Most procurement issues in solar lighting projects arise not from product defects, but from unanswered questions early in the decision process. The following questions help reveal whether a solution is designed for long-term success or short-term appearance.

System & Energy Balance

1.How is daily energy consumption calculated?

2.What assumptions are used for autonomy days?

3.How does the system behave during consecutive cloudy days?

Battery & Storage

4.Is battery capacity expressed in Wh or only Ah?

5.What depth of discharge is assumed?

6.How is battery aging considered?

Solar Charging

7.What effective charging conditions are assumed?

8.How does temperature affect charging efficiency?

9.How is seasonal variation addressed?

Lighting Performance

10.What illuminance levels are achieved on the ground?

11.How is glare controlled?

12.How does output change over time?

Control & Reliability

13.Is output fixed or adaptive?

14.What triggers dimming or protection modes?

15.How is battery protection implemented?

Application & Maintenance

16.What environment is this system designed for?

17.How often is maintenance expected?

18.Are replacement components standardized?

Project Risk

19.What assumptions would cause this system to fail?

20.What happens when those assumptions are wrong?

Engineering takeaway

The quality of a solar lighting project is determined by the questions asked before purchase—not by the specifications quoted afterward.