Solar Flashcards
Simplest type of system to size
Utility interactive
Limitations to size an interactive system? Voltage per nec
Space and budget
Fine balance when sizing a stand alone system
Supply and demand
Loads to consider in sizing a bi-modal system
Critical loads
Solar to generator tarot for a hybrid system?
90%: 10% to 40%:60%
Load an inverter should be rated for?
Largest AC load
Critical design ratio
Load demand vs. instillation ( for each month)
System availability
% of time a system meets load- requirements
In battery bank sizing it demands required capacity
Autonomy
Accessibility
Safe/ practical access to equipment
Cooler arrays
More reliable,last longer and more efficient
Preferred mounting types
Rack and stand off
Tracking system that receives the most solar irradiance
2-axis
Galvanic corrosion
2 metals reacting degrading the lesser metal.
Dead load
Permanent structural load -5to 10 psf
Live load
Temporary structural load – 5 to 10 PSF
Wind load
Structural load that comes from all directions – 25 to 50 PSF
Snow load
Structural load found at the AHJ
Vibration load
Structural load caused by equipment, roads, airports, trains, etc.
Self ballasting advantage
No roofing penetration
Maximum output-ciruit voltage for 1 and 2 family homes
600 volts
Correction factor for maximum pv output voltage per nec
Temperature correction factor.
Correction factor for maximum pv circuit current
125% or 1.25
2 places to fined temperature correction factors array open circuit voltage
Module manufacturers specifications or nec 690.7
Max inverter current can exceed nominal ratings under this condition
Match the highest current with the lowest voltage
Wire (conductor) size system
AWG
Ampacity
Current a wire can carry without exceeding its temperature rating
Derate
The action of reducing a wires rated ability
ampacify
What temperature does to a wires ampacity
Reduces a wires rated ability based on temperature
What is system availability when sizing a system?
% of time over a year the system meet load requirements
When selecting a battery bank what determines its required capacity
The autonomy period during the critical mounth
What is the fine balance required when sizing a stand alone system
Supply VS. demand
In critical design the ratio of energy demand to insulation is found how often
Each month
In a hybrid system design what is the typical range of solar energy generator ratios
90% pv 10% generator
When selecting an inverter what load should the inverter be rated for.
Slightly larger than the largest AC load
What is the main limitations one sizing and interactive system
Space for the array and the customers budget
In system sizing what is the simplest type of PV system to size
Utility interactive
When sizing a modal System which load should you consider
Critical loads
The percentage of the time the load is operating is called
Duty cycle
When PV modules are substituted for regular building materials this mounting is called
Building integrated
