Cost of electricity from a gas generator

[CaliSunHarvester]

I wonder if anyone has found or performed research about the cost of electricity from a gasoline generator.

A google search indicates that it is approximately 0.1Gallons of gasoline for 1 kWh.

That seems really low to me. 1 Gallon of gasoline costs here in California right now $4.60 , so that would be 46 cents of gasoline per kWh.

The utility charges 50 to 70 cents per kWh, depending on time of day and rate schedule.

Has anyone tried to verify the 0.1G estimate?

 

[Mkgough]

It cost me to run my 12k for 3 days, 1 gal per hour at $3/gal so NOT cheap.

 

[CaliSunHarvester]

to run my 12k

What does this mean? It's a 12000W generator?
How much power did you actually consume?

It may be inefficient to have a 1000W load on a 12000W generator. Better maybe to have 1000W load and push another 7000W into the battery bank? Total 8000/12000 utilized?

 

[seneysolar]

Dont forget the cost of the generator itself, the lifespan, the maintenance, the cost of going to get the fuel 5 gallons at a time, your time and attention....

 

[BentleyJ]

I believe David Poz on YouTube covered this issue a while back.

 

[Crowz]

Since people are throwing wrenches into the calculations don't forget those of us that use chargeverters.

I run my generator for a short time aka 1 or 2 hours and then I run the batteries all day or so. Then repeat.

 

[Rmart30]

This topic is one of the things that got me interested in solar/battery back up.
Even though we are very close to a major city, the road we live on is a dead end road thats 2 1/2 miles long and only has 10 houses on it.
We are the very last people to get power restored since only a few houses are affected.
We run a small dog rescue and usually always have at least 15 dogs that their quarters need to be heated/cooled. Running a generator for theirs, and one for the basic things in the house goes thru gas very quickly. We keep about 25-30 gallons on hand year round but it doesnt last long.

 

[timselectric]

Turn the crank by hand and you only have to figure for your time and the cost of food.

 

[ThaiTaffy]

This has me thinking if I build a treadmill attached to an alternator can I effectively use my dogs to charge my batteries? Apparently I have a similar amount of dogs to a rescue home in America and if I'm honest they are all starting to get a bit chubby so the exercise should do them good, you ppl can work out gallon to kWh and I'll work out chicken&kibble to kWh then we can compare which is cheaper.

 

[Brucey]

Usually can't beat a diesel for optimum fuel efficiency but often a premium to be paid unless you buy used

 

[ThaiTaffy]

Usually can't beat a diesel for optimum fuel efficiency but often a premium to be paid unless you buy used

Generators seem comparable here price wise and strangely diesel is cheaper than gasoline though diesel vehicles are far more expensive.

 

[robby]

This has me thinking if I build a treadmill attached to an alternator can I effectively use my dogs to charge my batteries? Apparently I have a similar amount of dogs to a rescue home in America and if I'm honest they are all starting to get a bit chubby so the exercise should do them good, you ppl can work out gallon to kWh and I'll work out chicken&kibble to kWh then we can compare which is cheaper.

Dogs
Absolutely not! Go give them enjoyable Walks you bum
The Wife on the other hand is allowed.
It's healthy for them and they lose weight. If you got Fat Kids then throw them on the Mill also.

 

[robby]

Just be careful with Generators vs Noise Level.
I almost got lynched running a loud generator at 10pm.
A group angry of neighbors actually came to my gate.
Also the cheap ones burn Gas like crazy even if they don't have much of a load on them.

 

[ThaiTaffy]

Dogs
Absolutely not! Go give them enjoyable Walks you bum
The Wife on the other hand is allowed.
It's healthy for them and they lose weight. If you got Fat Kids then throw them on the Mill also.

I walk 3 sets of 2 dogs daily dodging king cobras and various other poisonous animals I wouldn't call them enjoyable walks the rest of the dogs get to run free(less likely to kill anything they see) most are still podgy
I have pretty low body fat and work around the farm most of the day, my wife is 36kg/80lbs we have no kids but plenty of sunshine to charge the batteries.
I might build the dogs a treadmill for exercise at some point adding a alternator would just be for giggles to say my dogs power the house from time to time.

 

[Hedges]

Usually can't beat a diesel for optimum fuel efficiency but often a premium to be paid unless you buy used

TruckinBear came up with $1.00/kWh for his diesel generator usage.
That recharged forklift battery through Sunny Island.

Where I am (San Jose), diesel used to be less than regular. Now about same as premium $ +/-

Viable as backup, but as much PV as possible is preferred.

If used in winter, try to capture and use waste heat from exhaust and (ideally water) cooling system. "Combined Heat and Power"

 

[IGBT]

I don't think gasoline generators reach 10kWh per gallon of gas. Maybe some big super efficient industrial one?

Gasoline has 33.7kwh of energy per gallon. Most gasoline ICE engines run about 25% efficient, so there you are at 8.4kWh produced at the shaft. Then you have a conversion to electricity, which maybe is 85% efficient, so you are now have generated about 7kwh from your gallon of gas. This does seem about what I get from a Honda gen.

 

[Steve777]

Humans are a poor draft animal. The average person in good shape is perhaps good for 100W of output. And even that is similar to riding you bicycle up a steep hill; how long can you keep that up?

 

[CaliSunHarvester]

7kwh from your gallon of gas

Even that number surprises me. $4.60/7 = 65c per kWh .. Our PoCo charges 50 to 70c.

I realize there's the cost of the generator, oil, effort to stock fuel etc.

 

[IGBT]

Humans are a poor draft animal. The average person in good shape is perhaps good for 100W of output. And even that is similar to riding you bicycle up a steep hill; how long can you keep that up?

This is why when people poo poo electric boat motors that ONLY have 1kwh batteries, it still beats 10 hours of rowing.

 

[olivinelife]

7kwh from your gallon of gas

Household sized gasoline generators are "up to" ~20% efficient at rated output, so 7kwh is right. You can do further calculations based off that because cost of gas varies greatly by location.

The main issue is that efficiency decreases a lot at low loads, and most people using a generator for home backup will be subject to variable loads instead of consistent rated output. This is why the generator->chargeverter->battery setup is worth it even with the round trip losses ~15%.

 

[CaliSunHarvester]

I believe David Poz on YouTube covered this issue a while back.

Yes, here:

He got 5.8kWh out of 1G in his first test using a ChargeVerter charging at 70A.
And again 5.8kWh out of a Gallon when charging at 80A.
And again 5.8kWh out of a Gallon when charging at 90A.
And 5.9kWh out of a Gallon when charging at 100A.

I think the best use is to run the AIO with the generator input in pass-through mode (hopefully under 2000W, to avoid double conversion) and request another ~3000W to put into the battery.

 

[bolhuijo]

I really enjoyed Poz's generator videos. Having built one myself out of a lawnmower engine and an alternator years ago, I understand the challenges with the belts & the vibration etc. My generator build sucked, his was way cooler.

 

[Crowz]

I really enjoyed Poz's generator videos. Having built one myself out of a lawnmower engine and an alternator years ago, I understand the challenges with the belts & the vibration etc. My generator build sucked, his was way cooler.

I made one and it turned out great. When the deck rusted out on a riding mower I had I removed the deck and mounted a 24v alternator off to the side of where you put your feet riding the mower and then added an anderson connector to a long cable to connect it to my battery bank. Worked great.



One of the coolest features I finally found out the mower had was the automatic choke and how that allowed me to wire up another cable and crank the mower from inside the house when needed during bad weather

 

[timselectric]

A portable generator that you can ride.
Awesome

 

[seneysolar]

"Affordable DC Generators" makes a kit that you just mount a Alternator on a horizontal shaft engine. I have one that I was playing with. If you put a heavy load on like a big battery bank the alternator gets really hot, really fast. needs a way to regulate the field current. I was using a single wire alternator so the regulator was built in, not ideal.