alt.energy.homepower

We started with kWh/day;

System voltage 24 Volts
Battery Volts 2V
Daily load kWh
5 days autonomy
Battery bank capacity 1200Ah
Daily Depth of Discharge 1 %
Array output required 180Ah/day
PV module output 5A
Guaranteed current
Number of modules in series 2
Number of parallel strings 9


The next step is 15 kWh/day;


System voltage 24 Volts
Battery Volts 2V
Daily load 15kWh
2 days autonomy
Battery bank capacity 1200Ah
Daily Depth of Discharge %
Array output required /day
PV module output 6A
Guaranteed current
Number of modules in series 2
Number of parallel strings

So what do these two systems have in common.

Well, the first is the original system and the second is an attempt to
grow a 15 kWh system from the kWh system.

So, lets look at the reality. The original system as built contained
16 - 75 Watt Solarex panels that would produce around 1080 Watts in
real use. The builder would have you believe that they produce 1200
Watts.

You will note that the builder used only 16 panels when the sizing
design called for 18 panels. The loss of the two panels is offset by
the use of trackers for the arrays. The builder also added a 300 Watt
wind generator. This number is also high and would be more like 150
Watts

All in all a nice, well balanced 24 Volt system. It will provide a
kWh load.

Unfortunately the builder did not design this system. He copied it
after seeing it in a magazine. This would not have mattered if he had
the same requirements as the person who designed it.

As it was, the builder found it fell far short of his energy needs so
he set out to grow the system to meet his needs. The result being the
second example in this demonstration.

What he ended up with is a system that has 16 - 75 W panels and 8 -
100 W panels. The 75 W panels will in reality produce perhaps 1080 W
and the 100 watt panels perhaps another 800 in real use. That is 1880
Watts. He also added a second wind generator with a rating of 1000
Watts. Following his established method of operation he believes that
when the wind generator is turning it is producing 1000 Watts. This is
doubtful. You can see this system at

< /~wmbjk/ >