Posted by *bealiba* on July 8, 2008, 11:14 pm

On Jul 8, 10:39 am, wmbjkREM...@citlink.net wrote:

*> On Sun, 06 Jul 2008 22:44:54 -0400, Ron Rosenfeld*

*> >You can't even enter the OP's data correctly into your spreadsheet.*

*> >But if you want more real data, all you need to do is provide the specs on*

*> >your 180Ah battery, and the simulation is simple to do.*

*> >Give me the specs on your 180 Ah battery, and I'll give you the numbers for*

*> >a simulation of your 11 panel, 180 Ah battery system for Kilauea, HI.*

*> >George's Battery:*

*> >Nominal Capacity: 180Ah*

*> >Nominal Voltage: ???*

*> >Round Trip Efficiency ??*

*> >Min state of charge: ??*

*> >Float life: ?? yrs*

*> >Max charge rate: ? A/Ah*

*> >Max charge current: ? A*

*> >Lifetime throughput: ? kWh*

*> >Also a Capacity curve (A vs Ah) and a Lifetime curve (DOD vs Cycles to*

*> >failure)*

*> >Because of the location, there's probably no need for you to supply a Temp*

*> >vs capacity curve or coefficient. The temperatures don't vary that much*

*> >from the annual mean of 24C.*

*> >--ron*

*> Some save time by substituting rules of thumb for manufacturers'*

*> specs. This makes sense on Planet Ghio because somebody with a few*

*> years of experience with a propane tank and a 1kWh per day solar setup*

*> is obviously sure to know more than companies that build batteries...*

*> or anybody for that matter. In fact, our very own power consultant*

*> ghinius' brain has so many RoTs crammed into it that there simply*

*> isn't any room left for learning anything useful, er... new. It's*

*> apparently a case of stagnation due to knowing too much! <snorf>*

*> Wayne*

Oh look, Tweedledum is back with more of the same. All words, no

maths. How predictable.

Tell us about your system. What are your loads? What do they draw? How

long are they run? And let's not forget, How does increasing the load

reduce resistance in conductors?

Posted by *bealiba* on July 7, 2008, 2:07 am

*> On Sat, 5 Jul 2008 23:11:27 -0700 (PDT), beal...@gmail.com wrote:*

*> >While we wait for ron's next tirade of nonsense let's see what happens*

*> >when we change the battery capacity to 225 Ahs.*

*> George,*

*> YOU are the only one who has been lying. And all you have been spewing is*

*> nonsense.*

*> YOU have falsely claimed that I recommended some battery size to the OP.*

You offered Trojan T105s. Sound pretty specific.

*> YOU have done this by taking my recommendation for a *panel array size*,*

*> and running it through your useless (in your hands) spreadsheet, using*

*> inputs that you have made up. And YOUR spreadsheet provides for the same*

*> 20% factor in panel array sizing, which YOU obviously are unable to*

*> recognize!*

No. I sized the required system, in the correct order and did not add

20% on top of the inverter adjustment to the daily load.

*> YOU cannot even copy the OP's panel specifications to your spreadsheet*

*> properly!*

What! No proof?

*> YOU have recommended multiple systems that won't meet the requirement of*

*> daily running of the OP's system.*

A2 Daily load = 1250Wh

A4 Inverter Efficiency = 85%

A5 Account for inverter inefficiency - Load (A2/A4) = 1470.5

A7 System Voltage = 12

A8 Total A-hr demand per day (A5 / A7) = 122.55

B1 Number of days of autonomy = 1

B2 Maximum allowable depth of discharge = 70%

B3 Battery capacity (A8 x B1 / B2) = 175Ah

B4 Lowest 24 hour average temperature c

B5 Temperature correction factor =.97

B6 Adjusted battery capacity (B3 / B5) = 180.5

B7 Selected Battery

B8 Selected battery discharge rate 100

B9 A-hr capacity of selected battery = 225Ah

B10 Number of batteries in parallel (B6 / B9, rounded off) = 1

B11 Number of batteries in series (A7 / battery voltage) =1

B12 Check Capacity of selected battery at l00 Hr rate = 225

B13 Capacity of battery bank at 100 hr rate (B12 x B10) = 225

B14 Daily depth of discharge (100 x A8 / B13) = 54.47%

C1 Design tilt

C2 Design month

C3 Total energy demand per day (A8) 2.55Ah

C4 Battery efficiency = 90%

C5 Array output required per day (C3 / C4) = 136.2

C6 Peak sun hours at design tilt for design month = 5

C7 Selected module

C8 Selected module I at 14 volts at NOCT 2.94A

C9 Selected module nominal operating voltage. = 12V

C10 Guaranteed current (C8 x 0.9) = 2.65A

C11 Number of modules in series (A7 / C9) = 1

C12 Output per module (C10 x C6) = 13.2Ah

C13 Number of parallel strings of modules (C5 / C12) = 10.3

Prove it wrong.

*> YOUr last recommendation will NOT run the OP's system 24/7 at his location.*

*> Simple simulations show a 23% shortfall using a larger battery! Of course,*

*> you have never provided full specifications for your 180Ah battery which*

*> was the last one you recommended, so a more precise shortfall of your last*

*> proposed system cannot be predicted.*

Prove it. You claim a very precise 23% short fall. All you have to do

is show the numbers.

*> YOUR lowest recommendation for panels (amongst your many recommendations)*

*> is 10% MORE than my recommendation, yet you persist in claiming that mine*

*> is oversized!*

With your 20% added to the daily load, exactly where you put it:

A2 Daily load = 1250Wh

A4 Inverter Efficiency = 85%

A5 Account for inverter inefficiency - Load (A2/A4) = 1470.59

A7 System Voltage = 12

A8 Total A-hr demand per day (A5 / A7) = 144.17 (rons 20% added)

B1 Number of days of autonomy = 1

B2 Maximum allowable depth of discharge = 70%

B3 Battery capacity (A8 x B1 / B2) = 206Ah

B4 Lowest 24 hour average temperature = 15c

B5 Temperature correction factor =.97

B6 Adjusted battery capacity (B3 / B5) = 212.Ah

B7 Selected Battery

B8 Selected battery discharge rate 100

B9 A-hr capacity of selected battery = 212Ah

B10 Number of batteries in parallel (B6 / B9, rounded off) = 1

B11 Number of batteries in series (A7 / battery voltage) =1

B12 Check Capacity of selected battery at l00 Hr rate = 212

B13 Capacity of battery bank at 100 hr rate (B12 x B10) = 212

B14 Daily depth of discharge (100 x A8 / B13) = 68%

C1 Design tilt

C2 Design month

C3 Total energy demand per day (A8) 4.17Ah

C4 Battery efficiency = 90%

(Ron likes 80% here. If you use 80% the required panels come to 13.62)

C5 Array output required per day (C3 / C4) = 160.19

C6 Peak sun hours at design tilt for design month = 5

C7 Selected module

C8 Selected module I at 14 volts at NOCT 2.94A

C9 Selected module nominal operating voltage. = 12V

C10 Guaranteed current (C8 x 0.9) = 2.65A

C11 Number of modules in series (A7 / C9) = 1

C12 Output per module (C10 x C6) = 13.23Ah

C13 Number of parallel strings of modules (C5 / C12) = 12.11

*> YOU really are a piece of work.*

*> --ron*

Posted by *Ron Rosenfeld* on July 8, 2008, 3:37 am

On Sun, 6 Jul 2008 19:07:12 -0700 (PDT), bealiba@gmail.com wrote:

*>Prove it. You claim a very precise 23% short fall. All you have to do*

*>is show the numbers.*

That was for a hypothetical battery, which was proposed only because *you*

kept blathering on about battery recommendations, and misquoting (a kind

way of saying "lying" about) my panel array recommendation size.

With a hypothetical Trojan T105 battery (modified to 90% efficiency) in a

50 watt/panel, 11 panel system, that shortfall is predictable. I did not

propose that it be used in the system; it was proposed only because you did

not quote any particular battery or specifications other than the 180Ah

battery figure, which you use for the 100 hr rating.

*>> B9 A-hr capacity of selected battery = 180Ah*

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

That would mean that that your proposed battery can output a current of

1.8A for 100 hrs.

You also claim that your battery has a

*>> C4 Battery efficiency = 90%*

and a

*>> B2 Maximum allowable depth of discharge = 70%*

I don't have a battery in my database that matches those specifications of

yours. The closest is the Trojan T105 which has a capacity at the 20 hr

rate of 225Ah, and so would obviously be better than 180Ah at the 100 hr

rate. But its round trip efficiency is only 85%, vs the 90% in the battery

you are quoting.

Changing the efficiency to 90% in the specifications for the T105 and

leaving everything else the same results in the simulation showing a 23%

shortfall.

But I thought you would want to specify your own battery, to get a more

realistic result of your proposed 11 panel system with a 180Ah battery (at

the 100 hr rate).

If you are really interested in the simulation results of your proposed

system with a hypothetical T105 modified to 90% efficiency, I could post

that. But to what end -- that battery does not exist.

I think the simulation would be of more value with a "real" battery that

comes close to the parameters you are using. I could use the unmodified

T105, which has a 27% shortfall (if I recall correctly, or any other real

battery for which you can provide the specifications I mentioned.

--ron

Posted by *bealiba* on July 9, 2008, 6:24 am

*> On Sun, 6 Jul 2008 19:07:12 -0700 (PDT), beal...@gmail.com wrote:*

*> >Prove it. You claim a very precise 23% short fall. All you have to do*

*> >is show the numbers.*

*> That was for a hypothetical battery, which was proposed only because *you**

*> kept blathering on about battery recommendations, and misquoting (a kind*

*> way of saying "lying" about) my panel array recommendation size.*

*> With a hypothetical Trojan T105 battery (modified to 90% efficiency) in a*

*> 50 watt/panel, 11 panel system, that shortfall is predictable. I did not*

*> propose that it be used in the system; it was proposed only because you did*

*> not quote any particular battery or specifications other than the 180Ah*

*> battery figure, which you use for the 100 hr rating.*

*> >> B9 A-hr capacity of selected battery = 180Ah*

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

*> That would mean that that your proposed battery can output a current of*

*> 1.8A for 100 hrs.*

*> You also claim that your battery has a*

*> >> C4 Battery efficiency = 90%*

*> and a*

*> >> B2 Maximum allowable depth of discharge = 70%*

*> I don't have a battery in my database that matches those specifications of*

*> yours. The closest is the Trojan T105 which has a capacity at the 20 hr*

*> rate of 225Ah, and so would obviously be better than 180Ah at the 100 hr*

*> rate. But its round trip efficiency is only 85%, vs the 90% in the battery*

*> you are quoting.*

*> Changing the efficiency to 90% in the specifications for the T105 and*

*> leaving everything else the same results in the simulation showing a 23%*

*> shortfall.*

*> But I thought you would want to specify your own battery, to get a more*

*> realistic result of your proposed 11 panel system with a 180Ah battery (at*

*> the 100 hr rate).*

*> If you are really interested in the simulation results of your proposed*

*> system with a hypothetical T105 modified to 90% efficiency, I could post*

*> that. But to what end -- that battery does not exist.*

*> I think the simulation would be of more value with a "real" battery that*

*> comes close to the parameters you are using. I could use the unmodified*

*> T105, which has a 27% shortfall (if I recall correctly, or any other real*

*> battery for which you can provide the specifications I mentioned.*

*> --ron*

The battery size given in the calculation is the minimum capacity

required to run the stated pump for 30 minutes. The calculation allows

you the choose a battery.

Posted by *Ron Rosenfeld* on July 10, 2008, 3:29 am

On Tue, 8 Jul 2008 23:24:21 -0700 (PDT), bealiba@gmail.com wrote:

*>> On Sun, 6 Jul 2008 19:07:12 -0700 (PDT), beal...@gmail.com wrote:*

*>> >Prove it. You claim a very precise 23% short fall. All you have to do*

*>> >is show the numbers.*

*>>*

*>> That was for a hypothetical battery, which was proposed only because *you**

*>> kept blathering on about battery recommendations, and misquoting (a kind*

*>> way of saying "lying" about) my panel array recommendation size.*

*>>*

*>> With a hypothetical Trojan T105 battery (modified to 90% efficiency) in a*

*>> 50 watt/panel, 11 panel system, that shortfall is predictable. I did not*

*>> propose that it be used in the system; it was proposed only because you did*

*>> not quote any particular battery or specifications other than the 180Ah*

*>> battery figure, which you use for the 100 hr rating.*

*>>*

*>> >> B9 A-hr capacity of selected battery = 180Ah*

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

*>>*

*>> That would mean that that your proposed battery can output a current of*

*>> 1.8A for 100 hrs.*

*>>*

*>> You also claim that your battery has a*

*>>*

*>> >> C4 Battery efficiency = 90%*

*>>*

*>> and a*

*>>*

*>> >> B2 Maximum allowable depth of discharge = 70%*

*>>*

*>> I don't have a battery in my database that matches those specifications of*

*>> yours. The closest is the Trojan T105 which has a capacity at the 20 hr*

*>> rate of 225Ah, and so would obviously be better than 180Ah at the 100 hr*

*>> rate. But its round trip efficiency is only 85%, vs the 90% in the battery*

*>> you are quoting.*

*>>*

*>> Changing the efficiency to 90% in the specifications for the T105 and*

*>> leaving everything else the same results in the simulation showing a 23%*

*>> shortfall.*

*>>*

*>> But I thought you would want to specify your own battery, to get a more*

*>> realistic result of your proposed 11 panel system with a 180Ah battery (at*

*>> the 100 hr rate).*

*>>*

*>> If you are really interested in the simulation results of your proposed*

*>> system with a hypothetical T105 modified to 90% efficiency, I could post*

*>> that. But to what end -- that battery does not exist.*

*>>*

*>> I think the simulation would be of more value with a "real" battery that*

*>> comes close to the parameters you are using. I could use the unmodified*

*>> T105, which has a 27% shortfall (if I recall correctly, or any other real*

*>> battery for which you can provide the specifications I mentioned.*

*>> --ron*

*>The battery size given in the calculation is the minimum capacity*

*>required to run the stated pump for 30 minutes. The calculation allows*

*>you the choose a battery.*

It seems you will not (or cannot) specify a practical battery to use in

this application that matches the inputs you used in your spreadsheet.

I must say that doesn't surprise me, although I was hopeful of finding a

battery with a 90% efficiency, a flat current vs capacity curve in the 30

min to 100 hr range, along with an acceptable life when limited to 70%

maximum DOD.

If your system is going to work, your 180Ah capacity battery at the 100 hr

rate -- 1.8A, must also have the *same* capacity when putting out 245A for

the 1/2 hour that the pump will be running!

C'mon George, what kind of a battery is this? If you can't supply the

battery you specified, your system is pretty worthless.

--ron

> On Sun, 06 Jul 2008 22:44:54 -0400, Ron Rosenfeld> >You can't even enter the OP's data correctly into your spreadsheet.> >But if you want more real data, all you need to do is provide the specs on> >your 180Ah battery, and the simulation is simple to do.> >Give me the specs on your 180 Ah battery, and I'll give you the numbers for> >a simulation of your 11 panel, 180 Ah battery system for Kilauea, HI.> >George's Battery:> >Nominal Capacity: 180Ah> >Nominal Voltage: ???> >Round Trip Efficiency ??> >Min state of charge: ??> >Float life: ?? yrs> >Max charge rate: ? A/Ah> >Max charge current: ? A> >Lifetime throughput: ? kWh> >Also a Capacity curve (A vs Ah) and a Lifetime curve (DOD vs Cycles to> >failure)> >Because of the location, there's probably no need for you to supply a Temp> >vs capacity curve or coefficient. The temperatures don't vary that much> >from the annual mean of 24C.> >--ron> Some save time by substituting rules of thumb for manufacturers'> specs. This makes sense on Planet Ghio because somebody with a few> years of experience with a propane tank and a 1kWh per day solar setup> is obviously sure to know more than companies that build batteries...> or anybody for that matter. In fact, our very own power consultant> ghinius' brain has so many RoTs crammed into it that there simply> isn't any room left for learning anything useful, er... new. It's> apparently a case of stagnation due to knowing too much! <snorf>> Wayne