can no longer move upstream.

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Any cities or villages in the area of the reservoir will have to be abandoned.

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The Three Gorges Dam in China, completed in 2008, displaced 1.13 million people from the Yangtze River region.

Hydroelectric

Activity Hydroelectric Activity

Wind

Wind

Large turbines sit on towers that are up to 60 meters tall, and have blades that range from 30 to 50 meters long.

Wind

horizontal axis wind turbines consist of three big parts: the tower, the blades, and a box, called the nacelle.

Inside the nacelle is where most of the action takes place, where motion is turned into electricity.

Tidal Energy

Tidal Energy

A huge dam (called a "barrage") is built across a river estuary. When the tide goes in and out, the water flows through tunnels in the dam.

The ebb and flow of the tides can be used to turn a turbine, or it can be used to push air through a pipe, which then turns a turbine. Large lock gates, like the ones used on canals, allow ships to pass.

Advantages of using natural sources of energy

They are inexhaustible – they will always be available – they are renewable

They are clean and will not damage the Earth There are several types – so one or more of

them is present in each country Most natural sources can be used on a small

scale and serve local needs therefore cutting costs of transmitting the energy

Put forward arguments in favor of:

(a) Using natural gas instead of coal (b) using nuclear power rather than oil (c) using alternative sources of energy rather

than nuclear power

Quizziz