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diy solar

Let's Get Real about Solar Costs

One issue with the EG4 batteries that is givning me pause is the welded internal connections. Good luck trying to make any repairs when one cell does go bad.

The Schneider line has been around for a long time and has proven reliability that would make me confident about 10-year minimum life. The EG4 inverter gives me little confidence and I would expect them to last the least time.
 
forbin said:
You make a good point about sellers being here in 10 years to honor their warranties. That's worth thinking hard about. I have a different take on the money being gone, though. In my view, the money is not gone. It's still there, it just looks different. It used to look like numbers on a bank's web page, but now it looks like a wall of equipment. A lot of the money is right there in front of me, only in physical form. For the past few years, I've been spending about $200/mo. on energy, which all comes from propane. (We live off grid.) If I can install a DIY solar system for $20K that lasts 10 years, then I'll break even based on today's rates. However, I will also lock in today's energy costs and insulate myself from inflation, and guard against supply-chain problems. If an inverter craps out in 5 years, by then it should be cheap to get a replacement one with similar specs even considering inflation (if we stretch Moore's Law to apply to more than just ICs). Possibly the same could be true of batteries? In any case, I should probably start saving for replacement parts right after I buy the system.
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Spot on. With the exception of the solar panels (I bought 54 CS Bifacial 390's for $167 per), I have just committed to nearly the identical system for similar reasons...off-grid scenario. We will start with 4 of the noted batteries initially while we build our home and eventually go to 10.

That said, we admittedly have the option of going on-grid (800' away & across the road.) We then had planned on adding solar panels & inverters to net-zero it all...basically using the grid as our battery reservoir. Obviously this comes at a cost in so many ways and is debatable if you ever attain a true net zero anyway. The cost of hooking up to the utility alone is $35k...just to get it 800' to the tip of our property and then we need to trench it 1000' more feet up a hill at additional expense. All to attain the privilege of being gouged by the power company every month...& THEN adding the solar as noted. So since we intended to have solar panels and inverters...the only added cost over what I would have potentially spent is on batteries. Anything we come in under the $35k is a bonus and to me...the entire system is paid off and amortized the day we turn it on. Actually, we will likely be way under initial utility hookup charges with a 21k panels, 3 inverters, and 12 rack batteries. Hence every month I use them will be pure profit.

Lastly, 5 years from now or 10...or more...technology will likely continue to evolve and improve and we can likely upgrade cheaper than today.
 
Kornbread said:
If you have access to the grid, reasonable rates, and you add batteries to a solar system ... pffff, ROI and all that. About the only way I might justify batteries is due to frequent outages, but that ain't easy to cipher.
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Agreed...all bets are off if in a rural scenario when initially connecting to the grid too cost prohibitive. THAT is what drove me to a full off-grid system and feel I will save money on day one.
 
orangezero said:
We could all be playing this wrong and some unknown energy source could be plentiful and almost free in ten years.
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Several great points but I found this especially interesting. It would be nice...but sadly I have my doubts. It COULD happen but I doubt they will let it IMHO. Very interesting though...
 
It looked to me like only 5% of batteries lasted their rated life.
I would say look for a battery to last 25% as many cycles as claimed, make sure it is break-even or an OK deal even then. Beyond that, you might come out ahead.

I absolutely minimized size of my battery while sticking with inefficient appliances. When it comes time to replace (10 years), I'll see what's out there. If situation changes in the mean time so I use it daily rather than for backup I'll try to reduce my night time cycling from 70% to 15%.

If I was seriously anticipating SHTF I would buy a set of 2V FLA (dry) and either glass jars of acid or dry acid. That should have shelf life until I need them, and 20 years usage after that.

diysolarforum.com

Are LFP prices artificially high?

"Redflow" flow battery - that's the sort I would hope could provide large capacity long term storage, because energy is stored in the electrolyte, in a tank. Similar to concept of a fuel cell, there is a component that allows chemical reaction and produces electricity, fed by storage of...
diysolarforum.com diysolarforum.com
 
If you really wanted to get real about solar costs you would have to eliminate government mandating utility companies to act as batteries (grid tie) for individual solar power setups. Not to forget the alternative energy tax credit that those that are well off can access.

Terribly distorts the cost when you have welfare. Heck in some places the utility not only is forced to buy power from an individual but at retail cost! I always chuckle when I see claimed ROI that is based on this forced extortion. Frankly in many cases I think it would be cheaper and easier to manage for a utility to pay someone to not grid tie their solar setup.
 
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I ultimately decided on many more smaller 32650 cells because I wasn't confident I'd get 8 or 16 or 32 big cells that were all the same. A "warranty" was almost worthless in my decision making. I prefer a 30-80% discount on the front end vs a warranty.
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I identify strongly with this statement. I was a professional auto technician (still am, just switched to teaching ~7 years ago) and have installed a tremendous amount of new AND used components and I personally don't put much value on warranties either. Not to say no company will do what it says it will do, but I'd rather have a huge discount up front and own my own problems when and if they occur. My business experience basically boils down to if you pay more for a warranty, you are just pre-paying for the majority of the replacement part which you may never receive. Just like the high down payment on a cheap car sitting on a used car lot, is probably all the money they've got in that thing and if you ever make the first payment, they're in the green!

I don't have much solar-specific experience, but i bought 10kw of the literal cheapest used panels from SanTan solar with actual visible damage on them, wired them up almost totally in series (least forgiving of weak panels/wiring/shading etc etc?) and I have seen 7k output from them, which is fine with me because i 'bought more than i needed' and rarely have consumption over 5k in the middle of the day anyway. My theory was buy cheaper and buy more to insulate from underperformance or failure, and if underperformance or failure happens to be less than anticipated, then the system will outperform my expectations!

Sort of like cars in general. Used cars typically have well over 80% of their original functionality (sometimes 97% etc) but consistently go for a pittance of their original price. My old 2007 Prius (lives with a relative now) is up to 371k miles, and while it is a shadow of its former self due to battery degradation, it's STILL as good or better efficiency than a non-hybrid from 2007. But I do understand a lot of my opinion is also informed by my position as a highly technically capable DIY'er still in prime of life and not minding having to sink occasional work into my stuff. As i get less energetic and less interested in working on my own stuff, my preferences will adjust accordingly.
 
Hedges said:
It looked to me like only 5% of batteries lasted their rated life.
I would say look for a battery to last 25% as many cycles as claimed, make sure it is break-even or an OK deal even then. Beyond that, you might come out ahead.

I absolutely minimized size of my battery while sticking with inefficient appliances. When it comes time to replace (10 years), I'll see what's out there. If situation changes in the mean time so I use it daily rather than for backup I'll try to reduce my night time cycling from 70% to 15%.

If I was seriously anticipating SHTF I would buy a set of 2V FLA (dry) and either glass jars of acid or dry acid. That should have shelf life until I need them, and 20 years usage after that.

diysolarforum.com

Are LFP prices artificially high?

"Redflow" flow battery - that's the sort I would hope could provide large capacity long term storage, because energy is stored in the electrolyte, in a tank. Similar to concept of a fuel cell, there is a component that allows chemical reaction and produces electricity, fed by storage of...
diysolarforum.com diysolarforum.com
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Agreed. But I’m not sure you can buy dry FLA batteries anymore.
 
Given the direction electricity prices in the UK are headed the ROI is getting shorter by the day.
 
BigA1 said:
What War...? Its a special military operation...!!!
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I've been fighting the inch war for a few years now. Not sure that's contributing to the cost of energy though. ?

After the above comment and widening my scope to outside the UK and Europe I was surprised to find this is a global phenomenon. What's going on? Can't blame Ukraine for energy prices rocketing in the US & Oz etc.
 
Shimmy said:
One issue with the EG4 batteries that is givning me pause is the welded internal connections. Good luck trying to make any repairs when one cell does go bad.

The Schneider line has been around for a long time and has proven reliability that would make me confident about 10-year minimum life. The EG4 inverter gives me little confidence and I would expect them to last the least time.
Click to expand...
I thought the point of the welds was to increase the overall efficiency and reliability of the battery.
 
danmc said:
I've been fighting the inch war for a few years now. Not sure that's contributing to the cost of energy though. ?

After the above comment and widening my scope to outside the UK and Europe I was surprised to find this is a global phenomenon. What's going on? Can't blame Ukraine for energy prices rocketing in the US & Oz etc.
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Not blaming the Ukraine. They are the ones being attacked. I prey for them every day. And wish that we would all put an end to that maniac.
 
timselectric said:
Not blaming the Ukraine. They are the ones being attacked. I prey for them every day. And wish that we would all put an end to that maniac.
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No sorry. I meant blame the war in itself, not Ukraine particularly.

The war will definitely have an impact when Putin cuts the gas supply off, but prices (In the UK at least) have been on the rise for quite some time. Long before the first shots were fired in Ukraine.
 
forbin said:
I thought the point of the welds was to increase the overall efficiency and reliability of the battery.
Click to expand...

Welds are great, until you need to replace a cell. If the bolted SOK have low enough resistance to function per specs, I’d prefer them. Esp given the likelihood of a bad cell being the issue over a 20 year span.
 
forbin said:
You make a good point about sellers being here in 10 years to honor their warranties. That's worth thinking hard about. I have a different take on the money being gone, though. In my view, the money is not gone. It's still there, it just looks different. It used to look like numbers on a bank's web page, but now it looks like a wall of equipment. A lot of the money is right there in front of me, only in physical form. For the past few years, I've been spending about $200/mo. on energy, which all comes from propane. (We live off grid.) If I can install a DIY solar system for $20K that lasts 10 years, then I'll break even based on today's rates. However, I will also lock in today's energy costs and insulate myself from inflation, and guard against supply-chain problems. If an inverter craps out in 5 years, by then it should be cheap to get a replacement one with similar specs even considering inflation (if we stretch Moore's Law to apply to more than just ICs). Possibly the same could be true of batteries? In any case, I should probably start saving for replacement parts right after I buy the system.
Click to expand...
I like your handle mr Forbin. ?
 
forbin said:
I thought the point of the welds was to increase the overall efficiency and reliability of the battery.
Click to expand...
Yes, and for the system it does do that. The issue I was referring to was the failure rate of the cells themselves: now a single cell failure (1:16) makes the entire pack a lump of hazmat waste. If you have >4 modules, it is likely that you could otherwise scavenge cells and re-build n-1 modules.
 
forbin said:
We all know that manufacturers' specs are based on ideal test conditions and may also include a dose of wishful thinking, so I'm not going to quote any here. For those of you who are experienced with solar, what would you say is a realistic expectation for the useful lifetimes of components such as...

18 x SolarEver 455W Panels
2 x EG4 6500EX Inverters
6 x EG4 LifePo4 48V 100 Ah batteries

...if the equipment was used with moderate care. Let's assume the battery bank and electronics are stored indoors where the temperature is generally comfortable for humans, and are discharged to 80% DoD once per day. I've read the theory, but I'm looking for some gut reactions from pros and knowledgeable enthusiasts.
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Not sure about your parts, but my SMA/ LG panel system has been running since 2008 with zero issues.
 
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Bluedog225 said:
Welds are great, until you need to replace a cell. If the bolted SOK have low enough resistance to function per specs, I’d prefer them. Esp given the likelihood of a bad cell being the issue over a 20 year span.
Click to expand...

This is one of the reasons I DIY my pack. Cell goes bad, cell gets replaced, all good to go.

I think most of you know my set-up (if not, check my sig). I'm in my third year now without issues, with a set-up that cost <$10k that's size wise pretty comparable to the one OP has in mind (minus the extra inverter). No bad cells (and working on doubling the amount), no inverter issues (even though I do have spare parts for it), no charge controller issues. I think warranty is fine to have, but I'd rather have spare parts available in my drawer instead. Try getting those from top tier suppliers...
 
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