Generators

[FastWalk]

Due to storms and other silly reasons,  power grid can be (is) unpredictable.

How do you handle your backup generators.

My initial idea is wire a mid sized diesel with electric start to a switch box.  Not to big as I want to conserve fuel when needed but big enough to handle the house, even a couple AC.  And also to have a small portable hand start gas in case the battery is dead to start the diesel or to carry around if/as needed.  We should be able to store some containers of fuel safely as diesel doesn't explode.

comments ?    what have you all done for the same issue.

Thanks for any ideas.

[Hestecrefter]

We live off-grid on the ocean in western Canada.  We rely on solar and wind power to charge a bank of 8 Surrette Solar Batteries, 6V, 1156 AHr.

We have a 7.5 kw Kubota diesel generator wired so as to direct charge to the batteries should there be insufficient sun/wind to do the job. If for some reason we wish to bypass the batteries, there is a "bypass" switch which allows current to be directed directly into the house wiring and 7.5 kw is sufficient to power the whole place under just about any load.  We have a Makita 2400-watt gasoline generator that can be used for portable power, since the Kubota weighs about 1,000 lb.

I would say 7.5 kw would be all you would need.  As diesel gensets go, it's actually on the small side. 

[lost_in_samoa]

How do you handle your backup generators.

My perspective is biased to simplicity, maintenance, and longevity.  Not convenience or comfort.  So my solutions won't sit well with most folks.

I'll just throw a few thoughts out there.

I have heard, and I believe,  that gaseous fueled engines .... NG, LPG, etc far out last liquid fueled engines.

Diesel is better than Petrol.  Fuel stability is a real concern.

Inrush current is a problem.  It will flat shut a generator down if it is not dealt with.  Correct generator sizing or motor "soft starting".

I always found it easiest to have a mains in mechanical switch,  to cut out the grid and in the generator,  installed in such a way as to prevent both the feeds from ever being connected at the same time.   Back feeding into the grid can be a very bad thing.

I like to control the load at the breaker panel.  Every thing off.  Switch over to genny.  Bring her up to speed.  Then slowly energize only what I need to service. 

The best .... (most reliable, never failed when I needed it, easiest to service) ... genset I ever had was ......  and this is gonna chap a few expert's bottoms .....  An old hit and miss motor running off of LPG.

She was coldblooded .... a pain in the butt to start ..... but so simple even I could maintain it.

[JoeLP]

We just have a 4500 watt generator hooked straight to a breaker that goes straight to main power box.  Our Norsamelco power source does the same.  Cut off that breaker, turn on the generator, cut in it's power, and we are set.  Only Tina and I touch any of the breakers.  Just needed it yesterday as Norsamelco was doing some maintenance.  About once a month they take a Saturday for doing that.  Run our fridge, lights, some tvs and net off it is all.

I grew up with the lp gas generator and to this day my dad uses that.  He always had either city gas or the gas "pig" hooked to it.  Set it up the same way as I have my house now setup.  When power went out after a storm or something just flip the incoming power breaker and the generator one and we had power.  If we had a city gas or a large tank/pig I'd probably set that up here also.  Just don't use it enough to warrant that yet.

[lost_in_samoa]

Here is a photo of the cut over switch I cobbled together from what was available.  I have one in each building to select grid or solar / genny.

Two fused blade switches, (one inverted), mounted on a plywood plate off set from each other.  So that the handles match up and are bolted together.

[FastWalk]

We live off-grid on the ocean in western Canada.  We rely on solar and wind power to charge a bank of 8 Surrette Solar Batteries, 6V, 1156 AHr.

We have a 7.5 kw Kubota diesel generator wired so as to direct charge to the batteries should there be insufficient sun/wind to do the job. If for some reason we wish to bypass the batteries, there is a "bypass" switch which allows current to be directed directly into the house wiring and 7.5 kw is sufficient to power the whole place under just about any load.  We have a Makita 2400-watt gasoline generator that can be used for portable power, since the Kubota weighs about 1,000 lb.

I would say 7.5 kw would be all you would need.  As diesel gensets go, it's actually on the small side.

I remember you telling about your setup for this before.  It sounds really complete.  I might pick a Kubota,  I like the brand.

[FastWalk]

Here is a photo of the cut over switch I cobbled together from what was available.  I have one in each building to select grid or solar / genny.

Two fused blade switches, (one inverted), mounted on a plywood plate off set from each other.  So that the handles match up and are bolted together.

Thanks,  I have a brother in law that setup just like this but without the fuse for one of our farms.  I'll probably ask him to wire our house just the same like your diagram.

[M.C.A.]

Our house used to have those Dynamite like fuses... Had one of those fuses blow up once on me when I threw the switch so to speak, I was advised after that to get the modern fuses and fuse panels.

[Hestecrefter]

I remember you telling about your setup for this before.  It sounds really complete.  I might pick a Kubota,  I like the brand.

I can endorse the Kubota.  They do not come cheap, but they are bullet-proof.  With basic maintenance they should go 30,000 hours.  There are 2 around here with that much use and still going strong.  If you can pick up a cared-for used one with 3,000 or so hours on it, you'll save some pesos and have a reliable unit.

[Hestecrefter]

I have heard, and I believe,  that gaseous fueled engines .... NG, LPG, etc far out last liquid fueled engines.

Diesel is better than Petrol.  Fuel stability is a real concern.

I wanted to do a bit of research before saying any more than I did in my Kubota endorsement.  I was a bit startled by lost's comment about gaseous fuel = long engine life, since I grew up learning the opposite.  My few minutes of research turned up this website:

https://www.generatorjoe.net/html/genfuel.html

There, one reads (about diesel):

Engine life for liquid-cooled 1800 RPM engines can approach 20,000 hours if properly serviced depending on the application and environment.

And about gas:

Engine life for liquid-cooled 1800 RPM engines can approach 5,000 to 6,000 hours on industrial quality gaseous GenSets

The foregoing squares with what I have always believed.  BUT, if I spend a few more minutes on google, I can probably turn up a website relating that there are gas-fired gennys that came over on the Mayflower and are still in daily use. 

I DO disagree with the source cited about an 1800 rpm diesel running for only 20,000 hours if all goes well.  I am guessing that one I know of around here, used in a camp operation, is probably getting close to 40,000 hours as I write this. 

As for fuel storage, for me it's a non-issue.  We do not store copious amounts.  Our diesel genny and Kubota side-by-side ATV (another great Kubota product) sip fuel and probably burn all of 50 gallons in a year, if that.  We never have on hand anything close to that.  No need.  We bring gasoline over for our trucks, chainsaws, etc., but again, never more than 25 gallons in storage at any time.  We used to buy from the fuel boat, that would pull up to our beach and fill us up.  Then we would buy about 140 gallons at a time.  But we just don't use all that much, so hauling a few cans from town now and again is much more cost-effective.  One pays a premium for the convenience of the fuel boat.

[lost_in_samoa]

https://www.generatorjoe.net/html/genfuel.html

Great link.  I am researching it a bit deeper.  Might learn something new.  Thank you.

[lost_in_samoa]

Thanks to FW for starting the thread and HC for bringing this up.  Which is the best generator fuel?

I give "GeneratorJoe" a lot of weight.  But I looked around, did not see a burning bush, so he is not above question.


What I found was ....

Liquid fuels provide additional cooling to the upper portion of the engine.   Gaseous fuels do not.  Consequently the temps are higher.

Petrol engines wash the lubricating film out of the combustion path.  Gaseous engines do not.  Diesels actually provide additional lubrication.


The points I suspected are .....

Gaseous fuels burn more evenly and cleaner than either diesel or petrol.  With all of the maintenance benefits this entails.  This is where my opinion was formed from.

There are sites that list opposing results on engine lifespan.  I see that there is not much discussion of the lifespan between petrol and gaseous fueled generators.  The consensus is that gaseous is superior.  The question now becomes which is superior between Diesel and gaseous?

I'd say Diesel. But without a published paper, (which I'd love to see), I will rely on GeneratorJoe.


Other things to consider .....

Availability of fuels.   In the RP.  Forget-about-it.  Diesel.  That's your choice.  I have found no retail level infrastructure beyond "camper's bottles" of gaseous fuels.

Quality of fuels.   In the RP.  I'd suspect that the over time quality of gaseous fuels is superior to liquid fuels.  I have gotten diesel/gas that was great and crap.  I cannot ever remember getting a tankfull of bad LPG.  I am sure it does happen.


I've run Diesel, gasoline, and LPG generators.  I grew up on a ranch that had a large Kohler LPG generator.  In the military I supported multiple 10Kw Diesel gensets.   Afterwards, mostly 5kw and lower gasoline fueled, off the shelf stuff.  With the exception of a small 5Kw LPG fueled Deere Hit-n-Miss I inherited.  I am currently building a 5Hp 2Kw biogas fueled genset out of junk I have in my bodega.

Old dogs can learn new tricks.  Thanks.