A. As used in this article, the following electricity and energy terms shall have the meanings indicated:
ALTERNATING CURRENT (AC) — An electric current whose direction reverses cyclically, as opposed to
, whose direction remains constant. AC is the form of consumer electricity that is delivered to a home or business.
ALTERNATIVE ENERGY — As used in this chapter, the term “alternative energy” shall include geothermal energy,
, wind energy, and
energy sources. Alternative energy sources may at times be referred to as renewable energy sources.
DIRECT CURRENT (DC) — The constant flow of electric current in one direction. DC electricity always flows in the same direction, which distinguishes it from
.
ELECTRIC METER — A device used to measure and record the amount of electricity used or generated.
INTERCONNECTION — Interfacing an on-site electricity generator, to the electric distribution system (i.e., the grid). This configuration allows an on-site electricity generating system to operate in parallel with the grid. For small systems, the point of interconnection is through a circuit breaker of the main electric service panel on-site, or it could be a supply tap on the service line just before the main electric service panel.
INTERCONNECTION AGREEMENT — A legal document between a customer and an electric utility authorizing the connection of the customer’s on-site electricity generating system to the utility’s electric grid.
INVERTER — A device that converts
electricity into
electricity that can be used in a home or
.
LOAD — The amount of power carried by a utility system or the amount of power consumed by an electric customer at a specific time. Base load is the minimum constant level of electricity required by utility customers; peak load is the amount of electricity required at the time of greatest demand.
NET METERING — An approach for interconnecting and metering on-site electricity generating facilities. The means of measuring the difference between electricity supplied by an electric utility, electric distribution company, or electric generation supplier and the electricity generated by a customer-generator using
sources. Net metering allows customers to use excess on-site generated electricity to offset utility- purchased electricity on a monthly or annual basis.
NET METERING AGREEMENT — An agreement with a customer-generator and an electric utility, electric distribution company, or electric generation supplier and the electricity generated by a customer generator that allows customers to receive a credit at the retail price of electricity for surplus electricity generated on-site. Under
agreement, a bidirectional
is used to measure and record the flow of electricity in both directions from and to the customer-generator.
POWER PURCHASE AGREEMENT (PPA) — A contract to purchase energy. A PPA is usually established between a party that generates electricity and a party that purchases electricity. A PPA may also be a contract written between a
owner that wants to generate electricity on site and a third-party developer who will install, maintain and own the system used to generate the electricity, and then sell the electricity produced by the system to the
owner at a pre-determined rate.
TIME-OF-USE (TOU) METER — An
that measures and records the times when a customer consumes or generates electricity during utility defined on-peak and off- peak periods. This type of meter is used for customers who are on
.
TIME-OF-USE (TOU) RATES — Electricity prices that vary depending on the time period in which the energy is consumed or produced. In a time-of-use rate
, higher prices are charged during utility peak-
times. Such rates can provide an incentive for consumers to curb power use during peak times.
TONNAGE — A measure of cooling power. One ton of cooling power is produced by one ton of ice. One ton of cooling power is equal to 12,000 Btu/hr or 3.51 kW. In the United States, heat pumps and air conditioners are rated on tonnage. A typical U.S. residence of 2,000– 2,400 square feet will require a three to four ton cooling unit.
WATT — A unit of electric power measurement.
KILOWATT (kW) — A unit of electric power equal to 1,000
, which constitutes the basic unit of electric demand. The
is a measurement of power (not energy) and is the rate (not the duration) at which electricity is used. One thousand kW is equal to one
(MW).
KILOWATT—HOUR (kWh) — A unit of electric energy, equivalent to the use of one
of electricity for one full hour. One kilowatt-hour (kWh) = the amount of electricity required to burn a 100
light bulb for 10 hours. Utilities measure customers’ electric energy usage on the basis of
, and electricity rates are most commonly expressed in cents per kilowatt-hour.
MEGAWATT (MW) — Unit of electric power equal to 1,000 kW, or 1,000,000
.
WATT-HOUR (Wh) — A unit of energy measurement, equal to one
of power used for one hour.
B. As used in this article, the following geothermal energy terms shall have the meaning indicated:
GEOTHERMAL BOREHOLE or BOREHOLE — A hole drilled or bored into the earth into which piping is inserted for use in a
.
GEOTHERMAL ENERGY SYSTEM — An
system serving as a mechanism for heat exchange that
the Earth’s thermal properties in conjunction with electricity to provide greater efficiency in the heating and cooling of
. The most common form of geothermal energy in Pennsylvania comes from shallow bore heat pumps, which capitalize on the constant temperature within the Earth’s upper crust. A fluid in a system of tubes is used to transfer energy to and from the Earth to provide cooling in the summer and warmth in the winter.
are drilled and pipes are buried in the ground. Fluid is circulated through the system. In summer, the fluid takes heat from a
and moves it to the Earth. In winter, the fluid absorbs heat from the Earth and transfers it to the
. Geothermal heat pumps come in two basic configurations: closed loop and open loop systems.
CLOSED HORIZONTAL LOOP GEOTHERMAL SYSTEM — A mechanism for heat exchange that consists of the following basic elements: underground loops of piping; heat transfer fluid; a heat pump; and an air distribution system. An opening is made in the Earth. A series of pipes are installed into the opening and connected to a heat exchange system in the
. The pipes form a closed loop and are filled with a heat transfer fluid. The fluid is circulated through the piping from the opening into the heat exchanger and back. This type of geothermal system is usually the most cost effective when trenches are easy to dig and the available land area is adequate. Workers use a backhoe to dig the trenches three to six feet below the ground in which they lay a series of parallel plastic pipes. A typical horizontal loop will require 400–600 feet of tubing per ton of heating and cooling capacity.
CLOSED VERTICAL LOOP GEOTHERMAL SYSTEM—This type of geothermal mechanism for heat exchange is used where there is little available land area, when surface rocks make digging impractical, or when disruption to the landscape is to be avoided. Vertical
approximately 100 to 450 feet deep are bored into the ground, and a single loop of pipe with a U-bend at the bottom of the
is inserted before the
is filled. The pipes are connected to the heat exchanger and heat transfer fluid is circulated through the pipes.
OPEN HORIZONTAL LOOP GEOTHERMAL SYSTEM — Water is pumped from a water-well or surface water source into a heat exchanger located in a
. The water drawn from the Earth or water body is then pumped back into the ground or discharged to the water body. In the heating mode, cooler water is returned to the Earth or water body, and in the cooling mode, warmer water is returned to the Earth or water body.
STANDING COLUMN WELL GEOTHERMAL SYSTEM — A standing column well geothermal system is a specialized type of open loop system. It is a groundwater heat pump system that
groundwater drawn from wells in a semi-open loop arrangement. The ground heat exchanger in such systems consists of a vertical
that is filled with groundwater up to the level of the water table. Water is circulated from the well through the heat pump in an open-loop pipe circuit. Water is drawn from the bottom of a deep rock well, passed through a heat pump, and returned to the top of the well, where traveling downwards it exchanges heat with the surrounding bedrock.
C. As used in this article, the following
terms shall have the meaning indicated:
ACTIVE SOLAR ENERGY SYSTEM — Photovoltaic (PV) panels or solar thermal collectors that harness
. Active
increase the supply of energy and are considered supply side technologies.
ALBEDO — The ratio of reflected radiation from a surface to the incident radiation upon the surface (i.e., the reflection coefficient). Albedo is a measure of the reflectivity of a surface and may be used to quantify the amount of
from a
.
ARRAY — An assembly of electrically interconnected photovoltaic
providing a single electrical output.
ARRAY AREA — The total photovoltaic area of an entire solar field of
.
AZIMUTH — The horizontal angular distance between a vertical plane containing a point in the sky and true south.
BUILDING INTEGRATED PHOTOVOLTAIC (BIPV) SYSTEM — A BIPV system forms part of the
to which it is affixed. Typically integrated into a roofing system (e.g., solar shingles), BIPV systems can provide architectural interest and/or an unobtrusive
installation.
CONVERSION EFFICIENCY — The amount of the sun’s energy that a solar cell can convert into electricity; the balance is lost as heat or reflected light.
INSOLATION — The amount of
that shines on a
or area and usually expressed in annual
per square meter.
MODULE — An assembly of electrically interconnected PV cells providing a single electrical output. Modules are typically rated between 10
and 300
.
ORIENTATION — The direction that the surface of a solar
faces. The two components of orientation are the tilt angle (the angle of inclination a
makes from the horizontal) and the
.
PASSIVE SOLAR ENERGY SYSTEM — A
collection system that captures light or heat from the sun through use of materials with favorable thermal mass or light dispersing properties. Passive
are demand side systems and may be used to heat water, air, other
mass, or to direct sunlight into a
for illumination purposes.
SOLAR ACCESS — The ability of sunlight to shine on a property owner’s land, or more specifically, the owner’s
or
, without the sunlight being blocked by
, vegetation, or other obstructions on neighboring land.
SOLAR EASEMENT — A legal agreement that protects access to sunlight, or
, on a property.
SOLAR ELECTRIC SYSTEM — Converts sunlight into electricity. Also known as a “photovoltaic system.”
SOLAR ENERGY — Radiant light and heat from the sun.
SOLAR ENERGY FACILITY— An
facility that consists of one or more ground-mounted or free-standing solar collection devices,
related equipment and other associated infrastructure with the primary intention of generating electricity or otherwise converting
to a different form of energy for commercial or other off-site
.
SOLAR ENERGY SYSTEM — An
system that consists of one or more ground-mounted, free-standing, or
-mounted solar collection devices and
related equipment and other associated infrastructure with the primary intention of generating electricity or otherwise converting
to a different form of energy to reduce on-site consumption of purchased power, except that when a property upon which the system is installed also receives electricity supplied by a utility company, excess electricity generated and not presently needed for on-site
may be used off-site by a utility company.
SOLAR GLARE — The effect produced by light reflecting from a
with an intensity sufficient to cause annoyance, discomfort, or loss in visual performance and visibility. See “
” definition.
SOLAR HOT WATER SYSTEM — Uses
to heat water. The most common types of solar water heaters are evacuated tube collectors and glazed flat plate collectors generally used for domestic hot water; and unglazed plastic collectors used mainly to heat swimming pools.
SOLAR PANEL — A device containing one or more receptive cells equal to or greater than two square feet, the purpose of which is to convert
into electrical or thermal energy.
SOLAR PHOTOVOLTAIC (PV) SYSTEM —
that uses a semiconductor to convert sunlight directly into electricity. A solar cell, or photovoltaic (PV) cell, converts sunlight into electric current using the photoelectric effect. A flow of
electricity is produced when sunlight strikes solar cells containing a photovoltaic material. The DC energy produced by the
is then fed into an
that converts DC power into AC power, which in turn is fed into a main electrical panel to power a home or business. A PV solar cell produces a small amount of power. To produce more power, PV cells (about 40) may be interconnected to form PV panels or PV
. If more power is needed, several PV
may be installed in a rack to form a PV
.
SOLAR RELATED EQUIPMENT — Items including a solar photovoltaic cell, panel,
or
, or solar hot air or water collector device panels, lines, pumps, batteries, mounting brackets, framing and foundations used for or intended to be used for collection and conversion of
.
SOLAR THERMAL SYSTEM — Uses
to heat a fluid, such as water or an antifreeze solution, or to heat a gas, such as air. Solar thermal systems are most commonly utilized for heating domestic hot water systems, though they are also used for space heating, heating swimming pools, and even space cooling.
TRACKER OR TRACKING ARRAY — A number of PV
mounted such that they track the movement of the sun across the sky to maximize energy production, either with a single-axis or dual-axis mechanism.
D. As used in this article, the following wind energy terms shall have the meaning indicated:
ARCHITECTURALLY INTEGRATED WIND ENERGY SYSTEM — A
installed directly onto a
rooftop or designed as part of a
itself.
HUB HEIGHT — The vertical distance measured from the ground at a
foundation to the height of a
hub.
ROOF MOUNTED — A wind energy system installation where the system is mounted on the roof of and totally supported by a
.
ROTOR DIAMETER — The cross sectional dimension of the circle swept by the rotating blades of a
.
SHADOW FLICKER — The on-and-off flickering effect or alternating changes in light intensity caused by moving
blades casting shadows on the ground and on stationary objects.
TOWER — The monopole or freestanding
that supports a
.
TURBINE HEIGHT — the vertical distance measured from the ground at the
foundation to the tip of a
blade when the blade tip is at its highest point.
WIND ENERGY FACILITY — An
facility that consists of one or more
and other associated infrastructure with the primary intention of generating electricity for commercial or other off-site
. The term does not include
constructed primarily to generate electricity or otherwise convert wind energy for on-site
.
WIND ENERGY SYSTEM — An
system that converts wind energy into electricity or other usable forms of energy for on-site
. This equipment includes any base, blade, foundation, generator, nacelle, rotor,
, transformer, vane, wire,
, batteries or other component used in the system. A wind energy system is intended to primarily reduce on-site consumption of purchased power, except that when a parcel on which the system is installed also receives electricity supplied by a utility company, excess electricity generated and not needed for on-site
may be used off-site by a utility company.
WIND MILL — A
that uses wind energy to power mechanical equipment such as a water pump. For the purposes of this article, a wind mill shall be considered as a form of
.
WIND TURBINE — A wind energy conversion system that converts wind energy into electrical energy (i.e., electricity) or mechanical energy through the use of a
or other mechanism. When the wind spins the
’s blades, a rotor captures the kinetic energy of the wind and converts it into rotary motion to drive an electric generator. Wind turbines fall into two general classes depending on how they spin: horizontal axis and vertical axis. Vertical axis machines spin about an axis perpendicular to the ground and are usually ground mounted. Horizontal axis machines spin about an axis parallel to the ground, are usually
mounted, and are the dominate type of
.
WIND TURBINE GENERATOR — The blades and associated mechanical and electrical conversion components used to generate electricity through the conversion of wind energy to electrical energy.
E. As used in this article, the following
energy terms shall have the meaning indicated:
BIOMASS — Biological material, including plant matter such as wood, used as an energy source.
CLEAN WOOD — Natural wood that has been seasoned to reduce its water content and provide more efficient combustion. The term clean wood does not include wood that has been altered as follows:
(a) Coated with paint, stain, oil, resin or any other preservative, fire retardant or decorative materials.
(b) Impregnated with preservatives or fire retardants.
(c) Exposed to salt water.
(d) Manufactured with use of adhesives, polymers or resins, such as oriented strand, particle and veneer lumber and recycled lumber.
OUTDOOR WOOD-FIRED BOILER (HYDRONIC HEATER) — A fuel-burning device; also known as an outdoor hydronic heater, outdoor wood-fired furnace, outdoor wood-burning appliance, or wood-fired boiler; that is used as an
system. The outdoor wood-fired boiler is a variant of the classic indoor wood stove or boiler. An outdoor wood- fired boiler is designed for installation outdoors to transfer heat to
interiors. It often resembles a small shed with a smokestack on top. An outdoor wood-fired boiler works by heating a water jacket that surrounds the firebox. The heated water is then used to transfer heat to a heating system in a
. An outdoor wood-fired boiler is designed to:
(a) Burn
or other fuels specifically tested and listed for use by the manufacturer.
(b) Operate outdoors or in
not normally intended for habitation by humans or domestic animals (e.g., garages).
(c) Heat
space and/or water via distribution, typically through pipes, of a fluid heated in the device, typically water or a water/antifreeze mixture.
PHASE 2 OUTDOOR WOOD—FIRED BOILER (HYDRONIC HEATER) — An outdoor wood-fired boiler that has been certified or qualified by the U.S. Environmental Protection Agency as meeting a particulate matter emission limit of 0.32 pounds per million British Thermal Units (BTU) output.
STACK — A vertical
enclosing a flue(s) to carry off smoke or exhaust from a furnace or other fuel-burning device such as a wood-fired boiler.