Solar Flashcards
What is the STC wattage m2
1000 w square meters
What is STC degrees
25 degrees is what ?
Air mass for STC is
1.5
A string inverter works in a ? Circuit
Series
A micro inverter works in a ? Circuit
Parallel circuit
What is the effeciency of string invertor
They take the energy from the lowest performing solar panel and use that for all panels. So if a tree shades one panel 20% they all work at 20%
What is PPA
Power purchase agreement where you lease the panels and it goes on your roof. Price is lower but you never own panels so never get to 0
Remote net metering is what
Where you own two buildings with only one having solar so you offset the extra made to the building without
What does an inverter do
Changes current from DC into AC for the house
What does a charge controller do
Makes sure batteries don’t over or under charge
NEC
National electric code
What is article 690
The guildlines for solar
What is ballasted rack
Solar elevated on a angle good for flat roof
What is independent power producer
Someone who generally creates over 100/110 percent of their needs. Not allowed
How much can a panel loose when installed
10/20 percent. Power loses from loose wiring inverter dust temperature
What and who created photovoltaic effect ?
Alexandre bacquerel 1839 a process that produced voltage or current when exposed to light or radiant energy.
When was the first solar install
1883 in nyc Charles Fritta had effeciency of 1/2%
Who created the first viable solar panel
Bell labs 1954 10 perfect efficiency
How many solar satellites in 1970
1000
What was solar per watt in 1976 and what is average today
Cost was $100 PW and US average is $3/4 PW
How much will solar grow annually
0.16
What is gallium arsenide
The newest in solar cells out perform silicon Max out put 28 watts
What is solar constant
Solar constant is the total radiation received from the sun per unit of time and area. The value of the solar constant is 1.366 kilowatts per square meter
Electron
Carries a charge and smallest amount of electrical charge possible to have.
What is atomic model
Consist of atomic nucleus and electron shell. Electrons move around the nucleus like planets. Electrons are charged negatively while nucleus is composed of uncharged neutrons and positively charge protons. It’s overall charge it’s positive equal electrons and protons.
Beam radiation
When the solar panels face exactly towards the sun
Diffuse radiation
Diffuse radiation is solar radiation reaching earth’s surface after having been scattered from the direct solar beam by molecules or suspensoids in the atmosphere.
Insolation
The total amount of radiation emitted from sun that you can use for solar cells
Heliostat
When you follow or track facing directly to sun
When you follow or track facing directly to sun
A way to offset change in seasons to get most beam radiation from the sun
A way to offset change in seasons to get most beam radiation from the sun
Add or subtract 15 % degree offset to the latitude to accommodate for winter or summer
Azimuth
The compass angel as the sun moves East to west solar noon is consider azimuth angle of zero -90 to the East +90 to the west
Zenith
This is angle of sun looking up 90% at midday sunrise and sunset 0%
Formula to calculate system size
(Energy demand/annual full sun hours)/efficiency = PV system size
Solar insulation map
Shows the daily and annual averages for sunlight
which is incident light?
a light that falls on a subject (not what is reflected by it)
How much and where is Silicon
Very common in crust of earth. 20% of crust is silicon
Pauli exclusion principle
Electrons have 4 quantum numbers to fully describe them in an atom. No two electrons can have the same 4 quantum numbers in an atom meaning they repel each other and must move in opposite direction.
PIN structure
Positive Intrinsic Negative
What is doping
Adding impurities to change resistivity
Open circuit
Voc - A circuit that is open it has a break current won’t flow
Closed circuit
Switch closed current will flow
Short circuit
No resistance is high current
Pm
Maximum power
What does photovoltaic mean
Photo is light voltaic is electricity
PSH
Peak sun hours
Solar attenuation
The loss of solar irradiance as it passes through the atmosphere
When your modules are in series you increase by
By voltage
When your modules are in parallel you increase by
Currents
What is an array ?
More than one module put together
What is IV curve
V = volts I = current
What is Isc
short circuit current
What is PV curve
P = power V = volts
What is Imp
Maximum power current
Losses in an inverter are from
Heat
Vmp
Max power voltage
What does IV curve calculate
The max power point
To calculate max power point you need
Find product of Voc and Isc
MPPT
Maximum power point tracking charge controller l. Best on market. Converts high voltage produced from solar panel to lower voltage neccasry for battery
Shunt controller is ?
Simplest of charge controllers on off
PWM Pulse width modulation
Changes the charge depending on the load. Works 25% 50% 75%
Whenever there is resistance it creates
Heat
AHJ
Authorities having jurisdiction
How much is a megawatt
1000 kilowatts
VLSI
Very large scale integrated circuit
Anti islanding
Protection to shut of power going back to the grid if there is a failure or outage in grid
In an inverter heat creates what ?
Short circuit and damage to system
In an inverter what cables do you want
Short and think
Power optimizer
Optimizers the dc power as dc electricity to the battery from an array in a series.
Square wave
It’s when you have square waves that create harmonica and aren’t good for anything as it’s digital
Ohms law
Current goes up volts go up v = IR
Good conductor has what resistance
Low
Balance of system
BOS -Everything but the solar panels.
What is deep cycle batteries
Typically lead acid, generally used for small systems last 5/10 years and reclaim about 80% of energy powered into them
What is frequency of ac cycles
60 hertz or 60 cycles per second
Thermodynamics
Heat transmitted by Conduction Convection Radiation
What is the first Law of thermodynamics
Law of Conservation of Energy Energy can’t be created Can’t be destroyed Can’t be changed from one form to another Energy is conserved
2nd law of thermodynamics
The second law of thermodynamics states that the entropy of any isolated system always increases Meaning Perpetual motion machine isnt possible Some energy is wasted. Some energy is lost to another form
What kind of conductors should you use
Use conductors with least amount of resistance Large gauge cables
Energy balance
Energy supplies equal to energy used by device
Energy audit
App house hold load in watts Multiply by 1.25 for energy lost
Wp
Peak watts
What’s the average cost of solar installed
$20, 000 without rebates or credits
What is the potential increase in value to home for adding solar
$15 000
How much has the cost of solar dropped in last 5 years
0.2
what is PPW
Price per watt
What is a gigawatt and how much can it power
A gigawatt is one billion watts. It would power 725,000 homes and is more power produced than a conventional power plant
In the times of Carona, 3 reasons why solar will grow
- pollution reduction, people see the difference with air quality - the pandemic has us thinking globally, solar is healthier for all - security. Being able to take care of a fear of energy security in a crisis
agrivoltaic
Mixing of farm and solar
Mixing of farm and solar
What is a negawatt
What is a negawatt
A unit of energy saved as a result of conserving
DR
What happened to Albert Einstein in 1920 and prize?
What happened to Albert Einstein in 1920 and prize?
In 1921 he won Nobel prize for physics explaining the photovoltaic effect
What is albedo
The reflection of a surface.
What are bifacial solar panels and why are they good
Bifacial solar panels expose both the front and back of solar panels. Unlike mono facial panels, They take in reflection from underneath so they can take in the roof reflection, snow, sand in desert. from the ground. Some manufacturers say up too 30% increase in production.
Distributed solar
Solar that is produced and consumed close to each other
STC
Standard test conditions
How much energy in watts does an average home use?
Around 11 000 kilowatts per year 900 per month KWh
