Current in which charged particles travel through a circuit in one direction.
alternating current (AC)
current in which electrons move back and forth in a circuit.
transformer
an electrical device that changes the size of the potential difference of an alternating current.
eg. step-up transformers
circuit breaker
a safety device that is placed in series with other circuits, which lead to appliances and outlets.
fuse
a safety device that is found in older buildings and some appliances; like a circuit breaker it is placed in series with other circuits, that lead to appliances and outlets
electrical power
the rate at which an appliance uses electrical energy.
watt (W)
a unit of electrical power.
eg. clothes dryer= 5000W
kilowatt (kW)
a practical unit of electrical power; 1 kW = 1000 W
eg. clothes dryer=5kW
electrical energy
the energy that is used by an appliance at a given setting; determined by multiplying the power ratio of an appliance by the length of time it is used.
kilowatt-hour (kW x h)
the practical unit of electrical energy.
eg. electric clothes dryer= 912kW x h/year
EnerGuide label
a label that gives details about how much energy an appliance uses in one year of normal use.
smart meter
a meter that records the total electrical energy used hour by hour and sends this information to the utility company automatically.
time of use pricing
a system in which the cost of each kW x h of energy used is different at different times of the day.
phantom load
the electricity that is consumed by an appliance or device while it is turned off.
eg. clock displays that require phantom loads.
efficiency
the ratio of useful energy output to total energy input, expressed as a percentage.
eg. Percent efficiency=useful energy output/total energy input x 100%
base load
the continuous minimum demand for electrical power.
hydroelectric power generation
the generation of electrical power using a source of moving water.
eg. the James Bay hydroelectric project in Quebec.
renewable energy source
a source of energy that can be replaced in a relatively short period of time.
eg. hydroelectric energy
non-renewable energy source
a source of energy that cannot be replaced as quickly as it is used.
eg. coal
intermediate load
a demand for electricity that is greater than the base load, and is met by burning coal and natural gas.
peak load
the greatest demand for electricity; which is met by using hydroelectric power and natural gas.
wind farm
many large wind turbines at one location.
solar energy
energy that is directly converted from the Sun into electricity
photovoltaic effect
the generation of a direct current when certain materials are exposed to light.
biomass energy
energy that is generated from plant and animal matter