Enphase micro-inverter system

Has anyone tried swapping out the central inverters for micros?

I already have a 5Kw system on my roof which is 2 2.5KW systems going to 2 SunnyBoy central inverters. And wondering if it is worth bother. Granted my panels are already about 5 years old. One set is 20 160w BP panels and the other is 18 180w BP panels.

 

Why (Unless you have shading issues) would you want to swap out perfectly good, well wired inverters for a whole series of Enphase inverters, especially in an array that was not specifically designed for micro inverters?

 

I don't see how doing such a swap would be economical.
Enphase says they can increase production from 3%
to 9%. Let's be conservative and pick 5%.

On your 5kw system, then you are talking about gaining
250w. That is roughly equivalent to one current generation
PV panel, or say, $1500 installed.

The cost of the Enphase inverters for you would be:

(18+20) * $200 = $7200

In other words, installing one current generation PV
panel with one Enphase inverter would give you the
same gain as installing 38 Enphase inverters, at 1/4
the cost.

As a practical matter, Enphase doesn't support all brands
of PV panels, so in your case you might have PV panels
that are incompatible. [I posted their compatibility list
in a earlier post on this thread.]

 

Actually, looks like Enphase is compatible with at least some Sunpower modules now, though for some reason they say so with the caveat

Kind of strange as to why the two companies would need to have a relationship to be "approved". Maybe Sunpower doesn't like Enphase for some reason?

I think the others outline good reasons why it's not a good reason to economically. Would need to know the exact model number of you panels to see if they are compatible with the Enphase inverters, anyway.

And that doesn't even count the labor costs of installing the inverters - you have to pull all the panels and rewire the whole system - the wiring requirements are different enough between macro/micro inverters that you will need a substantial amount of rewiring.

Unless one of your arrays is experiencing substantial shading issues, it won't be economical to switch inverter types. And even if it is, it would probably be more economical to use something like SolarMagic to retrofit that array instead as that would likely avoid you having to completely rewire everything. Or if you do have shade issues - only install the microinverters on the panels that have the worst shade issues.

 

A lot of Sun Power panels are positive ground, and that might be the reason why they are not approved with Enphase inverters.

Icarus