wrote:

*> Has anyone worked it out yet ?*

*> I'm dying to hear the answer ! With or without battery storage and how*

*> the 2 methods compare in cost.*

*> Graham*

The guy who opened the thread never replied to anyone :)

It's just about wanabe scientists oversized egos!

BTW, watering - as air-conditioning, water desalination, ... - is a

very good job for solar energy: the less the sun shine, the less you

have to water; coupled with a windmill, it would be perfect - wind can

dries - so here too, the less wind the less you have to water.

Sholl

wrote:

*> Has anyone worked it out yet ?*

*> I'm dying to hear the answer ! With or without battery storage and how*

*> the 2 methods compare in cost.*

*> Graham*

It looks like this:

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 =15c

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 = 180Ah

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 = 180

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

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

C1 Design tilt

C2 Design month

C3 Total energy demand per day (A8) =122.55Ah

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

With batteries and a silly 20% added to daily load at A8 for system

losses. And while Ron whines about it, have a look at his post because

this is where he added the 20%, right after accounting for the

inverter inefficiency.

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) =144.17Ah

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

These sizings take into account the all "losses" within system sizing:

INVERTER

1) Inverter efficiency

BATTERIES

1) Maximum allowable Depth Of Discharge

2) Temperature correction

PANELS

1) Panels guaranteed current

2) Battery efficiency

Just adding 20% at any point is not good design practice. Every part

of system design depends on all the numbers in the right places.

Ron says you should take his word for it.

George says here is the formula, have fun, take nobodies word for it,

work it out for yourself.

On Thu, 3 Jul 2008 06:05:53 -0700 (PDT), bealiba@gmail.com wrote:

*>Ron says you should take his word for it.*

Ron wrote the single best post in this thread, answering the OP's

question directly and properly mentioned better solutions. If you

could learn to think and write half as well then you might not be the

butt of so many jokes.

*>George says here is the formula, have fun, take nobodies word for it,*

*>work it out for yourself.*

George has said a *lot*, beginning with a display of his confusion

about the difference between watts and amps, and his resultant

ludicrous recommendation of 154 panels. Only after everybody made fun

of him did he eventually settle on 10.3 panels, almost matching Ron's

estimate... many days and dozens of posts later. If George were

selling deeezines, he'd need to post his calculations on Usenet every

time to see if they were correct, or even in the ballpark.

Fortunately, nobody with an Internet connection would be dumb enough

to hire him.

Wayne

On Jul 4, 12:11 am, wmbjkREM...@citlink.net wrote:

*> On Thu, 3 Jul 2008 06:05:53 -0700 (PDT), beal...@gmail.com wrote:*

*> >Ron says you should take his word for it.*

*> Ron wrote the single best post in this thread, answering the OP's*

*> question directly and properly mentioned better solutions. If you*

*> could learn to think and write half as well then you might not be the*

*> butt of so many jokes.*

*> >George says here is the formula, have fun, take nobodies word for it,*

*> >work it out for yourself.*

*> George has said a *lot*, beginning with a display of his confusion*

*> about the difference between watts and amps, and his resultant*

*> ludicrous recommendation of 154 panels. Only after everybody made fun*

*> of him did he eventually settle on 10.3 panels, almost matching Ron's*

*> estimate... many days and dozens of posts later. If George were*

*> selling deeezines, he'd need to post his calculations on Usenet every*

*> time to see if they were correct, or even in the ballpark.*

*> Fortunately, nobody with an Internet connection would be dumb enough*

*> to hire him.*

*> Wayne*

Still no numbers to support his claims. Talking the talk is not the

same as walking the walk.

wayne is a talker.

This mite do the trick

[IMG]http://i37.tinypic.com/30k5csy.jpg [/IMG]

[IMG]http://i35.tinypic.com/r2pwrq.jpg [/IMG]

Peace along the way

Dennis the bus dweller N.Y.

wrote:

*> Has anyone worked it out yet ?*

*> I'm dying to hear the answer ! With or without battery storage and how*

*> the 2 methods compare in cost.*

*> Graham*

> Has anyone worked it out yet ?> I'm dying to hear the answer ! With or without battery storage and how> the 2 methods compare in cost.> Graham