[RE-wrenches] Metering

Tue Sep 30 07:53:07 PDT 2014

Hi Bill,

You have a good point about the burden of monitoring and how to keep up
with it. We have hundreds of monitored sites, some Enphase and some others,
and it is impossible to really check them thoroughly. However, most
monitoring sites have some basic warning capabilities which I find useful.
For example, Enphase will send us and the client an email if their system
stops producing power or if there is another type of inverter error. It
won’t catch minor issues but it does catch the major issues. SunPower has a
dashboard we log into each morning to catch any major problems – especially
“inverter down” errors. I’m hoping SunPower will implement an email warning
system as well.

The main problem I see with installing microinverters without the
proprietary monitoring device (Envoy for Enphase, CDD for ABB, etc) is that
there is no easy way for the client to know if all their micros are working
– there is no green light or red light to check.

Here in the Bay Area we’re finding more and more competitors selling leases
and production guarantees. I imagine that the larger of these companies
have some sort of automated monitoring system to check production but I
don’t know for certain. With our SunPower leases, SunPower sends us a
monthly email with production updates versus the simulated estimate based
on our shade and site conditions. This is a really quick way to see how our
fleet is doing.

To Ray Walters’ point about powerline communication with Enphase, we’ve had
very reliable monitoring with our Envoys once we started installing a
dedicated receptacle for the Envoy at the same load center where we
installed our microinverter breakers. I can’t think of a single instance
where communication hasn’t been reliable.

We also don’t sell monitoring to clients who show little interest in it.
They can check their string inverter on a regular basis or keep their eyes
on their bills and it does make everyone’s life a little easier.

Anyway, there is no doubt that monitoring adds a lot of overhead to our
business and we are trying to figure out better ways to setup expectations
with clients. As I’ve posted in the past, we end up dealing with a lot of
IT issues for homeowners.

Best,

August

Luminalt

*From:* RE-wrenches [mailto:re-wrenches-bounces at lists.re-wrenches.org] *On
Behalf Of *frenergy
*Sent:* Monday, September 29, 2014 7:02 PM
*To:* RE-wrenches
*Subject:* Re: [RE-wrenches] Metering

All,

        Great points and a little education of others' feelings about,
essentially how granular we need to be in monitoring.

        I'm curious who is monitoring the Enphase systems in the solar
world, seriously.  I know 95% of my customers are more concerned about
catching the bus or what's for dinner than if PV #8 has bird crap on it.
Do the folks at Enphase, through Enlighten have some software that spots
issues?  I know I, as an installer don't have time for it.  My experience
is the customer notices their power bill was higher last month, they take a
look at the inverter and no green light...CALL BILL.

        Thanks folks for the resources for meters, din rail too.

Bill

----- Original Message -----

*From:* Glenn Burt <glenn.burt at glbcc.com>

*To:* 'RE-wrenches' <re-wrenches at lists.re-wrenches.org>

*Sent:* Monday, September 29, 2014 5:17 PM

*Subject:* Re: [RE-wrenches] Metering

I would not classify what we are doing in PV as SCADA.

It is purely data acquisition at this point, and more commonly referred to
as DAS or a Data Acquisition System.

SCADA by its definition entails a two way path of both receiving data and
being able to send control signals, usually from a big picture program,
monitoring dozens of data points.

Let’s not try to make the simple into a more complex thing than it is.

-Glenn

*From:* RE-wrenches [mailto:re-wrenches-bounces at lists.re-wrenches.org
<re-wrenches-bounces at lists.re-wrenches.org>] *On Behalf Of *Ray Walters
*Sent:* Monday, September 29, 2014 2:31 PM
*To:* RE-wrenches
*Subject:* Re: [RE-wrenches] Metering

The 2nd problem with the Envoy besides cost is that it isn't always
reliable.    Communication through power lines is not a new or fresh idea,
and has Always been problematic.  Once you install something you are
expected to make it work, and that can be a nightmare on say an 8 module
system that keeps losing communication to one or two modules.  I've had
this exact case, and confirmed multiple times that each micro was working,
but the Envoy had other ideas.
This rush to mega data acquisition makes sense for larger PPA systems, but
can just add tons of call backs and the resulting financial losses and
frustrations for small systems.
I've spent as much time messing with SCADA, as I have with the entire
install itself; now that's ridiculous.  This isn't new either:  I had
SCADA systems back in the 90s, that had great promise, but ultimately were
extremely hard to implement, and the customer never used after anyway......
The question is:
What does the customer really need to operate the system vs. "bells and
whistles".....

R.Ray Walters

CTO, Solarray, Inc

Nabcep Certified PV Installer,

Licensed Master Electrician

Solar Design Engineer

303 505-8760

On 9/29/2014 12:12 PM, August Goers wrote:

Hi Bill,

One of the largest benefits of the microinverter system, in my opinion, is
the ability to monitor each module individually. It might seem like ~$500
is a lot for the Envoy but I think it is well worth it when you think about
the 25 year warranty period and included ongoing monitoring. We’ve had
enough Enphase failures that I would personally really want to be able to
keep my eye on each micro individually.

Just a thought, August

*From:* RE-wrenches [mailto:re-wrenches-bounces at lists.re-wrenches.org] *On
Behalf Of *frenergy
*Sent:* Sunday, September 28, 2014 2:26 PM
*To:* RE-wrenches
*Subject:* [RE-wrenches] Metering

CA wrenches,

        I'm trying to (for the sake of my monetarily impaired customers)
figure out a less expensive way to meter/monitor small enphase systems.
One of my local utilities will allow me to just use a remanufactured
utility-grade meter (ala AEE) These meters are inexpensive, robust and
accurate but only display total production.

        The Envoy retails for over $5 bills.  Most of my customers are not
interested in checking their PV system on the internet, well not after a
couple weeks.  I can't seem to find any requirement from PG&E other than in
Section 5.1 of the guidebook: " All systems receiving an EPBB incentive
must install a production meter accurate to +- 5% of actual system
output...."       which is pretty vague.  plus the is no CSI incentive
anymore.

        Anybody have a suggestion that is different from the remanu utility
meter?....and possibly gives current wattage output, and is "approved" by
PG&E interconnection?

TIA

Bill

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