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I believe I understand what you're writing, and that makes sense for commercial systems, but for residential systems it makes little sense to me to oversize an inverter beyond what the design calls for and probably something a bit less than the STC rating of what's driving the inverter.
Rather than seeing the purpose of the panels as keeping the inverter busy, I see the inverter's purpose as an interface and power conditioner between the panels and the grid, at least for a grid tie system, with the arrays sized to the design duty and the inverter(s) sized to meet and handle what the array(s) produce in the safest, most efficient and most cost-effective manner.
Arrays with multiple panel orientations can indeed produce a more even power output over a day but will do so at the expense of less overall power output per installed STC kW over the course of that day.
In terms of annual system output, multiple array orientations always mean more installed STC kW capacity will be required than for a single optimally oriented array.
Want examples ? Do a PVWatts run on a 2 STC kW array for any location and find the orientation that maximizes output. Then, find any 2 orientations for 1 STC kW arrays for the same location that provide greater output.
Q.E.D.
And while we both know that a single orientation array will mean more inverter capacity to handle the higher peak output, and so likely at (some) greater inverter cost, it will also mean lower panel and associated installation cost.
My educated guess is that an incremental panel STC W costs more than an incremental inverter capacity W, particularly when construction costs such as wiring/framing and construction costs are considered.
While there may be some exceptions such as max. kW output rates to the grid type of restraints, and maybe some other considerations, besides common sense, I've only to look at the number of single orientation large solar farms vs. the number of multiple array orientation farms for confirmation that a lot of solar farm designers that use PV panels seem to agree with me that given the choice, single array orientation is more cost effective and probably more practical.
Rather than seeing the purpose of the panels as keeping the inverter busy, I see the inverter's purpose as an interface and power conditioner between the panels and the grid, at least for a grid tie system, with the arrays sized to the design duty and the inverter(s) sized to meet and handle what the array(s) produce in the safest, most efficient and most cost-effective manner.
Arrays with multiple panel orientations can indeed produce a more even power output over a day but will do so at the expense of less overall power output per installed STC kW over the course of that day.
In terms of annual system output, multiple array orientations always mean more installed STC kW capacity will be required than for a single optimally oriented array.
Want examples ? Do a PVWatts run on a 2 STC kW array for any location and find the orientation that maximizes output. Then, find any 2 orientations for 1 STC kW arrays for the same location that provide greater output.
Q.E.D.
And while we both know that a single orientation array will mean more inverter capacity to handle the higher peak output, and so likely at (some) greater inverter cost, it will also mean lower panel and associated installation cost.
My educated guess is that an incremental panel STC W costs more than an incremental inverter capacity W, particularly when construction costs such as wiring/framing and construction costs are considered.
While there may be some exceptions such as max. kW output rates to the grid type of restraints, and maybe some other considerations, besides common sense, I've only to look at the number of single orientation large solar farms vs. the number of multiple array orientation farms for confirmation that a lot of solar farm designers that use PV panels seem to agree with me that given the choice, single array orientation is more cost effective and probably more practical.
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