Posted by bealiba on August 23, 2007, 9:55 pm
> Nearly new to this topic, just need a couple of points of view on my
> calculations for a small system design. Thanking you in anticipation.
Your sizing is out.
Your total use taking into account inverter inefficiency will be
66.67Ah
Battery Ah requirement will be 102Ah
Daily Depth of Discharge will be 88.89%, resulting in short battery
life (@ your battery capacity of 75Ah)
360 Watts of panel input required for 4 PSH
Posted by wmbjkREMOVE on August 23, 2007, 11:17 pm
On Thu, 23 Aug 2007 21:55:30 -0000, bealiba@gmail.com wrote:
>> Nearly new to this topic, just need a couple of points of view on my
>> calculations for a small system design. Thanking you in anticipation.
>Your sizing is out.
No, it's your reading comprehension that's out.
>Your total use taking into account inverter inefficiency will be
>66.67Ah
>Battery Ah requirement will be 102Ah
No. His spreadsheet indicates that he's planning to supplement with a
charger. So start by deducting the 264Wh charger output from the total
energy needed to calculate the solar portion required, ~450Wh.
>Daily Depth of Discharge will be 88.89%, resulting in short battery
>life (@ your battery capacity of 75Ah)
No. The loads total 180W, and the charger supplies 132W. So if the
loads are run concurrent with the charger and/or simultaneously, then
none of that energy need make a trip through the batteries. If not,
adjust calculations accordingly. Also depends how much, (if any) of
the loads will be concurrent with the solar production. Say, 600Wh,
probably less, which makes the DOD perhaps <65% with his planned
battery.
>360 Watts of panel input required for 4 PSH
No. His planned 200W should be about right. His numbers are well in
the ballpark, yours are stuck in traffic.... again. See here for
previous examples. http://www.citlink.net/~wmbjk/tbfduwisdumb.htm
Wayne
Posted by bealiba on August 24, 2007, 7:23 am
On Aug 24, 9:17 am, wmbjkREM...@citlink.net wrote:
> On Thu, 23 Aug 2007 21:55:30 -0000, beal...@gmail.com wrote:
> >> Nearly new to this topic, just need a couple of points of view on my
> >> calculations for a small system design. Thanking you in anticipation.
> >Your sizing is out.
> No, it's your reading comprehension that's out.
> >Your total use taking into account inverter inefficiency will be
> >66.67Ah
> >Battery Ah requirement will be 102Ah
> No. His spreadsheet indicates that he's planning to supplement with a
> charger. So start by deducting the 264Wh charger output from the total
> energy needed to calculate the solar portion required, ~450Wh.
> >Daily Depth of Discharge will be 88.89%, resulting in short battery
> >life (@ your battery capacity of 75Ah)
> No. The loads total 180W, and the charger supplies 132W. So if the
> loads are run concurrent with the charger and/or simultaneously, then
> none of that energy need make a trip through the batteries. If not,
> adjust calculations accordingly. Also depends how much, (if any) of
> the loads will be concurrent with the solar production. Say, 600Wh,
> probably less, which makes the DOD perhaps <65% with his planned
> battery.
> >360 Watts of panel input required for 4 PSH
> No. His planned 200W should be about right. His numbers are well in
> the ballpark, yours are stuck in traffic.... again. See here for
> previous examples. http://www.citlink.net/~wmbjk/tbfduwisdumb.htm
> Wayne
ROTFLMAO
Posted by bealiba on August 24, 2007, 7:46 am
On Aug 24, 9:17 am, wmbjkREM...@citlink.net wrote:
> On Thu, 23 Aug 2007 21:55:30 -0000, beal...@gmail.com wrote:
> >> Nearly new to this topic, just need a couple of points of view on my
> >> calculations for a small system design. Thanking you in anticipation.
> >Your sizing is out.
> No, it's your reading comprehension that's out.
> >Your total use taking into account inverter inefficiency will be
> >66.67Ah
> >Battery Ah requirement will be 102Ah
> No. His spreadsheet indicates that he's planning to supplement with a
> charger. So start by deducting the 264Wh charger output from the total
> energy needed to calculate the solar portion required, ~450Wh.
Oh my god, it really is just too funny to pass up. His spreadsheet
says that:
"Total Wattage per day 720W." I assume that he means Whs. With the
inverters inefficiency taken into account this is 833 Whs. Remember,
an inverter is a load as it uses energy from the batteries to run,
hence the need to take into account its efficiency. This is the load
that must be made up for by charging. Using a charger or panels or
wind or even a bicycle driven charger will not reduce the load one
iota.
Given the level of "expertise" shown in your first point there really
is no point in continuing.
> >Daily Depth of Discharge will be 88.89%, resulting in short battery
> >life (@ your battery capacity of 75Ah)
> No. The loads total 180W, and the charger supplies 132W. So if the
> loads are run concurrent with the charger and/or simultaneously, then
> none of that energy need make a trip through the batteries. If not,
> adjust calculations accordingly. Also depends how much, (if any) of
> the loads will be concurrent with the solar production. Say, 600Wh,
> probably less, which makes the DOD perhaps <65% with his planned
> battery.
> >360 Watts of panel input required for 4 PSH
> No. His planned 200W should be about right. His numbers are well in
> the ballpark, yours are stuck in traffic.... again. See here for
> previous examples. http://www.citlink.net/~wmbjk/tbfduwisdumb.htm
> Wayne
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> calculations for a small system design. Thanking you in anticipation.