Transcript Energy Efficiency

Incandescent
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
CFLs: Compact
Fluorescent Light Bulbs
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.
Motor
Incandescent
This 43% is wasted
unnecessarily, mostly
due to the
inefficiency of
incandescent lights,
furnaces, industrial
motors, coal and
nuclear power plants,
and motor vehicles.
Furnace
• The ability to do work
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 is…before you eat it.
In a perfect world, all the energy in
that hamburger would be
converted to something useful.
Energy in=Energy out.
Kinetic Energy: Energy in motion
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
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 energy…using as much as
you can without losing any!
The closer you can get to
energy in= energy out, the
more efficient the system is.
%E=work out/work in · 100%
Your jobs as adults will be
to find ways to efficiently
use the energy Earth has
available.
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.
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.
• 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.
How efficient are green plants at absorbing the sun’s energy?
How much of the sun’s energy that strikes the Earth’s 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!
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.
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 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?
Biodiesel is produced from vegetable oil extracted from
soybeans, rapeseeds, sunflowers, oil palms, and jatropha
shrubs. We can use animal fats to produce biodiesel.
We can even use waste oils
and fats from restaurants to
make biodiesel.
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.