Advice on 'Propane' 25 Kw Generator ?

Vic · February 2010

It is easy to buy a very solid Heavy Duty Diesel generator. BUT, am looking for a solid HD LP Gas generator rated at 25ish Kw Prime Power.

Any folks here have real-world experience with recent purchase of such a unit ? Seems like Generac has taken much of the market, and they are not rated for Prime power output. And the Generac units appear to be run close to their limits for a specific Kw rating.

The application is really grid-tied, but the Utility (PG&E) has become so unreliable that a new genset is in order. There have been over ten power outages in the past four months, the longest of which lasted 50 hours. Think that the total Grid down time is about 200 hours. The site uses mucho LP as it is, and the current old, tired generator runs on LP, so the new genset needs to be LP.

TIA for any info on recent experience info. Vic

backroad · February 2010

Re: Advice on 'Propane' 25 Kw Generator ?

You might want to contact Kim @ Hardy Solar (also listed as Hardy Diesel). Believe me, this gal can answer all your questions very effectively. I believe they do have a bit of propane powered generators, although I don't know why you would want to go that way. A propane generator is very inefficient in the fuel department and I mean in a very sad way.

I bought my 15KW Perkins diesel generator for her and am very happy with the unit. In fact I go out periodically and give it a big hug.

:):)

Good luck in your search...

Backroad in Bagdad.............................................................AZ......

halfcrazy · February 2010

Re: Advice on 'Propane' 25 Kw Generator ?

Backroad is right diesel is more efficient but if you really need propane look for something in the 1800 rpm range and maybe by Onan.

icarus · February 2010

Re: Advice on 'Propane' 25 Kw Generator ?

Second both opinions. Diesel will be way more efficient to run and probably significantly longer lived, but possibly more expensive to buy.

I would look to Onan Commercial series if you need propane.

A pretty good Onan forum can be found here: http://www.smokstak.com/forum/forumdisplay.php?f=1

Tony

Vic · February 2010

Re: Advice on 'Propane' 25 Kw Generator ?

Yes, I agree that there is no question that, generally, a Diesel is the way to go. However, this operation uses 12-15 thousand gallons of Propane per year. The current Genset is a big old 25 KW Propane unit. The Popane supplier will make a delivery within several hours of a request, 24/7. Very little Diesel is used on the site, and so on.

The Emissions regs have recently tightened here in CA, and Diesels seem to have about 90 or more percent of the market (because it is the no-brainer). So, just now, there are many fewer LP Gensets available here in CA.

And Backroad, I did look at Hardy, but IIRC ther largest LP generator they listed was 15 KW.

Thanks for the input, and I did find a few more LP generators that can be sold here in CA.

I use a Kubota 25 KW Diesel (plus a Honda EU) generator for my off grid site. I am a believer, but LP is the correct fuel for this commercial site.

Thanks again. Vic

RCinFLA · February 2010

Re: Advice on 'Propane' 25 Kw Generator ?

A 25kW propane unit will consume about 1.75 gallons (7.4 lbs) an hour with 6 kW load, about 4 gal/hr at 80% load. About 0.7 gal/hr. with no load. At over $3 a gallon for propane they are not cheap to run.

Make sure you plan for a large enough tank.

Vic · February 2010

Re: Advice on 'Propane' 25 Kw Generator ?

Yes, not cheap to run ! But probably will run 200-250 hours per year, unless the grid becomes even less reliable. In the scheme of LP useage it is a drop in der bucket.

I set up the current genset for Liquid feed, but none of the in-stock units have this option installed, and due to emissions regs, retrofitting for lliquid voids any warranty. Gotta love it !

OK Thanks again for all the advice. Vic

solarvic · February 2010

Re: Advice on 'Propane' 25 Kw Generator ?

Vic wrote: »

Yes, not cheap to run ! But probably will run 200-250 hours per year, unless the grid becomes even less reliable. In the scheme of LP useage it is a drop in der bucket.

I set up the current genset for Liquid feed, but none of the in-stock units have this option installed, and due to emissions regs, retrofitting for lliquid voids any warranty. Gotta love it !

OK Thanks again for all the advice. Vic

I just joined the forum a few days ago using the name solar vic. Sometimes I have signed my post Vic, not knowing there was another Vic here. So from now on I will try to remember not to sign as Vic Solar Vic

BB. · February 2010

Re: Advice on 'Propane' 25 Kw Generator ?

Know how many "Bill's" there are here and currently posting--something like three or four? They (we) all sign some version of "Bill / -Bill"... :roll:

-Bill "the other" B.

Vic · February 2010

Re: Advice on 'Propane' 25 Kw Generator ?

Hi solarvic,

Nice to see you on the Forum. Nice name! I'd not worry about it. Folks may think that I just became much brighter ! There have been a number of "jim"s and probably Johns here as well.

All the best, Vic

chevenstein · February 2010

Re: Advice on 'Propane' 25 Kw Generator ?

There are a few companies mating LP/nat. gas Ford and GM industrial engines with Kato, Marathon, and Dong Feng generator heads and selling them as packaged units. Stateline power comes to mind (www.statelinepower.com), I think they have a unit in the 20-30KW range with likely a 2.5L or 3L GM engine on it.

Good luck.

solarvic · February 2010

Re: Advice on 'Propane' 25 Kw Generator ?

chevenstein wrote: »

There are a few companies mating LP/nat. gas Ford and GM industrial engines with Kato, Marathon, and Dong Feng generator heads and selling them as packaged units. Stateline power comes to mind (www.statelinepower.com), I think they have a unit in the 20-30KW range with likely a 2.5L or 3L GM engine on it.

Good luck.

Don,t know much about using the 2.5 gm motor on a generator but can vouch that there are very good on a fork truck. They got a new clark fork truck where I work in a foundryand I put my name on it when it was new about 15 years ago. It gets lots of rough use on all 3 shifts and still don,t use any oil or make strange noises. It has thousands of hours on it bieing used in dusty conditions. The only thing that ever wore out was starters generators water pumps and the distributor. Solarvic

RCinFLA · February 2010

Re: Advice on 'Propane' 25 Kw Generator ?

A friend of mine got a Generac 45kW for his house backup system. He put in a 1000 gallon tank. He got sticker shock when he had the tank first filled. He also uses propane for hot water, clothes dryer, and heating.

The 45kW Generac uses a Ford Taurus V6 engine running at 1800 rpm's and boy does it suck down the propane.

On a pure BTU/gallon basis,

Diesel is about 139,200 btu's per gallon
Gasoline is about 125,000 btu's per gallon
Propane is about 91,500 btu's per gallon
Natural gas averages about 1050 btu's per cu. ft. at sea level (with 20% variation depending on what dinosaur's ate for dinner that night)

A lot depends on particular engine but generally propane will be less kWh's/gallon then gasoline which will be a lot less then diesel.

Propane's a clear winner on storage longevity, as long as you don't spring a leak. Also very little carbon monoxide emission.

BB. · February 2010

Re: Advice on 'Propane' 25 Kw Generator ?

I can guess why Vic is looking at propane backup power... Besides the fact the company has propane running out its ears for other uses--California has pretty much declared war on any diesel power engine.

For trucks, they are requiring a ~$7,000-$20,000 cat+filter retrofit--or the vehicles have to be out of state... This applies to heavy equipment and, I would guess, will somehow apply to fixed equipment too.

A friend of mine has seen diesel trucks go for $0.10 on the dollar and heavy equipment going for pennies on the dollar at auctions. And cost lots of construction/heavy equipment operators jobs and closed businesses (and those that have left the state).

-Bill

icarus · February 2010

Re: Advice on 'Propane' 25 Kw Generator ?

Not to pick nits, but propane has ~71,000 BTU/gallon.

What makes Diesel so efficient is that there are more BTUs per unit and the engines are significantly more thermally efficient, that is they get more power per BTU.

Tony

Vic · February 2010

Re: Advice on 'Propane' 25 Kw Generator ?

Hello again,

chevenstein, Yes, I would like to find an LP genset with an in-line engine, and somehow would prefer the GM over the Ford. The V-6 engines have had some head gasket issues IIRC. The nicest Prime Power genset that I've looked at for this project was the Cat Olympian which had a Ford V-6, and was rated at 31.5 Kw Prime. It is a bit too large, but had the lowest Noise rating at abt 61 dBA. It is huge and weighs 2500 Lbs. Thanks for the Stateline link. Used to see them carried by Northern Tool, but did not see the SL Gas models there when I started the search for this project.

And solarvic, I have no direct experience with the GM 2.5L, but that would be my preference, but expect that any genset using this displacement would only be about 22 Kw Prime, which may be OK. The current LP genset is Military surplus from the '60s, and runs a Continental in-line 6. A very robust 25 Kw genset.

RCinFLA, yes, Diesel is the most efficient, both from the BTU content, and the inherent efficiency of the Diesel engine. My Kubota 25 KVA Diesel uses 1.8 Gal per hour at full load, 1.0 gal/Hr at half load, and 0.7 GPH at quarter load. This is another benefit of the Diesel -- more effiicient at part loads compared to Gas engines. And the storage life of the LP fuel cannot be beat. For off-grid think that Diesels are the way to go if one needs apprecaible run times. Diesel is a bit dicy in my off-grid situation, where do not need a large generator too often. WInd up running that genset at times just to exercise it. Will need to get an electric water heater (or perhaps and electric furnace) to help load that generator more fully when it runs ... but it still is a very nice and quiet generator.

And BB, yes the emissions regs are getting very tight here in CA as well as with the EPA. But Diesels have such a large foothold as transport engines, that there has been lotta progress in emissisons reduction from them. Altho, the Particulate Trap seems like a real KLUDGE ! Speaking of scrapping Diesels, when at the Cat distributor, saw a few nice large Diesel gensets where came in as some sites were required to upgrade to cleaner models. The sales guy mentioned that it was illegal for them to be sold or used anywhere in the USA, and they were being snagged for a couple of hundred $ each and shipped to Asia, Think that that is even below scrap value. Seems crazy to me. Many of these are back-up units. And if our Grid were just more reliable, none of this nose bleeding would be required. OOPPPSSss, too much attitude.

EDIT: Hi Backroad, I DID note that you mentioned CALLING Hardie or is it Hardy (?), anyway I will call and discuss the requirements with your contact. Thanks again

Thanks again for all the input. Vic

backroad · February 2010

Re: Advice on 'Propane' 25 Kw Generator ?

Hey Vic, I do understand that the propane generator will fit your needs best. If you haven't actually talked with Kim @ Harday Solar PERSONALLY, you might want to do so. I believe that she has a bit more available that what's listed online. As I said before, she is an amazing fountain of knowledge.

Backroad in Bagdad..........................................................AZ.......

Mangas · February 2010

Re: Advice on 'Propane' 25 Kw Generator ?

I have an industrial 15 KW Generac SG-0015, water cooled 1800 rpm propane unit with sound and weatherproof cover. I believe they make a 25 KW too. You can get them without the H100 digital panel which I have.

It is a standby unit to boot the batteries once in awhile during the winter and not a prime source application.

I spent a lot of time studying this subject before deciding on the propane unit. I spoke extensively with techs who service all the brands, fuels and configs.

My reasons included one less fuel to deal with (I have propane furnaces), less noise, parts availability in our area, ease of service and maintenance which is the biggest expense. On the larger units, parts and how they are engineered was a major factor for me.

Whatever you buy make sure it's maintained by the book by someone who knows what they are doing. Also, don't buy it too big when it can't load up nor too small when it struggles. If propane derate it for altitude.

Finally, investigate their warranty specific to your application.

Advice on 'Propane' 25 Kw Generator ?

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