Renewable vs. Non-renewable Energy

Unit 27

What Does Energy Mean to Us?When you hear politicians and scientists

say things like “energy consumption” or “energy independence” what does

that really mean?

Energy Use Energy is generally divided into two

main types:

Electricity Production

and

Transportation

Non-renewable Energy Non-renewable means that the supply can

not be replenished. Once it runs out, it is gone forever. Fossil Fuels are the most common form of

non-renewable energy.

Examples of Fossil Fuels Coal- Ancient swamps that were buried by

sediments. Primarily containing peat moss and other vegetation.

Petroleum (Oil)- Primarily algae and plankton that sink to the bottom of the sea and are buried by sediments.

Natural Gas- Primarily algae that sink to the bottom of the sea are buried by sediments.

They are called fossil fuels because they are the remains of organisms that lived millions of years ago.

Uses of Fossil Fuels

• Coal- Used to generate electricity.• Used in the steel industry to melt iron

• Oil- Used to produce gasoline and diesel.• Used as lubricants, like motor oil.• Used to make plastics and asphalt

• Natural Gas- Use to generate electricity• Used to heat homes• Used as an alternative fuel for vehicles

Coal

The most abundant fossil fuel in the world.

It is estimated that there is about 200-300 years left of coal on Earth.

Because it is the most abundant fuel, it is the cheapest. Thus, it is used to generate electricity and in producing steel.

Coal represents about 40% of the electricity generated in the United States.

It is also the most polluting form of energy today, producing all kinds of toxic chemicals.

Coal

Coal Coal smoke is one of the largest

contributors to air pollution and smog. Prior to more modern smoke cleaning

technology, coal soot layers coated city buildings and trees.

Coal Power Plant Coal is burned It heats up water to turn it to steam The rising steam turns turbines which

generate electricity

Smog Smog is produced by chemicals released by

coal powerplants and automobiles. Here is Beijing, China The left image is a “sunny” day with thick smog and

on right image is after a rainstorm washed it all out.

Petroleum (Oil) Oil is a thick, black liquid formed from the

buried remains of microscopic marine organisms.

It is generally trapped under layers of rock and has to be pumped out.

But, there are a few spots where it can find its way to the surface.

Oil Wells First you drill down to find a deposit Then you use a oil rig to pump it up

Uses of Oil Oil is converted into many products we use

everyday, including gasoline, diesel, jet fuel, lubricants, plastics, among others.

Oil represents more than 90% of the transportation energy used today.

61% of oil is used for transportation

Oil Refining Oil can be heated and separated into

its different components

Diesel Fuel It is used for hauling goods. Trucks, Ships, and Railways use Diesel

Natural Gas It is primarily methane It is used to produce 20% of our electricity It is cleaner burning than coal It is used to heat homes.

Other Uses of Natural Gas The chemical reaction of natural gas

is very simple. CH4 + O2 CO2 + H2O

Problems with Fossil Fuels

All Fossil Fuels release Carbon Dioxide gas when burned which causes global warming.

Burning coal and oil produces toxic pollutants that result in smog, air pollution, lung diseases, and acid rain.

Our Fossil Fuels will run out soon, thus we need alternatives!

Renewable Resources These are sources of energy that

naturally regenerate themselves.

Wind Solar Hydroelectricity Biofuels Geothermal Tidal/Wave Energy

Energy from Wind Wind energy comes from wind

turning turbines to generate electricity.

It can only be used in regions that have a lot of wind.

It is the fastest growing source of alternative energy today.

Currently, about 2% of electricity in U.S. is from wind. But, it is over 20% in Denmark!

Wind Farm

Advantages: Wind energy is nonpolluting

Disadvantages: Not all places are windy enough Sometimes the wind slows or stops It can kill birds in migratory paths

Solar Energy There are two ways to generate

electricity from the sun.

Photovoltaic cells

Solar thermal energy

Solar cells• Must face south to get the maximal sun, if on a roof.• Some systems have the ability to rotate to follow the

sun through the day

Solar Thermal Systems

Sunlight is focused on a fluid that boils to spin a turbine to generate electricity

Passive Solar Heating

Sunlight can be used to save energy without even generating electricity

Solar Energy Solar energy can save money by heating or

lighting buildings passively. Solar energy can heat water, saving energy

needed for water heaters. Solar energy can generate electricity Solar produces no pollution

Disadvantages of Solar energy It does not work well on cloudy days

It does not work at night.

It is less effective the further north you go

It is difficult to store large amounts of energy in batteries

Hydroelectricity Dams hold large amounts of water back. Water flowing through forces turbines to

spin and create electricity.

Run of the River DamUses force of the river to push turbines

Gravity DamsCreates a vertical displacement and water

is dropped onto the turbines

Hydroelectricity Generates about 20% of electricity in U.S. No pollution and is renewable. But, causes environmental damage. It floods lands, alters rivers temperature

and character and can kill fish species

Tidal and Wave Energy In the early stages of development Moving water can spin turbines and

generate electricity

Biofuels Using crop waste, leaves, and wood products

to generate fuel. Renewable because you can always grow

more. Still produces carbon dioxide when burned.

Geothermal Energy Using hot water from the Earth Can only be used in certain areas with

volcanic or geothermal activity Iceland is the world’s largest producer If we could drill deep enough, everywhere

could have geothermal.

Geothermal Plant in Iceland

Nuclear Power

It is a non-renewable resource since the uranium used as the fuel has a finite quantity.

Nuclear Power Nuclear Power is clean and non-polluting.

Only water vapor is released. It is the most efficient form of electricity

generation available.

About 20% ofelectricity in U.S. is from nuclear

Nuclear Waste The primary drawback of nuclear power is

the nuclear waste. The waste is radioactive and have to be

stored in secure and safe locations.

Risks of Nuclear Power Nuclear Power is the safest form of energy

production. But, a disaster can be devastating with the

release of radiation.

An actual nuclear bomb type explosion is not really possiblethe way the reactors are run

Chernobyl is the only majordisaster ever, but it was apoorly run and aging complex