Explanation of Solar Terms

---

Glossary of Electrical Terms

What Is A Watt? (With Power usage Chart)

---

Glossary of Electrical Terms
By Charlie Collins

… alternating current (ac)an electrical current in which the current periodically reverses its direction of -flow many times per second

… alternator an electrical generator that produces alternating current

… ammeter a device used for measuring current in amps

… BTU British Thermal Unit: -a unit of energy used in heating --1 watt-hr = 3.413 BTU

… charge controller a device which regulates the voltage of a battery to insure that it is not over charged

… cycle one complete charge/discharge cycle of the battery

… deep cycle battery a battery designed to regularly discharge 60 to 80 percent of its capacity before recharging

… depth of discharge the amount of energy withdrawn from a battery expressed as a percentage -of its rated capacity

… diode a device which allows electrical current to -flow through it in only one direction

… direct current (DC) an electrical current which flows in one direction only

… equalizing charge a controlled overcharge of a battery to restore all the individual - cells within the battery

… insolation the amount of solar energy striking a surface, measured -in watts per square meter

… inverter a device which converts battery stored DC voltage / current to ac voltage/current

… line/wire loss refers to the voltage or power lost due to the resistance of any wire - in any electrical circuit

… linear current booster (LCB) an electronic circuit that matches PV output directly to a motor

… load refers to any electrical device which draws current -from a source, for ex. any household appliance

… lumen a unit of measurement quantifying the amount of light emitted -from a light source similar to candle light

… ohm resistance to electrical -flow

… parallel connection and electrical circuit with more than one possible path for electricity to flow .

… photovoltaic (PV) refers to any device which produces free electrons when exposed to sun and therefore generates electricity

… power describes the rate of energy use per unit time, measured -in watts

… PV array two or more photovoltaic (solar electric) panels

… resistance refers to the resistance of a material to the flow -of electrons

… self-discharge represents -energy lost to internal chemical reactions within the battery cell.

… series connection an electrical circuit with only one possible path for electrical flow .

… shunt a resistive load through which electricity is diverted

… surge capacity refers to the maximum amount of ac power a inverter may deliver to a load for a second or two .

… tracker any device used direct solar panels to the sun .

… volt (V) the unit of measurement that measures difference -in the strength of the electric field

… voltmeter a device for measuring the voltage in an electrical circuit .

… watt a unit of measurement of power

---

What Is A Watt?

© Copyright 1995 By Charlie Collins From "Ask Mr. Solar" Column Published October 10, 1993 Daily Spectrum

Question:I don't know the difference between watts, amps and volts. I feel that if I understood this difference then I would be in a better position to realize what is happening in our home. I would like to learn more about electrical equipment. I realizer that some electrical appliances use much more electricity than others and therefore I think that I should know what is going on. Would you please explain this to me in turns that I can understand.

Jane T., Cane Beds AZ.

Mr. Solar: Jane, This is a very timely question. First you should understand that watts are the total of volts times amps. A Volts is the electrical potential similar to the pressure in a water system. An amp is the electrical current flowing and watts was the total electrical power generated or used. Electrical power is the rate which electricity is used and measured in watts. This is better understood by the formula:

Power(watts) = Voltage (V) X Current (Amps)

As you know many appliances are rated in either watts or amps at a given voltage. You are charged for the power that you use in kilowatts, which is 1,000 watts of power. As you can see by the above formula the power or watts of an appliance is measured by the increase of the amps. The power companies charge approximately $0.07 per kilowatt used. This is measured on the meter and a bill is sent to the home owner. When we use solar to generate electricity we are using the sun and there is no monthly bill. Listed below is an outline of popular items in the home and their cost to operate using grid power. If you have your own electrical system as we do then you can better understand the need for energy efficient appliances. Please note the chart below and you will see where your moneys go