[RE-wrenches] Reconsidering Generac for Off-Grid

Wed Jun 15 13:05:24 PDT 2011

Interesting the 2600 RPM = 57.7 MPH. times 500 hours is a
28,885 mile interval on the oil change. 

Are they requiring synthetic oil? The best AMSOIL product is
currently 25,000 miles between oil changes.

Glad to hear they are thinking but time will tell.  Except
for [1] 30KW unit I have yet to see one survive more than a
year before catastrophic failure or all consuming fire.

I do not know of any ONAN or Kohler units that do not need a
PV module to back up the standby power requirements of the
control loads run off of the generator start battery, It
almost seems a separate deep cycle battery for the wasteful
controls would be smart. AN more expense.

Dana Orzel

Great Solar Works, Inc

E - dana at solarwork.com

V - 970.626.5253

F - 970.626.4140

C - 970.209.4076

web - www.solarwork.com

"Responsible Technologies for Responsible People since 1988"

Do not ever believe anything, but seriously trust through
action.

From: re-wrenches-bounces at lists.re-wrenches.org
[mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf
Of Allan Sindelar
Sent: Wednesday, June 15, 2011 1:52 PM
To: RE-wrenches
Subject: [RE-wrenches] Reconsidering Generac for Off-Grid

Fellow Wrenches,
I have been wanting to write this post for weeks now, but
have put it off because it has felt risky to me. Years ago
this list had a fair amount of criticism of Generac
generators. I followed that advice back then. Now I'm
reconsidering the brand because of a specific new model, and
I'm encouraging other Wrenches to do the same.

Generac has introduced a 6kW propane unit specifically
designed and built for off-grid use. I have been testing one
out in my home (a production unit supplied by Generac). I am
genuinely impressed with it, even if the model name - the
"EcoGen" - is a little bit hokey. I have begun recommending
them to some of my customers. (Although we were and
technically remain Kohler dealers, and very occasionally
sell a Yamaha inverter-generator, we have moved away from
any generator sales and service.)

Here are some features that impress me:
The oversized (530cc twin) V-twin engine for the 6kW output
runs at 2600 rpm, using a vertical shaft and belt drive to
spin the armature at 3600 rpm while reducing sound and
increasing engine life.
It comes wired for straight 120VAC output (as mine is set
up), but a 120/240 kit is optional.
It's set up to run on LP only.
It has standard two-wire remote signal and electric start.
It has a large external oil reservoir and a 500-hour (!)
recommended maintenance interval.
It has a steel enclosure with sound-deadening material, so
doesn't need a pad or weather protection. The enclosure is
tight, so rodents can't get in.
It is noticeably and surprisingly quiet. It's quieter than
the ancient Onan 6.5 Commercial that it replaced in my home,
and that 1800 rpm flathead twin was famously quiet.
My understanding from asking questions is that the engine is
specific to this model, with hardened internal moving parts
for longevity.
  It comes with a two-year/3000 hour warranty when used in
off-grid applications.

So far, I have had one minor performance issue and one
design flaw, as I see it. The performance issue is that the
unit uses an electric solenoid to close a choke when
cold-starting - the choke serves to draw more propane in for
a few seconds. The engine was slow to start at first. A
tweak on the choke linkage with a needle-nose pliers
effectively shortened the linkage by a millimeter or so and
the problem hasn't recurred. 

So far, the only design flaw, in my opinion, is that the
unit has an electronic controller/display/memory that relies
on a small built-in AC charger to maintain the starting
battery SOC. Beside the 8 watt standby draw (as I have
measured it; max ~200 watt-hours/day, but I don't think the
8W draw is continuous), nobody who's replacing an existing
generator is likely to have a 120V AC convenience outlet or
feed at their generator location - that's something the
home-standby units crowd has, not off-grid. I have given
Generac focused feedback on this battery charging issue in
particular. I'm using the on-board AC charger, because
coincidentally I had run one additional AC hot conductor (in
case I needed to input 240V AC) when I installed my buried
generator input/signal lines years ago, and had subsequently
used this as a hot load feeder to a nearby outbuilding. I
tapped off of that conductor. I also had an extra signal
conductor pair, so I can monitor gennie battery voltage
remotely in my home via the extra Bat2 voltage function on
the new TriMetric TM2025. But I told Generac that in all my
years I don't recall more than one installation with an AC
load circuit out to the generator location, and that this
was kind of a big deal. It turns out that they are aware of
this and responsive to my feedback, are open to adding a PV
module and regulator as an optional kit, and a site-specific
homebrew solution would not void the warranty. I suggested a
remote mount kit (too many generators are installed where
the sun never shines), and several module sizes depending on
the region of the country. It could be a 30W module in
sunnier climates and a 40W or 50W module, and a SunGuard or
equivalent, in cloudier areas. I also suggested that this
issue be discussed as acceptable in the owner's manual or in
a technical bulletin for the customer.

My unit was installed in March, so being in New Mexico I
haven't put many hours on it yet. So my endorsement is based
on features and observations, more than on long hours of
operation. But I'm impressed so far. This unit fills a niche
that has been pretty much ignored by most generator
manufacturers as they move toward "home standby" units with
heaters and fancy controllers that are inappropriate for
off-grid applications.

I'll continue to suggest this unit for some of our
installations, requesting feedback from homeowners after
installation. I'll share any issues here if they come up.
I'd be interested in hearing from other Wrenches who have
installed or worked with one of these units.
Allan

-- 
Allan Sindelar
 <mailto:Allan at positiveenergysolar.com>
Allan at positiveenergysolar.com
NABCEP Certified Photovoltaic Installer
NABCEP Certified Technical Sales Professional
New Mexico EE98J Journeyman Electrician
Positive Energy, Inc.
3201 Calle Marie
Santa Fe, New Mexico 87507
505 424-1112
www.positiveenergysolar.com
<http://www.positiveenergysolar.com/>  

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