Autonomous wifi bridge
--------------- --------------- | |-|| ||-| |-|| ||-| | | | | | | | | Location1 | | | | Location 2 | | | | | | | _______________ ___ _______________ <-----------815m--------------> <-----763m--->
Note: no osbtacles
|| WiFi antenna
Power needs estimation
- 2 Ubiquiti Nanostation LocoM 5 24v, 5,5W each, so approx 12W
- 1 Ubiquiti ToughSwitch 5PoE 24v, 1,5W
- TOTAL => So to have some margin, 15W
The estimation is voluntary "high". If we assume that the setup is used 24 hours a day at 100% of its capacity, it means 15*24=360Wh per dey. The solar panel have to produce at least 360Wh per day. The maximum debited current from the batteries to the WiFi installation is 15/24 = 0.625.
At the Goutailloux, the solar power is 1,46kWh/m**2/d, so we can take large : 1,40. If we take a 300Wc solar panel, the average power delivered a day is 300*1,4=420Wh per day, for the worst case (the december month). https://www.myshop-solaire.com/panneau-solaire-300w-mono-solarworld-_r_676_i_1560.html : 305€
The setup has to be robust, with low temperature and humidity. So we have to take great hardware. The MPPT 100/15 seems to be great, it can take 400w under 24v solar panels. https://www.myshop-solaire.com/regulateur-solaire-victron-energy-mppt-75-15a-_r_370_i_10.html : 91.80€
We want to have native 24v because we don't need DC/DC converter for the PoE. We can take 4 batteries of 80Ah each. We can assemble 2 batteries in series to make a pack of 24v/80Ah, then do the same with the 2 others. Finally, we can assemble this 2 packs (connected in series) in parallel to obtain 24v/160Ah.
The adopted choice is to have 2 AGM batteries of 25Ah in series. We will have to use this battery at 60%, so approximately 700 cycles, which is sufficient.
These batteries are not so expansive and seems to fit our needs.
WiFi relay prices
WiFi antennas will be loan.
What do we need
We can buy some stuff, but we would like to recover as mush as possible from motivated people :)