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Solar Power System

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Living with Off-Grid Solar Power

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Solar Electric Power System
Design Worksheet
Step 1: Load Analysis
Qty Load Watts hr/day day/wk Load
819 0
1650 0
300 0
300 0
1800 0
15120 0
Raw Watt-hours/week 19989 0
Inverter Efficiency (AC loads only)  
Averaged over one week (7 days)
AC & DC Watt-hours/day
3570 0
Add   more loads to table
Step 2: Site Data
Average Daily Insolation hrs
  Use Worst Case Data
   Usually during Winter Months
Get Insolation Data
Step 3: Specify PV Array
Required Amp-hr per Day   Derived from Load Analysis
  and Battery Voltage
142 Required Charging Amps from PV Array
  Derived from required Amp-hrs/day and average Daily Insolation
Panel Wattage (Rated)  Watts
Total PV panels required: 14
Step 4: Specify Battery Pack
System Voltage 
  If DC Loads are specified, then System will usually be 12VDC
  Larger Systems will usually be 24VDC or 48VDC
Battery Type 
  T105s suitable for very small systems only
  Most systems use the L16 or L16HD
  Larger Systems benefit by using the KS-21s
Battery Reserve Capacity days
  Best range is 5-8 days, this minimizes
   Generator run time during long periods
   of cloudy weather
Battery Depth of Discharge  %
  DoD > 50% greatly reduces battery lifetime
  DoD < 25% greatly increases battery lifetime
Battery Charging Efficiency   %
  Typical Range is 85-94%
Required Battery Pack:  Battery Type:  L16
Parallel Strings:  5
Each series string:  Qty 4 Batteries
Total Number of Batteries:  20

Created by Lochsa Design