[RE-wrenches] Enphase 215

[Jason Szumlanski]

Similar to my previous contention about module warranties, as PV module
and microinverter prices plummet, it becomes less important to squeeze
every watt out of a module. True, we have limited physical space to deal
with, but ultimately it boils down to $/watt, or more accurately
$/watt-hour.

 

If standardization results in significantly lower costs with some lost
efficiency, does it really matter? Something to think about...

 

Jason Szumlanski

Fafco Solar 

 

 

From: re-wrenches-bounces at lists.re-wrenches.org
[mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of Keith
Cronin
Sent: Wednesday, August 24, 2011 9:24 PM
To: William Miller; RE-Wrenches
Subject: Re: [RE-wrenches] Enphase 215

 

William

 

It seems like the product tries to be everything to all mod manu's,
which is hard to do, at best.

 

Don't know if its a limitation in the electronics or design
architecture. Could also be a strategic position to clamp down on what
can be plugged into the circuit per NEC to limit their exposure to
liability and keeping up with the myriad of modules hitting the market
every month.

 

As you point out, its a delicate balance- insolation vs max harvest.
Sites that are free and clear of any shading are penalized, so to speak.

 

I suspect they are aware of this design challenge and in the future, we
will see matched inverters to the mod wattage output to not leave any
watts on the table.

 

Within 24 months, we could even see things go a different direction-
mods labeled AC rating first and DC second. If the inverter is built
into the modules already, this make the language universal, like
virtually all AC wiring in a home.

 

 

Keith

________________________________

From: William Miller <william at millersolar.com>
To: Keith Cronin <electrichi01 at yahoo.com>; RE-wrenches
<re-wrenches at lists.re-wrenches.org>
Sent: Wednesday, August 24, 2011 10:49 AM
Subject: Re: [RE-wrenches] Enphase 215

Keith:

Her's my guess:  Through the MPPT algorithm.  The processor indicates
near maximum output, the MPPT impedance reduces to throttle back power
production.  

This is pure speculation, but I'm stickin' with it (untold told
otherwise).

Throwing away power?  Yes.  If MPPT is not at maximum power transfer at
all times then your investment in PV is not earning it's full return.
However, your inverter investment is not earning it's full return during
the many hours of less than optimum insolation.  These are the two
factors to balance in system design.

William


At 01:01 PM 8/24/2011, you wrote:



David, et al

Yes, their literature states max output power of 215. Not sure how that
is controlled, except for electronically. 

So this could be the shunt, so to speak and must take into consideration
voltage to follow some algorithm to keep things humming along at that
threshold.

Having said this- are we "throwing away" power then?

Keith

 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20110825/192f82f0/attachment-0004.html>