Power - Calculations for Solar Arrays and Battery Backup
Calculations for Solar Arrays and Battery Backup
Please feel free to use the calculator below to do your own calculations for solar arrays and battery backup.
Use the following equations to determine solar array size and battery backup requirements based on 12V nominal system voltage.
A permanent station with a Trimble receiver, cellular phone, modem, and computer located in Boulder, Colorado, approximately at latitude 40´02´´ N, 105´14´´ W, elevation 1602 meters.
Daily amp-hour load:
Efficiency and loss-corrected load:
33 Ah / 0.8 = 42 Ah.
Worst case equivalent sun hours (ESH) for Boulder, CO:
Solar array current requirement:
42 Ah / 3.5 h = 12A
Number of solar panels in parallel:
Three solar modules are currently being used in UNAVCO designs:
Choosing the M75 module, four panels are needed to cover the solar array current requirements: 12A / 3.02A per panel = 3.97 panels
Autonomy or reserve time:
Choosing five days of autonomy with 50% maximum discharge:
Battery bank (backup) size:
Three types of sealed deep cycle batteries are currently being used in UNAVCO designs:
As an example, if you choose the Deka 90Ah, five batteries are needed to provide the required autonomy. 420Ah / 90Ah per battery = 4.67 batteries.
|Posted by: Beth Bartel - Wed, Oct 31, 2012 at 5:58 PM. This article has been viewed 72149 times.|
|Online URL: https://kb.unavco.org/kb/article/power-calculations-for-solar-arrays-and-battery-backup-463.html|