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Basic units in electricity

Basic units in electricity
- Watt (W) is a unit of power. A watt (W) is a joule (J) of energy used or produced per second.Alsoa watt is a method of measuring the rate of energy transfer of an appliance
- Voltage(V) is measured in volts. The pressure that allows electrons to flow
- Current(I) is the rate at which electric charge flows in a circuit at a particular point / how quickly electrons move in a wire.
- Amperage(amps) is measure of current / measure of the volume of electrons / movement of charge per second
- Resistance (R) is measured in ohms.
DC stands for Direct Current, DC current is defined as a unidirectional flow of electric charge. In DC current, the electrons move from an area of negative charge to an area of positive charge without changing direction
ACalternating current circuits where current can flow in both directions.

Single Phase vs Three Phase

Phase refers to the distribution of a load.
Single-phase power is a two-wire alternating current (ac) power circuit. Typically, there is one power wire—the phase wire—and one neutral wire, with current flowing between the power wire (through the load) and the neutral wire.
Three-phase power is a three-wire AC power circuit with each phase AC signal 240 Volts

PV Module Specifications Terms

PV Module Specifications Terms. You will find this information on the backside of every PV Panel

Standard Test Conditions (STC) Testing of a PV Module under STC. Since Voltage and Current changes based on temperature and intensity of light. STC Temp is 25 C (77 F)
Normal Operating Cell Temperature (NOCT)
Open Circuit Voltage (Voc) : Solar Panel Output Volts with no load. Is also Maximum Voltage. Voc value is used to determine the number solar panels you can wire in series going in to inverter / charge controller
Short Circuit Current (Isc) :Isc is amps (i.e current) when not connected to a load, Helps how many amps to connect to a solar charger / inverter, generally multiplied by 1.25
Maximum Power Point (Pmax) : is the sweet spot of solar power output, volts x Amps = watts, Pmax = Vmpp x Impp
Maximum Power Point Voltage (Vmpp): this is the acual voltage you want to see when connected to mppt
Maximum Power Point Current (Impp): Actual Amperage when connected to mppt
Series Circuit Connect + to -, Volts add up Amps won't change
Parallel Circuit Connect + to + & - to -, Amps add up Volts won't change

Solar Inverter Types

PWM Based – it stands for pulse width modulation, these inverter low on efficiency but prices are very low.
MPPT Based – it stands for Maximum power point tracking. If your purpose of investment in solar is to save electricity bill, then it is strongly recommended to opt for MPPT based inverters

Solar Panel Types

Solar panels for photovoltaic (PV) system come in two types:

Monocrystalline Solar Panel is a solar panel comprising monocrystalline solar cells. These cells are made from a cylindrical silicon ingot grown from a single crystal of silicon of high purity in the same way as a semiconductor. The cylindrical ingot is sliced into wafers forming cells
Polycrystalline Solar Panels are also referred to as “multi-crystalline,” or many-crystal silicon. Because there are many crystals in each cell, there is less freedom for the electrons to move. As a result, polycrystalline solar panels have lower efficiency ratings than monocrystalline panels.

Key Differences

Difference	Polycrystalline / Multi-crystalline	Monocrystalline
Source of Energy	Sun	Sun
Material in Solar Cell	Solar Cell made from Silicon fragments melted together	Solar Cell made from single Silicon crystal
Efficiency	Lower Efficiency – Since the cell composed of many / multi crystal silicon the electrons movement would be less	Higher Efficiency – Since the Cell composed of single-crystal silicon, the electrons generate flow of electricity have more room to move
How to identify	Blue Hue	Black Hue
Cost	Less Expensive	More Expensive
Life / Longevity	25+ years	25+ years
Production in Units	Approx. 4 to 6 Units per 1 Kw on a sunny day	Approx. 4 to 6 Units per 1 Kw on a sunny day