
324 Principles of Sustainable Energy Systems
© 2008 Taylor & Francis Group, LLC
Since the system voltage is 24 V, but each panel produces only 12 V, an even number of
panels will be needed. Therefore, the number of panels = 8.
Farmington, New Mexico, is a very sunny location, so 3 days of storage are sufcient.
Assuming a battery efciency of 75% and a maximum depth of discharge of 70%,
Storage173/7579714 Wh=×=()()(. .)00 00
Number of batteries 9714 Wh / 125 Ah 6 V 13 rounded off=
×=()
to the next
Since the system voltage is 24 V, and each battery provides 6 V, the number of batteries
is increased to 16. In a detailed design, the ...