Real-World Generator Burn Data

[GreyCoyote]

I am starting this thread with the notion that others will follow and contribute their data from their particular generators. It seems prudent to publish some real-world numbers and experiences for the various portable generator types. The goal is to let fellow burners make informed decisions about how much fuel to bring and what to expect from any given model of generator.

Me first.

We just returned from the 2014 Flipside regional burn in Texas. I took a single Honda EU2000i (1600 watts continuous, 2000 watts for several minutes) to power the camp. This genny was modified on the day of purchase with a tach and hourmeter. Other than this, it is a completely box-stock unit. It had 54 hours on the meter before we left for Flipside.

Our loads were:
1). An 8 cu/ft chest freezer (Haier brand, Sams Club purchase) - 100 to 150 watts, load was temperature dependant. Thermostat set to -10F
2). Ceiling fan in dome. 75 watts.
3). Dome lighting. String of 30 ea 5-watt bulbs - 150 watts.
4). Battery charger (30 amps @ 12 volts) for 4x110ah Group 29 wet cells. (Rarely kicked-on, likely discountable)
5). 15w CF area light
6). High velocity 24 inch fan - 175 watts
7). Charger for 18v cordless drills - 35 watts
. Charger for 2-meter handsets - 15 watts.
9). Gaggle of iPhone/iPad/Android chargers - minimal, not measured.

As an experiment, the freezer was set to 3/4 of "max cold" a couple of days before we left, and the thermostat was left in that position for the entire burn. According to the WattsUp power monitor, the compressor ran 80% of the time and the internal temp never got above 0F for more than a few minutes. We were in and out of the freezer a LOT.

The 60-inch ceiling fan in the dome ran pretty much 24/7. (Note to those poor sods sweating in high-humidity areas in an airless tent: "neener-neener-neener". It was SO nice to be able to sleep soundly, with gentle air movement, and not sweat to death!)

The dome lighting ran for about 6 hours a day, and the area light was on 24/7. The big fan ran sporadically about 8 hours a day as needed by overheated campmates. The rest of the loads were sporadic and largely discountable from the fuel equasion.

Ambient temperature ranged from 75 to 93F, and we saw RH from 65% up to 95%. The genny started out with a fresh change of Mobil 1 Synthetic 0w30 Advanced. I changed the oil after the second day with Pennzoil conventional 10w30. We ran on the Honda's "EcoThrottle" setting at all times. Fuel was 87-octane containing up to 10% ethanol treated with an "enzyme-based" stabilizer. Altitude was less than 30 above MSL. It was rare to hear the Honda come off-idle (3000 rpm) for more than a few seconds. It quietly loafed along at 3000 rpm all weekend.

At the end of the day, we ran the genny a total of 101 hours, used 11 gallons of gas, for a daily burn of 2-3/4 gallons per day.

A comment: there was an observable difference between the burn rates on synthetic vs conventional oil. The synthetic oil resulted in less fuel used. I cant quantify it yet, but it is clear to me there is a benefit here. Since the oil capacity is only a third of a liter, I just cant make an expense-based argument for using a non-synthetic.

Some may protest the use of a 0wXX oil. If so, go here to learn about why this is a good idea: http://www.bobistheoilguy.com and read-up on the strategy.

In the final analysis, I plan on bringing 3 gals per day to BM, "just in case". This will give me lots of power to share and a buffer in case we get rain. I will use only 0w30 synthetic and change it daily.

Would love to have others contribute their experiences and burn rates with their gennys!

[Elliot]

Wow... I have no such detailed information.
But my last three burns I ran a Honda EU-3000 pretty much 24/7, for the primary purpose of powering a regular household refrigerator with top freezer. There were other loads, like the air compressor for filling tires, and assorted battery chargers and lights, but these other loads probably did not amount to much.

The generator rose above idle only occasionally and briefly, when a motor started (refrigerator, compressor).

The generator needed refueling roughly every 20 to 22 hours. According to the catalog, the tank holds 3.4 gallons.

The EU-3000 may seem like overkill for the purpose, but I also own an EU-1000, and it will not start the air compressor. And the 3000 is a little bit quieter than the hand-carried ones (1000 and 2000).

The EU-3000 has battery start, but that battery died many years ago. It still starts just fine with the pull-cord. I have never changed the spark plug, but will now that I have read that a fresh plug may burn less fuel. I will also change to synthetic oil.
It has never gotten significant dust in the air filter, even after 14 days straight running.

One concern: Last year it seemed to me that the generator was louder than before. I’m wondering if the muffler burns out after a while.

[Captain Goddammit]

Maybe it's my imagination but I kinda' think my EU2000s aren't quite as quiet as they used to be. If that's really true I'll try new mufflers.
I know that freshly rebuilt big-truck diesel engines are a LOT quieter, hooked up to the same old exhaust. Maybe the Honda's engine is just getting looser.

I didn't keep records of my fuel use… I'll start doing that for this thread and my own curiosity. I think I burned about 4 gallons a day, running twin EU2000s to power A/C during the day.

[kowtow]

I'm trying to figure out what I need for generator on time, given the following details:

swamp cooler pump (6 hours) 3.60
swamp cooler fan (med) 6 hours 13.50
Exhaust fan (6 hours) 4.50
12VDC Cooler (24 hours) 48.00
Lights 3.12
Dynaco Fan 8.64

Total 81.36AHrs
Solar power (16AmpsMax*50%*9hrs)72.00
Battery needs 9.36

Essentially there will be a need to recover 9.36AHrs(10A) that will be depleted from the batteries daily. I have a 1000Watt (10AHr) generator, so does this mean that I will need to run the generator 1 hour a day to keep the batteries at 100%?

[TT120]

You're going to have losses in the charge controller for the solar panels and from the battery charger your using to charge the battery from the generator. Figure those in to your equation. Your "actual" numbers are going to be way different once you get there.

[kowtow]

You're going to have losses in the charge controller for the solar panels and from the battery charger your using to charge the battery from the generator. Figure those in to your equation. Your "actual" numbers are going to be way different once you get there.

That's why I assumed a very conservative 50% of the (16Amp) max capacity on the solar panels. While spending a week in Yuma, AZ in April, I was averaging 10-11Amps/hr charging rate at the batteries between 10am and 5pm.

[Captain Goddammit]

Your generator run time to recharge depends primarily on how powerful a battery charger you have plugged into it.
Forget entirely about the built in 12 volt battery charging circuit. That's ok for watch batteries. Not much else.

[GreyCoyote]

Kowtow: Efficient charging is also a matter of when you charge, not just how much. You may have a 100 amp charger, but if the batteries are already more than 70% charged, you'll only be pushing a fraction of that rate into the batteries.

If you are running a combo genny/solar system to charge batteries, you will want to run the genny during the bulk-charge portion of the cycle, ie, when the batteries are below 70% of full charge. This lets the charger use the high-rate charging profile and quickly brings the batteries up from a deeply discharged state with minimal running time on the genset. Once the charger switches to float or equalize, you can let the solar panels do the rest. The panels will give the batteries a long, slow finishing charge needed for 100% capacity and best battery life.

This strategy assures you minimize generator runtime while at the same time giving you an ample reserve in the panels if you have active loads during the day.

Bottom line: gensets are expensive power (fuel, oil, filters, etc), while solar is cheap (in the recurring sense), so use the expensive power where it makes sense, and the cheap power for topping-up.

[kowtow]

Great advice! I didn't think of that. I will use the genie when the batteries are at their lowest state, likely between 6:00-9:00am. I'll give the batteries a couple/three hours of serious 10-15Amp charging time and then let the solar panels pump their goods for the remaining daylight hours.

Since I don't have a Honda, I'll be adding "hushbox" to the list of last minute projects that need to be completed in the next 84 days or so...

[FIGJAM]

Your genny may not be popular between 6 and 9 AM.

[Elliot]

Your genny may not be popular between 6 and 9 AM.

It has been suggested to me that I might get away with -- that is, my refrigerator might get away with -- shutting off the generator for some hours in the cool of night. But I don't even try that, because humans tend to sleep fine thru a steady hum, but awaken when a new noise cranks up.

[GreyCoyote]

At least with the Hondas, you can sleep fine 15 feet away from the exhaust. It isn't loud or objectionable. In fact, at the regional burn, I had to get up twice because I thought the generator had stopped. Nope. Still humming away. The wind had shifted a bit, making it impossible for me to hear it just 20 feet away.

But yeah. If you've got a loud one, muffle that puppy (or turn it off) and be a hero to your neighbors in the wee hours.

[FIGJAM]

Hell Elliot, the only times I heard yours was when I put fuel in it or we moved it!

[Elliot]

Hell Elliot, the only times I heard yours was when I put fuel in it or we moved it!

That's why I spent the money for the Honda EU-series. (Well, one reason.) But I'm still planning baffles now, since I am very sensitive to such things. Noisy generators are just wrong.

[Odie]

word on other brands besides the Honda's

Powerhouse
Yamaha

[kowtow]

Your genny may not be popular between 6 and 9 AM.

Story of my life. Why does everyone get up so late? My life starts at 3am and ends at 7pm.

Figured I was being gracious by waiting until 6am to fire it up the genie.

[GreyCoyote]

Your genny may not be popular between 6 and 9 AM.

Story of my life. Why does everyone get up so late? My life starts at 3am and ends at 7pm.

Figured I was being gracious by waiting until 6am to fire it up the genie.

I think with that ethic you'd be on pretty good terms with most of your neighbors in Defaultia, but not so much when you're in BRC.

While having a loud genny is unlikely to get you mugged, it does tend to confer "asshat" status rather quickly. A good baffle-box would go a long way to being a good neighbor. They are not difficult to build. A plywood A-frame lined with eggcrate foam will get you a nice reduction in dB, as would a "barrel" approach (a circle of boards open at the top, with or without padding). If you could restrict your runtime to after the sun has driven the last of the sleepers out of their tents, you'd get double points and a Good Housekeeping award.

An inverter-based Honda or Yamaha is something you can quite literally sleep right next to and not be aware of it. Their minimal acoustic footprint gets completely lost in the background din, and many fine the low hum soothing. If you can afford one, you won't regret it, and your neighbors will love you for it.

[maladroit]

word on other brands besides the Honda's

Powerhouse
Yamaha

I have anecdotal "it worked, was very quiet" data for a couple of Champion 2000W inverter generators last year. I've been starting up and lightly using one every few months since then and it seems fine, we'll see how it lasts through the second burn.

Really, despite all the dust, a burner's generator has an easy life compared to something that lives on job sites.

[trilobyte]

It's probably worth pointing out that your mileage may will vary, not only from really subtle stuff like age and brands/models of stuff being used, but also elevation (flipside's at a much lower elevation than brc, for example).

I'll also suggest that anyone using a generator, including those of us using Hondas or other whisper-quiet class generators, strongly consider a baffle. Even the low amount of noise they generate can seem unbearable if the noise is all throwing in the direction of your tentflap while you're trying to sleep, and you definitely don't want to be the person who inflicts that upon a neighbor. But noise isn't the half of it. A baffle also serves as a wind (and dust) break, and it's a nice added layer of security. While theft at BRC isn't common, there have been mentions in more than a few threads about people with fancy generators having something swiped. If your generator is a shiny new easily-identifiable expensive thing sitting at arm's length from your tent, it may be more easily spotted and targeted by nefarious types. If you've got a baffle in place, the shifty person can't see what you've got without calling attention to themselves.

When it comes to fuel budgets, the rule of thumb we tend to have is to ballpark our needs on the high side. Our generator uses the same kind of fuel as our vehicles If, at the end of the week, we use less than we expected, the unused fuel is used to top off the gas tank of our van, camp's rental truck, campmate's cars, etc.

[GreyCoyote]

Trilo brings-up a good point. Seemed obvious to me just because it's such a well-ingrained habit, but what is habit for some is alien to others.

Lock 'em up. Tight.

At 45 lbs, with that nice carrying handle, these small units are truly portable. Because they are highly-sought and a popular commodity, once they walk you will never see them again. They all look alike, too. So I use a heavy plastic-coated chain looped through the handle twice and then through the trailer tongue. No way it's going to walk-off chained like this unless they cut the chain or the genny handle.

In the case of the Honda EU2000i, it is possible to cut the handle, so the manufacturer makes a metal reinforcement bar that fits within the handle. This makes it very hard to saw into the handle to free the genny, and its big enough that bolt cutters cant get a grip. It's about 90 bucks, and well worth it.

[Captain Goddammit]

D'oh! I just got finished disassembling and cleaning up my EU2000s carburetors… had I been thinking, I'd have taken photos and made a step-by-step "infopost". I guess I could still do that.
Maybe I will… but for now, here's a tip a lot of people miss while cleaning up Honda carbs: stick a skinny flat blade screwdriver in the tube at the bottom of the carb and unscrew the brass jet. There's a brass thingy (I can't ever remember what they call it) about an inch long BEHIND the jet that frequently doesn't fall out after you remove the jet… tap the carb on the bench and it'll come out unless it's really badly mucked up. Clean that thing really well, spray carb cleaner through it, then put it back in, small end first, and screw the jet (that you also cleaned) back on top of it.
This will usually cure that annoying "won't run without the choke half on" condition.

[GreyCoyote]

Capt: That critter is called the "emulsion tube", and it's the one that doesn't like the gel many unstabilized ethanol blends get after a few weeks of standing.

Another hot tip to prevent this goop from happening (besides running the genny occasionally), is to drain the carb completely with the petcock on the bottom of the bowl before storage. When you are ready to run it again, open the fuel feed, wait a minute, and dribble a bowl full of fuel out the petcock. Make sure it's fresh and ready to start instantly... usually on the first pull.

[Jackass]

Needle jet, pilot jet?

[kowtow]

Alright, you are all bringing out the sparkle pony in me! lol...

I haven't yet added up what this birgin vurn has cost me but it's north of $20k and I still have never seen the playa. I started out dreaming of all these grandiose art projects I wanted to tackle, but now I'm cash poor just trying to keep my ass comfy for a week+ and I've shelved any art idea to an obscure corner of the attic never to be found even once the x-mas decorations have been pulled from the joists of the attic.

All that said you guys are the best. Even if you prod me to build swamp coolers, monkey huts, solar arrays, evap ponds, rations, showers, dry ice, multiple coolers, organic soaps, water tanks, costumes to include a fuckin' kilt, not to mention the damn cargo trailer I bought and outfitted for the sole purpose of dragging it out to the playa. I'm on the verge of wondering if this preparation will ever end...

Can this be like those peeps who play World of Warcraft? Can I sell my playa identity for 10's of thousands of dollars, so that the next guy is setup and ready to go?

Is this what is recognized as thread drift? Sorry GreyCoyote, I didn't mean to yank the rug out from under your Burn Data. Who know's maybe the census group will make more of an effort to capture practical data like "Generator Burn Data" and spend less time trying to figure out if I have a graduate degree and voted for M. Dukakis in '88.



Forgive me, but I do believe the Dark Russians have obscured my judgement at the moment.

[maladroit]

Haha, 20K...wait until you run into someone on playa that seems totally happy and well situated, and you find out they flew from another country and brought all their gear in a carry-on. Not me, I load up with 1000 plus pounds of gear, but it's possible.

[kowtow]

Does a generator perform better in cooler weather? Is it more efficient and incur less stress on the engine?

I had this idea... what if you had a hushbox that you cooled with a swamp cooler? Most generators come with 12vdc terminals. That would provide the power to drive a fan and pump (I know obviously using more power thereby reducing one's gas mileage).

It just seems that having a hushbox is great, but that the enclosed, insulated box, could also pose it's own problems for generators both for performance and health reasons.

[FIGJAM]

The hush box or Baffle box is open to the sky.

It just directs the noise up instead of at the neighbors.

[kowtow]

Oh okay, when I've looked up hushboxes in the past they where five sided, four sides and a cover. Usually one of the sides had an opening for the exhaust, but they were pretty well enclosed to where i wondered about heat dissipation.

[FIGJAM]

The basic box is 2 sheets of plywood cut in half and lined with the plushest carpet you can find.

[kowtow]

The basic box is 2 sheets of plywood

- Check √

cut in half and lined with the plushest carpet you can find.

- Check √, Check √