Power consumption efficiency is quite important to Big Cat Brother as it should be for any Wildlife and Nature conservation project using technology. I read a lot of concepts from Douglas Tompkins which kept in my head. It is obvious that Solar Energy has its own advantages in terms of reducing contamination, but this guy always kept the beauty of the landscape in mind, so, in his way of thinking, power lines crossing a forest is almost a crime, energy should be generated near the place it is required. That is a very solid and integral point of view.

 

The concept of Solar power is straight forward, photovoltaic cells on a solar panel convert the light and heat out of the sun into energy, that is easy. But sometimes easy looking things are not that easy and you have to invest a lot of time in testing to do things right and durable. I work with three levels of voltages, 12v, 5v and 3.7v, being 3.7v the most important.

 

The first thing to say about solar energy is that you cannot connect a solar panel to your equipment, that is because the power delivered by solar panels is obviously volatile and depends on how sun light reaches the panel (Light clouds can affect the delivered power), some equipment can be damaged if the input voltage is too low. So, what you do is to use batteries that will store the energy and deliver it with more consistency. While the concepts are almost the same, 12v setups will require a regulator between the solar panel, the battery and your equipment. In the low voltage world, I use a simple LiPo (Lithium Polymer) battery charger fed by the solar power. That doesn’t seem that complex at all, but it is for two reasons: batteries themselves and the environment.

 

There are many different kind of batteries, GEL, Ion Lithium, LiPo and all of them have some pros and cons, from cost to durability. GEL batteries are massively affected by the temperature and humidity of the working environment, that means that their life cycle (charge – discharge) will be reduced drastically in very hot places. On the other side, Ion Lithium batteries are cheaper than LiPo batteries, but they need more space and the behavior of charge cycles and power delivery are worse.

 

The final thing to take into account is that solar chargers you find in the market could not have an integrated circuit protection and that could end up damaging MCUs if, for instance, you don’t cut the power once it is getting below a given limit. The physical protection of the battery itself needs to be addressed too, the puncture of LiPo or Lithium battery could leak toxic fluids and even start fires.

 

Cutting edge MCUs can make an extremely effective use of energy, you could deploy a functional device that will be running for several months with a single charge (that will need some measurements and calculations taking into account several factors). Solar powered devices can run for several years, so, the gain is huge. You will notice the benefit the moment you have to deploy lots of devices and most of all, the moment you deploy devices in hard to access places.

 

I will be posting schemes used by BCB, 12v setups and 5v / 3.7v setups and all the details about the topics mentioned in this overview. Stay Tuned!