[RE-wrenches] Request for Enphase inverter comments

[Mark Frye]

I appreciate that the Enphase is a ground breaking new product.

I am not antagonist on principle.

It appears that the warranty has been extended to 15 year from the initial
10 year offering. This is good.

But, we are talking about two very different long term service models.

Single large inverter manufactures provide a field service fee of about $100
which nominally covers the cost of going out, trouble shooting, opening some
disconnects, and replacing the inverter, all without going on the roof and
touching the array.  With a single inverter this is a once or twice in a
lifetime event.

If we look ahead at the Enphase we see a very different situation. Here we
are still getting replacement of the inverter. Instead of a field service
fee for the installer, the customer gets a cost of energy refund? But now,
in order to service the inverter, we have to get on the roof, disassemble
the array, replace the inverter, re-assemble the array. And this will may
have to be done multiple many time over the life of the system.  The real
cost to the installer/customer here is huge and not even nominally close to
the value of lost energy production.

I agree with Bill, that in this case the nature of the warranty is not the
really significant issue here.  The issue is the cost to maintain and
operate a system that falls to the owner after the manufacture and
installers are long gone.

I am disappointed by the warranty offering not so much for what it is, but
that it is offered as a substitute for reasonable representations as to the
projected life-cycle cost of ownership of systems based this product.

I give my customers a 25 ROI projection for each of my systems.  I include
nominal array maintainence costs and inverter replacement costs (parts and
labor) at year 12.
The question arises, what model for real maintenance costs over a 25 year
term should be included in estimates for an Enphase system.  

Our industry is mature enough that we should expect this kind of information
from all providers, old and new.

Mark Frye
Berkeley Solar Electric Systems
303 Redbud Way
Nevada City,  CA 95959
(530) 401-8024
www.berkeleysolar.com 

-----Original Message-----
From: re-wrenches-bounces at lists.re-wrenches.org
[mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of Bill Brooks
Sent: Friday, October 24, 2008 8:51 PM
To: 'RE-wrenches'
Subject: Re: [RE-wrenches] Request for Enphase inverter comments

Mark,

I'm surprised that you are disappointed and put so much stock in warranties.
Working with any new product and new company requires a go-slow mentality at
the start to establish a track record and field experience. A warranty is
only as valuable as the company behind the warranty. Enphase is a promising
new company, but installers do both Enphase and themselves a disservice if
they go whole hog after this technology and treat it like other more-mature
options. Installations should be close to the shop on roofs that are easily
accessible.

Expecting a warranty beyond 10 years is excessive. Quite frankly, warranties
beyond 5 years don't make any sense to me (but the law is the law). We will
not fix long-term performance with warranties. Remember that a 25-year
performance warranty on modules is really not what most people think it is.
It is a good failure warranty and a terrible performance warranty. Long-term
performance comes from quality equipment, quality design, quality
installation, and good maintenance.

Keep up the quality work.

Bill.