Cogenerators and grid tie?

[ToddT]

Along those lines, I've been experimenting with desiccant dehumidification. I live in the South where humidity is a bigger issue than cooling sometimes. It also stands to reason that it would take less energy to cool dry air than wet. A desiccant wheel can dry the inside air and be recharged with heat from the generator (or solar or whatever). My thinking is a systems approach where different things contribute and we can reach the same goal with different means.

[Number21]

In this case if you wanted the heat, I'd just set up a Waste oil burner.  Certainly going to be incomprably cheaper than the purchase of a generator which really the heat is the only benifit of.  At a 1c a KWH, return, the thing will never payitself back in it's lifetime on power.  Given you could knock out a wvo Burner for about $100 do produce any amount of heat you wanted and have no setup or regulations, it may be a better option...... If the heat is valueable enough to you.

I was palying with a burner of mine today and measured over 350KW output. That's going to heat a very big space with no problems. 

My issue with that becomes liability. If it catches on fire, I'm always responsible, the end. Doesn't matter if it was my fault or not. A fire in this building would be an enormous loss in dollars. On the other hand, if an engine caught fire, (seems less likely) I think it would go over better with the authorities. It was the engine's fault. (If I installed everything correctly)

Plus a burner doesn't make cool vroom vroom noises!

I would also like to experiment with thermoelectric generators from the waste heat. I've seen experimental units for cars that work on the exhaust heat and produce in the range of 1kw. That could significantly improve the watts/gallon numbers!

[Number21]

Here are some of the numbers I found for KWH/gallon on WVO, if anybody knows of any other data I would love to see it.
http://organicmechanic.com/vegetable-oil-generator/

13.5kw x 75% load = 10.125 KWH from .75 gallons = 13.5 KWH per gallon
60kw x 75% load = 45 KWH from 2.7 gallons = 16.6 KWH per gallon
450kw x 75% load = 337.5 KWH from 19.6 gallons = 17.2 KWH per gallon

Those numbers seem a bit optimistic, but they do show the bigger generator to be a lot more efficient, and it would make sense that a modern high speed engine is more efficient than an old style listeroid. (Especially one cheaply manufactured in a third world country)

[Number21]

Looking a little harder at the grid tie inverters, there are a few cheaper ones on ebay. If I got an inverter like this could I simply hook up the output of any 240vac generator to the input on the inverter? That seems too easy...
http://www.ebay.com/itm/SMA-Sunny-Boy-3000-US-Grid-Tie-Solar-Inverter-DC-Disconnect-/251473170510?pt=LH_DefaultDomain_0&hash=item3a8cf8104e

[Tom Reed]

It's fairly well established that with a Listeroid you can generate 1kw with .125 gal of fuel. It will make 3kw continuous and that will run it about 3 hours so I figure a real world small system could generate 9kw per gal of WVO.

[Carlb]

Looking a little harder at the grid tie inverters, there are a few cheaper ones on ebay. If I got an inverter like this could I simply hook up the output of any 240vac generator to the input on the inverter? That seems too easy...
http://www.ebay.com/itm/SMA-Sunny-Boy-3000-US-Grid-Tie-Solar-Inverter-DC-Disconnect-/251473170510?pt=LH_DefaultDomain_0&hash=item3a8cf8104e

The input needs to be DC not AC

[glort]

Looking a little harder at the grid tie inverters, there are a few cheaper ones on ebay. If I got an inverter like this could I simply hook up the output of any 240vac generator to the input on the inverter? That seems too easy...
http://www.ebay.com/itm/SMA-Sunny-Boy-3000-US-Grid-Tie-Solar-Inverter-DC-Disconnect-/251473170510?pt=LH_DefaultDomain_0&hash=item3a8cf8104e

$1500 for 3.5 Kw, not exactly cheap.  Well, maybe it is where you are. Going to be costly to get the 20Kw you want though.

As far as DC, I just built a simple bridge rectifier setup but you can get them off ebay up to 100A prebuilt ready to hook up and they are not at all expensive. 

I got offered something else today that may be interesting in this application... a 40 Kw UPS.
The thing is 3 phase which is OK as I could run it off the 3 phase motor or get a 3 phase STC genny head.  These High end Units basicly take the mains power to run a battery charger and the output is taken from the batterys using an inverter.
This one only had new batteries a year ago so should have some decent life in the thing. Wouldn't be hard just to plug the Solar inverters into that and backfeed to the grid. 

A Unit like this could be hooked up to run some machines direct therefore eliminating the need to connect to the grid at all.  Run your generator into the thing and plug in whatever load you want to drive. I see these things going cheap all the time here so maybe an inexpensive option there as well.

The one I'll be getting does 14Min run time at 40 KW.
I imagine it will last a good long time at 3 Kw or less the house normally takes!

[Number21]

That is one thing I thought about, UPS's. (and 40KW...WOW!) I have seen much smaller ones pretty cheap without batteries.

I think what I'm leaning towards right now is just a listeroid, because I've always wanted one, as an experiment, and then I can scale up from there. That is definitely a plus of using inverters, easy to add capacity. And then wait until I see that 500kw surplus generator for sale cheap. 

[bryanb]

With a 200 hr oil change requirement you will be doing an oil change every 8 or 9 days if you run the engine 24/7.

Just wondering where you got this information from?  I am in the process of setting up my cogen system and plan on using WVO.
BTW I am in Southern Vancouver Island as well.

Bryan

[buickanddeere]

  Closet numbers that I can make work in the winter. Is to take a 6HP Yanmar clone aircooled and run it in the garage at 1875 rpm direct coupled to a 3HP single phase induction motor/generator.
   If natural gas is ever routed to the area. The Yanmar would be NG fueled and diesel pilot ignition used.
  Depending on the time of year steady base load varies from 0.75 to 4KW during daytime peak rates.
  Just adjust the throttle to obtain a net of zero watts at the utility meter from 7:00AM to 7:00PM Monday to Friday. The heat from the cooling fins and the exhaust stack would keep the garage warm.
   Induction motor/generator simplifies " synchronization" to the grid.  A little tweaking with the compression release would allow the 3HP motor to start the diesel.
   Spring , summer and fall would be solar to obtain a near zero net in the daytime. There are four months of the year here where a solar panel's primary function is a snow fence.
  As expensive as off peak power is. I can't generate power for that price let alone store it for later use.

[Number21]

  Just adjust the throttle to obtain a net of zero watts at the utility meter from 7:00AM to 7:00PM Monday to Friday.

I would LOVE to find some kind of device that would do this for me automatically. It doesn't seem all that complicated...but beyond my electronics ability. It probably already exists somewhere as part of some fancy out of reach commercial cogen system.

[mobile_bob]

best of class gensets (those in ~7-10 kwatt) do about 11kw/hrs per gallon US diesel.

that at or near full rated load, anything less the efficiency goes down.

there are a few exceptions, but none that i know of will do much better than this.

the reported numbers of 13plus kw/hrs/gallon of veggie seems a bit flakey to me, perhaps there are other things they are factoring in?  not sure of an imperial gallon, maybe that helps a bit? i can't imagine veggie oil would beat pump diesel by any significant margin, that is if it can even get close?

something wrong with the numbers reported in my opinion.

a doable goal is about 10 kw/hrs/gallon(US) diesel,  and in some cases closer to 11kw/hrs/gallon (US) diesel if you do things just right, that using a newer engine design of course and properly setup and more importantly ran at or near full rated load.

my 02 worth

bob g

[Jens]

With a 200 hr oil change requirement you will be doing an oil change every 8 or 9 days if you run the engine 24/7.

Just wondering where you got this information from?  I am in the process of setting up my cogen system and plan on using WVO.
BTW I am in Southern Vancouver Island as well.

Bryan

My 20/2 Listeroid recommends oil changes at either 100 or 150 hrs in the manual. I did them at about 100 hrs because of the thickened consistency of the oil by that time - I assume that some veg oil made it past the rings and contaminated the oil. I am not running the engine any more so my recollection is a bit fuzzy.

[buickanddeere]

  I suppose the simplest would be the before mentioned grid tie inverter. Supply the grid tie with rectumfied DC from a standard AC alternator.

[glort]

  I suppose the simplest would be the before mentioned grid tie inverter. Supply the grid tie with rectumfied DC from a standard AC alternator.

Won't work if it's a solar type Inverter. They have a higher kick in voltage than a car alternator. Mine are 90V.  Maybe you could take the regulator out of the alt and spin the hell out of it but it wouldn't be a standard alternator then. Also some alts I have looked at this isn't easy at all to do. Maybe the Leeces would be OK?
The other thing would be to use a 12V plugin type inverter like the " Powerjack" types on fleabay. Varying reports about those and not exactly cheap either. Also very limited power output wise. Most are under 1000W and even the 1KW jobs are pricey.  Don't know if they even go over that.

Personally I would much rather use higher quality components and those designed for longer hours. 3 phase motors are designed to run long periods and I'd be willing to bet even if they are made in china, to get certification from the electric authourities for solar installation and connection to the grid. The solar panel inverters would be made a lot better than the ebay plug in items.