Sun Tracking for Solar Power – Part 4 – The Video

May 16, 2016 Grove OLED, IOT, Kickstarter, Projects, Raspberry Pi, Solar Power, SunAirPlus, SwitchDoc Products

Sun Tracking for Solar Power – Part 4 – The VideoIMG_7036 2

SwitchDoc Labs has built a lot of solar power systems over the past few years.   Project Curacao,  SunAirPlus,  WeatherPi and the recent Solar Powered ESP8266.  We have fooled around with sun tracking systems, but we have never built one all the way out and then gathered the data to figure out if it was worth it.   Now that the sun has returned to the pacific northwest, it was time to do it.

In this series of postings, we are going to show you how to build a simple solar tracking system using a Raspberry Pi and a stepper motor.   The purpose of this project is to verify experimentally the gain in power from a solar panel from using tracking versus a fixed solar panel.

All the graphs in this series of posting are done using MatPlotLib on the Raspberry Pi.

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There are four parts in this series of postings.

The Video

This video shows  a full day of Sun Tracking (on April 1, 2016).   It was done with an iPad Air on a tripod using the app “lapse it”.   We have used this application a number of times during projects and are quite pleased with the functionality.

 

Conclusion

Strictly from a power point of view, it is clearly worth it.  28% more power from the same cell.  There are trade-offs to be made and to consider.  You have added cost and reliability issues by adding the stepper motor and the mechanical linkages.   Why not just add a second solar panel?   The problem of that is again how solar LiPo chargers work.   You are limited to how fast you can charge a given LiPo battery.  SunAirPlus limits the charge to 1000mA for example.   If you put more solar panels on the system, you will increase the charge during the lower parts of the curve, but at the peak of the day, it doesn’t matter how much power is available to the charger, anything over 1000mA is wasted (and you will see the solar panel voltage go up as we did in Part 2 of this series).

This was a fun project and it was great to see that we could get pretty close to the theoretical value with some simple hardware and a Raspberry Pi.