Lifepo4 Solar Charging

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Re: Lifepo4 Solar Charging

Postby Burgerman » 01 Aug 2020, 11:56

What size is your solar system?

Hard to tell from a photo.
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Re: Lifepo4 Solar Charging

Postby flagman1776 » 01 Aug 2020, 16:12

I don't know off hand what the panels max production rating is if installed differently. It's kind of meaningless. The installation was limited by my roof angle and direction which was calculated.
The 35 panels with micro inverters form 1 Array, SW facing, Azimuth: 225°
There are 14 in top row (vertical)
There are 8 in middle row (horizontal)
There are 13 in bottom row (vertical)
There are gaps for plumbing vents and chimney shade.

I wish I'd had my roofer move the vents.
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Re: Lifepo4 Solar Charging

Postby Burgerman » 01 Aug 2020, 18:51

Is each panel 100 watts? 200? 250? They look smaller than my 250 watt panels. But photos cant easily tell.

The area of your panels appears to be about 4kw. So maybe 100w panels. But its all but impossible to say from a photo. Even if 6kw, it seems to be producing around twice as much power as it should.

You must know what you paid for? Its not meaningless. A 3kw system can only make 3kw in perfect cool conditions, full sun, clear sky, panels aimed directly at sun. Mostly it will never reach that. Other than in spring when its cool temperatures and full direct sun.

Yeild is a different thing.

My panels are 6 foot 4 inches x 4 foot wide each, and 18% efficient. Thats pretty much the standard for a 250W panel. I have 10 panels, and so only 2.5kw of solar capability.

This is a 250 watt panel. In my kitchen. Its huge. https://www.wheelchairdriver.com/images ... olar-2.jpg
This is what 1000 watts looks like. https://www.wheelchairdriver.com/images ... e/four.jpg each the same length as a bed and 48 inches wide.

So its hard to understand your figures because while you may be correct it doesent seem to add up! By around 3x. Unless you are only giving good day figures.

Even is all your panels are the highest output super efficient ones that typically cost double, and are say 250/280 watts each, thats a 10kw system. And it doesent look like one. However, even still, that would generate: 35 panels x 30kWh (the amount a 250/280watt panel generates in rhode island every 30 days according to the calculators, in perfect south facing non shadowed conditions) - thats 35x 30days = 1050kwh per month. or around 12,600 kwh per year.
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Re: Lifepo4 Solar Charging

Postby flagman1776 » 01 Aug 2020, 23:37

I carefully totaled the daily kwh from February 2020. I'm not sure why you don't believe me. That's on you.
Here are my daily totals for July 2020 just finished.
1. 31.98 kwh
2. 53.79
3. 26.26
4. 55.24
5. 53.47
6. 59.04
7. 44.40
8. 39.72
9. 55.35
10. 26.61
11. 35.80
12. 55.75
13. 52.88
14. 42.68
15. 33.36
16. 53.90
17. 8.92
18. 56.28
19. 58.99
20. 47.93
21. 55.30
22. 48.72
23. 43.77
24. 36.90
25. 52.69
26. 54.61
27. 58.00
28. 43.02
29. 58.34
30. 42.55
31. 32.06
------------
1,418.31 kwh July total
ave 45.75 kwh daily

Stick your calculator where the sun... I get a complete read out of each panel, every day, with a total.
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Re: Lifepo4 Solar Charging

Postby Burgerman » 02 Aug 2020, 01:19

I didnt say I dont believe you. I am trying to find out what SIZE your solar system is. I was trying to find out since the first post.

The figures you show would need a 10kw system. And it just looks much smaller. I already said its hard to see the size of a panel on a photo. I dont understand how you can have a system fitted and pay for it and not know what the size is! Because thats a pretty good way to compare dollar per kwh generated. And so value for money.

And its not my calculator. Theres dozens of such calculators on the web and some even allow you to enter your exact rhodes island location. They are very accurate based on millions of systems installed and connected up all over the planet. And a typical 4, or 6 or 10kw system do not vary much at all. Maybe 10 to 15%. Unless less due to shading.
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Re: Lifepo4 Solar Charging

Postby flagman1776 » 02 Aug 2020, 03:27

I have MS. You know that causes memory problems, right? The contracts are stored someplace I don't have physical access to. The theoretical wattage of a panel or 36 panels under ideal conditions means squat when they can not be installed that way. No, it wasn't a bargain basement.
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Re: Lifepo4 Solar Charging

Postby Burgerman » 02 Aug 2020, 04:55

Well it actually does mean something.

The roof angle from totally flat to a huge 60 degree from flat only makes a pretty small difference. South, or sw, se, also makes a surprisingly small difference. Yes in total there may be 15% less power made than the perfect angle, and south facing. But its not a massive difference.

Also on a flat angled roof, like yours, with no shading drom say a chimney or trees, solar edge or similar individual panel inverters dont gain you much either. Those things work best where theres multiple angles, shading in a morning or evening in parts.

But judging by your performance, it must be a 10kw system. Because a 6 or 8kw system couldnt have that yield. If I had a 10kw system I would be tempted to fit at least enough batteries to run for a day with the big appliances like heat, turned off to automatically get over any power cuts. Since you have them. You can get a device that handles all of that solar input, and only uses mains AC power when needed, and keeps your batteries topped up. When power goes off, it seamlessely runs from the batteries, disconnects the grid, and you only know the power is off because of an alarm. Everything keeps working as normal. In order to save battery power you would turn off heavy wattage appliances.

When power returns, it automatically puts the solar and the grid back on, and charges the batteries.

Such as https://www.victronenergy.com/inverters ... 12v-1600va
Victron do many devices. This one will keep a battery bank topped up (you decide when like when theres a excess of AC power, but that will naturally happen anyway) and seamlessely swap over. Your solar will continue to add power to the AC provided by the victron. Even when the grid is down. The battery will only be used if the AC demand is higher than the panels provide. Like at night or clouds. It works with lithium or lead.
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Re: Lifepo4 Solar Charging

Postby terry2 » 02 Aug 2020, 06:19

Burgerman wrote:$13k to over 17K for a 4.5 kilowatt system is the approx cost adcertised in the US online in 2020.

Thats what the guy in the video has on the roof.
He also picks rather optimistic figures out of the air. Also presumes that we will drive like my gran. And no winter use - heater needed! We will ignore all of that. Which might half his actual real world miles.

He also ignores all the losses. The inverter(s) used on solar pannels, MPPT devices and then inverters, are between 90% and 95% efficient if you spend enough, realistically. At certain times of the day, with the correct amount of sun, and with the correct idealised string voltage or individual panel inverters that can be a little higher. But that adds hugely to the cost of an instalation, and gains only around 2 to 3 percent on a simple single plain instalation. Where theres shadowing, from trees, chimneys, or panels are at several angles, then the losses are greater and theres some advantages to using undividual inverters at a panel level. As mine are. But then theres further losses from cables, connections, and the cars charger. That will lose another 10% approx. Then theres the cells themselves. That will lose another few percent as heat on charging. He ignores all of that.

And then theres the cost. 13 to 17K buys an awful lot of fuel... Which he is ignoring! How long does it take to pay back the cost of a solar instalation? Approx 15 years in many cases, before any solar power becomes free as he claims in the vid...

And he has conviniently ignored the fact that over winter in most of the world - like here - the solar system makes litterally 10% of the summer peak output. And even in summer, like this july, its been heavy cloud for a month! Bar a few days. My output is only a fraction of june! And in winter a 50 watt panel on my van cannot even keep a full battery full...



Are you using a calculator to get your figures, or did you watch every video to what type\brand ect he fitted?

The guy is awesome.

He was a normal guy who fell ill then became disabled.
Then he was homeless and went to soup kitchens to live.

BUT.
In 5 years he turned his life around. Paid off his house in CA in 3 years.
Bought his car with cash. And is now buying his mom a house.

I like his videos.

Maybe you should try doing videos to help people?
But there again. you would do a video that was 4 hours long on bolts :D :D
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Re: Lifepo4 Solar Charging

Postby Burgerman » 02 Aug 2020, 10:55

My figures?

Yes well known and easily found verifiable data and some generic efficiency data. Easily verified. Solar yeild data can easily be found online. And its fairly accurate. But its not completely accurate to the last few percent. But close enough. That last few percent makes no difference. I understand the physics. I understand the figures. I understand the way to work it out.

And what makes you think I have anything against him? I just pointed out that his "free" power cost him 10 to 15 years payback time frst. And around 17k up front on his system. I know solar works, because I am in credit (its summer!). But it isnt free. At least the first 10 to 15 years isnt. Its very expensive. Solar does pay back, eventually. Thats why I did it. But his tesla is costing him around 17k to charge!

You think he does vids to help people? You dont understand the internet! He does vids because youtube ads, affiliate links,product or suggestions sponsors etc pays those that get it right, extremely well. 100K a year is common for the successful. Some make millions. He isnt doing it for you. He is doing it to make money via his sponsors. And thats why I ignore most youtube vids because most are by frankly ignorant people that know little, and are leading the blind to buy products or to show off products or companies. Most of it is either garbage or has an alternative agenda.

There are a few that are genuine. But beware! Even if they are, they are doing it for money. They make all sorts of claims and teach "you guys" stuff they barely understand themselves. I was making similar amounts at one time from thousands of pages with ads on them. I know how that works. I gave it up 20 years ago when my benefits and care became means tested. Because its a lot of work and it wasnt sustainable enough to cover my care and income etc in the end.
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Re: Lifepo4 Solar Charging

Postby Burgerman » 02 Aug 2020, 11:17

But there again. you would do a video that was 4 hours long on bolts :D


And I could. Question. Theres at LEAST 4 hours woth of info I could give on bolts. Of course it would have to be split into 80x 5 minute long parts.
QUESTION... Do you know why?

If not then this explains why you do not understand how you tube works!!!

How would the vast majority of youtube watchers that dont have a clue figure out if my info was good info, and correct. Or if all the other garbage on bolts and practically everything else they watch was correct?

You cant help most people. Because to them, anyone that seems to know more than they do is an "expert"... banghead
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Re: Lifepo4 Solar Charging

Postby flagman1776 » 02 Aug 2020, 16:33

If we are going to discuss alternative power sources like solar, one must know, alternative to what?

In the US the utility companies are a regulated public utility company but privately owned. Changes in the laws resulted in old companies changing themselves Separating functions. Now there are unregulated power generation companies and regulated power delivery companies who just "pass through" power generation charges. Electric power costs started rising. Houses which were very energy efficient when they were built in 1990, became expensive to keep over the years.

Buying an expensive power generating system is "prepaying" your future electric power costs. Yes, it takes a lot of years to break even. I looked into it 20 years ago and the pay back just wasn't there. The technology just wasn't there yet. Now it is.
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Re: Lifepo4 Solar Charging

Postby Burgerman » 02 Aug 2020, 19:41

The improvement in solar inverters efficiency over the last 20 years is non existent. With efficiencies between 90 to 98% depending on actual votages/strings etc at the time. Then and still today. Because in ideal conditions you cant improve much on nearly 100%!

Improvements in solar panels mean efficiency per square area unit has risen from 15% in 2008 to typically 18% today. 3% More. It means a 250 or 260 watt panel now is a 280 or 290 watt panel... Hardly a big deal. What has really changed is the cost of panels. Thats dropped significantly. But when I did my DIY cheap setup, for around 1/3rd the cost of having solar installed "proffesionally" that cost was already cheap enough at trade prices with cheap chinese solar grid tie inverters that my small 2.5kw system has already paid for itself. In 5 years. Its been pure free energy for the last 3 years. So the real change has been the cost of a solar kw of panel. But it stll takes around 10 to 15 years to pay for itself.

And for what its worth my system is making exactly the same as a more expensive proffesionally installed system kw per kw of system. Just at a massively lower price. But it took some work to install. And is a little more complicates because all of my panels are on 3 different roofs, and different angles. So all are wired in parallel not series, to 3 different grid tie inverters.
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Re: Lifepo4 Solar Charging

Postby Burgerman » 02 Aug 2020, 19:48

Best most efficient common domestic panels in 2020.

LG 21.4%
Panasonic 19.7%
Canadian Solar 19.89%
Solarcentury & IKEA 16.82%
Sharp 20%
SolarWorld 17.89%
Yingli Solar 19.1%

Varies from 17 to 21% which isnt really a lot. And 3 percent better than 20 years ago. And remember that panels lose efficiency at between .5 to 1% per year. So after say 15 years they are only making 80% of the power they once were.
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Re: Lifepo4 Solar Charging

Postby Rye » 03 Aug 2020, 03:57

Maybe I can get a tesla style panel.
Tesla-Cybertruck-solar-roof.jpg
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Re: Lifepo4 Solar Charging

Postby Burgerman » 03 Aug 2020, 09:03

Solar city/tesla use panasonic panels rebranded and sold as tesla. So ya cant! Those would be 290 watts each. So IN COOL weather, full sun, around the best 5 hours of the day in summer it may make approx 80% of that. Ignoring that, and using 100% efficiency we get the following. To charge the cyber trucks estimated 300 kwh battery will take that 3x 290w - 870w total.

So 300kwh will need 300 div by .87 = 344 hours. (actually around 10% more). You will need a very long day. 67 days at the US standardised 5 hours sunshine average per day.

https://www.solar-electric.com/learning ... maps.html/
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Re: Lifepo4 Solar Charging

Postby daunjan » 03 Aug 2020, 11:20

Burgerman you thought of building your own powerwall for storage? Can use second 18650 batteries, usually have 80% life left in them
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Re: Lifepo4 Solar Charging

Postby Burgerman » 03 Aug 2020, 13:19

Nothing to gain. And I would only use new cells because as they age you lose efficiency because of impedance. But my meter rus both ways and we dont really get power outages. Cannot remember more than 3 in 60 years, longest was about 30 mins.
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Re: Lifepo4 Solar Charging

Postby flagman1776 » 04 Aug 2020, 22:46

We are on generator power. I heard a tree took the power lines down several miles from here... started a fire in the woods. The wind exceeds the limits for putting a bucket truck up.
Hope everybody in US east coast is safe.
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Re: Lifepo4 Solar Charging

Postby Arima » 04 Aug 2020, 23:04

How do you get internet when the power is out? Had to use my cell for a hotspot a few weeks ago when the building router got confused for 3 days. If it happens again I'll be paying up for a data plan.
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Re: Lifepo4 Solar Charging

Postby flagman1776 » 05 Aug 2020, 20:00

Power went out about 4pm. Cox cable stayed up until 9pm. Stole somebody's signal later on to check email. Got power back about 2:30. 90,000 out in tiny RI. A hurricane will do that. Reports are some of state may be 3 days. Cox still not back. Stole wife's phone for mobile hot spot. I'm going to owe her a data upgrade.
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Re: Lifepo4 Solar Charging

Postby Burgerman » 06 Aug 2020, 18:24

Dont worry, musk will have you covered in a few months.
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