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Old 09-24-12, 03:46 AM   #9
classradiance
2012
 
Join Date: Sep 2012
Location: England
Posts: 28
Thanks: 12
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This is my effort, and I hope it can help you in some way.

HOW TO CALCULATE YOUR MONEY SAVING SYSTEM
1.Add up the hours that each light will be on for to get the Total of Energy Consumed.
2.From that you can Calculate everything you need IE: Solar Panel / Battery / Regulator
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My Calculations
14 Zones
15 X LED SPOT @ 10W + 1 x LED FLOOD @ 15W
on for (SEE CHART) hours per night
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-Watt/Hour Chart- - Only ever use 12 volt LED lights -
Down Stairs
kitchen 15W on when required daily average use -- 3 hours = 45wh
bed1 10W on when required daily average use -- 7 hours = 70wh
bed2 10W on when required daily average use - 7 hours = 70wh
hall 20W on when required daily average use - 2 hours = 40wh
toilet 10W on when required daily average use - 4 hours = 40wh
bed3 10W on when required daily average use - 1 hours = 10wh
utility 10W on when required daily average use - 2 hours = 20wh
front Room 20W on when required daily average use - 8 hours = 160wh
outside front 10W on when required daily average use - 1 hour = 10wh
outside back 10W on when required daily average use - 1 hour = 10wh

Up Stairs
stairs top 10W hardly used daily average use - 2 hours = 20wh
toilet 10W on when required daily average use - void as 2 exist
bed4 10W on when required daily average use - 8 hours = 80wh
bed5 10W on when required daily average use - 4 hours = 40wh

Total usage per night in Winter = 615wh/d
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-Load and Battery -
House Lights Consumption = 615Wh
615 watt-hours divided by 12 volts = 51.25 amp hours. Because we can only use half the energy in a lead acid battery without harming the battery, the minimum battery size is 51.25 amps x 2 = 102.5 amp hours.
(only do this if using a Lead acid Battery)
I want my system to be reliable if we have four consecutive days of cloudy weather,
4 days of autonomy x 102.5 = 410 amp hours for the battery. = 410 + amp hour battery
(Required Battery Bank = 2 x 220Ah or 4 x 110Ah or 8 x 55Ah
Autonomy allows for No charge over 4 days flat
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-Charging Battery from Panel-
This installation is in a location that gets 5 hours of full sun (insolation) per day.
Check the charts for this depending on the month in the Season.
To recharge the battery for one day of use we need 102.5 amps in 5 hours = 102.5 / 5 = 20.5 amps from a 12 volt solar panel array.
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-Solar Panel Array-
Most load calculations include a discount factor for the inefficiency of recharging the battery. 20 percent is typical. 20.5 / 0.8 = 25.7 amps.
A (5 panel) 500W solar array that has an Impp (amps maximum power point) of 25.7A would be suitable
The Panels SUM ( Impp ) must be more than the 25.7A ( 5 x 5.79A = 28.95A)
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-Charge Controller Rating in AMPS-
The 500W solar array has a short circuit amp rating (Isc) of 5 X 6.46A = 32.3A. 32.3A x 1.25 = 40.375A
use a 41A amp or larger charge controller with this array to charge the battery.
Cheap example - 50A CM5024Z JUTA PWM Charge Controller
For best efficiency available for charging the batteries use a MPPT charge controller for lead acid.
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-Cost of mentioned Materials - 20 years / 2k = 8 month
100w watt poly solar panel = 80 + 15 delivery x 5 = 475 UK delivery
50A CM5024Z JUTA PWM Charge Controller = 85
Yuasa 12v 220Ah Cargo Batt For trucks 234.47x 2= 468.94 + shipping
1 x 15W Flood = 20, 15 x 10W Spot = 180 -- Total = 200
Twin & Earth 1mm x 100m = 29.58 from Electrical wholesaler
Max Length for 15w@12V = 6m of .75/Max Length for 10w@12V = 9m of .75
Total Cost can be either + or - dependent on your Budget . 2k / 20years = 8 per month
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-Solar Panel specification-
Related power
100W
Open circuit voltage Voc(V)
21.5V
Short-circuit current Isc(A)
6.460A
Optimum operation voltage Vmp(V)
17.3V
Optimum operation current Imp(A)
5.79A
.......................

Thanks to everyone who places information out there on the WEB
Hope the above can inspire you.
Not mentioned above are Switches, Inverters, Distribution, Heating, Health & Safety,
etc ... Caution -12V Batteries can Cause Fire if not Fused or Stored Correctly-
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