LPG Powered Generators

Hi there..
I have just bought a house totally off grid. I'm looking to have solar and a generator back up. I've been looking at the Yamaha generator that you can convert to LPG. As the house also runs on bottled gas I thought that this may be a more economical way to go. Does anyone here have any experience with LPG?
Thanks Steve

wrote in message

Hi there..
I have just bought a house totally off grid. I'm looking to have solar and a generator back up. I've been looking at the Yamaha generator that you can convert to LPG. As the house also runs on bottled gas I thought that this may be a more economical way to go. Does anyone here have any experience with LPG?

Like gasoline, propane is subject to varying market conditions. At any given moment, it may be cheaper or more expensive than gasoline. Propane has a real advantage for standby generators in that you can store it forever without fear of it going bad. Dual fuel should be possible with that Yamaha generator, and then you can burn whatever is cheaper or more available.
Particularly if you live in a rural area, you might also consider a diesel generator fueled with off-road (untaxed) diesel fuel.
Vaughn

Welcome -
I have a bit of experience.
What size load do you have?
We need about 4000 continuous with surges for motor starts. We handle it very well with an 8000watt Briggs unit with advertised surge to 13500...
We have 3 units. We believe in redundancy based on the problems we had with prior small units. Lots of different things can happen, and having complete separate units allow you to continue to run, while making repairs and replacing parts.
One unit is an older Dayton with v4 wisconsin flat head engine. I think it is about 20KW. It is pure LP. Though it is the largest, we use it for backup because it seems to use more fuel than the smaller engines.
One unit is a Briggs EXL8000 with TRI-FUEL - It has an AARDVARK regulator and mixer, which allows it to run on LP, NG or Gasoline. We have used both gasoline and LP successfully and somewhat interchangeably. Just turn off one fuel supply and turn on the other. This unit has a 15 hp Briggs Vanguard Engine with a "splash" lube system and no oil pump or oil filter. We run 5-50 syntec oil in it. So far, we have about 200 hours on it - about half propane.
We got the above unit from Central Maine Diesel with the TRI-FUEL installed. See: http://www.generatorsales.com/order/1019_tri_fuel.asp?page=1019_tri_fuel We had some delivery problems and got caught in a model change, but we were VERY pleased with the service in the end.
Our third unit is a Generac Portable Power Systems EXL7550 from Home Depot. Briggs now owns the Generac Portable Power Systems, but this unit has a Generac 410cc engine - also about 15hp. We bought it for $799 plus tax as a closeout.
We have ordered a second Aardvark regulator and mixer for this Generac engine. We intend to also run it primarily as Propane with Gasoline backup. See: http://aafs-sp.com/ About $215 delivered from Aardvark.
The propane is very convient.
The tri-fuel gasoline option gives us flexibilty if there is a late fuel delivery. It also is good to have if something goes wrong with the propane. One of our folks damaged the regulator; we were able to continue to run just by pouring gasoline into the tank and starting the engine.
I suggest that you check the fuel usage specs for the unit you choose. Diesel was not an option for us, but I think you may find it less expensive to run.
Good Luck! Phil

franklin.sr@gmail.com wrote:

Hi there..
I have just bought a house totally off grid. I'm looking to have solar and a generator back up. I've been looking at the Yamaha generator that you can convert to LPG. As the house also runs on bottled gas I thought that this may be a more economical way to go. Does anyone here have any experience with LPG?
Thanks Steve

I have used a 5kw propane powered generator at my camp for close to 15 years. My neighbors have used one for 20 years.
No worries about the fuel going bad. I ran off 20lb tanks for most of those years, but have recently connected to a 240 gallon tank that I tap to use a stove, and hot water heater, and eventually my main heat.
It is a lot cheaper to buy propane for larger bulk tanks. For example, if you buy in 100lb tanks instead of 20lb tanks, it is like getting one 20 pounder for free. With larger tanks, you can get delivery.
Even with a small tank, it is less of a mess and safer to refuel with LPG than with gasoline.
There is less engine maintenance with LPG. The oil stays cleaner and there is no wash down of the cylinders as there is with gasoline.
I never had any starting problems, even in very cold conditions.
Since you already use LPG for other appliances, it is a very good choice. Propane lighting also works nicely for wide area lighting for cooler months, but I still prefer compact fluorescent lighting over gas lights.
I agree with other posters about there being an advantage to having a multi-fuel capability for flexibility. But, if I had to chose one or the other I'd choose LPG over gasoline.

wrote in message

Hi there..
I have just bought a house totally off grid. I'm looking to have solar and a generator back up. I've been looking at the Yamaha generator that you can convert to LPG. As the house also runs on bottled gas I thought that this may be a more economical way to go. Does anyone here have any experience with LPG?
Thanks Steve

On 22 Mar 2006 17:41:30 -0800, franklin.sr@gmail.com wrote:

Hi there..
I have just bought a house totally off grid. I'm looking to have solar and a generator back up. I've been looking at the Yamaha generator that you can convert to LPG. As the house also runs on bottled gas I thought that this may be a more economical way to go. Does anyone here have any experience with LPG?
Thanks Steve

There are a number of facts you need to take into account in deciding on the kind of generator engine to install.
Reliability, longevity, maintenance, etc.
In my case there was also the express wishes of SWMBO (she who must be obeyed) that we only have a single fuel source.
The advantages of propane (compared with gasoline) is that it is clean and doesn't deteriorate with storage. The oil seems to stay cleaner which translates to a longer time between oil changes. Spark plugs stay cleaner also.
Diesel engines generally last longer, since they are beefier to begin with. But depending on your climate, you may have starting issues in the winter.
My recommendation is that if your generator will be running a lot you should definitely go with diesel. If it will be running only occasionally -- say less than 200 hrs/year, then I would recommend propane for ease of storage.
In any case, you should be looking at 1800 rpm water-cooled units rather than 3600 rpm air-cooled units as the former will last longer. The latter can be used, and have been used successfully by many, but they frequently don't last as long as the slower turning units.
-- ron (off the grid in Downeast Maine)

wrote in message

Hi there..
I have just bought a house totally off grid. I'm looking to have solar and a generator back up. I've been looking at the Yamaha generator that you can convert to LPG. As the house also runs on bottled gas I thought that this may be a more economical way to go. Does anyone here have any experience with LPG?
Thanks Steve

Engines that were built for gas will burn valves, unless you have the special valves and seats installed for propane.

I disagree with the part about the 1800 rpm engines..
Consider total cost of ownership.
I think that while the 1800s may last longer, they will likely cost more to begin with.
And, the fuel usage may be more.
And service may mean paying portal-to-portal service travel time...
Ron Rosenfeld wrote:

On 22 Mar 2006 17:41:30 -0800, franklin.sr@gmail.com wrote:
Hi there..
I have just bought a house totally off grid. I'm looking to have solar and a generator back up. I've been looking at the Yamaha generator that you can convert to LPG. As the house also runs on bottled gas I thought that this may be a more economical way to go. Does anyone here have any experience with LPG?
Thanks Steve
There are a number of facts you need to take into account in deciding on the kind of generator engine to install.
Reliability, longevity, maintenance, etc.
In my case there was also the express wishes of SWMBO (she who must be obeyed) that we only have a single fuel source.
The advantages of propane (compared with gasoline) is that it is clean and doesn't deteriorate with storage. The oil seems to stay cleaner which translates to a longer time between oil changes. Spark plugs stay cleaner also.
Diesel engines generally last longer, since they are beefier to begin with. But depending on your climate, you may have starting issues in the winter.
My recommendation is that if your generator will be running a lot you should definitely go with diesel. If it will be running only occasionally -- say less than 200 hrs/year, then I would recommend propane for ease of storage.
In any case, you should be looking at 1800 rpm water-cooled units rather than 3600 rpm air-cooled units as the former will last longer. The latter can be used, and have been used successfully by many, but they frequently don't last as long as the slower turning units.
-- ron (off the grid in Downeast Maine)

I talked with the folks at Briggs about that LP and valves.
Many modern engines including theirs are fine. I've heard that the removal of lead from engines force the manufactures to deal with the reduced lubrication.

Richard W. wrote:

franklin.sr@gmail.com> wrote in message Hi there..
I have just bought a house totally off grid. I'm looking to have solar and a generator back up. I've been looking at the Yamaha generator that you can convert to LPG. As the house also runs on bottled gas I thought that this may be a more economical way to go. Does anyone here have any experience with LPG?
Thanks Steve
Engines that were built for gas will burn valves, unless you have the special valves and seats installed for propane.

On 23 Mar 2006 18:38:47 -0800, "philkryder" wrote:

I disagree with the part about the 1800 rpm engines..
Consider total cost of ownership.
I think that while the 1800s may last longer, they will likely cost more to begin with.
And, the fuel usage may be more.
And service may mean paying portal-to-portal service travel time...

As I implied, TCO will vary depending on usage.
For a unit that is used for electrical grid backup, where outages are likely to be short-lived and infrequent, a 3600 rpm unit may be adequate.
Likewise for an off-grid system where the design of the system is such that the backup generator is rarely used.
But once you get into the 100-200 hr/year usage with a larger generator (let's say greater than the portable 5-6kW size), it is unlikely that an air-cooled 3600 rpm generator will hold up for years of use.
As a matter of fact, I was initially going to purchase a 3600/air-cooled ONAN unit -- about 10 or 12 kW (I forget the model RS12000 or something like that). It was even delivered. After perusing the literature, it became apparent that the factory warranty was limited to 2 years or TWO HUNDRED (200) hours, whichever came first. (Contrary to what both I and the dealer had been informed by a salesperson). I returned it and went with a (1800rpm/water-cooled) Kohler unit. The latter was more expensive but had a 2000 hour warrantee.
The "fine-tuning" and installation was done by technicians from the dealer -- but that was all part of the warrantee service.
Routine servicing consists merely of changing filters, oil and spark plugs -- something even I can do. More involved service would require someone with more skills than I, but there are plenty of small engine mechanics around who could service the Ford engine (or I could pay for the dealer tech to come here). So far that has not been necessary for six years. -- ron (off the grid in Downeast Maine)

On Fri, 24 Mar 2006 08:13:17 -0500, Ron Rosenfeld wrote:

For a unit that is used for electrical grid backup, where outages are likely to be short-lived and infrequent, a 3600 rpm unit may be adequate.

The cheapest brand-name 3600 RPM units are often fine for that. I know one contractor who got about 3000 hours from a crummy 5kW portable despite infrequent oil checking and changes. They'd probably still be using it if they hadn't run it completely dry.

But once you get into the 100-200 hr/year usage with a larger generator (let's say greater than the portable 5-6kW size), it is unlikely that an air-cooled 3600 rpm generator will hold up for years of use.

Consider (to name just one example) the number of 3600 RPM welder-generators in the 16 to 20 hp class being used daily. The usual Onan, Kohler, and Honda air-cooled twins. I wouldn't be surprised if many have 10,000 hours or more. I expect that those new Generac 27 and 30 hp air cooled 3600 RPM setups should make 3000 hours, perhaps more. They won't be as long-lived as what you have, but at just over $2k (portable) the price is attractive. Not that I'm recommending them, I think they're way too big for most home power applications.
Wayne

On Fri, 24 Mar 2006 21:06:19 GMT, wmbjk wrote:

On Fri, 24 Mar 2006 08:13:17 -0500, Ron Rosenfeld ronrosenfeld@nospam.org> wrote:
For a unit that is used for electrical grid backup, where outages are likely to be short-lived and infrequent, a 3600 rpm unit may be adequate.
The cheapest brand-name 3600 RPM units are often fine for that. I know one contractor who got about 3000 hours from a crummy 5kW portable despite infrequent oil checking and changes. They'd probably still be using it if they hadn't run it completely dry.
But once you get into the 100-200 hr/year usage with a larger generator (let's say greater than the portable 5-6kW size), it is unlikely that an air-cooled 3600 rpm generator will hold up for years of use.
Consider (to name just one example) the number of 3600 RPM welder-generators in the 16 to 20 hp class being used daily. The usual Onan, Kohler, and Honda air-cooled twins. I wouldn't be surprised if many have 10,000 hours or more. I expect that those new Generac 27 and 30 hp air cooled 3600 RPM setups should make 3000 hours, perhaps more. They won't be as long-lived as what you have, but at just over $2k (portable) the price is attractive. Not that I'm recommending them, I think they're way too big for most home power applications.
Wayne

That style may well have the longevity.
I was impressed, though, by the limited warrantee (200 hours/2 years whichever is less) on an Onan 12kW 3600 rpm generator designed for home standby use, compared with the 1800 rpm variety.
But a $2,000 unit that will last 10,000 hours would be very attractive. Do you have some specifics? What kind of fuel consumption?
-- ron (off the grid in Downeast Maine)

In article , Ron Rosenfeld wrote:

On Fri, 24 Mar 2006 21:06:19 GMT, wmbjk wrote:
Consider (to name just one example) the number of 3600 RPM welder-generators in the 16 to 20 hp class being used daily. The usual Onan, Kohler, and Honda air-cooled twins. I wouldn't be surprised if many have 10,000 hours or more.
But a $2,000 unit that will last 10,000 hours would be very attractive. Do you have some specifics? What kind of fuel consumption?

Well, as I happens, I have some experience here. To begin with, LOUD, even with an extra muffler.
High fuel consumption, which is among many reasons why I'm shopping for a water-cooled diesel. About 0.28 gallon gasoline/KWH on the full load end, _much_ worse when running lightly loaded (no better than ~1 gallon an hour no matter how little electricity you are using). I cannot buy no-tax gasoline, no tax diesel is easy to get, as are 0.08 gallon diesel/KWH generators. The math is rather simple, or $imple.
I rather doubt 10,000 hours, but I'll let you know in 9,800 (or a lot less, if it dies first) - my unit has already been in for one major welding-related repair under warrantee. If it has a failure out of warrantee it's clear that the parts are priced so that it will be non-economical to fix it, unless the failure is quite simple and located external to the circuit boards, which get swapped out as units. I got one when I thought the grid connection was going to be reasonable, and I needed to weld some stuff "right now". Had I known where I was headed, I probably would have spent more for the liquid-cooled low-speed diesel variant, which exists in these units as well.
I don't think that the engines (same sort seen in lawn tractors) get a magical lease on life from being in a welder-generator, and I've seen quite a few on the used market described as "needs work", often meaning either dead alternator or dead engine - or dead circuit boards which cost more than a working used welder-generator. Koehler would have been better than Onan for gas engines - service intervals are twice as long, IIRC. But a diesel is still the better choice, IMHO.
-- Cats, coffee, chocolate...vices to live by

philkryder wrote:

See: http://www.generatorsales.com/order/1019_tri_fuel.asp?page=1019_tri_fuel

would you know what the "100 amp pre-wired transfer system" means?
I have a manual transfer switch already installed, complete with a plug-in box on wall and 20 feet of cable (male plug on one end and female on the other end) for a 220v hookup to gen

philkryder wrote:

I disagree with the part about the 1800 rpm engines.. And, the fuel usage may be more.

Wot I wonder is whether it is cheaper to use town gas or LPG to run an electrical generator than the cost of electricity from the grid.
-- Regards, Peter. http://www.pelicom.net.nz

On Sat, 25 Mar 2006 02:36:40 GMT, Ecnerwal wrote:

In article , Ron Rosenfeld wrote:
On Fri, 24 Mar 2006 21:06:19 GMT, wmbjk wrote:
Consider (to name just one example) the number of 3600 RPM welder-generators in the 16 to 20 hp class being used daily. The usual Onan, Kohler, and Honda air-cooled twins. I wouldn't be surprised if many have 10,000 hours or more.
But a $2,000 unit that will last 10,000 hours would be very attractive. Do you have some specifics? What kind of fuel consumption?
Well, as I happens, I have some experience here. To begin with, LOUD, even with an extra muffler.

Our 12kW Kohler (propane, liquid-cooled, 1800RPM) is loud, but in the garage -- we barely hear it in the house unless we have the windows open on that side of the house. No problem sleeping with it running.

High fuel consumption, which is among many reasons why I'm shopping for a water-cooled diesel. About 0.28 gallon gasoline/KWH on the full load end, _much_ worse when running lightly loaded (no better than ~1 gallon an hour no matter how little electricity you are using). I cannot buy no-tax gasoline, no tax diesel is easy to get, as are 0.08 gallon diesel/KWH generators. The math is rather simple, or $imple.

Our fuel consumption is more in your range. At full output, it's supposed to be about 0.17 gal/kW output. At 10kW, which is what it runs at when battery charging, it's about 0.18 per kW. However, when you consider the inefficiency of battery charging, and the fact that some time is spent in Hold (or Absorption) mode when charging, I'm probably at about 0.28gal/kW. Of course, propane costs me about $1.90/gal, so it's cheaper than gasoline.

I rather doubt 10,000 hours, but I'll let you know in 9,800 (or a lot less, if it dies first) - my unit has already been in for one major welding-related repair under warrantee. If it has a failure out of warrantee it's clear that the parts are priced so that it will be non-economical to fix it, unless the failure is quite simple and located external to the circuit boards, which get swapped out as units. I got one when I thought the grid connection was going to be reasonable, and I needed to weld some stuff "right now". Had I known where I was headed, I probably would have spent more for the liquid-cooled low-speed diesel variant, which exists in these units as well.

If mine dies, I'll look at the diesels. Those fuel consumption specifics are enticing. But I've had no warrantee problems over six years and about 1400 hours. I change the oil about every 150 hours; air filter every 400; and the spark plugs from time to time (supposed to be at 400, but I need a RoundTuit to do the next change). There was some initial "tinkering" to get it to run and start properly in automatic mode -- a couple of board swaps; but no problems in years. My average annual run time is about 180 hours.
-- ron (off the grid in Downeast Maine)