Off-grid system review

[Sunking]

Looks like the cult may be better at revelry than understanding electricity.

There is so much wrong with what he says makes me think it is all Make Believe. He does not even know a 48 volt 824 AH battery has a capacity of 40 Kwh with only 10 Kwh/daily usable. So where is the missing 3900 Kwh going too? I know, the land of OZ. Only off by a factor of 100.

[Cult of Dionysus]

Yup, sorry, those should be periods, not commas. I'm so used to reading the MATE3, which gives KwH readings as 4.100 KwH.

lol

Sunking, your correct, my bank has about 40kWh. Though I rarely use more than about 5 KwH per night (to about 85% SOC), and that's with 70" tv, dishwasher, lights, and about 2 hours of irrigation. They are rated to be drawn down to 50% SOC (perhaps not every day, but regularly). So they have more than 10kWh/nighly of useable power.

[Cult of Dionysus]

Here's a pic of the house and a pic of my system. Not sure how good the resolution is, but the bats needs some cleaning and maintenance. Have neglected them a bit of late.

[Cult of Dionysus]

"4,000 KwH (sic) of power from sunrise to sunset" ? I kinda' doubt it.

What I meant to say is that he has 4kWh of useable battery power available from sunset to sunrise, as the Rolls S550s should not be drawn below 80% SOC, unlike my 6 CS 27Ps, which can handle much more abuse. Last night, with about 3 hours of tv, he drew down to 87%. Had he used his dishwasher, it would be around 82%. Exactly as I planned. I'll post some photos of his panels and system.

And again, we are blessed to be in one of the driest, sunniest parts of Hawaii. Probably only 10 of really cloudy weather per year. So we can get away with very modest sized battery banks, principally to get us through the night. If we were on the other side of the island, or most parts of the mainland, we'd probably have to go 5x bigger or more (plus many more panels), plus run the gensets a lot, lot more, in line with the various stickies atop this sub-forum.

[J.P.M.]

Yup, sorry, those should be periods, not commas. I'm so used to reading the MATE3, which gives KwH readings as 4.100 KwH.

lol

Sunking, your correct, my bank has about 40KwH. Though I rarely use more than about 5 KwH per night (to about 85% SOC), and that's with 70" tv, dishwasher, lights, and about 2 hours of irrigation. They are rated to be drawn down to 50% SOC (perhaps not every day, but regularly). So they have more than 10KwH/nighly of useable power.

As long as you're attempting to get things correct, if you want to be taken more, or at all, seriously, you might also consider getting the capitalization conventions right: KwH is mostly considered incorrect, or at least ignorant, and ought better to be written as kWh. Doing so will make it easier for knowledgeable people to take what you're trying to communicate, and you, seriously.

Derived S.I. units (and their abbreviations) named in honor of people associated with the phenomena described by those units are first letter capitalized. Hence, Watts or W, not watts or w; Joules or J, not joules or j. Farad, or F, not farad of f. Common system units such as meter (m), kilogram (kg) and second (s), and their derivatives like centimeter (cm), gram (g), and hour (hr) are not capitalized.

BTW, technically, the terms Watt-hour and kiloWatt-hour are old metric units and so are not actual S.I. units, but are commonly used and understood by most folks, but they sometimes cause problems in heat transfer calcs and also complicate things for checking work by units cancellation.

[Cult of Dionysus]

Point taken. Makes perfect sense, and I'll apply that going forward.

Find it interesting, however, that the extremely knowledgeable Sunking also refers to Kwh in some of his stickies, including:

https://www.solarpaneltalk.com/forum/off-grid-solar/off-grid-solar-panel-systems/5140-solar-off-grid-battery-design

Did not come here to pick fights or to get accosted. I've just wanted to provide an update two years after the fact. And I'm pretty stunned at how petty, insular and frankly rude (in a subtle, back-handed way) some of you folks are. I am a lay person, not putting myself out as an expert in any of this. Any reasonable person knows exactly what I'm talking about when I refer to kwh/Kwh/kwH, and even that initial mistake, of using 4,000Kwh, was pretty damn clear, in the context of my post, what I was referring to.

I'm glad I spelled Surrette with two r's and two t's, can't imagine the flack I would have gotten had I gotten that wrong. lol

[bcroe]

Some pros here are offering good experience for free, your obligation includes getting the facts right.
Especially, numbers and the units of those numbers. Correcting those should be taken as educational
and obligatory to solving the issues. Please DO NOT expect us to be mind readers too. Bruce Roe

[J.P.M.]

Point taken. Makes perfect sense, and I'll apply that going forward.

Find it interesting, however, that the extremely knowledgeable Sunking also refers to Kwh in some of his stickies, including:

https://www.solarpaneltalk.com/forum/off-grid-solar/off-grid-solar-panel-systems/5140-solar-off-grid-battery-design

Did not come here to pick fights or to get accosted. I've just wanted to provide an update two years after the fact. And I'm pretty stunned at how petty, insular and frankly rude (in a subtle, back-handed way) some of you folks are. I am a lay person, not putting myself out as an expert in any of this. Any reasonable person knows exactly what I'm talking about when I refer to kwh/Kwh/kwH, and even that initial mistake, of using 4,000Kwh, was pretty damn clear, in the context of my post, what I was referring to.

I'm glad I spelled Surrette with two r's and two t's, can't imagine the flack I would have gotten had I gotten that wrong. lol

Opinions vary. You think some of the communication around here to be petty, insular and rude. So be it. In such cases I suggest you take what you want that you think makes perfect sense and scrap the rest.

I make more typos than most around here and get corrected/called out for it. If the corrector is right (the usual case), I make a point to thank the corrector and apologize for any time or problems my error(s) caused others. That's one way I learn and hopefully don't make the same error again. But that's just me and I'm very aware that a lot of my ways of thinking and acting are anachronistic. So be it.

I've learned that sometimes, particularly in technical fields, sloppy/incorrect usage can be dangerous. You may notice that engineers around here are more picky than others about terms, concepts, units and typos. There's a reason for that, and it has nothing to do with engineers sometimes being no more than a bunch of sullen, condescending pricks. Knowing the consequences, and having seen the results of uncorrected/missed errors, most trained technical folks welcome the correction, and know there is nothing petty, insular or rude about citing errors. Quite the contrary as a matter of fact. Hell, even after being retired for 15 + years, I still miss and wish I had others checking my work. Think about it.

There's also one other, and possibly related reason for the corrections around here, and it's more than just about you and your ignorance. Others, often no more knowledgeable than you, may well come here, read what you write, and come away with the same incomplete and incorrect information you've conveyed. Probably not a good outcome.

Believe it or not, some folks want to have the communications around here as correct and complete as this limited format can allow. Errors will always happen. Not correcting them as much as possible doesn't help. Some, and perhaps contrary to your opinion, may consider the non correction as petty, insular, and frankly, rude. But, as I wrote, opinions vary.

Then, there's the matter of common sense and enlightened self interest. If you want to be taken seriously by knowledgeable people, I'd respectfully suggest you'll be taken more seriously if you start by making some effort to be courteous by probably/maybe wasting less or others' time who are trying to figure out what you're trying to communicate, by you having a better understanding of the basics of what you're trying to communicate, or at least not having your thin, snowflake skin so easily bruised. It's more than all about you. Not making such an effort is, IMO only, lazy, disrespectful and counterproductive. I bet you'll also be taken more seriously by knowledgeable folks who have a lot of free information to share if they see you've taken the time and made the effort to be at least informed enough be prepared and know what you want to ask.

Respectfully,

[Cult of Dionysus]

Opinions vary. You think some of the communication around here to be petty, insular and rude. So be it. In such cases I suggest you take what you want that you think makes perfect sense and scrap the rest.

I make more typos than most around here and get corrected/called out for it. If the corrector is right (the usual case), I make a point to thank the corrector and apologize for any time or problems my error(s) caused others. That's one way I learn and hopefully don't make the same error again. But that's just me and I'm very aware that a lot of my ways of thinking and acting are anachronistic. So be it.

I've learned that sometimes, particularly in technical fields, sloppy/incorrect usage can be dangerous. You may notice that engineers around here are more picky than others about terms, concepts, units and typos. There's a reason for that, and it has nothing to do with engineers sometimes being no more than a bunch of sullen, condescending pricks. Knowing the consequences, and having seen the results of uncorrected/missed errors, most trained technical folks welcome the correction, and know there is nothing petty, insular or rude about citing errors. Quite the contrary as a matter of fact. Hell, even after being retired for 15 + years, I still miss and wish I had others checking my work. Think about it.

There's also one other, and possibly related reason for the corrections around here, and it's more than just about you and your ignorance. Others, often no more knowledgeable than you, may well come here, read what you write, and come away with the same incomplete and incorrect information you've conveyed. Probably not a good outcome.

Believe it or not, some folks want to have the communications around here as correct and complete as this limited format can allow. Errors will always happen. Not correcting them as much as possible doesn't help. Some, and perhaps contrary to your opinion, may consider the non correction as petty, insular, and frankly, rude. But, as I wrote, opinions vary.

Then, there's the matter of common sense and enlightened self interest. If you want to be taken seriously by knowledgeable people, I'd respectfully suggest you'll be taken more seriously if you start by making some effort to be courteous by probably/maybe wasting less or others' time who are trying to figure out what you're trying to communicate, by you having a better understanding of the basics of what you're trying to communicate, or at least not having your thin, snowflake skin so easily bruised. It's more than all about you. Not making such an effort is, IMO only, lazy, disrespectful and counterproductive. I bet you'll also be taken more seriously by knowledgeable folks who have a lot of free information to share if they see you've taken the time and made the effort to be at least informed enough be prepared and know what you want to ask.

Respectfully,

Right. I didn't make an effort. I posted my systems specs in some detail and gave an update, 24 - 30 months after first coming here. I got my commas and periods mixed up and referred to KwH, which I now understand, thanks to your input, should be kWh, a rather common and rather harmless mistake, though one I won't make again. I've been polite and have tried to correct my errors as soon as pointed out, including editing my recent posts. I welcome corrections, more so than most people and I never said that providing corrections is in any way wrong or inappropriate. Found your initial response to be really great, in that it pointed out my error with a bit of levity (the crack about revelry, which is a play on my user name).

You just spent a fair bit of time to type out a great post, and I appreciate that, though I think you sully your effort with the needless ad hominem in the last paragraph. If I may make a suggestion, you probably should consider deleting the thin, snowflake skin crack. It just undermines what is otherwise a rather amazing post, that I take to heart.

I do want to acknowledge that the input that I received here some 30 months ago was extremely helpful in specing my system, a system which has now served me and my family extremely well, and which I have now replicated for my dad's house. .

[J.P.M.]

Right. I didn't make an effort. I posted my systems specs in some detail and gave an update, 24 - 30 months after first coming here. I got my commas and periods mixed up and referred to KwH, which I now understand, thanks to your input, should be kWh, a rather common and rather harmless mistake, though one I won't make again. I've been polite and have tried to correct my errors as soon as pointed out, including editing my recent posts. I welcome corrections, more so than most people and I never said that providing corrections is in any way wrong or inappropriate. Found your initial response to be really great, in that it pointed out my error with a bit of levity (the crack about revelry, which is a play on my user name).

You just spent a fair bit of time to type out a great post, and I appreciate that, though I think you sully your effort with the needless ad hominem in the last paragraph. If I may make a suggestion, you probably should consider deleting the thin, snowflake skin crack. It just undermines what is otherwise a rather amazing post, that I take to heart.

I do want to acknowledge that the input that I received here some 30 months ago was extremely helpful in specing my system, a system which has now served me and my family extremely well, and which I have now replicated for my dad's house. .

Understood. IMO, not amazing and took not a lot of time.

It's all opinion around here anyway, with opinions being like noses in that everyone has their own and most of them smell, at least some of the time. One of mine is that attitudes such as you seem to display here are those of a thin skinned snowflake. I learned long ago, and far away, that not everyone who tells me what I don't necessarily like or agree with is trying to hurt my feelings.

To reiterate, take what you want of my mental spoor and scrap the rest.

[sdold]

Cult: I think your posts are fine and thanks for the update. The "4,000 KwH" thing was so off that it was obviously a screw up that would have been clarified one way or another. Thanks for hanging in there. No matter the method of delivery, the technical info you'll receive here is 99% accurate and the best you'll find on the web. Just don't ask us about women or today's music.

[Sunking]

Find it interesting, however, that the extremely knowledgeable Sunking also refers to Kwh in some of his stickies, including:

https://www.solarpaneltalk.com/forum...battery-design

Not sure where you are going with that, but I use the terms correctly

4000 wh = 4 Kwh = .4 Gwh = .0004 Twh

4,000 Kwh = 4 Gwh = .4 Twh = 4,000,000 wh

Your point is taken, we all make mistakes. Learn to take what I say with a grain of salt and a sense of humor. I got your attention real quick. Being from a military family and serving for 10 years is still with me. Call me anything you want, SOB is fine with me. But no one will go as far as I will to help you. In person I am one of the nicest easiest going folk you will meet. Just learn to laugh at yourself.

Happy New Year.

[Mike90250]

So, is there some special sequence of the capitalization of the letters ? I always thought the K for Kilo was Capitalized. I generally write Kwh not kWh or KwH.

https://en.wikipedia.org/wiki/Kilowatt_hour#Symbol_and_abbreviations_for_kilowatt_hour

kWh is in IEEE Std 260.1-2004 yet the other power units are Capitalized? capitalization is critical in milli vs Mega and pico vs Penta

"... All the SI prefixes are commonly applied to the watt hour: a kilowatt hour is 1,000 W⋅h (symbols kW⋅h, kWh or kW h; a megawatt hour is 1 million W⋅h, (symbols MW⋅h, MWh or MW h); a milliwatt hour is 1/1000 W⋅h (symbols mW⋅h, mWh or mW h) and so on. The kilowatt hour is commonly used by electrical distribution providers for purposes of billing, since the monthly energy consumption of a typical residential customer ranges from a few hundred to a few thousand kilowatt hours. Megawatt hours (MWh), gigawatt hours (GWh), and terawatt hours (TWh) are often used for metering larger amounts of electrical energy to industrial customers and in power generation. The terawatt hour and petawatt hour (PWh)... "

knowing the rational behind the standard would help me correct my typing muscle memory

[J.P.M.]

So, is there some special sequence of the capitalization of the letters ? I always thought the K for Kilo was Capitalized. I generally write Kwh not kWh or KwH.

https://en.wikipedia.org/wiki/Kilowatt_hour#Symbol_and_abbreviations_for_kilowatt_hour

kWh is in IEEE Std 260.1-2004 yet the other power units are Capitalized? capitalization is critical in milli vs Mega and pico vs Penta

"... All the SI prefixes are commonly applied to the watt hour: a kilowatt hour is 1,000 W⋅h (symbols kW⋅h, kWh or kW h; a megawatt hour is 1 million W⋅h, (symbols MW⋅h, MWh or MW h); a milliwatt hour is 1/1000 W⋅h (symbols mW⋅h, mWh or mW h) and so on. The kilowatt hour is commonly used by electrical distribution providers for purposes of billing, since the monthly energy consumption of a typical residential customer ranges from a few hundred to a few thousand kilowatt hours. Megawatt hours (MWh), gigawatt hours (GWh), and terawatt hours (TWh) are often used for metering larger amounts of electrical energy to industrial customers and in power generation. The terawatt hour and petawatt hour (PWh)... "

knowing the rational behind the standard would help me correct my typing muscle memory

Using NIST direction, my understanding is that all prefixes designating powers of 10 that are equal to or less than 3, including negative powers such as, for example, milliwatt (mW) are not capitalized, when used as either the full prefix ("kilo") or its abbreviation ("k"). Prefixes designating powers of 6 or more are capitalized. So, its kilowatts (kW), not Kilowatts and Megawatts (MW), not megawatts (mW).

Also, correcting an error I made in a portion of the second paragraph of my post of 1819 hrs. P.S.T., 12/30/2017, the first letter of the full names of derived S.I. (and C.G.S system units also) that are named after famous people is not capitalized, unless of course it's the first letter of a sentence.

So, for example, I erred in saying that the correct style use of the S.I. term for power is Watts. That is incorrect. The correct full term is "watts", not first letter capitalized.

I apologize to the forum for my error and any confusion my error caused for readers of this forum.

Mea Culpa.

I'm pretty sure I've got this right now, at least in conformance with NIST publication "NIST Guide to the S.I", chap. 6: Rules and Style Conventions for Printing and Using Units".

If so, the correct S.I. term for power is watts, not first letter capitalized "Watts" as I wrote previously. However, and as I wrote on 12/30, posted at 1819 hrs. P.S.T., the abbreviations for such terms that are named after famous people ( that is, all derived S.I. units) is capitalized. So, single letter abbreviation of such named derived units (or the first letter of such derived units if that unit has more than one letter (Wb for weber for example)) is capitalized.

So, what's the length of 10 GA, with a ring diacentric over the "A" as in the Swedish alphabet ? Anyone ?

[BackwoodsEE]

Did not come here to pick fights or to get accosted. I've just wanted to provide an update two years after the fact. And I'm pretty stunned at how petty, insular and frankly rude (in a subtle, back-handed way) some of you folks are. I am a lay person, not putting myself out as an expert in any of this. Any reasonable person knows exactly what I'm talking about when I refer to kwh/Kwh/kwH, and even that initial mistake, of using 4,000Kwh, was pretty damn clear, in the context of my post, what I was referring to.

I'm glad I spelled Surrette with two r's and two t's, can't imagine the flack I would have gotten had I gotten that wrong. lol

That was exactly my reaction to the silly sniping replies to your update about a very cool working system. Great work, and may you and it have many sunny days ahead!