Modifying a diesel generator for WVO/SVO

I know there are kits for vehicles, but what about for generators?  Searching online, I see that much of the information about biodiesel/wvo/svo is dated, and many of the online communities are abandoned.  I'm sure it has a lot to do with the $1/gal rendering credit going away.  Still, I have a supply of wvo available to me, and a need for more and cheaper electricity, and I would really like to find a way to marry these things.

One idea I've had is to hire an old engine mechanic off craigslist to help me split off the fuel line, and install a valve that will switch from the stick fuel tank to an external tank with wvo once  the fuel is hot enough.

I would appreciate any tips or insights, especially as to what type of genset would be easiest to modify, and any potential pitfalls that I'm not seeing (e.g. maybe this is not as simple or viable as I think).

I'm interested enough to have gone out a buy a diesel truck, but I haven't yet burned anything except pump-bought biodiesel.

My understanding is that you can mix up to 50:50 waste vegetable oil directly into diesel and have it flow through the injectors properly.  Maybe more if you blend it with winter diesel (diesel #1).

My understanding of a dual-fuel step-up though is that you need exact pressure requirements for the fuels to go through the injectors properly, so simply splitting the fuel line might not be enough.  You may need two different fuel pumps forcing fuel at the right pressures.

I'd recommend starting with just WVO:diesel#2 blends at various concentrations, and see how far you get.  It's going to work better in the summer than the winter, though if you're off-grid, I can see you needing the generator more in winter.

Michael Qulek wrote:
My understanding is that you can mix up to 50:50 waste vegetable oil directly into diesel and have it flow through the injectors properly.  Maybe more if you blend it with winter diesel (diesel #1).

Intetesting, but I wonder if this would lead to more coke buildup than heated oil?

In any case, some napkin math suggests that the economics would not work out.  It would make more sense to run a NG generator with gas from the public utility.

It would probably make more sense in other places, depending on energy prices, and NG availability.

Michael Qulek wrote:
My understanding of a dual-fuel step-up though is that you need exact pressure requirements for the fuels to go through the injectors properly, so simply splitting the fuel line might not be enough.  You may need two different fuel pumps forcing fuel at the right pressures.

I google searched a bit, a found that many businesses/individuals stopped selling conversion kits.  Many of the websites are down alltogether.  I'm guessing that congress' failure to renew the $1/gallon tax credit for biodiesel rendering has trickled down disinterest in WVO overall.

I contacted the companies who seemed like they could be helpful.  3 responded.  One was US-based and pretty clearly had no interest in my business.  Another turned out to be German, and said he could not do business overseas due to some red tape.  Finally, a guy out of Canada ( drbjornsauto.com ) responded.

He's been very helpful, and suggested a conversion would not be that complicated, given the right generator.

To your point about fuel pressure, Michael, one thing he suggested was to not get a genset with a direct injection engine.

I'll not put words in his mouth, but separately I found some academic research that suggests SVO will not aerosolize the same as diesel, even when heated (perhaps, not surprisingly).  The paper suggested the end result would be a shorter engine lifespan.  I assume this could be true as well-- to a lesser extent -- for a diesel:wvo blend.

So, now I'm trying to find a generator that meets the spec and won't break the bank.  This is harder than it sounds.  I didn't reslize good and compatible diesel gensets were nearly an order of magnutude more expensive than entry level gas gensets, at the same power output.

My guru will not permit me to simply buy something from alibaba.

Many things conspired to end WVO for most people, the main one is the supply side.  Many states require restaurants to recycle their oil through a licensed recycler, basically cutting off the supply for the diyer.

Kubota has probably the cheapest new diesel generator, and yes it is 5 grand for what would be $500 for a bottom end gas genny.  Two best sources for used are from RV junk yards and the old work light trailers the DOT used for night road work

I built my own a couple of times.  I have a little one with a hatz 3.7hp hooked to an alternator.  It runs good off of any oil I run as long as it is clean.  The other is a lister st1 6hp and a 2000w generator.  It also runs good off of straight wvo or svo.  I usually am given about 50 gal a year from the locals.  These little engine just sip fuel.  I have ran a 2003 tdi for 200,000 miles off of biodiesel.  

I did this with a DD 2-71. I plumbed a Mercruiser transmission oil cooler in with the radiator to use it as a fuel heater, then use 2 Racor 1000’s fuel filters on the suction side of the engine driven fuel pump. 2 selector valves, one for supply, one for return. It’s a cantankerous setup, Detroit’s are finicky if there is any air in the line or system, it will die or won’t start. Start on diesel, run for about 10 mine then switch to SVO. I usually let the WVO sit in a 500 gal cubie tank for a good year, then transfer from the top of the tank, I assume the bottom is pretty nasty after settling. My Racor’s filter to 2 microns.

Hi Fred,

Welcome to Permies.