Prototype Performance

The tabs below outline the testing and performance results of our system prototype.

Testing & Results

  • Charging under lamps set to 1kW/m^2
  • Charging 1 battery with constant DC source
    • Parallel (1A at 5V) and Series (0.5A at 10V)
    • With and without SunnyBuddy MPPT
  • Charging multiple batteriesIndividual, all at once
  • Charging with tracking
    • One-axis, two-axis
  • Discharge following all charging tests (demonstrates effectiveness/ battery round-trip efficiency)

1 Battery Charge DC Graph

Charging 1 battery from DC source (used to maximize length of test)

Configuration Charging Rate (kJ/hr) Roundtrip Efficiency
Series, Sunny Buddy 6.67 61.8%
Parallel, Sunny Buddy 7.91 56.9%
Parallel 13.80 73.2%
Components Daily Energy Consumption (kJ)
Servos, Two-Axis Tracking [1] 0.025
Servos, One-Axis Tracking [2] 0.011
Arduino and Relays, Individual Charging [3] 33.97
Arduino and Relays, Parallel Charging [4] 3.73

 *Full battery capacity in our system is approximately 66 kJ

Daily Incident Energy, Target Region 5479.5 Wh/m^2
Energy Harvested with Losses, 4 Cells in Parallel 106.6 kJ
LED Runtime 6.17 hrs
  • ‘Losses’  include all components with two-axis tracking, charging batteries in parallel
  • Only 3.4% of daily energy harvested