Natural Gas generator efficiency

[Hedges]

Diesel 12,000 to 20,000 hours?

Diesel Engine Generators Life Expectancy - How Long Do They Last?

Diesel engine generators are known for their longevity, especially in comparison to natural gas engines - but how many hours and years do they run for?

www.wpowerproducts.com

DIY Lister diesel generator:

The Listeroid Slow-Speed Co-Generator

I'm curious about the possibility of running 75% natural gas, 25% diesel, in an unmodified engine.

 

[Nobodybusiness]

By who? a lubetube video of a perpetual motion machine Electric Companies don’t want you to see?

If TOU rates sky rocket for peak hours I think that’s the only thing that could make financial sense.

But smallish (<25kwhr) standby generators by the big marketing companies (kholer, generac) aren’t designed for say 10000 hours of use. More like 50hr/year for 10 years. Generator heads will wear out, bearings of the motor will give out.

That’s why you need one of those old iron Detroit 2-71 that used to run 24/7 on reefer cars.

I have one from 1953 and it still runs great.
It’s 3 phase though.
You can put a different genhead on it but now your back to burning diesel for power.

Still think it’s better just to invest in More batteries and panels personally.

 

[YRanch]

Thanks everyone for your help. I hope many enjoy reading this. I have a new question:
What's the cheapest way to provide electricity automatically from natural gas. Not cost / kw, but cost of accusation.

Least expensive auto start sol ark 15k generator

Starting here: https://diysolarforum.com/threads/natural-gas-generator-efficiency.49756/ We find if you're already on grid it's cheaper to buy power from the grid. If you're off grid, it's likely that solar and batteries play a roll in reducing costs. If space is limited and your power is...

diysolarforum.com

Actually i looked a little closer to my bill and I looked up generic's efficiency on google: (not sure if this is a legit source but put some numbers together quick:

Guardian 22kW Largest Most Efficient Home Standby Generator | Norwall PowerSystems

Now the Nationwide Best Selling Home Standby Generator–Better fuel economy–More power than other generators–Free Shipping 5-Year Warranty

blog.norwall.com

I purchase natural gas for
0.7106​	$ / therm
0.007107​	$ / cu ft N.G.

Generac Natural Gas Generators

Natural Gas (ft³/hr)

50% Load

Efficiency

Electricity cost

100% Load

Efficiency

Electricity cost

16kW

193

24.1 ft/kW

24.1

ft/kw

0.17128886

$/kw

312

19.5 ft/kW

19.5​

ft/kw

0.13859472

$/kw

20kW

205

20.5 ft/kW

20.5

ft/kw

0.14570214

$/kw

308

16.4 ft/kW

16.4​

ft/kw

0.11656171

$/kw

22kW

184

16.7 ft/kW

16.7

ft/kw

0.11869394

$/kw

281

12.7 ft/kW

12.7​

ft/kw

0.09026425

$/kw

So we never find rates that beat the utility off peak $0.08.
For on peak we do beat the $0.18 rate.

HOWEVER

These are all 16kW and up units. The few web searches I did say they output 200 AMPS of 240v. That sounds like crap, maybe peak. I believe a 16kW generator at best would put out 66 amps (16kw/240v). I won't have batteries that will charge that fast (take that much current) for a while. Even if I did there are always losses in efficiency.

The smallest I saw was the 7.5kw (/ 240v = 31.25 AMPS). That seems reasonable for a battery goal with a sol ark 15k.

All this considered.

If the 7.5kw could produce the power at $0.14 / kw (not likely but if it could). Then there is still the acquisition cost, maintenance cost, real-estate cost, noise and replacement / warranty. Are these costs lower than the costs of being free from the grid / utility / NEC codes and inspectors?

In my case no.

However it's inspiring to know that we can, with modern technology get great value from solar power if we consume first, store second and sell third. If you need insurance, a small generator on auto start will give you an ability to consider cost effectively going off grid if you have no cheap existing on grid solution.

Thanks everyone who took this adventure with me.

 

[YRanch]

Just keep in mind, the article you referenced is 8 years old. The efficiency of the current Generac line-up will likely be different.

 

[Nobodybusiness]

Diesel 12,000 to 20,000 hours?

Diesel Engine Generators Life Expectancy - How Long Do They Last?

Diesel engine generators are known for their longevity, especially in comparison to natural gas engines - but how many hours and years do they run for?

www.wpowerproducts.com

DIY Lister diesel generator:

The Listeroid Slow-Speed Co-Generator

I'm curious about the possibility of running 75% natural gas, 25% diesel, in an unmodified engine.

If you could find a True Lister JP4 or JP3 they will last that long but you can’t even import the Lister clones made in India (which were garbage) anymore.

I talked to George from utterpower many years ago.

He was importing the lister clones and Changfa single cylinder Diesels and the Chinese ST heads.

EPA put a stop to that.

I have tried via Alibaba.com to get someone to send me a big Changfa but they won’t because they know it won’t get through customs.

I did have one suggest sending it in pieces though.

 

[byteharmony]

If you want to generate power most efficiently from natural gas, you use it to fuel a gas turbine power plant, then used the waste heat in a steam power plant (combined cycle), then you use the low grade waste heat for process or domestic heat.

My college, Iowa State University did this with coal. The heat was piped to the school buildings.

You're point combined with another thought is my favorite today.

If you're going to make your own power by burning stuff it's likely that there will be little to no sun, which means there will likely be cold outside. If you can capture and make useful the heat generated then the extreme expenses of owning the devices may make your hobby something that is cost effective.

Does anyone make a natural gas furnace / generator???

Anyone with a wood boiler (usually in a separate shed) could perhaps get a water jacket engine and exhaust heat capture to pause their wood burn while they make power. Now perhaps we're getting into the complexities generated.

Especially in a place like Milwaukee (or Canada), where I have a wood burning stove that can heat. Should I run low on power I could stop burning wood and start producing power AND HEAT)

You say you have a lot of batteries. What technology?

I own an IT company so I get batteries out of laptops free, server battery backup units and the like. Anyone can purchase cheap from battery hookup.

I'm planning on purchasing a Trophy Battery(s) to get it started and pass inspection.

I think AGM costs $0.50/kWh (over its lifespan), FLA costs $0.25/kWh. Commercial lithium can be as much as $0.50 or as little as $0.05/kWh, if cycled the thousands of times claimed.

I did a little hobby test with SLA car / tractor batteries and AGM batteries. Recycling them. Didn't work out for me. Results didn't hold a charge and it was extremely space consuming, time intensive and less than pleasurable to do.

Probably a lot different with big old school deep cells. I don't have them. Does anyone here really love SLA? Can you make it something I love?

PV at $0.025 (and less, operated beyond 20 years) is the best deal but only works on a sunny day.

Agree.

As for your Generac natural gas tables, what is it when you add in amortized capital cost over usable life, and maintenance?

Exactly.

I found it to be far more efficient to burn gas to heat water, cooking, dry clothes than to power generator to do the same through batteries.

Couldn't agree more. My present home uses gas for those thing, however if I can get the cost of electric to come down it may make sense to switch some of those things over to electric.

This a bit of a tangent but had to comment, CHP is interesting technology but unfortunately has not really become popular probably due to the initial costs plus ongoing maintenance needs.

That is so sad. I hope as technology and intelligence grow we can get back to higher efficiency's. Imagine a world in a place like where I live where we could have towns with cold weather only burning when the climate is cold and perhaps a few hours at night (for maintenance and testing of generators). The urban planners who want to put meters on our own well pumps could take the heat produced and use it to heat a efficiently designed city.

As for any natural gas generator you have to talk to your gas utility, the rate you see for heating may not be the same if you have a generator added on plus may require a regulator change out.

There is so much great information that is guiding my thought process here AND entertaining me. I want automation so while I'm traveling, if power fails the system has backup. Given that we lose power for a day, maybe two a year, if I have that much battery power I'd be fine. I'm also usually home and could start a generator so it's probably going to be illogical to consider replacing my little AC Gas powered portable generator.

DIY Lister diesel generator:

The Listeroid Slow-Speed Co-Generator

I have a friend with 500 archers in wisconsin. I may consider a place like that someday. I have fun thinking about a gasifier that burns the wood for heat and creates gas that runs a generator for power (and could extract heat) would be very efficient. I also enjoy working with wood. Making lumber, firewood, etc. The idea that a tree is a solar panel taking energy from the sun and storing it for the winter makes my heart warm.

I'm curious about the possibility of running 75% natural gas, 25% diesel, in an unmodified engine.

Hmmmmm, to increase efficiency, allow automation, etc. Complexity would likely make the solution unreasonable?

 

[OffGridInTheCity]

Based on my experiences so far - I use 4kwh/gal as my working estimate for my dual fuel generator on propane. I would think natural gas would be similar. This means, to generate a 1,000kwh thru the winter (low-PV months) I need 250 gallons of propane and hundreds of hours of run time. Generator run-time is expensive as others have pointed out.

As "Off-grid in the city" (e.g. City person) I'd note that natural gas can be cut-off in certain emergencies such as an earthquake or even foul-ups by the gas company. I don't view natural gas as being off-grid because it's a utility out of my control no different than the electric company.

The bottom line for me - I view my generator as more of a limited, emergency backup power source than a regular solution. Say when you have those multiple days in a row of rain/clouds/low-PV.

Panels: Using my West roof and adding panels - even thought not as good PV production as South facing - will be better than trying to use a generator to make up those kwh.

Heat: Stocking some k-1 kerosene (like propane, stores long term OK) / kerosene heater to reduce heat-pump electricity demands for heating on those multiple days in a row of rain/clouds with very low PV.

Both of these moves should reduce generator run-time needs significantly (and maintenance). It's all a balance for the individual situation

 

[byteharmony]

This means, to generate a 1,000kwh thru the winter (low-PV months) I need 250 gallons of propane and hundreds of hours of run time. Generator run-time is expensive as others have pointed out.

You are amazing, I knew there had to be people on this form that have done what I dream!

Do you capture that heat to gain the efficiency or do you just find it's more logical, to burn wood or propane?

The bottom line for me - I view my generator as more of a limited, emergency backup power source than a regular solution.

Exactly, given that I am grid tied and I can not remember power ever being down for even 24 hours in winter I've shifted thinking to tiny wattage auto start generator. Even submitted a request to sol ark to see about DC coupled generator start:

Least expensive auto start sol ark 15k generator

Starting here: https://diysolarforum.com/threads/natural-gas-generator-efficiency.49756/ We find if you're already on grid it's cheaper to buy power from the grid. If you're off grid, it's likely that solar and batteries play a roll in reducing costs. If space is limited and your power is...

diysolarforum.com

Say when you have those 4 days in a row of no PV. And as such, I'm redoubling my efforts to expand my panels and alternatives. Looks like using my West roof and adding panels will be better than trying to use a generator routinely. Also stocking some k-1 kerosene / kerosene heater to reduce heat-pump electricity demands for heating on those 4 days in a row of clouds (very low PV). Both of these moves should greatly reduce generator run-time needs.

I can understand the rational for the enormous battery power you have.

I have a wood burning stove, we use it for over 50% of our heating needs. Do you not have access to wood? For us the cost effectiveness of starting a wood fire is amazing.

 

[OffGridInTheCity]

I have a wood burning stove, we use it for over 50% of our heating needs. Do you not have access to wood? For us the cost effectiveness of starting a wood fire is amazing.

Unfortunately, our house is not built to allow wood-burning stoves or inserts! and the City rules/permits are designed to discourage as we have smoke issues in our valley. The estimator was coming in at obscene prices.

 

[byteharmony]

Unfortunately, our house is not built to allow wood-burning stoves or inserts! and the City rules/permits are designed to discourage as we have smoke issues in our valley. The estimator was starting to talk in the range of 20K! Yikes that will buy a lot of panels.

OMG, sorry to hear that, wood is such a cheap, natural fuel source. It wasn't easy but I found a way to put a wood stove that was super efficient on my home that I even got government tax money for it.

What about harvesting heat off your generator to improve efficiency? It would reduce how often your heat pump runs by making heat and generate the power you need to run your pump.

 

[Hedges]

Does anyone make a natural gas furnace / generator???

There was a dealer in Canada selling Yanmar CHP. That was a diesel engine.
But one of his component vendors went away.

Anyone with a wood boiler (usually in a separate shed) could perhaps get a water jacket engine and exhaust heat capture to pause their wood burn while they make power. Now perhaps we're getting into the complexities generated.

I figure air to water (aircooled) or water to water (water cooled), followed to exhaust gas to water. That should capture a considerable amount of heat.

So long as electricity generated is more than sufficient and thermal is less, supplement heating with the surplus electric.

I own an IT company so I get batteries out of laptops free, server battery backup units and the like. Anyone can purchase cheap from battery hookup.

I asked, because lead-acid would not be good cost per kWh of cycle.

Your small free lithium batteries probably not worth the labor. Although, one member has sorted and assembled thousands.

I think 100 Ah server rack batteries, based on claimed 6000 cycles, would be $0.05/kWh over 16 years. DIY with 280 Ah cells would be $0.05/kWh over 3000 cycles.
If they last. One study, only 5% of brands lasted their spec'd number of cycles before failure.

Hmmmmm, to increase efficiency, allow automation, etc. Complexity would likely make the solution unreasonable?

I've read up to 75% could be natural gas or propane, vs. diesel.
Not sure if you have to carburate and get the right mixture, or just add gaseous fuel to unthrottled air intake, let it be lean. Diesel provides the timing. I envision a gas valve being operated in proportion to percentage of time injectors are active. For my pickup truck, that is available as an electrical signal to solenoid driver. (well, I guess RPM plus percentage open time would be proportional to diesel delivered.)

 

[byteharmony]

There was a dealer in Canada selling Yanmar CHP. That was a diesel engine.
But one of his component vendors went away.

What a shame generac doesn't do it. If their HQ is still right here in MKE they should know better. Would be amazing to have it be water cooled in home with glycol that could be switched to radiators inside and outside the home .

I asked, because lead-acid would not be good cost per kWh of cycle.

And I hear over and over about it being a problem to mix and match old and new lead acid cells.

Were as with lithium that is not a concern.

Your small free lithium batteries probably not worth the labor. Although, one member has sorted and assembled thousands.

I like that member .

I think 100 Ah server rack batteries, based on claimed 6000 cycles, would be $0.05/kWh over 16 years. DIY with 280 Ah cells would be $0.05/kWh over 3000 cycles.
If they last. One study, only 5% of brands lasted their spec'd number of cycles before failure.

I think that study is based on discharge and charge values that are significant. The more I learn about 18650's the more I am coming to understand that they become less useful when charge discharge grows to more than .5 AMPS / cell. If you can keep it below that we may hit 7,000. Perhaps LFP will go higher than 6000 with the same kind handling.

I've read up to 75% could be natural gas or propane, vs. diesel.
Not sure if you have to carburate and get the right mixture, or just add gaseous fuel to unthrottled air intake, let it be lean. Diesel provides the timing. I envision a gas valve being operated in proportion to percentage of time injectors are active. For my pickup truck, that is available as an electrical signal to solenoid driver. (well, I guess RPM plus percentage open time would be proportional to diesel delivered.)

Fun to think about being off grid and being able to make power any way you want.
I have a friend that owns 3x lakes and has 3 waterways that the water moves through. He has a 300 watt generator I'll get to play with next year!! No one has referenced that kind of power yet, but I imagine hydro power is amazing. Sadly, when frozen it's results are likely bad.

 

[schmism]

If your seriously considering a NG stationary generator check your local Marketplace. 50's through 80s had Onan building real NG gensets mostly with ford industrial engines. Small engine mechanic has a good series on the Roiline he rebuilt and got up and running. (he also talks about the difficulties in getting NG supply to keep up)

There is currently a NG unit on my Marketplace for a 15Kw Onan complete unit for $1200.

 

[740GLE]

Diesel 12,000 to 20,000 hours?

Diesel Engine Generators Life Expectancy - How Long Do They Last?

Diesel engine generators are known for their longevity, especially in comparison to natural gas engines - but how many hours and years do they run for?

www.wpowerproducts.com

DIY Lister diesel generator:

The Listeroid Slow-Speed Co-Generator

I'm curious about the possibility of running 75% natural gas, 25% diesel, in an unmodified engine.

Pretty common for on road trucking diesels to hit those hours, granted not sure how many EPA mandated emissions control systems would need to be replaced over those hours. But those emissions systems love constant load and RPMs of a standby genset, it’s the varying load and RPMs of typical driving that puts more strain on them.

 

[byteharmony]

There is currently a NG unit on my Marketplace for a 15Kw Onan complete unit for $1200.

If your seriously considering a NG stationary generator check your local Marketplace. 50's through 80s had Onan building real NG gensets mostly with ford industrial engines. Small engine mechanic has a good series on the Roiline he rebuilt and got up and running. (he also talks about the difficulties in getting NG supply to keep up)

There is currently a NG unit on my Marketplace for a 15Kw Onan complete unit for $1200.

140kw, that video is showing a monster! The are awesome people on this forum but I don't think anyone can use that much power.

Smaller unit splits power which I'm sure is normal. To get some efficiency I'd have to wire the 240 into the solark 20 amps, 120v I to 48v charger
12v into DC boost 48v.

Hard to beat the used prices. May be a perfect super power backup!

Thx!

It’s the varying load and RPMs of typical driving that puts more strain on them.

Could sol ark partner with generac to make a fixed rpm single output generator. A glorified 48v charger?

Or I found this.

V5 AutoGen 48v DC Generator | Smartest 48v DC Generator

V5 AutoGen Automatic Start 48v DC Generator. Designed to automatically startup and charge low battery banks. Accessible over wifi through our ...

dcautogen.com

It's a great sign people are moving this way.

 

[sunsurfer]

How about a generator that has only 1 moving part and is simple to rebuild? What if it could be build cheaply? Efficiency is not good but if you combine heating water/air it could fair fine.

Wood Fueled Battery Charger

I've been working on a design for months now. Anyone interested in helping me design a test build? Goals 1 - Simplest possible (few moving parts) power from wood source while also heating water. 2 - Keep cost down 3 - Use off the shelf parts 4 - Automated 5 - reliable hours of use and easy...

diysolarforum.com

 

[740GLE]

140kw, that video is showing a monster! The are awesome people on this forum but I don't think anyone can use that much power.

Smaller unit splits power which I'm sure is normal. To get some efficiency I'd have to wire the 240 into the solark 20 amps, 120v I to 48v charger
12v into DC boost 48v.

Hard to beat the used prices. May be a perfect super power backup!

Thx!

Could sol ark partner with generac to make a fixed rpm single output generator. A glorified 48v charger?

Or I found this.

V5 AutoGen 48v DC Generator | Smartest 48v DC Generator

V5 AutoGen Automatic Start 48v DC Generator. Designed to automatically startup and charge low battery banks. Accessible over wifi through our ...

dcautogen.com

It's a great sign people are moving this way.

So so I think Honda makes inverter based DC only portable generators, I forget the voltage. It’s very common in populated areas during power outages telco companies roll them out and plug them into booster stations out on the telco lines. On our road it’s common to see Comcast chain up a generator to the pole to keep the area internet going.

I even stopped one storm and filled it up and fired it up. I can’t work if I don’t have the internets.

 

[sunsurfer]

I have always wanted to find a Honda with a dead inverter. I think the DC out of the rectifier is around 320v DC from what I have read. Likely, the coils on the permanent magnet generator are in series, one could rewire them for parallel or just down convert some how.

 

[Checkthisout]

I have always wanted to find a Honda with a dead inverter. I think the DC out of the rectifier is around 320v DC from what I have read. Likely, the coils on the permanent magnet generator are in series, one could rewire them for parallel or just down convert some how.

Then nothing else works on them. The throttle control is inop without the inverter.

You could make your own dc generator with $150.00 engine and $150.00 alternator.


OP, you're not going to be on the winning side trying to arbitrage grid power with a home generator.

 

[Checkthisout]

Since Hedges answered the economics part of your question here is another piece of the puzzle that may be of interest.

Couple of years ago I converted a Champion Gasoline open frame inverter generator to dual fuel by adding a Nat Gas Kit consisting of a regulator and the venturi adapter plate & some hardware. In the process of researching I discovered the combustion characteristics of nat gas vs. gasoline are different.
Enough so that a typical gasoline engine with a compression ratio of 8-9 is not ideal for nat gas and the output is reduced by 10 to 15%. Generators that are tuned for nat gas have higher compression ratios around 12. While you could use gasoline also at that higher compression ratio, it would require octane additives or aviation fuel.
Moral of the story, there is really no such thing as a dual or tri-fuel generator. Any products that claim to be are compromises and its necessary to adjust your expectations based on what fuel you want to use.

The power reduction when converting from gasoline to NG or Propane is simply because NG and Propane are gaseous fuels and displace air in the cylinder which means less power can be made per unit of displacement.