Energy Use

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Energy Use
Fossil fuels currently supply roughly 86 of
worldwide commercial energy. These fuels are
easy and convenient to use, but they have
environmental, political, and social costs.

• To reduce or even eliminate dependence on fossil
  fuels or nuclear energy, these sources have to be
  used more efficiently and new technology for
  renewable sources needs to be relied upon.
• Solar energy is a vast and significant resource.
  Solar energy is responsible for other types of
  renewable resources such as wind power,
  hydropower, and tidal energy.

• None of the renewable sources mentioned here are
  likely to completely replace fossil fuels,
  however, it is possible to use them in
  combination to make a significant difference in
  our energy needs.
• Transportation is one of the biggest areas of
  energy use today, but it is also the area that
  shows the most promise for conservation and new
  technology.

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Efficiency and Waste
The best way to conserve energy is to improve
energy efficiency. Energy Efficiency is the
measure of how much work we can get from each
unit of energy we use.
84 of all of the commercial energy used in the
US is wasted. 43 of this energy is wasted
unavoidably because of what the second law of
thermodynamics has taught us.
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This 43 is wasted unnecessarily, mostly due to
the inefficiency of incandescent lights,
furnaces, industrial motors, coal and nuclear
power plants, and motor vehicles.
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Laws of Thermodynamics

• Energy is transferred in natural processes. The
  study of these transfers is known as
  thermodynamics. While there are three laws, the
  only two that well be using are the first and
  the second. Here is a summary

The First Law Energy is neither created nor
destroyed as it moves through natural
systems. The Second Law Energy is constantly
degraded to lower forms as it is used. Entropy,
a state of disorder, increases in natural systems.
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Let's remember...
Energy is defined as

• The ability to do work

Types of energy
Potential
Energy that is stored
Lake Mead is behind the Hoover dam, and
represents a huge amount of potential mechanical
energy The energy stored inside coal, oil and
natural gas (before it is burned) is potential
chemical energy, just as the burger on your plate
isbefore you eat it.
In a perfect world, all the energy in that
hamburger would be converted to something useful.
Energy inEnergy out. This is, of course, not
what happens. (2nd Law of thermodynamics)
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Kinetic Energy
Energy in motion
Kinetic energy is based on an objects mass and
speed or velocity. We can use these moving
objects to generate electrical energy.
On the American side of the border, the Robert
Moses Niagara Power Plant and the Lewiston Pump
Generating Plant, together generate more than 2.4
million kilowatts of electricity, enough to power
24 million 100-watt light bulbs.
Kinetic energy and electricity production is
accomplished with the help of a technological
breakthrough called a turbine. A turbine is a
rotary engine that extracts energy from a fluid
flowing and converting it into useful work, with
the exception of photovoltaic cells, it is this
technology that we employ to generate nearly ALL
of our electricity.
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Efficiency...
So since energy in, rarely if ever is equal to
energy out, we have to set a definition for
efficiency. Energy many times gets lost to the
ecosystem in the form of thermal energy. (heat)
Energy efficiency is basically a measure of the
usefulness of energyusing as much as you can
without losing any! The closer you can get to
energy in energy out, the more efficient the
system is.
Ework out/work in 100
Your jobs as adults will be to find ways to
efficiently use the energy Earth has available.
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Another reason for energy inefficiency is that so
many of us live and work in leaky and poorly
insulated buildings.
This thermal image shows the poorly insulated
home losing heat energy.
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Wrong and Right
The US and Canada, as well as most developing
countries are extremely wasteful of energy
resources. Only 5 of us rely on mass transit.
Japan, Germany and France, however, are two to
three times more energy efficient than the US is.

Widely Used, and Largely Wasteful

• Incandescent light bulbs Use only 5-10 of the
  electricity they draw to produce light. The rest
  is wasted as heat energy.
• Motor Vehicles with internal combustion engines
  waste about 94 of the energy available in fuel.

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• Nuclear power plants producing electricity
  wastes about 83 of the energy in its nuclear
  fuel and probably 92 when we add in the
  additional cost of mining and processing the
  uranium, and storing the waste for thousands of
  years.

Resistance heating occurs when the passage of an
electrical current through a conductor releases
heat.

• Coal-fired power plants waste 66 of the energy
  released by burning coal to produce electricity
  and probably 75-80 if we include the energy
  needed to mine, and transport it to the plant.

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Plant Efficiency
How efficient are green plants at absorbing the
suns energy? How much of the suns energy that
strikes the Earths surface gets converted into
carbohydrates by plants to feed consumers?
Would you be surprised to learn that less than 1
of the energy of the sun actually goes into
manufacturing carbohydrates!
Even plants are inefficient!
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Passive Solar Comparison
By contrast, with passive solar heating, only
about 10 of the incoming solar energy is wasted.
Passive Solar Energy homes are successful at
dramatically cutting heating energy costs while
providing a healthy environment to live in.
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Active Solar Power
Active solar technologies are employed to convert
solar energy into usable light, heat, cause
air-movement for ventilation or cooling, or store
heat for future use. Active solar uses electrical
or mechanical equipment, such as pumps and fans,
to increase the usable heat in a system.
Biodiesel...compared to gasoline

• Biodiesel reduces emissions of CO, and CO2
• Higher net energy yield
• Reduced hydrocarbon emissions
• Better gas mileage (40 better)
• Potentially renewable

How could biodiesel possibly be non-renewable?
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Biodiesel
Biodiesel is produced from vegetable oil
extracted from soybeans, rapeseeds, sunflowers,
oil palms, and jatropha shrubs. We can also use
animal fats to produce biodiesel.
We can even use waste oils and fats from
restaurants to make biodiesel.
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Oilgae
Algae grow naturally all over the world. Under
optimal conditions, it can be grown in massive,
almost limitless, amounts. Half of algae's
composition, by weight, is oil. Scientists have
been studying this oil for decades to convert it
into algae biodiesel -- a fuel that burns cleaner
and more efficiently than petroleum.
Algae biodiesel manufacturers are building
biodiesel plants close to energy manufacturing
plants that produce lots of carbon dioxide,
because the algae use CO2 to photosynthesize.
Recycling carbon dioxide reduces pollution.