Posted by *bealiba* on July 12, 2008, 4:51 am

*> On Fri, 11 Jul 2008 17:33:53 -0700 (PDT), beal...@gmail.com wrote:*

*> >> But you remain unwilling to specify a real world battery that would have*

*> >> those characteristics, along with the 90% efficiency and 30% maximum DOD*

*> >> that you also specified in your useless spreadsheet.*

*> >Lying about the numbers is the hallmark of a shyster. The Maximum DOD*

*> >is clearly stated as 70%. This leaves 30% remaining in the battery.*

*> You're correct George. I made a typo in quoting your data. I wrote 30%*

*> maximum DOD when I should have written 30% SOC or 70% DOD.*

*> But you still can't specify a battery that meets *your* specifications of*

*> 180Ah at 100 hr rate*

*> 90% efficiency*

*> 70% maximum DOD*

*> and will also have a capacity of 180Ah at its 30 minute rate.*

Sigh, The battery capacity is the minimum required. I have not

specified a battery. If you require the 30 minute rate then the chosen

battery will need a minimum of 180Ahs capacity at the 30 minute rate.

The formula requires this information from the user for the users

chosen battery. The formula is correct.

*> You can make up imaginary specifications all you want, but if you can't*

*> produce a battery that meets them, or even comes close, your specifications*

*> are useless.*

I have not made up any specifications. I have not specified a battery.

*> You probably don't realize that a battery with a 180Ah capacity at its 100*

*> hr rate, as you specify in your useless spreadsheet, will have a *much**

*> lower capacity at its 30 minute rate.*

The 180 Ah capacity is the minimum required, not a battery

recommendation.

*> And you can't even read, comprehend, or debate intelligently. Your tactic*

*> of taking phrases out of context, deliberately misunderstanding what was*

*> written, name-calling, false attributions, and the like, of which you are*

*> guilty, are the true signs of a shyster: "A person who gets along by*

*> petty, sharp practices".*

The formula is correct.

*> Thanks for the entertainment, George. But I'm tired of dealing with your*

*> name-calling and childish techniques.*

*> By the way, I think your final attempt of 11 panels and 8 T105 batteries*

*> should work at the OP's location. (The T105 is a 6V battery, so I adjusted*

*> your calculation accordingly).*

*> Of course, a system of 10 panels and 4 T105's would also work, with a*

*> minimum SOC of 40% during the winter months, and no less than 50% the rest*

*> of the year. So your system would have 10% more panels and twice as many*

*> batteries as is necessary to run this system using battery storage with a*

*> goal of no energy shortfall.*

*> One could use more expensive batteries to reduce the number of strings from*

*> your 4 or my 2 to just one, but you'd have to look closely at the*

*> trade-offs, both economic and in maintenance.*

*> --ron*

The formula is correct. It requires an amount of user input. Given the

correct input it will correctly size a system.

I presented the formula as it is. If you want to use it feel free, or,

you can have it as a spreadsheet, also free form me at the email

address that can be found in my profile. I am always happy to discuss

system sizing at any time so if you need any help with the formula or

Spreadsheet you can drop me an email.

Neither Tweedledee or Tweedledum have as yet proven the formula to be

incorrect in any way.

Tweedledee has said:

*> You, on the other hand, have posed at least three systems which you claim*

*> would work -- but none of them will work reliably 24/7.*

And:

*> In your useless spreadsheet, you specified a minimum battery capacity of*

*> 180Ah at the 100 hr rate. Now you are writing that this battery will also*

*> have a capacity of 180Ah at the 30 minute rate.*

Plain to see that you can't have it both ways 24/7 or 30 minutes.

Use the formula or not. Take a guess or use real numbers. Get it right

or get it wrong.

Totally up to you.

Posted by *Ron Rosenfeld* on July 12, 2008, 12:55 pm

On Fri, 11 Jul 2008 21:51:15 -0700 (PDT), bealiba@gmail.com wrote:

*>The formula is correct. It requires an amount of user input. Given the*

*>correct input it will correctly size a system.*

The formula may be "correct", but the user inputs you provided with your 5

day of autonomy guesstimate result in a significantly oversized system.

And your sheet has no way of accurately estimating system components and

performance for a particular location.

Your initial 1 day of autonomy was a guess.

Your subsequent 5 days of autonomy is another guess.

Neither are correct for the location and panel array size calculated.

Your specification of 180Ah at the 100 hr rate was wrong.

Your input for panel voltage did not agree with that of the OP's panels.

Your input for ambient temperature was wrong.

Your technique, properly applied, may have been useful years ago, but both

data availability and computer techniques have advanced; allowing better

tailored results.

As you so properly write:

*>Take a guess or use real numbers.*

You have been taking guesses.

*> Get it right or get it wrong.*

Many of your inputs have been wrong.

And, although your last system will work, it is significantly oversized,

with more panels and more batteries than would be required at the OP's

location. But this is probably the best you can do with your spreadsheet.

Without doing simulations, though, there is no good way to figure this out.

And since you are the designer, you should not expect the OP to have

knowledge of ten year averages and ranges for solar insolation; required

days of autonomy for his location; temperature ranges, etc. You are the

one that should be supplying this "user input".

Simulations supplied with pricing data can also figure out the most

economic system, and even compare it with grid extension costs and grid

power costs.

--ron

Posted by *bealiba* on July 12, 2008, 1:29 pm

*> On Fri, 11 Jul 2008 21:51:15 -0700 (PDT), beal...@gmail.com wrote:*

*> >The formula is correct. It requires an amount of user input. Given the*

*> >correct input it will correctly size a system.*

*> The formula may be "correct", but the user inputs you provided with your 5*

*> day of autonomy guesstimate result in a significantly oversized system.*

Back to the same old same old. All you have to do is prove it, a

single set of calculations.

*> And your sheet has no way of accurately estimating system components and*

*> performance for a particular location.*

Nonsense

*> Your initial 1 day of autonomy was a guess.*

No

*> Your subsequent 5 days of autonomy is another guess.*

No

*> Neither are correct for the location and panel array size calculated.*

Lie.

*> Your specification of 180Ah at the 100 hr rate was wrong.*

No. The 180Ah is the correct minimum capacity. If you choose a battery

and apply a discharge rate of C 0.5 the minimum capacity is still

180Ah

*> Your input for panel voltage did not agree with that of the OP's panels.*

It was correct.

*> Your input for ambient temperature was wrong.*

I did not provide any information for ambient temperature. I did

provide lowest average temperature

*> Your technique, properly applied, may have been useful years ago, but both*

*> data availability and computer techniques have advanced; allowing better*

*> tailored results.*

Show us

*> As you so properly write:*

*> >Take a guess or use real numbers.*

*> You have been taking guesses.*

No

*> > Get it right or get it wrong.*

I'm right, you are wrong

*> Many of your inputs have been wrong.*

No

*> And, although your last system will work, it is significantly oversized,*

*> with more panels and more batteries than would be required at the OP's*

*> location. But this is probably the best you can do with your spreadsheet.*

All you have to do is prove it, a single set of calculations.

*> Without doing simulations, though, there is no good way to figure this out.*

*> And since you are the designer, you should not expect the OP to have*

*> knowledge of ten year averages and ranges for solar insolation; required*

*> days of autonomy for his location; temperature ranges, etc. You are the*

*> one that should be supplying this "user input".*

Why not. All the info can be found on many sites from the local

weather to NASA. All I provided was the formula to do the sizing. It

is correct. There are two ways to get a standalone PV system - 1) Hire

someone to do it for you, in which case you don't need to come here

and ask questions. - 2) Be prepared to learn how to do it for your

self, in which case you need to apply your self to the job and chase

your own information.

*> Simulations supplied with pricing data can also figure out the most*

*> economic system, and even compare it with grid extension costs and grid*

*> power costs.*

Yeah, I'll go along with that. Mind you it would be a huge program

having to contain all the worlds suppliers catalogs and price lists

not to mention the complete meteorology of the world as well. Tell you

what, why don't you write it up over the weekend and post it here on

Monday?

If you are not prepared to find the info you need, you are not

prepared to be in control of your own energy supply. The calculation

for system sizing is correct, as long as the info "YOU" put in is

correct.

Now you can tell us how 28 Amps of panels at 12 Volts will run a 230

Volt pump that draws 2500 Watts without batteries.

Oh dear, is that the sound of Running feet?

*> --ron*

Posted by *Ron Rosenfeld* on July 12, 2008, 6:18 pm

On Sat, 12 Jul 2008 06:29:54 -0700 (PDT), bealiba@gmail.com wrote:

*>> On Fri, 11 Jul 2008 21:51:15 -0700 (PDT), beal...@gmail.com wrote:*

*>> >The formula is correct. It requires an amount of user input. Given the*

*>> >correct input it will correctly size a system.*

*>>*

*>> The formula may be "correct", but the user inputs you provided with your 5*

*>> day of autonomy guesstimate result in a significantly oversized system.*

*>Back to the same old same old. All you have to do is prove it, a*

*>single set of calculations.*

*>>*

*>> And your sheet has no way of accurately estimating system components and*

*>> performance for a particular location.*

*>Nonsense*

*>>*

*>> Your initial 1 day of autonomy was a guess.*

*>No*

If not a guess, then it was a wrong input.

*>>*

*>> Your subsequent 5 days of autonomy is another guess.*

*>No*

*>>*

*>> Neither are correct for the location and panel array size calculated.*

*>Lie.*

*>>*

*>> Your specification of 180Ah at the 100 hr rate was wrong.*

*>No. The 180Ah is the correct minimum capacity. If you choose a battery*

*>and apply a discharge rate of C 0.5 the minimum capacity is still*

*>180Ah*

I see. So you are claiming that when you posted:

B13 Capacity of battery bank at 100 hr rate (B12 x B10) = 180

That we should understand that this is not at the 100 hr rate, but rather

at the 30 minute rate?

Or are you claiming that this battery has the same capacity at the 100 hr

rate vs the 30 minute rate?

*>>*

*>> Your input for panel voltage did not agree with that of the OP's panels.*

*>It was correct.*

Could you explain then, the difference between your 14V input and the OP's

17V panels?

OP: the panels are 50 watt, 17 vdc, 2.94 amp

GG: C8 Selected module I at 14 volts at NOCT 2.94A

*>>*

*>> Your input for ambient temperature was wrong.*

*>I did not provide any information for ambient temperature. I did*

*>provide lowest average temperature*

It was still wrong. The lowest average temperature for that area is

21.5°C; the lowest average daily low temperature is about 17.5°C

*>>*

*>> Your technique, properly applied, may have been useful years ago, but both*

*>> data availability and computer techniques have advanced; allowing better*

*>> tailored results.*

*>Show us*

*>>*

*>> As you so properly write:*

*>>*

*>> >Take a guess or use real numbers.*

*>>*

*>> You have been taking guesses.*

*>No*

*>>*

*>> > Get it right or get it wrong.*

*>I'm right, you are wrong*

*>>*

*>> Many of your inputs have been wrong.*

*>No*

*>>*

*>> And, although your last system will work, it is significantly oversized,*

*>> with more panels and more batteries than would be required at the OP's*

*>> location. But this is probably the best you can do with your spreadsheet.*

*>All you have to do is prove it, a single set of calculations.*

see below

*>If you are not prepared to find the info you need, you are not*

*>prepared to be in control of your own energy supply. The calculation*

*>for system sizing is correct, as long as the info "YOU" put in is*

*>correct.*

I'm going to respond to this in a separate message, since it deserves more

comment.

*>Now you can tell us how 28 Amps of panels at 12 Volts will run a 230*

*>Volt pump that draws 2500 Watts without batteries.*

I never said it would. You are the only one making that preposterous

claim. I stated that energy storage would be required. I can't help it if

your application of your spreadsheet to my data came up with a wrong

result.

--ron

Posted by *bealiba* on July 13, 2008, 12:21 am

*> On Sat, 12 Jul 2008 06:29:54 -0700 (PDT), beal...@gmail.com wrote:*

*> >> On Fri, 11 Jul 2008 21:51:15 -0700 (PDT), beal...@gmail.com wrote:*

*> >> >The formula is correct. It requires an amount of user input. Given the*

*> >> >correct input it will correctly size a system.*

*> >> The formula may be "correct", but the user inputs you provided with your 5*

*> >> day of autonomy guesstimate result in a significantly oversized system.*

*> >Back to the same old same old. All you have to do is prove it, a*

*> >single set of calculations.*

*> >> And your sheet has no way of accurately estimating system components and*

*> >> performance for a particular location.*

*> >Nonsense*

*> >> Your initial 1 day of autonomy was a guess.*

*> >No*

*> If not a guess, then it was a wrong input.*

*> >> Your subsequent 5 days of autonomy is another guess.*

*> >No*

*> >> Neither are correct for the location and panel array size calculated.*

*> >Lie.*

*> >> Your specification of 180Ah at the 100 hr rate was wrong.*

*> >No. The 180Ah is the correct minimum capacity. If you choose a battery*

*> >and apply a discharge rate of C 0.5 the minimum capacity is still*

*> >180Ah*

*> I see. So you are claiming that when you posted:*

*> B13 Capacity of battery bank at 100 hr rate (B12 x B10) = 180*

180Ah is the minimum required capacity for the job. IF the system is

expected to use the C0.5 rate or a C120 rate the minimum battery

capacity for the same load will still be 180Ahs

*> That we should understand that this is not at the 100 hr rate, but rather*

*> at the 30 minute rate?*

You must understand that this is user input and will be for the

battery you choose.

*> Or are you claiming that this battery has the same capacity at the 100 hr*

*> rate vs the 30 minute rate?*

No. This come from your ability to understand user input.

*> >> Your input for panel voltage did not agree with that of the OP's panels.*

*> >It was correct.*

*> Could you explain then, the difference between your 14V input and the OP's*

*> 17V panels?*

*> OP: the panels are 50 watt, 17 vdc, 2.94 amp*

*> GG: C8 Selected module I at 14 volts at NOCT 2.94A*

14 volts is the test standard at 25C. 17 volts is what the produces

when not connected to a load. Surprised you don't know this.

*> >> Your input for ambient temperature was wrong.*

*> >I did not provide any information for ambient temperature. I did*

*> >provide lowest average temperature*

*> It was still wrong. The lowest average temperature for that area is*

*> 21.5C; the lowest average daily low temperature is about 17.5C*

Oh, I see. As we are talking here about the lowest average daily

temperature the difference between 15C and 17.5C is not going to make

much difference and is in fact around 3Ahs

*> >> Your technique, properly applied, may have been useful years ago, but both*

*> >> data availability and computer techniques have advanced; allowing better*

*> >> tailored results.*

*> >Show us*

*> >> As you so properly write:*

*> >> >Take a guess or use real numbers.*

*> >> You have been taking guesses.*

*> >No*

*> >> > Get it right or get it wrong.*

*> >I'm right, you are wrong*

*> >> Many of your inputs have been wrong.*

*> >No*

*> >> And, although your last system will work, it is significantly oversized,*

*> >> with more panels and more batteries than would be required at the OP's*

*> >> location. But this is probably the best you can do with your spreadsheet.*

*> >All you have to do is prove it, a single set of calculations.*

*> see below*

Below is empty

*> >If you are not prepared to find the info you need, you are not*

*> >prepared to be in control of your own energy supply. The calculation*

*> >for system sizing is correct, as long as the info "YOU" put in is*

*> >correct.*

*> I'm going to respond to this in a separate message, since it deserves more*

*> comment.*

*> >Now you can tell us how 28 Amps of panels at 12 Volts will run a 230*

*> >Volt pump that draws 2500 Watts without batteries.*

*> I never said it would. You are the only one making that preposterous*

*> claim. I stated that energy storage would be required. I can't help it if*

*> your application of your spreadsheet to my data came up with a wrong*

*> result*

*> --ron*

Here we are at the "Below" and not a single calculation in sight.

> On Fri, 11 Jul 2008 17:33:53 -0700 (PDT), beal...@gmail.com wrote:> >> But you remain unwilling to specify a real world battery that would have> >> those characteristics, along with the 90% efficiency and 30% maximum DOD> >> that you also specified in your useless spreadsheet.> >Lying about the numbers is the hallmark of a shyster. The Maximum DOD> >is clearly stated as 70%. This leaves 30% remaining in the battery.> You're correct George. I made a typo in quoting your data. I wrote 30%> maximum DOD when I should have written 30% SOC or 70% DOD.> But you still can't specify a battery that meets *your* specifications of> 180Ah at 100 hr rate> 90% efficiency> 70% maximum DOD> and will also have a capacity of 180Ah at its 30 minute rate.