NONRENEWABLE ENERGY VS.

RENEWABLE ENERGY

Chapters 31 and 32

NONRENEWABLE ENERGY Current common fuel sources

CoalPetroleumNatural Gas

Our wasteful practices are driving up the cost of these resources both economically and environmentally

WHERE DO FOSSIL FUELS COME FROM? Coal, petroleum, natural gas and peat

Formed from remains of plants and animalsThese take so long to form, we will run out

before Earth and replenish the supplySupply ~90% of Earth’s energy needsEnvironmental damage from burning these

fuels Air pollution Global warming Harmful to Human health

EARLY FUELS Wood was the first fuel used Bitumen (asphalt) was mined

by ancient Egyptians and used in mummification, making bricks for buildings and as a bonding material for ships, tools and weapons

Coal became popular ~300 years ago Invention of Steam engine

promoted wide-spread use Petroleum and natural gas are

the current fuels of choice These fuels were formed most

recently Used in the production of almost

EVERY SINGLE PRODUCT ON THE MARKET!

COAL Most abundant fossil fuel Made from decomposed

plant matter ~300 million years ago

No. America, China and former Soviet Union contain more than 2/3rds of the world’s coal

High environmental costs during mining and burning Makes it a less popular fuel

sorce in developed countries

PETROLEUM Similar to coal Made from marine plants and

animals that were decomposed by bacteria ~100 million years ago

As rock strata folded, created pockets of porous rock (like solid sponge) were petroleum was trapped

Pockets of petroleum often capped by pockets of natural gas

Persian Gulf contains ~2/3rds the worlds supply

NATURAL GAS Relatively clean-burning

Produces ½ as much CO2 as coal or petroleum burning

Free of contaminants that may be found in coal or petroleum

Difficult to store or ship Accomplished using an

extensive network of pipelines in various regions of the USA

Bulk of worlds Natural Gas is found in former Soviet Union and Iran

ENVIRONMENTAL CONCERNS Mining of coal leads to land pollution as topsoil

is removed (strip-mining or surface mining) Federal Surface Mine Reclamation Act

Federal law that states topsoil and natural vegetation must be replaced after mining to encourage the regrowth of the land

Huge, ugly scars are left behind despite the law Air pollution directly results from coal-mining Most countries cannot contain/use natural gas

The gas is treated as a waste and therefore burned Tapping pockets of natural gas can cause

subsidence where the land sinks

RENEWABLE ENERGY RESOURCES Energy sources that come from a constant

source, therefore, they will never run out Currently

More expensive than fossil fuels They will become more affordable as demand

increases More energy efficient

They will not waste as much energy and therefore contribute less to pollution and global warming

Types: Solar, hydroelectric, Wind, geothermal, biomass

SOLAR ENERGY Created as the energy from the suns rays are

collected and used for heating, cooling and generating electricity

Passive Solar Energy Suns rays are used to heat and cool a home based on

architectural layout of the home/building and the path of the sun

Does not require special materials Active Solar Energy

The energy from the suns rays are collected and stored in photovoltaic cells (similar to how a plant uses sun in photosynthesis)

This energy is converted into electricity and can be shared with the local electrical grid What every energy is not used by the owners can be sold back to

the community, and if needed, extra energy may be bought from the community grid

DRAWBACKS TO SOLAR ENERGY

The solar panel units are expensive to install Maintenance is usually

free and once installed, the energy obtained is free

Weather may affect the efficiency of the panels

Location is important Sunny areas are more

likely to benefit than rainy areas

Ie: So. California vs. London, England

HYDROELECTRIC ENERGY Water has kinetic energy

(energy produced from movement)

As water moves from an area of high elevation to an area of lower elevation and passes through a turbine, electricity is generated

Largest renewable contributor to the US and very efficient 85% of the energy in moving

water is harnessed Very clean energy, no air

pollution and inexpensive

TURBINE GENERATOR Water moves through a

tapered pipe As the water passes

through the pipe, it spins a paddle wheel (the turbine)

The turbine creates friction in the generator Heat energy is converted

into electrical energy Electricity is sent

through wires out to be used

DISADVANTAGES OF HYDROELECTRIC Lose lots of fresh water due

to evaporation Most available sites are

already in use Damages the environment

by altering ecosystems Destroys access to spawning

grounds for fish “fish ladders” have been built

in response Flooding during creation of

dam can displace humans and flood towns China in process of making

worlds largest Hydroelectric plant

1.3 million people will be displaced

WIND ENERGY Wind is created by unequal heating of the

Earth’s atmosphere Warmer air rises and cooler air moves

underneath This creates vertical wind currents which lead to

variations in air pressure As wind moves from an area of high

pressure to low pressure across the Earth’s surface, it can create stead, unchanging patterns of wind Prevailing winds- usually blow in one direction

and in a steady fashion Not always reliable…periods of calm can occur

USING THE WIND One of the oldest

renewable resources we use

Old-fashioned windmills used to Pump water Process grain into flour Create small amounts of

electricity Sail ships

To harness lots of energy, wind farms must be used Lots of windmills in one

location generating electricity to a common source

Use same turbine generator as hydroelectric

Wind powers the turbine

• Requires large amounts of land• Land may also be used

for farming or livestock grazing

• Can create many jobs•Safe, non-polluting energy source• Except for birds

DISADVANTAGES OF WIND

Super noisy Unattractive Kills birds Expensive

energy~40% more in

cost than oil-powered generators

FUTURE MODIFICATIONS Wind

Storage batteries may harness more energy from wind than we are currently getting

Wind might be used to create and pump water into a dam; when the wind is calm, energy can be produce via hydroelectric turbine generators

Use of “flywheels” possibleDifferent mechanisms are being explored

Ie: A giant “wind sock” may be spread at a cross-section of a valley in a mountain range; as wind blows through the valley, it will be funnelled into the wind sock to spin a turbine at the end

GEOTHERMAL ENERGY The farther into the Earth’s

crust, the hotter the temperatures

Water seeps many kilometers into the Earth’s crust where it is boiled and turned into steam by the Earth’s heat Escaping steam erupts

through cracks and creates geysers and hot springs

Water is replenished into Earth during next rain fall or snow storm

Energy may be harnessed by using gushing steam to spin a turbine generator

DRAWBACKS VS. ADVANTAGES

Advantages Disadvantages

Thermal energy under the US is equal to trillions of tons of coal

Fairly widespread source of energy Mostly in US, New

Zealand, Philippines, Iceland, and Italy

Fairly clean source of energy No air pollution

Not all sources are renewable

Creation of Thermal plants may lead to pollution of rivers and subsidence

Many pockets of geothermal energy contain corrosive dissolved salts that can damage generator equipment

Practical only in areas where source is close to surface

BIOMASS ENERGY Biomass = all living material in

an ecosystem Biomass energy = energy

harness by plants in photosynthesis and passed through trophic levels

Supplies about 20% of Earth’s energy needs

Examples of biomass fuel: Wood Animal manure Animal fats

Can be burned directly or converted into methane gas or alcohol

Burning wood can have heavy environmental impacts by destroying habitats, promoting green house effect, and promoting soil errosion