The voltage(s) at which the controller will take
action to protect the batteries.
Amperage interrupt capability. DC fuses should be rated with a sufficient
AIC to interrupt the highest possible load.
Alternating Current (AC):
Electrical current (flow of electrons) in which
the direction of flow is reversed at constant intervals, such as 60 cycles
A collection of photovoltaic modules electrically wired together
in one structure to produce a specific amount of power.
British Thermal Unit (Btu):
The quantity of heat needed to raise the
temperature of 1 pound of water by 1°F at or near 39.2°F.
Centrifugal Pump (rotating pump):
A water pump using a rotating element
or screw to move water. The faster the rotation, the greater the flow.
A component of a photovoltaic system that controls
the flow of current to and from the battery subsystem to protect batteries
from overcharge, over discharge, or other control functions. The charge
controller may also monitor system operational status.
The production of electricity and another form of useful
energy (such as heat or steam) used for industrial, commercial, heating,
or cooling purposes.
A building with more than 50 percent of its floor
space used for commercial activities. Commercial buildings include stores,
offices, schools, churches, gymnasiums, libraries, museums, hospitals,
clinics, warehouses, and jails. Government buildings are also included,
except buildings on military bases or reservations.
Business establishments that are not engaged in transportation
or in manufacturing or other types of industrial activity (agriculture,
mining, or construction). Commercial establishments include hotels, motels,
restaurants, wholesale businesses, retail stores, laundries, and other
service enterprises; religious and nonprofit organizations; health, social,
and educational institutions; and federal, state, and local governments.
Street lights, pumps, bridges, and public services are also included if
the establishment operating them is considered commercial.
A number that translates units of one system into
corresponding values of another system. Conversion factors can be used
to translate physical units of measure for various fuels into Btu equivalents.
Direct Current (DC):
Electric current (flow of electrons) in which the flow is in only one direction.
Displaced or Volumetric Pump:
A type of water pump that utilizes a piston,
cylinder and stop valves to move packets of water.
Steam or hot water from an outside source used as an energy
source in a building. The steam or hot water is produced in a central
plant and is piped into the building. District heat may be purchased from
a utility or provided by a physical plant in a separate building that
is part of the same facility (for example, a hospital complex or university).
The amount of time an inverter (power conditioning unit)
can produce at full rated power.
The vertical distance from the center of the pump to the
point of free discharge of the water. Pipe friction is included.
Electric Power Plant:
A station containing prime movers, electric generators,
and auxiliary equipment for converting mechanical, chemical, and/or fission
energy into electric energy.
The process of producing electric energy or transforming
other forms of energy into electric energy. Also, the amount of electric
energy produced or ex pressed in watt-hours (Wh).
The residential, commercial, industrial, and transportation
sectors of the economy.
The capacity for doing work as measured by the capability of
doing work (potential energy), or the conversion of this capability to
motion (kinetic energy). Energy has several forms, some of which are easily
convertible and can be changed to another form useful for work. Most of
the world’s convertible energy comes from fossil fuels that are
burned to produce heat that is then used as a transfer medium to mechanical
or other means in order to accomplish tasks. Electrical energy is usually
measured in kilowatt-hours, while heat energy is usually measured in British
The use of energy as a source of heat or power or
as an input in the manufacturing process.
The ratio of the energy available from a battery to its
volume (wh/m^3) or weight (wh/kg).
A substance, such as oil, natural gas, or coal, that supplies
heat or power. Electricity and renewable forms of energy, such as wood,
waste, geothermal, wind, and solar, are considered to be energy sources.
Shipments of goods from the 50 states and the District of Columbia
to foreign countries and to Puerto Rico, the Virgin Islands, and other
U.S. possessions and territories.
Federal Energy Regulatory Commission (FERC):
The federal agency with
jurisdiction over interstate electricity sales, wholesale electric rates,
hydroelectric licensing, natural gas pricing, oil pipeline rates, and
gas pipeline certification. FERC is an independent regulatory agency within
the Department of Energy and is the successor to the Federal Power Commission.
The energy that must be overcome by the pump to offset
the friction losses of the water moving through a pipe.
High Voltage Disconnect Hysteresis:
The voltage difference between the
high voltage disconnect set point and the voltage at which the full PV array
current will be reapplied.
Independent Power Producer:
Wholesale electricity producers (other than
qualifying facilities under the Public Utilities Regulatory Policies Act
of 1978) that are unaffiliated with franchised utilities in the area in
which the independent power producers are selling power and that lack
significant marketing power. Unlike traditional electric utilities, independent
power producers do not possess transmission facilities that are essential
to their customers and do not sell power in any retail service territory
where they have a franchise.
Manufacturing industries, which make up the largest
part of the sector, along with mining, construction, agriculture, fisheries,
and forestry. Establishments in this sector range from steel mills, to
small farms, to companies assembling electronic components.
The amount of energy in sunlight reaching an area. Usually
expressed in watts per square meter (W/m^2), but also expressed on a daily
basis as watts per square meter per day (W/m^2/day).
Any device or appliance in an electrical circuit that uses power,
such as a light bulb.
Low Voltage Disconnect Hysteresis:
The voltage difference between the
low voltage disconnect set point and the voltage at which the load will
Low Voltage Warning:
A warning buzzer or light that indicates the low
battery voltage set point has been reached.
A number of photovoltaic cells wired together to form a unit,
usually in a sealed frame of convenient size for handling and assembling
into arrays. Also called a panel.
Metal Oxide Varistor. Used to protect electronic circuits from
surge currents such as produced by lighting.
National Electrical Manufacturers Association. This organization
sets standards for some non-electronic products like junctions boxes.
North American Electric Reliability Council (NERC):
A council formed
in 1968 by the electric utility industry to promote the reliability and
adequacy of bulk power supply in the electric utility systems of North
America. The NERC consists of ten regional reliability councils and encompasses
essentially all the power systems of the contiguous United States and
Organization for Economic Cooperation and Development (OECD):
members are Australia, Austria, Belgium, Canada, Czech Republic, Denmark
and its territories (Faroe Islands and Greenland), Finland, France, Germany,
Greece, Greenland, Hungary, Iceland, Ireland, Italy, Japan, Luxembourg,
Mexico, the Netherlands, New Zealand, Norway, Poland, Portugal, South
Korea, Spain, Sweden, Switzerland, Turkey, United Kingdom, and United
States and its territories (Guam, Puerto Rico, and Virgin Islands).
Organization of Petroleum Exporting Countries (OPEC):
have organized for the purpose of negotiating with oil companies on matters
of oil production, prices, and future concession rights. Current members
are Algeria, Indonesia, Iran, Iraq, Kuwait, Libya, Nigeria, Qatar, Saudi
Arabia, United Arab Emirates, and Venezuela.
Gas by-products, primarily hydrogen, produced when
charging a battery. Also, termed out-gassing.
Peak Sun Hours:
The equivalent number of hours when solar insolation averages
1000 watts per square meter and produces the same total insolation as
actual sun conditions.
Direct-current electricity generated from sunlight
through solid-state semiconductor devices that have no moving parts.
Photovoltaic (PV) System:
A complete set of interconnect components for
converting sunlight into electricity by the photovoltaic process, including
array, balance-of-system components, and the load.
An instrument used for measuring direct beams of solar
irradiance. Uses an aperture of 5.7 deg. to transcribe the solar disc.
Energy obtained from sources that are essentially inexhaustible
(unlike, for example, fossil fuels, of which there is a finite supply).
Renewable sources of energy include conventional hydroelectric power,
wood, waste, geothermal, wind, photovoltaic, and solar thermal energy.
Root Mean Square (RMS):
The square root of the average square of the
instantaneous values of an AC output. For a sine wave the RMS value is
0.707 times the peak value. The equivalent value of AC current, I, that
will produce the same heating in a conductor with resistance, R, as a
DC current of value I.the corrosion of the protected structure.
The vertical distance from the water level to the point
of free discharge of the water. It is measured when the pump is not operating.
A piece of metal buried near a structure that is
to be protected from corrosion. The metal of the sacrificial anode is intended
to corrode and reduce the corrosion of the protected structure.
Solar Insolation (Insolation):
The solar radiation incident on an area
over time. Equivalent to energy and usually expressed in kilowatt-hours
per square meter.
Supplies of fuel or other energy source(s) stored for future
use. Stocks are reported as of the end of the reporting period.
This term has dual meaning for water pump systems. Storage can
be achieved by pumping water to a storage tank, or storing energy in a
The vertical distance from the surface of the water source
to the center of the pump (when the pump is located above the water level).
TC, TW, THHN, UF, USE (Wire Types):
See article 300 of National Electric
Code for more information.
Private and public vehicles that move people and
commodities. Included are automobiles, trucks, buses, motorcycles, railroads,
and railways (including streetcars), aircraft, ships, barges, and natural
A voltage-dependant variable resistor. Normally used to protect
sensitive equipment from power spikes or lightning strikes by shunting
the energy to ground.
A measure of the force or "push" given the electrons
in an electrical circuit; a measure of electrical potential. One volt
produces one amp of current when acting against a resistance of one ohm.
A measure of electrical power or amount of work done in a unit
of time and equal to the rate of current flow (amps) multiplied by the
voltage of that flow (volts). One amp of current flowing at a potential
of one volt produces one watt of power.
The kinetic energy of wind converted into mechanical energy
by wind turbines (i.e., blades rotating from a hub) that drive generators
to produce electricity.