diy solar

diy solar

How efficient is your generator?

Correct me if I’m wrong but the smart shunt is messing on the DC side in the negative line what goes in and out of the battery. So the eff is the battery efficiency and not of the charger from AC to DC.
If you can measure on the AC side of a charger and on the DC how much energy goes in and comes out an eff calculation can be made. But the smart shunt just indicates battery efficiency which is around 4% for a lifepo4.
I probably could tease that data out too but it would take more time and effort than I’m willing to put forth. I would have to go look at every charge cycle then look at my AC load at the time then subtract everything except the inverter then compare the DC current produced and then somehow figure in the current flows through the BMS it would probably end up being an entire blackboard of calcs. However as a rule, with quality components less is more. Every component every solder joint, every connection in general has a neg effect on current flow and therefore efficiency. In simple terms like a water pipe, the smoother and straighter the run the greater the flow.
 
Last edited by a moderator:
I like my solark for charging as well. But NOT from generator. The way it passes thru power from generator to house is really annoying. It makes all my LED constantly flicker. Even if it's phase locked exactly 60hz and 112V on each line. That was the whole reason I made my growatt setup.
 
I like my solark for charging as well. But NOT from generator. The way it passes thru power from generator to house is really annoying. It makes all my LED constantly flicker. Even if it's phase locked exactly 60hz and 112V on each line. That was the whole reason I made my growatt setup.
We have not seen that issue with our generator. We have had a small issue coming off gen back to PV. Small blip we can see in out shop lights and we have two Cyberpower UPS’s that want to completely drop out during this period. I have two APC brand UPS that have not issue with the transfer.
 
Let's keep it on topic folks. The point of this thread is examining the efficiency of the ICE generator units themselves - potentially including onboard inverter hardware, but not including other system components which are separate from the physical generator hardware. e.g. Sol-Ark AIOs or battery chargers.

I think exploring the efficiency of other components is great too, but please start dedicated threads...
 
I like my solark for charging as well. But NOT from generator. The way it passes thru power from generator to house is really annoying. It makes all my LED constantly flicker. Even if it's phase locked exactly 60hz and 112V on each line. That was the whole reason I made my growatt setup.
That’s weird. Never had that problem.

My 2 charges exclusively from Generator if needed but never had that issue.

Are your Sol-Ark fairly new or old?
What version of Firmware you running?
 
That’s weird. Never had that problem.

My 2 charges exclusively from Generator if needed but never had that issue.

Are your Sol-Ark fairly new or old?
What version of Firmware you running?
It's a fairly new 15K. New from September. I'll try to get a video of this and post it in a separate thread. I only charge at night because of this reason. Newest firmware as well.
 
The most recent tank that I have the full data for got 14.24% efficiency and $1.08 USD/kWh. That seems pretty clearly to be as a result of the increased load. (Compared with as little as 10% efficiency at around 32% load.)

The DuroMAX XP9000iH is rated at 7,200 running watts on propane. So the average ~4,700 watts I've been loading it with is 65% of its rated steady-state wattage.

Interestingly, the Champion 100263 is rated at 2,790 running watts on propane. So the average ~1,800 watts I'd been putting on that is also right around 65%, but the efficiency of that generator at that loading was much lower at around 11.5%.

This suggests that; the two generators are just capable of different efficiencies and/or that the optimal efficiency loading for the two generators is at different percentages of their peak load.
 
i'd like to see the prius gallons consumption per kwh of use for sure!
Not really what you need, especially for charging a battery (making AC out of DC, then reversing the process) but may be of some interest, especially if you have a Prius! https://www.torquenews.com/8113/make-your-toyota-prius-top-quality-generator-neat-add and this : https://forum.solar-electric.com/discussion/11546/using-a-prius-as-a-generator/p2 One difference between small ICE engines commonly used in gensets and the Prius, the Prius uses the Atkinson cycle, not the Otto cycle. More efficent is my takeaway from that, I'll let others figure out if what I just typed makes any sense! Prius nerds (which I don't really consider myself to be) are somewhat a bit over enthusiastic at times, so take it for what it's worth. If nothing else, for someone looking for a modest source of backup power AND that had a Prius, using it, something they have already and drive every day, may make more sense then buying a genset that then largely gathers dust.
 
for someone looking for a modest source of backup power AND that had a Prius, using it, something they have already and drive every day, may make more sense then buying a genset that then largely gathers dust.

Agreed in the case of folks needing generator power only in exceptional circumstances. For those who anticipate somewhat regular usage though, knowing how efficient it is could be part of the basis for deciding whether a dedicated generator makes sense - especially since the Prius serving double-duty means it needs to stay in proximity to the loads (e.g. not traveling to the grocery store and running one's refrigerator at the same time) and one might need extra fuel on hand for an extended outage.

I read through some of those forum.solar-electric.com threads, but nowhere that I saw did anyone measure both the cumulative kWh production and fuel usage.

I did run into this post - which maybe has anecdotal value from 2014, but doesn't state what the fuel price was for the calculation:

1672416753630.png
 
nowhere that I saw did anyone measure both the cumulative kWh production and fuel usage

There's also this answer on the PriUPS website:

But, as you stare at the empty columns, console yourself with the notion that it doesn't matter. The whole point of using the Prius for electricity is that it's for occasional, emergency use. When a hurricane is coming, you don't go to ten stores to get a bargain on duct tape.
 
I've been working on setting up a Generator -> Charger(s) -> Battery bank. Finally got the wiring hooked up and the results were devestating.

I bought 8 x YZPOWER 48v @ 15a chargers and put each on it's own circuit breaker - https://www.ebay.com/itm/285232822732
I bought a Champion 100297 8000w duel fuel generator - https://www.championpowerequipment.com/product/100297-8000-watt-dual-fuel-generator/

My thought was to fire up the generator and then have the ability to turn on 1 (15a @ 50v = 750w) thru 8 (120a @ 50v = 6000w) to find the max and most efficient charging. In my defense, the EG4 Chargeverter was not on the scene yet when I ordered these.
1681842389873.png

What a disaster. I do get the 15a @ 50v = 750w of DC charging out of each charger but each charger is taking 11.3a @ 120v on the AC side. 11a @ 120v = 1,320w AC input for 750w DC output = ~57% efficiency. The generator maxes out at "Propane Running Amps at 240v = 30.2a" and has a 30a circuit breaker on the front panel - so I can't even do 6 x chargers as that's ~34a / 120v leg.

Before someone asks about pure sine wave vs dirty sine wave from the Champion, it just so happens that I had to repair a 12,000w SGP 240v/120v split-phase pure sine wave inverter and I used the chargers for a load to test the repair. Same results - 11a @ 120v per charger.

Total miscalculation on my part as I assumed each charger would be at least 85% efficient in terms of AC in -> DC out. 60% efficiency is sooooo bad it's not even worth doing tests.

I've just ordered an EG4 Chargeverter but it looks like they're back ordered so it may be a while longer till I can actually run some tests on efficiency / gallon of propane etc.

Maybe we should start a thread titled "How efficient is your charger" and use YZPOWER as the #1 charger to avoid :(
 
Last edited:
Update: I added the data for my system through the last generator run in the spring (April 23rd) to my initial post (page #1).

My main takeaways (beyond the fuel type efficiency differences noted earlier in this thread) are:
  • At around 60% of the nominal rating of my generator (on propane) I'm getting around 15% efficiency and ~$1.14/kWh
  • I clocked around 77 hours up to the winter solstice and around 58 hours after
  • With my battery/solar upgrades (14kWh -> 42kWh battery and 4.250 kW -> 5.750 kW solar) along with a particularly sunny fall I've only needed 82 minutes of generator so far compared with 41.5 hours last fall (to date)
 
Total miscalculation on my part as I assumed each charger would be at least 85% efficient in terms of AC in -> DC out. 60% efficiency is sooooo bad it's not even worth doing tests.

I've just ordered an EG4 Chargeverter but it looks like they're back ordered so it may be a while longer till I can actually run some tests on efficiency / gallon of propane etc.

Maybe we should start a thread titled "How efficient is your charger" and use YZPOWER as the #1 charger to avoid :(

@OffGridInTheCity Did you get the EG4 Chargeverter(s) and do you have any efficiency data? Maybe you'd like to start that thread?
 
@OffGridInTheCity Did you get the EG4 Chargeverter(s) and do you have any efficiency data? Maybe you'd like to start that thread?
I did get the EG4 Chargeverter5000 and my equipment shows ~90% efficiency using a Champion Model 100297.
1700590046516.png

I'm still working on fuel (gas/propane) -> kwh efficiency as I don't quite have the exhaust good enough to do multi-hour runs in my generator shed. The flexible (plastic) hi-temp exhaust hose shown here (orange) is burning thru with the Champion exhaust heat. A metal exhaust pipe is on the way and eventually I plan to do some runs of fuel -> kwh.
1700589939661.png

TMI: The Honda eu3000is is quiet outside the shed like an idling car and was hoping to achieve the same with a frame generator so I can run it multiple hours without neighbors being annoyed. However, the Champion is LOUD at 74dBA according to the specs and the shed only reduces this to 45-50db range according to an iphone app - which is much better than 74db but still, not what I'd call quiet like an idling car.

The shed has 2 x 6" framing with R26 pink insulation and 2 layers of wall board (with carpet glue in-between) and home style siding on the outside + a baffled exhaust box with 4" of rockwool.
 
Last edited:
I can't really contribute my own example as I just don't use my generator all that much.

In term of energy supply hierarchy, it's:
i. Grid-tied solar + Off-grid solar & LiFePO₄ battery
ii. Grid
iii. Off-grid solar & Lead acid battery
iv. Generator

iii. and iv. are my backup.
My list has now changed with the addition of an EV with vehicle to load capability:

In term of energy supply hierarchy, it's:
i. Grid-tied solar + Off-grid solar & LiFePO₄ battery
ii. Grid
iii. Off-grid solar & Lead acid battery
iv. Our EV's V2L using a charge controller to charge the off-grid battery
v. Generator

iii., iv. and v. are my backup.
 
over the past 3 months I have gotten into generators. I have bought 4, fairly dirt cheap generators (mostly 5kw and abovd) and actually fixed them (they all were non-working).

My best find (and now my main house generator) is a 25 yea old Winco, running a V2 B&S Vanguard 16HP engine and factory Tri-Fuel. Cost $50. The seller used it at his cabin, well maintained, and always used propane on it. One day it stopped producing power. So he felt time to get rid of it


power center near exhaust.jpg


The unit is brushless and after going through the testing process I found the following issue and SIMPLE fix:

Holding fried CAP lead.jpg

one of the leads going to the 3 caps (40uFD each) had shorted out and melted against a frame part.

Fixed that and it produces power, save the voltage is too low.
120v no load and 108v @4300 watts

Replaced the caps to new ones, and it brought it up 2 volts o 110v @ 4300 watts. Goal is 115v

Going to upgrade to 50uFD caps and try that to see if the voltage comes up even more

but wow, great find

I will feed it into my XW Pro system, but will use the EG4 Chargeverter most of the time to charge batteries. This will reduce the time of possible dirty power going through the inverter/charger, although I think the XW Pro can handle it

I did add a GenSilencer muffler and it cut down on the noise. Am building a "shed" to store and run it in more quietly, eventually

with new muffler.jpg


this a great thread thanks and will add data when I get it all working
 
Last edited:
my best find (and now my main house generator) is a Winco, running a V2 B&S Vanguard and factory Tri-Fuel. Cost $50.
Being a V-twin it's possibly (for a brushless) not too bad for total harmonic distortion. Worth checking with a tester or a suitably set up oscilloscope (with all the 'scope caveats of measuring mains level AC voltages - I have to use a step down transformer for that).
 
~4.2 kWh / LPG Gallon

Sorry if this has been answered already

Do you know how much an LPG gallon is in KG of lpg ? Its difficult to find online , I have seen 1.86kg per LPG gallon but it's very unclear , do you think that is correct ?
 
Being a V-twin it's possibly (for a brushless) not too bad for total harmonic distortion. Worth checking with a tester or a suitably set up oscilloscope (with all the 'scope caveats of measuring mains level AC voltages - I have to use a step down transformer for that).
thanks

have the oscilloscope in the "GET THIS" queue

I found James Condon on Youtube and learned a huge amount on generators and repair skills. Since I have stopped working on cars (I am too old and little space) the generators scratch my engine "FIX IT" itch

He did a video repair on a brushless genny that was the best THD he had ever seen in a non-inverter genset.
This uses the same engine as in my Winco above:


the THD test here 5.7% with 9kw load


here is the scope James uses


the THD tester is too much for my budget
 
Last edited:
Sorry if this has been answered already

Do you know how much an LPG gallon is in KG of lpg ? Its difficult to find online , I have seen 1.86kg per LPG gallon but it's very unclear , do you think that is correct ?
Googling just now - yes. A gallon of propane is 4.11lbs or 1.86kg. https://learnmetrics.com/propane-weight-per-gallon-how-much-does-gallon-of-propane-weigh-20-lb/ And just from hands-on experience with 30lb and 100lb tanks, I can attest this is roughly correct.

Seems like there can be a little bit of variation based on temperature - but not huge.
 
Back
Top