What you are actually selling.
WHAT A SYSTEM TYPICALLY CONTAINS
Panels, which generate A charge controller or its equivalent, managing charging Batteries, which store An inverter, converting stored energy for use Mounting structure Protection devices and wiring Monitoring, where fitted
WHAT PANELS DO
Convert sunlight into electricity, at an output depending on conditions.
WHY RATED OUTPUT IS NOT ACTUAL OUTPUT
Rating is measured under standard test conditions that do not occur in normal use.
WHAT AFFECTS ACTUAL OUTPUT
Irradiance Temperature, which reduces output as panels heat Shading Orientation and tilt Dirt Cable losses
WHY TEMPERATURE MATTERS HERE PARTICULARLY
Panels lose output as they get hot, and it is frequently ignored in sizing.
WHAT BATTERIES DETERMINE
How long the system supplies load without generation.
WHAT INVERTERS DETERMINE
What load can be supplied at once, and whether it can be supplied at all.
WHY SURGE CAPACITY MATTERS
Motors draw far more on starting, and an inverter sized on running load fails.
WHAT DETERMINES SYSTEM COST
Battery capacity, mostly.
WHY
Batteries are the most expensive component and the shortest-lived.
WHAT THAT MEANS FOR DESIGN
Reducing load reduces cost more than any other decision.
WHAT TO ESTABLISH WITH CUSTOMERS
That reducing consumption comes before generating.