Natural Gas generator efficiency

[Sanwizard]

Thx guys, I'm not looking for a quick simple fix that is costly. Looking more for efficiency. What would something like a 7.5kW Generac PowerPact

I would have my Sol Ark 15k auto trigger the start of the generator when the battery is low.

The Sol Ark would be programmed to draw the maximum power efficiency amount (30 - 50 amps.. I'd need to know exactly what).

The sol ark would apply that power to loads first, the charger second. After batteries reach a predefined level it would be turned off by the sol ark.


Cost per therm here is $0.5597

I will have about 50 panels.

My plan is to start with grid tie net meter 1 month billing. Time of use is 2 rates, 7 AM to 7 PM $0.18, $0.08 after hours.
My sol ark will switch to battery primary at 7 AM to avoid the $0.18.
Any solar created goes to loads, then battery, then grid.

To pay for a $2000 generator over a 25 year period if it is just used for overage, if it produced power at $0.08 it would only need to produce 66 kwh per month.

That's why I'm asking about generator efficiency.

I understand most people run generators and do not draw the load the generator can produce resulting in a huge amount of waste. Since I would only run the generator when I can draw all the power into the battery my efficiency would be higher. How high? That is the question.

I had a Generac 20K whole house generator, and used it to charge my batteries and have as a secondary source for the grid. My solar was primary, with batteries at night, and Generac natural gas generator for long bad weather with no grid, or SHTF.

 

[MurphyGuy]

I think a generator is going to cost more like $0.50 to $1.00/kWh.
The natural gas itself could be a fraction of that, but look up engine efficiency, energy per BTU (or whatever your units) and check the math yourself.

One guy here with a diesel generator calculated total cost of $1.00/kWh

I think PV can be $0.025/kWh, amortized over 20 years, if you capture and use all of it. More likely, you install 2x to 3x what you need in the best conditions so it supplies enough in almost all conditions, costing $0.075

But "weather is bad", PV may not make much.
How often is weather that bad? $0.18/kWh on cloudy days (from the utility) sounds like a bargain. Just buy it.
Use generator during occasional power failure if required.
Use PV (possibly zero export) when the sun shines.

I have a little Coleman Powermate 5500/6500 generator with a Tecumseh 10hp motor. The generator was manufactured to run on gasoline but I converted it to be a tri-fuel unit using one of US Carb's natural gas conversion kits.

The very first power outage told me I had made a good choice in doing that.

Anyhow, we ran the generator for 3 days and it runs the entire house as if nothing is wrong. Our home draws about 20 to 24 kWh of energy per 24hr period so I can assume we sucked up 60 - 70 kWh's over those 3 days. Our natural gas bill went up $15 for that month which works out to about $0.25/kWh

Of course, the price of natural gas goes up and down, and I think we did this back in 2016 when the price was under $3/MBtu. It was at $8 earlier this year and Henry Hub is showing $5.66 right now.

 

[Checkthisout]

Those are probably hours consisting of 60 minutes each.
My old Caterpillars have "hour" meters, but those are really revolution counters.
Perhaps most of your engine hours were at relatively low RPM, cruising.
So not as comparable to (non inverter) generator hours. Assumed freeway speeds would come closer, but still varies with transmission gearing; load and hills.

The speed the vehicle is traveling is less important than the load on the engine.

Truck gets 9.5 MPG over its whole life so it's under load all the time.

Highway miles on a vehicle are the least wearing miles the vehicle experiences. Vehicles driven on the freeway at freeway speeds all the time always last the longest.

I forget the point of the conversation now?

 

[eXodus]

I wonder with the use being so sparse in my case, would the radiator actually become a heat sync while it waited to fire making the heating part of a generator more of a pain the pleasure?

like I said - it KWK is only used when you run the generator constant to produce heat. If you don't use it as much it's not a good option, you are correct.