Koshland Lafayette, CA residential house
What components does a Solar PV system require?
What components does a Solar PV system require?

Solar photo-voltaic systems do not only consist of solar modules and inverters. It is true that 60% to 80% of the total system cost is the cost of solar modules, however choosing the right balance of system equipment is an important part of the design.

It can take couple of minutes to get a quote for solar panel and inverter pricing and to decide on a brand. However, it can take more than couple of hours to figure out how to install the modules on the roof, selecting the correct racking system, attachments, flashings, and sizing the cables etc. If you need any assistance in your design, please fill out this form.

In the below table, I wanted to show the must-have's of a solar PV system.

Equipment Decision Factors

Solar panels Roof dimensions, price, availability, project size (consumption)

Inverter System sizing, availability

Racking and Mounting Mounting preference (roof, ground, tilted, flush, standoff etc.), local fire code, Flashing, Roof type (shingle, tile, flat, composite etc.) Grounding wires, clips, lugsSystem size, racking type, local code

Combiner, junction box Inverter specification, installer

DC and AC Disconnects Inverter specification, local code

Breakers and switches AC and DC disconnects, wire size, current flowing on wire

Wire size and type Distance, ambient conditions (humidity, solar radiation etc.), voltage and current, voltage drop calculations

Module connectors Module type (MC4, Radox, Tyco, MC3, Amphenol etc..)

Lighting arrestor Local code, local weather

Monitoring Owner preferredSignage (Warning Signs), Local code Metering Local code (Check with the utility company)

Off-Grid Systems

Battery Bank System voltage, energy consumption, number of days of autonomy, application (wet, agm, gel)

Charge controller Battery voltage, PV system voltage and current

Battery cables Distance to charge controller and inverter

Battery monitoring Battery type, charge controller brand


Jon Steel commented 13 years 4 months ago

I know there isn't a typical solar PV system, but can anyone give me rule of thumb to help with estimtes?   Of the cost of equipment in a solar installation, what percentage does the balance-of-system (BOS) cost?   (When  I say BOS I mean balance of the panels)   Thanks for the help on this.

Good questions.  I am sure this answer will be challenged as it can vary greatly but of the cost of equipment, the panels will run around 55-65% of the cost while the inverter should be roughly 10-20%.  The racking can have a very wide range based on the application but it should run around 5-15% of the equipment cost and the electrical equipment and additional balance-of-system equipment wil be roughly 3-8%.  The size of your system and application will make these rough estimates vary widely but this should give you a rule of thumb.  I hope this helps.

Missing Missing commented 12 years 4 months ago

Solar Systems are really good as they help us generate electricity from solar energy. The installation of PV cell is really an interesting one. Thanks for the interesting procedure.

13 years 4 months ago
Written by
Levent Bas