Glossary
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Abiotic
Non-living components of an ecosystem.
Absorb
The process of taking in something.
Absorber
Material used in building design that is intended to
collect sunshine and retain thermal energy that will be re-radiated to
heat the air in the room.
AC
Alternative electrical current, such as the household
variety. AC is electrical energy that flows both directions in a
circuit, alternating back and forth at 60 cycles every second.
Active solar heating
A solar heating
system that uses a mechanical system to transfer the sun's heat from a solar
collector to various parts of a home or building for space heating and water
heating purposes.
Air Distribution
The way air is circulated around a room, house, or
building is by natural convection. Fans, ducts, and blowers are examples
of air distributors.
Altitude
The altitude of the sun is the angle between the
position of the sun in the sky and a point directly below on the
horizon. This altitude varies by 47° during the course of one year.
Amorphous
Amorphous PV panels are dark blue or black in color and
appear uniform in color with no appearance of cells or crystals.
Ampere (abbrev.
Amp; pl. Amperes [Amps])
A unit of
electric current. One ampere of current is equal to one coulomb (6.25 x
1,018) of electrons passing a point in a circuit in one second. See
Electric Current.
Anemometer
An instrument for measuring wind force and velocity.
Angle of incidence
The relation between azimuth and elevation. As the angle
of incidence increases, energy transmission through the glass surface of
all solar collectors decreases and the amount of energy reflected off
the glazing increases. Energy density decreases with an increase in
angle of incidence as well.
Aperture
The area where the sunlight enters the building, also
known as the collector.
Array
See
Photovoltaic panel.
Atmospheric
ozone
Gaseous compound of
three oxygen atoms that forms a thin layer in the atmosphere that absorbs
harmful solar ultraviolet radiation. Compare to Ground Level Ozone.
Atom
1. The smallest
unit of an element, consisting of a dense, central core (the nucleus) made
of protons and neutrons that is surrounded by orbiting electrons. 2. The
smallest unit of matter than can enter into a chemical reaction. See
Electron.
Autotroph
An organism capable of synthesizing its own
food from inorganic substances using light or chemical energy. Examples of autotrophs include plants and some protozoans.
Azimuth
The east and west path of the sun.
Battery
A device that
converts chemical energy into electrical energy, producing an electric
current when connected to a circuit; batteries store electricity for later
use
Bioenergy
The conversion of
the complex carbohydrates in organic material into energy.
Biodiversity
The variety of individual organisms (genetic), species,
and ecosystems.
Biogeochemical cycle
A natural process that
cycles nutrients in various chemical forms from the environment, to
organisms, and then back to the environment. Examples are the carbon,
oxygen, nitrogen, phosphorus, and hydrologic cycles.
Biological community
All the organisms (e.g.,
plants, animals, bacteria) that live in an area and interact with each
other. See Ecosystem.
Biomass energy
Energy produced
by the conversion of biomass directly to heat or to a liquid or gas that can
be converted to energy.
Biosphere
The parts of Earth where life is found,
including the land, bodies of water, and the lower part of the atmosphere.
Biotic
Living components of an ecosystem.
Boiler
1. A type of
space heating system that heats water or produces steam. The heated water or
steam is circulated throughout a home or building using pipes and radiators.
2. Equipment or vessel that heats water or produces steam for any purpose.
Boiling water
reactor
A type of nuclear
reactor in which the heat from nuclear fission is used to boil water inside
the pressure vessel. The resulting steam is used directly to turn a turbine
connected to an electric generator.
British thermal
unit (abbrev. Btu; pl. Btu)
1. A unit of
energy equal to 1,055 joules or 252 calories. 2. The amount of energy needed
to raise the temperature of one pound of water one degree Fahrenheit. 3. The
approximate amount of energy in one match tip.
Btu
See
British thermal unit.
Building science
The branch of science dealing with construction,
maintenance, safety, and energy efficiency of buildings.
Calorie (abbrev. cal; pl. calories;
also small calorie)
1. A unit of energy content of food. One
calorie equals 4.187 joules or 0.003969 Btu. 2. The amount of energy
needed to raise the temperature of one gram of water one degree Celsius.
Calorimeter
A device used to measure the
heat energy that flows into or out of a substance.
Carbohydrate
An organic compound produced by
photosynthesis, such as sugar, starch, and cellulose and used as a source
of food energy by organisms.
Carbon cycle
A biogeochemical cycle in which
carbon and its compounds are exchanged between organisms and Earth's
oceans, atmosphere, and crust. See
Biogeochemical cycle.
Carbon dioxide
(formula: CO2)
A colorless,
odorless gas formed during respiration, organic decomposition, and
combustion of fossil and other carbon-based fuels. Carbon dioxide is taken
up by green plants during photosynthesis, dissolved in bodies of water, and
circulated in Earth's atmosphere.
Carbon monoxide
(formula: CO)
A colorless,
odorless, poisonous gas formed by the incomplete burning of carbon-based
fuels such as coal, gasoline, natural gas, and wood and listed as a criteria
pollutant.
Carnivore
An organism that obtains its food
energy by eating animals. See
Secondary consumer.
CCF
One hundred cubic feet of water or natural gas. One CCF of natural
gas is about equal to one therm.
Cell
The smallest living unit of an organism. A
cell consists of genetic material contained in one or more nuclei plus
other organelles to perform various life functions, all of which are
encased in an outer membrane.
Celsius (also Celsius scale, centigrade.
Celsius is the term preferred over centigrade.)
A temperature scale on
which the freezing point of water is 0 degrees Celsius and the boiling
point of water is 100 degrees Celsius (at one atmosphere of pressure). The
formula for converting temperatures from the Celsius scale to the
Fahrenheit scale is o C=5/9 (oF-32). See
Fahrenheit.
Centralized
energy system
Energy system in
which large amounts of an energy resource are converted from one form into
another form in a central location. The energy is then distributed to and
used by a large number of consumers located within a large area. Electricity
generated by a nuclear power plant and distributed by transmission lines to
a large number of homes and businesses is an example of a centralized energy
system.
Chain reaction (also Nuclear chain
reaction)
1. A reaction that stimulates its own repetition. 2. For
example, nuclear reaction occurs when neutrons released from a split atom
such as a uranium-235 (U235)
nucleus go on to fission other nuclei. This reaction
produces additional neutrons that cause more fissions, which release still
more neutrons to cause even more fissions, which release even more
neutrons, and so on. See Fission.
Chemical bond
An attractive force that holds
atoms together to form molecules.
Chemical energy
See
Chemical potential energy.
Chemical potential energy
The energy in
chemical bonds holding the atoms of a compound together. Food, wood,
batteries, and fossil fuels contain chemical potential energy. See
Chemical
bond.
Coal
A fossil fuel
made of sedimentary organic rock that contains more than 40 percent carbon
by weight after moisture has been removed. It is formed from plant matter
that decayed in swamps and bogs that has been compressed and altered by
geological processes over millions of years. Four main types of coal have
been identified and ranked based on how much carbon and energy they contain:
lignite, subbituminous coal, bituminous coal, and anthracite.
Combustion
1. The process of
burning. 2. A rapid chemical change in which a substance reacts with oxygen
and generates heat and light.
Community
supported agriculture (CSA)
A process where
households or individuals purchase shares of a local farmer's crop prior to
the growing season. The shareholder receives installments of produce, often
weekly, of a variety of harvested crops.
Compact
fluorescent lamp (abbrev. CFL)
A small
fluorescent lamp designed to fit in light fixtures that use standard
incandescent lamps. See
Incandescent lamp.
Compact
fluorescent light bulb
See
Compact fluorescent lamp.
Conduction
1. Heat transfer
from particle to particle, occurring most effectively in solids. 2. Transfer
of electrical energy through a material via the flow of charged particles,
usually electrons.
Conductivity
1. Heat transfer from particle to particle, occurring
most effectively in solids. 2. Transfer of electrical energy through a
material via the flow of charged particles, usually electrons.
Conservation
Wise use and
careful management of resources, so as to obtain the maximum possible social
benefits from them for present and future generations. Energy resources can
be conserved by reducing wasteful energy use, using energy for a given
purpose more efficiently, or by reducing energy use altogether. See
Energy conservation.
Consumer
1. An organism
that obtains nutrients and energy by eating other organisms. 2. A person or
group of persons who buys and uses goods and services.
Consumption
The process of
using natural resources, materials, or finished products to satisfy human
wants of needs.
Convection
Heat transfer by
the movement of liquids and gases.
Current (electric)
A flow of electrons in a circuit. It refers to the
movement (strength or rate) of electricity past a given point in a fixed
amount of time. Electrical current is measured in Amperes (Amps).
Customer charge
A monthly charge
that covers the cost of making electric or natural gas service available to
a utility's customers. The customer charge includes the cost of meters,
meter reading, connecting electric lines or natural gas pipelines to
customers, and billing and record-keeping expenses.
Data
Information that is factual, used in reasoning.
DC
Direct electrical current. DC is electrical energy
flowing in one direction in a given circuit.
Decentralized
energy system
Energy system in
which small amounts of an energy resource are converted from one form into
another form for use by an individual or small number of consumers. The
conversion and consumption of the energy resource usually occurs in the same
location. A solar water heater used to provide hot water for a home is an
example of a decentralized energy system.
Decomposer
An organism, such as a bacterium
or fungus, that feeds on and breaks down parts of dead organisms and the
waste products of living organisms.
Degree
A unit of measure used to describe a
temperature scale. See Celsius,
Fahrenheit.
Demand schedule
A chart or table
showing the relationship between the price and the quantity of a good or
service demanded by customers according to the law of demand. See
Law of demand.
Developing nation
Nonindustrial agricultural societies that modify their
natural environments primarily to domestic food sources. They depend on
modest technologies to provide energy and materials.
Economic sector
A general
economic activity that produces and consumes goods and services for the same
or for similar purposes. The five major economic sectors include the
residential, commercial, industrial, agricultural, and transportation
sectors.
Ecosystem
Self-regulating natural community or
organisms (e.g., plants, animals, bacteria) interacting with one another
and with their nonliving environment. Wetlands, forests, and lakes are
examples of ecosystems.
Efficiency
The ratio or
percentage of useful output to the total input in any system. See
Efficient,
Energy efficiency,
Inefficient
Efficient
Accomplishing a
task with a minimum of effort and waste. See
Efficiency,
Inefficient.
Elastic potential energy
The energy in a
solid object when it is stretched or compressed. A stretched rubber band
has elastic potential energy.
Electric current
(also Current)
A flow of
electrically charged particles such as electrons within a conductor or a
circuit.
See
Conduction.
Electrical
circuit (also Electric circuit)
A closed,
conducting path or route through which an electric current travels.
Electrical
(electromagnetic) energy
Kinetic and
potential energy associated with electric charges (e.g., electrons) and
their movement. See
Electrical potential energy.
Electrical
generator
See
Generator.
Electrical grid
The power lines and
support systems across which electricity travels from utilities to end
users.
Electrical
potential energy
Potential energy
stored by separating positive and negative electrical charges against
electrical forces. A charged battery has electrical potential energy stored
in it. See
Electrical (electromagnetic) energy.
Electricity
1. The behavior
of negative and positive charges (electrons and protons) due to their
attraction and repulsion. 2. The flow of electrons; electric current. See
Electrical (electromagnetic) energy,
Electric current.
Electromagnet
A magnet with a
coil of wire that has a current passing through it. The magnetic field can
be made stronger by coiling the wire around an iron core.
Electron
1. A subatomic
particle with a negative electric charge that orbits the nucleus of an atom.
2. The basic particle that makes up an electric current.
Elevation (tilt angle)
The angle at which a PV panel should be tilted for best
solar collection. The elevation of the panel should equal the geographic
latitude of where the panel is placed. For example, homeowners located
at 45 degrees latitude should angle their panels at 45 degrees from
horizontal.
Embodied energy
The total amount
of energy needed to manufacture a finished product from raw materials,
including the energy used to transport the product.
Emissions
The release of gases to the atmosphere, usually resulting
from fuel combustion.
End use
A set of devices,
products, and systems that use energy for the same or for similar purposes.
Examples of residential end uses include cooking, lighting, and
refrigeration.
Energy
The ability to
organize or change matter; the ability to do work.
Energy charge
The cost of
electricity or natural gas energy used by a utility consumer. The energy
charge equals the amount of electricity or natural gas used by the customer
times the electric or natural gas rate.
Energy conservation
Wise use and
careful management of energy resources by reducing wasteful energy use,
using energy for a given purpose more efficiently, or reducing energy use
altogether. See
Conservation.
Energy conversion
The process of
changing one form of energy into another. For example, the chemical energy
in gasoline can be converted into kinetic energy (energy of motion) by an
automobile engine. See
Energy conversion device.
Energy conversion
device
A device
specifically designed to convert one form of energy into another. For
example, a solar cell is a device that converts solar energy into electrical
energy. See
Energy conversion.
Energy efficient design
An aspect of green home design that takes into
consideration the energy source a home utilizes and how energy is used
in the building envelope, mechanical equipment, and appliances.
Energy efficiency
The ratio or
percentage of useful work or energy output to total work or energy input in
any energy system. For example, the efficiency of a home heating system is
equal to the percentage of energy in the fuel or other source that is
converted into useful heat. See
Efficiency,
Efficient,
Inefficient.
Energy forms
Basic kinds of
energy that are different and distinct from each other. Two main forms of
energy are potential energy (the energy in matter) and kinetic energy (the
energy of motion). More specific forms of energy include thermal, elastic,
electromagnetic (e.g., light, electrical, magnetic), gravitational,
chemical, and nuclear energy.
Energy resource
Energy source
that is used to meet the needs of a human society. For example, oil is an
energy resource because it is used to produce fuel for transportation and
heating needs. Energy resources are subsets of energy sources.
Energy resource
management
Actions and
strategies taken by an individual or group to meet their needs by using a
specific type of energy resource, reducing wasteful energy use, using energy
efficiently, or reducing energy use altogether. See
Energy use practice.
Energy source
Matter or system
from which one or more forms of energy can be obtained. For instance,
natural gas is a source of thermal energy, and sugarcane is a source of
chemical energy.
Energy storage
The process of storing or converting energy from one
form to another for later use; storage devices and systems including
batteries, conventional and pumped storage hydroelectric, flywheels,
compressed gas, and thermal mass.
Energy use practice
The way an
individual, a group of people, or a society generally use energy.
Enhanced greenhouse
effect
When the
natural greenhouse effect has been enhanced by human activities, such as
accelerated emissions of greenhouse gases. Also called
Global warming and
Global climate change.
Entropy
1. A measure of the dispersal or
degradation of energy. 2. A measure of the disorder or randomness in a
closed system. For example, the entropy of an unburned piece of wood
and its surroundings is lower than the entropy of the ashes, burnt
remains, and warmed surroundings due to burning the that piece of wood.
Ethanol
Ethyl alcohol. It is made by fermentation and advanced
distillation process from crops and vegetable matter such as corn.
Externality cost
Portion of the
cost of production and marketing of a product that is borne by society, not
by the producer, and thus is not included in the price of the product. For
example, the cost of cleaning up a beach after an oil spill is usually not
included in the price of motor oil bought at an automotive supply store.
Export
Sending products from one country to another.
Fahrenheit
A temperature scale on which the
freezing point of water is 32 degrees F and the boiling point of water is
212 degree F (at one atmosphere of pressure). The formula for converting
temperatures from the Fahrenheit scale to the Celsius scale is o F
- 9/5 (o C + 32). See Celsius.
Finite
1. The condition of having boundaries or limits. 2. The
condition of having a defined or measurable quantity of value.
First law of
thermodynamics
Energy cannot be
created or destroyed; it can only be converted from one form into another.
For example, the chemical energy in coal can be converted into thermal
energy.
Fission (also Nuclear fission)
A nuclear
process in which the nuclei of a heavy atom (e.g., uranium is split by a
neutron, releasing a large amount of energy and additional neutrons.
Fixture
The parts of a
lighting device that include the socket, shade, reflector, internal wiring,
and mounting components.
Flexible-fuel vehicle (FFV)
Vehicles designed to run on all blends up to 85 percent
ethanol and 15 percent gasoline.
Food calorie (abbrev. Cal, kcal;
also Calorie [written with a capital C], Kilocalorie, Large
calorie)
A unit of energy equal to one kilocalorie. The food calorie
is often used when measuring the energy content of food.
Food chain
The transfer of stored (potential
chemical) energy through
a series of organisms, each eating or decomposing the previous one.
Foot candle
A unit of measure of the intensity of light falling on a
surface, equal to one lumen per square foot and originally define with
reference to a standardized candle burning at one foot from a given surface.
Fossil fuels
Carbon-rich fuel formed from the remains of ancient
animals and plants. Coal, oil, and natural gas are all fossil fuels.
Frame
The fixed, outer
portion of a window that holds the sash.
Friction
A force that resists motion between two
objects in contact. Friction results in the conversion of mechanical
energy into waste heat that dissipates into the surrounding environment.
Fuel
Substances that
are burned or consumed by some means to produce energy. Examples of fuels
include coal, food, natural gas, and fissionable uranium.
Fuel cell
An
electrochemical device that converts chemical energy directly into
electricity.
Fuel oil
A liquid fuel
composed of a mixture of medium-sized or heavy hydrocarbons and produced by
refining crude oil. Lighter varieties of fuel oil include diesel fuel,
home-heating oil, kerosene, and jet fuel, while heavier fuel oils are used
by industries, ships, and electric power plants to generate heat and power.
Furnace
1. A type of
space heating system that heats air. The heated air is circulated throughout
a home or building using air ducts and registers. 2. Equipment or enclosure
used to convert energy in a fuel into heat for any purpose; a combustion
chamber.
Fusion (also Nuclear fusion)
A nuclear
process in which the nuclei of two light, non-radioactive elements (such
as isotopes of hydrogen) are forced together at ultra-high temperatures
and pressures to form the nucleus of a slightly heavier element (such as
helium) with the release of substantial amount of energy. The sun's energy
comes from nuclear fusion.
Gasoline
A liquid fuel
composed of a mixture of small, light hydrocarbons and produced by refining
crude oil. Gasoline is mainly used by automobiles, trucks, and other motor
vehicles.
Generator
A device or
machine that converts mechanical energy into electrical energy.
Geothermal energy
Energy produced
by the internal heat of the earth; geothermal heat sources include:
hydrothermal convective systems; pressurized water reservoirs; hot dry
rocks; manual gradients; and magma. Geothermal energy can be used directly
for heating or to produce electric power.
Geothermal heat pump
A system that consists of a series of underground pipes
or loops that takes advantage of the more constant temperatures just six
feet beneath Earth's surface. In winter, Earth's heat is transferred
from the ground to the house or building. In summer, the process is
reversed. Similar to how a refrigerator works, the warmer indoor air is
pumped or drawn back into the cooler ground. Also called ground source
heat pump system.
Global warming
An enhanced
greenhouse effect caused by an increase of human-generated greenhouse gases
resulting in more heat trapped by the atmosphere. A projected climate change
by some scientists. See
Greenhouse effect and
Global climate change.
Global climate
change
An interconnected
chain of climatic events brought about by an increase in trapped heat in the
atmosphere. The trapped heat alters atmospheric processes and their
interaction with the oceans and the land. The climate--the product of that
interaction--changes as well, causing altered weather patterns that bring
unexpected rain or dry spells, sudden severe storms and temperature changes.
Gravitational potential energy
A form of
potential energy in objects by separating them from other objects
against the force of gravity. A rock sitting on top of a cliff has
gravitational potential energy with respect to the ground (the Earth). See
Potential energy.
Grazing food chain
A food chain sequence
beginning with producers converting solar energy to chemical energy in organic compounds, followed by primary consumers eating producers, and
secondary consumers eating primary consumers.
Green building
A sustainable home or commercial structure that is
designed and built in an ecologically balanced and resource-efficient
manner. Green buildings meet objectives such as protecting occupant
health, using energy, water, and other resources more efficiently, and
promoting environmental protection. See Green design.
Green design
The construction or renovation of a building with the
principles of green home design in mind (e.g., Green design follows
sustainable design and construction principles such as the natural
elements of the building site and orientation, resource efficiency,
occupancy health, and takes an integrated whole-building approach. See
Green building and Whole-building design.
Green power
An environmentally friendly electricity product that is
generated from renewable energy sources.
Green
products
The term
"green" is often used as a descriptor to identify environmentally friendly
items.
Greenhouse effect
The process by
which Earth's atmosphere allows solar radiation to reach Earth's surface and
prevents heat radiated back from the surface from escaping into space.
Carbon dioxide and other gases in Earth's atmosphere are responsible for
causing the greenhouse effect.
Grid
Utility electric power distribution system or network.
Grid-tied system
A PV system that is connected to the utility electrical
grid.
Heat
(thermal) energy
The transfer of
energy from one object at a higher temperature to another object at a lower
temperature. Heat can be transferred by conduction, convection, or
radiation. Although technically incorrect, the word heat is often used to
mean "thermal energy.
Heat equivalent
The amount of energy supplied by one resource to
complete a particular task (heating a room) in comparison to if solar
gain were used to complete that task, such as using solar gain to
replace natural gas.
Herbivore
An organism that obtains its food
energy by eating plants. See Primary consumer.
Heterotroph
An organism that cannot synthesize
its own food and is dependent on complex organic substances for nutrition.
Examples of heterotrophs include mammals.
Horsepower
(abbrev. hp)
A unit of power.
One horsepower equals 550 foot-ponds per second or 746 watts. See
Power.
Human energy
Energy produced by a human to do
work or complete a specific task.
Hybrid renewable
energy system
A renewable
energy system that includes two different types of renewable energy
technologies that produce the same type of energy; for e.g., a wind turbine
and a solar photovoltaic array combined to meet a power demand.
Hydrocarbon
An organic
compound containing only carbon and hydrogen. Large, heavy hydrocarbons may
have up to 90 carbon atoms per molecule while small, light hydrocarbons may
have only one to four carbon atoms per molecule. Different types and sizes
of hydrocarbon molecules make up crude oil and natural gas.
Hydroelectric
power
Electricity
produced by the conversion of kinetic energy from falling water using a
generator. See
Hydropower.
Hydrogen
A chemical
element that can be used as a fuel since it has a very high energy content.
Hydropower
Electricity or
mechanical energy produced by the conversion of energy from falling water.
Sometimes used to refer only to the production of electricity from falling
water. See
Hydroelectric power.
Import
bringing products from one country into another.
Incandescent lamp
A lamp that
contains a wire filament that produces light when heated by an electric
current. See
Compact fluorescent lamp.
Incandescent
light bulb
See
Incandescent lamp.
Industrialized nation
Societies that attempt to remake and control their
environment. They have high rates of energy consumption, depend on
sophisticated technologies, and require substantial energy subsidy to
provide energy and materials for residential, commercial, industrial,
agricultural, and transportation needs.
Inefficient
1. Producing only
a small useful output from a large total input. 2. Wasteful of time, energy
or materials; not efficient; ineffective. See
Efficiency,
Efficient.
Insolation
The intensity and duration of solar radiation.
Insulating glass
unit (IG)
A unit consisting of two or more layers of
glass separated by a spacer.
Insulation
Material that
opposes the passage or transmission of heat or electricity.
Inverter
The part of the PV system that converts the solar
generated DC electricity into AC electricity, a form capable of powering
household appliances or back-feeding the utility grid.
Isotope
Different forms of atoms of the same
element that have different numbers of neutrons in their nuclei. An
element may have a number of isotopes. For example, the three isotopes of
hydrogen are protium, deuterium, and tritium. All three have one proton in
their nuclei, but deuterium also has one neutron, and tritium has two
neutrons.
Joule
A unit of energy. One joule equals 0.2388
calories or 0.0009481 Btu.
Kilocalorie (abbrev. Cal, kcal;
also Calorie [written with a capital C], Food Calorie, Large
calorie)
1. A unit of energy equal to 1,000 calories, 4,187 joules, or
3.969 Btu. 2.The amount of energy needed to raise the temperature of one
kilogram of water one degree Celsius. See
Calorie,
Food calorie.
Kilowatt
(abbrev. kW; pl. Kilowatts)
A unit of power
equal to 1,000 watts. See
Watt.
Kilowatt-hour
(abbrev. kWh; pl. Kilowatt-hours)
1. A unit of
energy equal to 3,413 Btu or 3,600,000 joules. 2. An amount of energy that
results from the steady production and consumption of one kilowatt of power
for a period of one hour.
Kinetic energy
The energy possessed by a moving object. The formula for
kinetic energy is 1/2 (mass) x (velocity)2.
Latitude
A measurement of a position on Earth's surface in
relation to the equator (in 90 degree angle increments).
Law of demand
The price of a
good or service is inversely related to the quantity of demanded by
customers, other things being equal or constant. Increasing the price of a
good or service decreases the quantity demanded. Decreasing the price of a
good or service increases the quantity demanded. See
Demand schedule.
Law of supply
The price of a
good or service is directly related to the quantity supplied by producers,
other things being equal or constant. Increasing the price of a good or
service increases the quantity supplied. Decreasing the price of a good or
service decreases the quantity supplied. See
Supply schedule.
Leaking
electricity
The energy used
by an appliance when the appliance is in its lowest power mode (typically
when the appliance is off). A variety of appliances--especially those with
remote control devices--consume electricity even after they are turned off.
Other appliances--including those with built-in clocks--never stop using
electricity.
Light
A form of
electromagnetic radiation composed of different wavelengths ranging from
violet to red that are visible to the naked eye. Light is also a means by
which energy can be transferred.
Light energy
See Light.
Lumen
A measurement of
light output from a lamp, tube, or bulb. See
Light.
Mechanical energy
A combination of potential and
kinetic energy. A spring that is expanding and contracting back and forth
has mechanical energy. See Kinetic energy,
Potential energy.
Megawatt
(abbrev. MW; pl. Megawatts)
A unit of power
equal to one million watts or 1,000 kilowatts. See
Watt.
Meter
A device used to
measure and record the amount of electricity or natural gas a utility
customer uses.
Meter reader
Utility personnel
who read and record information from a customer's electric and natural gas
meters so that energy use and energy costs can be calculated. See
Meter.
Microclimate
Special conditions of light,
moisture, and temperature that occur in a narrowly restricted area within
an ecosystem, for example, under a bush or in a small woodland opening.
Miles per
gallon
A unit of fuel efficiency expressed as the number of miles a vehicle can
travel on one gallon of motor fuel. The higher the miles per gallon
figure for a vehicle, the more fuel efficient it is.
Monocrystalline
PV panels that are typically manufactured with grey or
black, round, semi-circular or square cells.
Motor
A device or machine that converts other
forms of energy into mechanical energy.
Multicrystalline
PV panels that typically square and have a blue
crystalline color.
Natural gas
An odorless,
colorless, gaseous hydrocarbon mixture made up of methane (CH4) and a small
percentage of other light hydrocarbons. Natural gas is found naturally
underground or produced by gasification of coal. Natural gas is the cleanest
burning fossil fuel.
Nitrogen
oxides
(formulas: NO, NO2, N2O)
Gaseous compounds
of nitrogen and oxygen produced directly or indirectly from the combustion
of fossil fuels and from processes used in chemical plants. Three forms of
nitrogen oxides are nitric oxide (NO), nitrogen dioxide (NO2) and
nitrous oxide (N2O). Atmospheric emissions of nitrogen oxide
combine with oxygen to form nitrogen dioxide, which in turn reacts with
water vapor to form nitric acid, a component of acid deposition. Nitrogen
dioxide is listed as a criteria pollutant.
N-layer
A layer of
material used in computer chips, solar cells, and transistors and made by
mixing a semiconductor (such as silicon) with substances that have more
electrons than the semiconductor has. The n-layer has a negative charge and
the excess electrons within it are free to move as part of an electric
current. See
P-layer,
P-N junction,
Semiconductor.
Nonrenewable
energy
Energy derived
from resources
that are either replenished very slowly or are not replenished at all by
natural processes. A nonrenewable resource can ultimately be totally
depleted or depleted to the point where it is too expensive to extract and
process for human use. Fossil fuels are examples of nonrenewable energy
resources.
Nonrenewable
energy resource (see Nonrenewable energy)
Nuclear energy
A form of
potential energy in the he nuclei of atoms and released by fission (the
splitting of nuclei of heavy atoms such as uranium) or by fusion (the
combining of nuclei of light atoms such as hydrogen).
Nuclear fission (or Fission)
Nuclear
fission occurs when a neutron splits the nucleus of a large atom, such as U235,
into two smaller nuclei, releasing energy and additional neutrons.
The extra neutrons then split other nuclei, producing
still more neutrons that split more nuclei, and so on.
This process is called a nuclear chain reaction.
Nuclear waste (also Radioactive waste)
Any
waste that results from using radioactive materials for purposes that
include electricity production by nuclear power plants, defense activities
and nuclear weapons manufacture, medical treatment, nuclear research,
industrial processes, and mining and milling of uranium ore.
Ocean thermal energy conversion (OTEC)
An energy technology that converts solar radiation to
electric power by using the ocean's natural thermal gradient to drive a
power-producing cycle.
Omnivore
An organism that obtains its food
energy by eating both plants and animals. Humans are examples of
omnivores.
Ozone
A colorless, odorless, reactive gas composed of three
oxygen atoms. Ozone located in the stratosphere (the ozone layer) absorbs
ultraviolet radiation that would otherwise be harmful to organisms on
Earth's surface. However, ozone located near Earth's surface adversely
affects human health.
Parallel circuit
(also Parallel connection)
An electrical
circuit in which each component of the circuit (e.g., a set of light bulbs)
is connected across a voltage source (e.g., a battery) so that an electric
current flows through each component along a separate path. See
Series circuit.
Passive solar heat gain
A solar heating system that uses a simple solar
collector, building materials, or an architectural design to capture and
store the sun's heat, but does not include any mechanical system to
transfer the heat to various parts of a home or building.
Passive solar
heating
A solar heating
system that uses a simple solar collector, building materials, or an
architectural design to capture and store the sun's heat, but that does not
include any mechanical system to transfer heat to various parts of a home or
building.
Payback
The amount of time required for positive cash flows to
equal the total investment costs.
Petroleum
A mixture of
liquid, gaseous, and solid hydrocarbon compounds found naturally
underground. The liquid form of petroleum is called crude oil. Petroleum can
be processed (refined) into a number of useful products including asphalt,
diesel fuel, fuel oil, gasoline, jet fuel, lubrication oil, and plastics.
See
Fuel oil,
Gasoline,
Hydrocarbon.
Photon
A particle of light composed of a miniscule quantity of
electromagnetic energy.
Photosynthesis
The process by which green plants
use sunlight to produce carbohydrates such as glucose, other nutrients,
and oxygen from simple compounds such as water and carbon dioxide. In
energy terms, photosynthesis converts solar energy into chemical potential
energy that is in carbohydrates.
Photovoltaic cell
(abbrevs. pv, PV, pv cell; also Solar cell)
A device that
converts solar energy directly into electricity. For example, photovoltaic
cells provide electricity for handheld calculators, watches, battery
chargers, homes, and satellites.
Photovoltaic module
See
Photovoltaic (PV) panel.
Photovoltaic (PV) panel
A flat surface onto which photovoltaic cells are
mounted. Also called modules or arrays. See
Photovoltaic cell.
Photovoltaic (solar) system
A complete PV power system composed of the module (or
array), and balance-of-system (BOS) components including the array
supports, electrical conductors/wiring, fuses, safety disconnects, and
grounds, charge controllers, inverters, battery storage, etc.
Photovoltaics
(PVs)
Of, or related
to, the use of photovoltaic (solar) cells for producing electricity. See
Photovoltaic cell.
P-layer
A layer of
material used in computer chips, solar cells, and transistors and made by
mixing a semiconductor (such as silicon) with substances that have fewer
electrons than the semiconductor has. The p-layer has a positive charge that
aids in the attraction of electrons and the flow of electric current. See
N-layer,
P-N junction,
Semiconductor.
P-N junction
The boundary
between the n-layer and the p-layer in a semiconductor device such as a
solar cell or transistor. The p-n junction forms an electrical barrier that
keeps excess electrons in the n-layer separated from the p-layer, which
allows the device to work properly in an electrical circuit. See
N-layer,
P-layer,
Semiconductor.
Potential energy
The energy in an
object because of its position or the arrangement of its parts. Form of
potential energy include chemical, elastic, electrical (electromagnetic),
gravitational, nuclear, and thermal energy. Potential energy is often
referred to as "stored" energy.
Power
1. The rate in
which energy is transferred or converted per unit of time. 2. The rate in
which work is done. See
Horsepower, Kilowatt, Megawatt, Watt for units of power.
Power plant
(also Electric power plant)
1. A human-made
industrial system composed of machinery, equipment, and structures designed
to convert various energy resources into electricity, usually on a large
scale. Examples include coal-fired and nuclear power plants and
hydroelectric dams. 2. Any human-made equipment or system that produces
power, including the structure that contains it.
Primary consumer
An organism, such as an
animal, that feeds on plants or other producers; an herbivore. See
Herbivore.
Primary energy source
Source of energy either found or stored in nature, such
as the sun, coal, and oil.
Producer
An organism, such as a plant or
bacterium, that uses solar or chemical energy to manufacture the nutrients
and organic compounds it needs from simple inorganic compounds. See
Photosynthesis.
Propane
(formula: C3H8)
A colorless
hydrocarbon fuel that occurs in both gaseous and liquid form and that is
produced from natural gas or crude oil.
Public Service
Commission of Wisconsin
(abbrevs. PSC, PSCW)
The state agency
that regulates Wisconsin's public utilities. PSC personnel investigate,
analyze, and research public service regulatory issues. The PSC staff
includes accountants, engineers, attorneys, consumer specialists and
clerical support staff.
Radiation
Energy transfer, including heat transfer, via
electromagnetic waves.
Rate
The cost per unit
of electricity or natural gas charged to a utility customer. Examples of
rates include $0.60 per therm for natural gas and $0.07 per kilowatt-hour
for electricity.
Reading date
The date when a
meter reader collects consumption information from an electric or natural
gas meter.
Reflect
To bend or throw back light.
Renewable energy
Energy derived
from resources that are regenerative or for all practical purposes cannot be
depleted. Types of renewable energy resources include moving water (hydro,
tidal and wave power), thermal gradients in ocean water, biomass, geothermal
energy, solar energy, and wind energy. Municipal solid waste (MSW) is also
considered to be a renewable energy resource.
Renewable
energy resource
Energy resources
that can be quickly replenished. Certain renewable resources will always be
available no matter how they are used (e.g., solar energy), while other
renewable resources can be depleted when their rate of use exceeds their
rate of replacement (e.g., wood).
Resistance
The opposition of
electric current by a material or electrical device. Electrical energy is
converted into thermal energy and other forms of energy when work is done by
a current to overcome resistance.
Respiration
Process by which the cells of
organisms use oxygen to break down carbohydrates and other nutrients to
release energy and produce carbon dioxide and water as byproducts.
R-value
A measure of the
ability of a material to insulate against heat loss. The higher the R-value,
the better the material is at insulating. R-values are usually expressed in
terms of a standard unit of thickness of the material. For example, loose
fiberglass insulation has an average R-value of 2.7 per inch, while rigid
boards made of expanded polystyrene insulation have an R-value of 4 per
inch.
Sash
The portion of the window that houses the glass
(typically the movable members of a window).
Sash replacement kit
A kit that includes replacement sashes, jamb
liners, and containing hardware.
Seasonally adjusted system
PV systems in where the angle of the panels is increased
15 degrees in the winter and decreased by 15 degrees in the summer.
Second Law of Thermodynamics
1. Each time energy
is converted from one form to another, some of the energy is always
degraded to a lower-quality, more dispersed, less useful form. 2. No
system can convert energy from one form to another useful for with 100
percent efficiency. 3. Energy cannot be spontaneously transferred from a
cold body to a hot body. 4. The entropy of a system increases over time.
Secondary consumer
An organism, such as a
carnivore, that feeds only on primary consumers. See
Carnivore,
Primary
consumer.
Secondary energy resource
Energy resource that is produced from a primary energy
resource using technology (e.g., electricity produced from solar energy
by photovoltaic cells).
Semiconductor
A substance or
material that conducts electricity better than an insulator but not as well
as a conductor. Examples of semiconductors include silicon and germanium.
Series circuit
(also Series connection)
An electrical
circuit in which a voltage course (e.g., a battery) and each component of
the circuit (e.g., a set of light bulbs) are connected one after the other
so that an electric current can only flow along one path. See
Parallel
circuit.
Shortage
A condition that
occurs when the demand for a good or service exceeds its supply. Shortages
occur when the price for a good or service is lower than its equilibrium
price.
Silicon (symbol: Si)
A nonmetallic element (atomic number 14; atomic weight
28.086) that is plentiful in Earth's crust (e.g., sand is silicon
dioxide). Its properties as a semiconductor have led to its use in
computer chips, solar cells, and transistors. Silicon is also used in
glass, pottery, and silicone compounds. See Semiconductor.
Solar access
The availability of unobstructed, direct sunlight.
Solar cell
See Photovoltaic
cell
Solar collector
A piece of equipment or apparatus designed to absorb
sunlight. Collector types include passive solar design; solar thermal
collectors such as flat-plate collectors, which heat water or fluids;
and photovoltaic, or solar electric, collectors.
Solar cooker
See Solar oven.
Solar energy
Electromagnetic
energy transmitted from the sun (solar radiation). The amount that reaches
the earth is equal to one billionth of total solar energy generated, or the
equivalent of about 420 trillion kilowatt-hours.
A colorless gas
with an odor like a struck match produced by burning fossil fuels that
contain a percentage of sulfur such as coal, oil, and natural gas.
Atmospheric emissions of sulfur dioxide combine with water vapor and oxygen
to form sulfuric acid, a component of acid deposition. Sulfur dioxide is
listed as a criteria pollutant.
Sun
A yellow star around which Earth and the other planets
of the solar system orbit. The sun provides nearly all the energy needed
to sustain life on Earth. See Solar energy.
Supply schedule
A chart or table
showing the relationship between the price and quantity of a good or service
demanded by customers according to the law of supply. See
Law of supply.
Surplus
A condition that
occurs when the supply of a good or service exceeds its demand. Surpluses
occur when the price for a good or service is higher than its equilibrium
price.
Sustainable
society
Society based on
working with nature by recycling and reusing discarded matter, conserving
matter and energy resources by reducing unnecessary waste and use, and by
building things that are easy to recycle, reuse, and repair.
Switch
A device used to
open or close an electric circuit or to divert electric current from one
part of a circuit to another.
System
1. A group of interacting, interrelated,
or interdependent parts made up of matter and energy that form a complex
whole. 2. Anything that uses matter and energy to organize, maintain, or
change itself (e.g., the sun, a glass of water, a frog, a city).
Temperature
The level of heat
(thermal energy) in a substance, an object, or the surrounding environment
as measured on a standard scale. In other words, temperature refers to
whether something is hot or cold. See Thermometer.
Temperature control
Operable vents and dampers, automatic thermostats,
window quilts, and landscaping techniques are all examples of how
temperature can be regulated within a structure.
Therm
(pl. Therms)
A unit describing
energy contained in natural gas. One therm equals 100,000 Btu. See
Btu.
Thermal energy
The total internal kinetic and potential energy of an
object due to the random motion of its atoms and molecules. An object
that feels hot has more thermal energy inside it than it does after it
has cooled down. Although technically incorrect, the word "heat" is
often used to mean thermal energy. See
Heat (thermal) energy.
Thermal mass
The material that retains or stores the sun's heat and
energy when it strikes an absorber.
Thermometer
An instrument,
used to measure temperature, that is made up of a glass tube marked with a
scale and filled with a liquid (e.g., mercury, alcohol) that rises in the
tube as temperature increases. A thermometer may use either a Celsius,
Fahrenheit, or Kelvin temperature scale. See
Temperature.
Tilt angle
See Elevation.
Tracker
PV systems that include a drive mechanism that
automatically will move the panel to follow the sun.
Transmission
The system that transfers energy from the motor to the
wheels, also responsible for trading speed for torque.
Trophic level
A feeding level in a food
chain in which an organism belongs. For example, producers (e.g., plants)
are members of the first trophic level. See
Consumer,
Producer.
Turbine
A machine that
converts the kinetic energy of a moving fluid (e.g., pressurized steam) into
mechanical energy (the rotating motion of a shaft).
Turbulence
Irregular motion in regards to atmosphere.
U-factor
A measure of the rate of heat loss through a
material or assembly. For windows, the U-factor is typically stated for the
entire window product. The lower the U-factor, the lower the heat loss.
Volt
(abbrev. V; pl. Volts)
A unit of voltage
(potential difference). One volt is equal to performing one joule of work to
move or separate one coulomb (6.25 x 1,018) of electrons.
Water
A transparent, odorless, tasteless liquid; a compound of
hydrogen and oxygen, H20, that constitutes rain, oceans, lakes,
and rivers.
Water cycle
A biogeochemical cycle in which water
is used, collected, distributed, and exchanged between organisms and
Earth's environment.
Watt
(abbrev. W; pl. Watts)
A unit of power.
One watt equals the production or use of one joule per second. See
Kilowatt,
Megawatt,
Power.
Wave power
The
concept of capturing and converting the energy available in the motion of
ocean waves to energy.
Whole-building design
Consideration of all construction components during the
design phase of buildings, including the interrelation of building site,
energy use, green materials, indoor air quality, acoustics, natural
resources.
Wind
The movement and circulation of Earth's atmosphere near
its surface; moving air.
Wind energy
Energy
available from the movement of air across a landscape caused by the
heating of the atmosphere, earth, and oceans by the sun.
Wind generator
A generator specifically designed to convert the kinetic energy in wind into
electrical energy. See Generator.
Wind turbine
A mechanical structure with rotating blades that are
mechanically coupled to an electrical generator. See
Generator.
Windmill
An engine powered by the energy of wind. It often refers
to small tower mounted wind engines used to pump water on farms.
Window parts
Head (top), Jamb (sides), Sill (bottom), Meeting Rail (center horizontal or
vertical mullion), Stool (trim piece on exterior of jamb).
Work
The transfer of energy from one object or system to
another by applying a force over a distance. The formula for work is
(force) x (distance).
Send comments and suggestions to KEEP,
energy@uwsp.edu
or call 715-346-4770.
Copyright 2001 KEEP
