How does your wife feel about that lol
My System Efficiency is 81.3%. Prove me wrong or show me your math.
- Thread starter GregTR
- Start date
timselectric
If I can do it, you can do it.
- Joined
- Feb 5, 2022
- Messages
- 25,209
Couldn't find a wife who could save or make me money. I rent my women. lol
You could if you rent them out.
timselectric
If I can do it, you can do it.
- Joined
- Feb 5, 2022
- Messages
- 25,209
Edit: legally
Like as a house-keeper or ?
robby
Electronic Engineer
- Joined
- May 1, 2021
- Messages
- 5,292
If the SHTF with China a system like that might double in value.
I would pay more for a house with a professionally installed solar system and battery backup.
Checkthisout
Emperor Of Solar
- Joined
- Nov 14, 2021
- Messages
- 5,439
Why would a now non-servicable system, due to lack of parts, have appreciating value?
Which part of my system is non-serviceable? Sol-Ark HQ is 30 minutes from my house, the panels are as maintenance free as anything can get and the batteries have a solid warranty but can be easily replaced should they be non-serviceable.
I don't think any PV system is an appreciating asset, but historically a PV system had been proven to add about 4% value to a home. Given the price of my home I think I'll come out alright on that equation.
timselectric
If I can do it, you can do it.
- Joined
- Feb 5, 2022
- Messages
- 25,209
But made in China.
Hopefully Sol-Ark is stocking up on spare parts.
Ampster
Renewable Energy Hobbyist
System efficiency is low on my list of priorities, assuming they all are going to be fairly close.. The value to me is to be able to take advantage of solar and TOU rates in California.
We cannot
. The Load that Sol-Ark data estimates is far more than the actual load is as I have demonstrated.The only thing I care about in my equation is:
Theoretical Profit = ((Measured Load + Grid Export - Grid Import) * cost per kWh from utility)* Estimated Potential Self Consumption Percentage + purchase price per kWh from utility * (1-Estimated Potential Self Consumption Percentage).
Actual Realized Profit compared to having no PV installed = (Measured Load * cost per kWh from utility) - Utility bill.
Currently my theoretical profit is way lower than my actual profit as I am on a free nights plan which I could not use if I didn't have Solar/Battery or not in a net positive sense.
So my theoretical profit over 5+ months is only about $640 but my realized profit is a bit over $1,100 due to the special utility plan that I'm on. If the plan goes away my "profit" will dwindle to an abysmal value as long as electricity cost is $0.10/kWh.
Math is vastly different in California than in TX. I'll revisit my math after a whole year of use but I'm expecting that my ROI will still be way more than I originally expected it to be. At 80% efficiency it's adding another 25% to my already super long ROI period which is significant!
robby
Electronic Engineer
- Joined
- May 1, 2021
- Messages
- 5,292
Non-Servicable??
Even if Sol-Ark could not get boards from China most of the parts that blow in an Inverter are easily replaceable on a chip level.
In the good old days just 25 Years ago, units would come back in and a technician would diagnose the problem and replace the burnt out component. Most of the time you have spare boards for fast turn over but as soon as a dead one is pulled out it's sent to a technician for repair and then added back to Inventory.
If the SHTF with China the supply of Inverters and batteries across all brands would dry up very quickly and even when they start making them again in some other country, the price is not going to be nearly as cheap. In the in-between years the value of existing systems will sky rocket before they settle down to probably 30-50% higher than today.
Hedges
I See Electromagnetic Fields!
- Joined
- Mar 28, 2020
- Messages
- 23,147
My 6kW Sunny Island draws 25W generating AC with no load. No way a display etc. should consume that much.
My yard rope lights are a big drain on small batteries. So long as you account for them when computing efficiency.
Amateurs!
That depends on the future cost of power in his neck of the woods.
We pay up to $0.50/kWh in California. Natural gas just went up several fold and is being made illegal.
Yes but, as banks crash all around us, you'll have a PV system rather than just old bank statements (or "Error 404, not found" on your computer screen.)
If you played for the other team, maybe you could make money selling yourself?
(Alternatively, did Heidi Fleiss' "Stud Farm" ever get off the ground?)
As someone said, power factor. Not all meters are true RMS, and of course need watts digitally computed in small slices to be accurate. Maybe old mechanical meters were better at that.
It could be that with purely resistive loads would be more accurately reported.
Unlike my LF inverter which has large ripple current on battery, I think your HF will get all 60/120 Hz ripple from capacitors. I measured about 1% for GT PV inverters. At least at PV terminals, don't know if it has separate MPPT between PV and capacitors, then also GT inverter. I would guess only one conversion.
I'm well on my way toward $200k spent, not considering rebates and credits. 2/3 of that was almost 20 years ago, when panels cost 5x to 10x more.
If shtf with China I'd imagine about 90% of everything we do in the west would be unserviceable
Checkthisout
Emperor Of Solar
- Joined
- Nov 14, 2021
- Messages
- 5,439
Grid power would still work.
Maybe so , I'm not sure how much of the US' power grid contains imported Chinese parts ? I bet it's more than you think, lots of micro chips are
We are all very much reliant on international trade now , so WW3 would cause a lot of trouble in a lot of different areas
Checkthisout
Emperor Of Solar
- Joined
- Nov 14, 2021
- Messages
- 5,439
Yeah. It's monitored with Chinese stuff. Outage detection etc.
The rest of it is pretty basic analog.
Getting back to your original issue.
What I would do in your shoes is actually figure out all of the constant drains, and troubleshoot the ones that don't make sense. Your batteries should NOT be drawing 45-100W constantly, screen monitoring or no; thats a full on gaming PC or server at idle, not remotely acceptable.
Control-able RGB lighting should also NOT be drawing 100W when off, it's either garbage, you've got a full 1000meters of it, or something else is going on.
Only once you have your constant drains and loads figured out should you proceed.
Also, if you are sending power to the grid from your batteries, stop doing that.
As to claimed efficiency, no one is going to claim the round trip to and from battery unless they break it out, since you get hit coming and going. This really isn't the bats, it's the charger and then the inverter. If both were EXACTLY 95% (which would be really really good honestly) you're looking at 90.25%.
Most AIO Inverters that bother to give you a breakdown do better with PV-AC than they do with Bat-AC. As will all marketing, the biggest real number goes on the box, even if thats "under ideal conditions".
System losses outside of the control of the AIO shouldn't be factored in if you are comparing claims to reality. If you underside your PV wire so bad you have a 20% drop (as an example) that's not on them.
For measuring AC loads you really need something that will show you VA and Watts.
Does not sound all that abysmal. It takes power to make power. However as others have noted it does not hurt to double check everything so that there is nothing that is causing you to get less than you should. The handy thing about establishing your best efficiency is later on if you see a sharp drop it will indicate a problem.
Sorry if real world numbers are not as good as those that theory would give you. In theory it should be better in practice it rarely is.
Ampster
Renewable Energy Hobbyist
It is the inverter that draws the power due to overhead. I think mine draws oner a hundred Watts an hour or 1.2 kWh per day.
Hedges
I See Electromagnetic Fields!
- Joined
- Mar 28, 2020
- Messages
- 23,147
Most inverter specs give "peak" efficiency, which is achieved at some particular load. And with a "real" or resistive load, so no extra current flowing in and out of reactive components.
SolArk might hit their published number at around 20% load, could be twice that loss at other loads. Can you measure a value while loaded, not include the times it is relatively idle? One figure should be battery to AC, with PV disconnected. Another, PV to AC, with battery floating.
Often, reported losses appear to be a constant number of watts, plus a loss proportional to square of output current (I^2R loss in resistance of FETs and inductors/transformers, which in actuality will vary with temperature as it heats up over time.)
About the most complete I've seen is documented for Sunny Island.
Peak 96%, achieved near 20% load.
Above 90% from 5% through 120% load
94% weighted according to CEC.
At no-load it would be zero, because still consuming 25W even though output is zero.
Note the curve is low for 63V battery, highest for 41V battery. Lowest voltage conversion has least loss.
This sort of curve would be good for a battery inverter, spends much of its time well below full load. Or at zero output (no-load power is very important.)
For current model SB7.7-1SP-US-41, no graph given, just numbers around 97%
Earlier SB 5000-US (transformer type GT PV), similar graph to battery inverter except efficiency only slightly reduced at 100% load, which is where it operates for hours in the middle of the day.
Transformerless 11000TLUS-12
Checkthisout
Emperor Of Solar
- Joined
- Nov 14, 2021
- Messages
- 5,439
To summarize.
You're saying you get let's say 100 watts out of your panels but only 80 of that 100 is usable once all system losses are accounted for?
I think that's right in line with what's expected.
The only loss you could address would be if significant portion is do to high idle draw but otherwise I think you're doing fine.
You're saying you get let's say 100 watts out of your panels but only 80 of that 100 is usable once all system losses are accounted for?
I think that's right in line with what's expected.
The only loss you could address would be if significant portion is do to high idle draw but otherwise I think you're doing fine.
That is the same for Ohio. We have a min $29.00 meter fee even if you use 0KWH. I have no ROI, I tell folks I only buy solar to be independent of the system when it goes down. They also charge $500 application fee, and another $750 Meter fee to backfeed to the grid. They do not want the power we produce. The last nail in the coffin in Ohio is that you can only backfeed 20% of your last years usage, which gets lower the longer you are off grid. If you backfeed more, they charge you for the power. The only Green in Green energy is the Green of Money.I get paid $0.03 for every kWh I send to the grid and I pay $0.29/kWh between 7AM and 9PM and pay $0.00/kWh between 9PM and 7AM. I think this is pretty good
But ROI on my system in Texas is still 18+ years....
Similar threads
