#01 OFFGRID MICRO SERVERS

A simple offgrid solar system can be created using a Raspberry Pi (or equivalent), a standard 12v solar panel with MPPT and a battery. This system

Raspberry Pi

Raspberry Pi provides a Linux environment which is equivalent to a traditional VPS where a regular stack with Apache or Nginx can be deployed. For reducing power use, the devices are run without a desktop interface (CLI only).

1. Raspberry Pi 4 with up to 8gb: A full size Raspberry Pi with 8gb provides a powerful device for running a web server for websites without massive traffic. It can run a CMS like Wordpress using PHP, MySQL, or equivalent back-end solutions. The power usage is around 265mA.
2. Raspberry Pi Zero 2 W: A smaller Zero 2W can reduce power consumption to half, but it reduces the performance and it is more suited to run static sites. It doesn’t have ethernet but runs on WiFi which is suitable for outdoor solar installations. The power usage is more minimal around 100mA idle to 140mA load (0.5W to 0.7W).

Solar system and battery

The solar system includes a solar panel, a MPPT regulator, a battery, and some cables to connect all together.

Solar panel

In our system we have a cheaper full-size 12v panel of 100W bought from a big box store. This panel is oversized for running a Raspberry Pi above most of the year, but needed for battery charging during the darkest months.

Solar controller

Our first prototype uses a simple MPPT regulator with a USB output where the raspberry Pi can be connected directly. A negative point of that MPPT is that it does not provide information about the battery charge.

Software

A regular server stack can be built using Apache or Nginx, with PHP, Python, MariaDB, MongoDB or any other services needed. The full size version (RPi 4 8g) is run using Nginx, MariaDB, PHP and Python. It can run both statics sites, wordpress installations and other services. The minimal version (RPi Zero 2W) is run with Nginx serving static sites created with Jekyll and deployed through Git.