[RE-wrenches] Question on Back up generators

Thu Apr 9 17:17:51 EDT 2015

I used an Ecogen recently, and I liked many aspects of it.  However the=20
continuous draw of the on board electronics is just ridiculous for an=20
off grid generator.
A 15 w solar module charging the start battery was barely able to keep=20
up with the draw.  Running AC off the inverter to the generator is also=20
just another unnecessary 24/7 phantom load.
We may be 20 years into the future, but no one has built a generator=20
that can hold a candle to the old water cooled, 1800 RPM Kohlers. Most=20
of those are still in service, and had simple 2 wire start. The Ecogen's=20
onboard computer is a serious design flaw IMO.   We don't need the=20
generator to "think" in an off grid system; we already have inverters=20
that do a much better job of that.  The generator just needs to start=20
reliably when its called upon.
I would appreciate if someone with more experience with the Ecogens=20
could explain why the on board electronics are good, or...... how to=20
bypass them completely.
We had a great off grid generator solution 2 decades ago, and the closer=20
today's manufacturers can get back to that, the better we and our=20
customers will all be.

R.Ray Walters
CTO, Solarray, Inc
Nabcep Certified PV Installer,
Licensed Master Electrician
Solar Design Engineer
303 505-8760

On 4/9/2015 2:40 PM, Gary Willett wrote:
> Dana:
>
> Take a look at the new Generac EcoGen 15kW that was purpose built for=20
> a renewable energy system*
> /* including an inverter, battery bank and alternative energy power=20
> source/
>
> http://gens.lccdn.com/generaccorporate/media/library/content/all-products=
/generators/home-generators/ecogen-series/15kw-6103/0k8466-c-15kw-ecogen-hs=
b.pdf
>
> The 15kW EcoGen has the same footprint as the 6kW EcoGen (LP only) and=20
> is natural gas or LP gas capable. The generator has a constant=20
> frequency / variable speed AVR based on electrical demand.
>
> Also, 500 run hours between oil changes. And a 3-year or 2000 hour=20
> warranty.
> http://gens.lccdn.com/generaccorporate/media/library/content/all-products=
/generators/home-generators/ecogen-series/ecogen-warranty-0j1629-revb.pdf
>
> Regards,
>
> Gary Willett
> Icarus Engineering & Solar Services LLC
>
>
> On 4/9/15 9:56 AM, Dana wrote:
>>
>> I agree but full load charging usually only lasts but a few minutes=20
>> as the inverter charge rate drops readily as voltage rises. 8300 watt=20
>> -10,000 watts or 13000 watts the point is why we are installing air=20
>> cooled throw away generators that run so fast & hot that they need to=20
>> be replaced in 2,000 hours, not to mention the fuel consumed at 80 MPH?
>>
>> Is there a slow speed (1200-1800 rpm) water cooled 8-13 KW generator=20
>> out there?
>>
>> ------------------------------------------------------------------------=
----
>>
>> Dana Orzel
>>
>> Great Solar Works, Inc -  NABCEP # 051112-136
>>
>> E - dana at solarwork.com - Web - solarwork.com
>>
>> O - 970.626.5253  C - 208.721.7003
>>
>> "Responsible Technologies for Responsible People since 1988"
>>
>> *P*Please consider the environment before printing this email.
>>
>> *From:*Jerry Shafer [mailto:jerrysgarage01 at gmail.com]
>> *Sent:* Wednesday, April 08, 2015 7:02 PM
>> *To:* dana at solarwork.com; RE-wrenches
>> *Subject:* Re: [RE-wrenches] Question on Back up generators
>>
>> We don't install anything smaller then a 13 k its air cooled but=20
>> works well, as far as the numbers you have, Mine are somewhat=20
>> different I use max potential load and max potential charge as when=20
>> the batteries are low the genny must not only supply the home but=20
>> also charge the bank back up at a reasonable rate, so if the loads=20
>> are high and the genny only has enough to maintain that load then=20
>> what about the batteries plus I only use 75% of the genny rating for=20
>> optimum or improved duty cycle. This is only me and I am sure every=20
>> shop has there own math.
>>
>> Jerry
>>
>> On Wed, Apr 8, 2015 at 11:23 AM, Dana <dana at solarwork.com=20
>> <mailto:dana at solarwork.com>> wrote:
>>
>> Hey All =E2=80=93
>>
>> I just got off of a phone call with my Onan generator supplier. Last=20
>> conversation with Kohler was the same story basically.
>>
>> I was informed that their smallest water cooled generator, the RS22=20
>> (22 KW) is now no longer =E2=80=9Crated =E2=80=9Cfor off grid. They actu=
ally called=20
>> me to confirm that this generator was for backup power to a utility=20
>> inter connected house. Tier 4 generators in the EPA CFR 40 is the=20
>> Federal code what covers this, & you are allowed 100 hours of run=20
>> time for standby power and maintenance per year.
>>
>> Q - Why am I using ridiculous sized generators for something that an=20
>> 82-8300 watt generator does just fine?
>>
>> A - The EPA current requirements, a shrinking economy, &=20
>> manufacturers that have to meet very expensive air quality compliance.
>>
>> The Penalty - If you get caught running a =E2=80=9Cstandby power only=E2=
=80=9D=20
>> generator the fine is now $39,000 per day!
>>
>> Now I am far from a polluting kind of individual and all for air=20
>> quality but this is getting the best of us. The 13KW air cooled=20
>> generators are only good for 2000 hours, & the water cooled go 20=20
>> years of moderate usage but cost a boat load. I hate having the=20
>> =E2=80=9CGenerator=E2=80=9D talk with a new client they look at me like =
I am crazy.=20
>> So the air cooled units are basically throwaways and the 22KW units=20
>> are way more than we need and what a client needs to spend money on,=20
>> unless you are at 10,000 ft el.
>>
>> If you figure 30 amps/120 VAC input per inverter +/- x 2 =3D 7.2KW plus =

>> say 10-15% fudge or elevation factors would require an 8200-8300 watt=20
>> generator. Air cooled at 3600 RPM =3D 80 MPH & 1800 RPM =3D 40 MPH.  Eve=
n=20
>> if the generator were a bit smaller, ran slow (1200-1800 rpm) and ran=20
>> a bit longer that would be acceptable.
>>
>> So, why are we installing even 13KW air cooled or 22 KW water generators?
>>
>> There is a business opportunity here folks.
>>
>> What are you all installing?
>>
>> Why?
>>
>> Is it reliable?
>>
>> Would you use it on your house?
>>
>> Thanks for sharing all the wisdom and knowledge.
>>
>> ------------------------------------------------------------------------=
----
>>
>> *Dana Orzel*
>>
>> _Great Solar Works, Inc - *NABCEP # 051112-136*_
>>
>> *E*- dana at solarwork.com <mailto:dana at solarwork.com> - *Web* -=20
>> solarwork.com <http://solarwork.com>
>>
>> *O*- 970.626.5253 <tel:970.626.5253> *C *- 208.721.7003=20
>> <tel:208.721.7003> - No FAX Line
>>
>> *_"Responsible Technologies for Responsible People since 1988" _*
>>
>> *P*Please consider the environment before printing this email.
>>
>>
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