Author Topic: Sizing question  (Read 3382 times)

ceiii2000

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Sizing question
« on: March 10, 2006, 05:40:46 PM »
So I am staring at my $164 electric bill and doing some quick math. Electric is pretty cheap in Oregon .055 per. So I used 2666 kwh in the last 28 days. My average daily usage was around 50 kwh in June and over 110 in December. December was abnormally cold as November I was down around 55.

Going by these numbers what is the best way to size a generator so I can rob enough heat from it to flatten out some of the demand in the winter, yet not run at almost no load in the summer?

My house is fully electric and I also have a wirefeed welder and hot tub (outdoor). My wife likes it cold and we run the AC pretty hard in August.

I plan on burning WVO and operate as much off grid as I possibly can.

One thing I have thought of is oversizing the generator and running say 16 hours on it and charging a battery bank then turning it off at night. Issues I see are having a load of batteries around and having to start and stop on diesel.

I thought I wanted a 16/2 with a 10K but this seems like it might be a bit large for my needs.

Thanks
Ce

rocket

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Re: Sizing question
« Reply #1 on: March 10, 2006, 07:10:22 PM »
16/2 sounds about right, but if my electric was .055 i would just pay it for now.... ours is .10+ now and rising and i think that is cheaper than most around here

ceiii2000

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Re: Sizing question
« Reply #2 on: March 11, 2006, 01:13:20 AM »
Actually saving money isn't the number 1 reason for this little project. A friend wants me to do the grunt work for him. He has $$ and I, he thinks, have enough knowledge/ability/time to put it together. I alread run my VW Jetta on waste oil and have access to more.

He thought he wanted a 271 connected to a 12kw generator but I did some research and though parts are probably easier and maybe even cheaper, fuel consumption seemed a bit high along with noise abatement. Plus I like the idea of simple slow and beefy lister(oids).

So do I have this right? I keep reading that a 12/2 (500rpm) 16/2 (650), 20/2 (850) are the same engine ran at different RPM. SO couldn't I just buy a slightly oversized generator head say 12kw and run the same engine at different speeds winter and summer?

Just need different pulleys?

Ce

solarguy

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Re: Sizing question
« Reply #3 on: March 11, 2006, 06:21:30 PM »
Another possibility, which I am considering for my next setup, is two seperate 8 horse singles both driving the same "oversized" generator.  Run two when you need lots, and one when you don't.  That also gives you some backup protection in case you have a bad event with one engine, you're not totally without juice while you get things fixed up.

I just haven't figured out the slick way to easily drive one or both or either at a moment's notice.

Finest regards,

troy

kpgv

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Re: Sizing question
« Reply #4 on: March 11, 2006, 06:36:56 PM »
Troy,
The other way that popped into my head was to mount two heads straddled by two engines so that either engine can drive either head.
For the heads, use one ST, and one converted "motor".
The "motor" will self sync with the ST, so less problems getting them in phase, and for emergency, the ST will lead the "motor". In a non-emergency sitch, run whichever wou like.
If there's a harder way, Ill find it ;D

Kevin


GuyFawkes

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Re: Sizing question
« Reply #5 on: March 11, 2006, 08:39:44 PM »

I just haven't figured out the slick way to easily drive one or both or either at a moment's notice.



sir wants a differential
--
Original Lister CS 6/1 Start-o-matic 2.5 Kw (radiator conversion)
3Kw 130 VDC Dynamo to be added. (compressor + hyd pump)
Original Lister D, megasquirt multifuel project, compressor and truck alternator.
Current status - project / standby, Fuel, good old pump diesel.

ceiii2000

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Re: Sizing question
« Reply #6 on: March 12, 2006, 07:18:27 AM »
Those are cool ideas. So why not combine them. Two 6/1's 1 ST say 5k and 1 motor. No differential needed everything syncs up nice. I still don't fully understand using a motor as a generator thing. Might have to come up with a way to mount everything so you can swap engines and heads easily. Or maybe even drive both off one for a short time or something.
« Last Edit: March 13, 2006, 12:00:36 AM by ceiii2000 »