Preamble
When I came into possession of some reclaimed solar panels, it seemed like a good opportunity to make my own solar-powered website. lowtechmagazine is a great source of detailed useful information on how to make your own solar web server setup. I didn’t refer to their site when setting up this project, as I was interested in working through the process myself. On these how-to pages I will share some basic info about my setup, but this isn’t primarily a ‘tech’ site. Check lowtechmagazine and other sources if you want to set up your own.
In future posts I may go into more technical detail and share code resources I have created.
Battery or grid?
You could just run a web server from your house, or wherever, using grid-supplied electricity from a green energy supplier, and that might reasonably be described as a ‘solar-powered’ website. However, for this site, that would be missing the point, which is to question the whole notion of the ‘always-on’ web, and to highlight the tendency of digital networks to give the appearance of existing in a separate reality—‘withdrawn from the contemplation of present objects’. There are many hidden real-world costs involved in maintaining this illusion.
Using a battery, powered by the sun via a solar panel, makes the interferences between the physical world and the ‘online network’ world concrete and tangible.
How does it work?
Here’s a boring diagram:
- A solar panel (1) transforms sunlight into electrical energy
- The resultant energy is managed by a solar charge controller (2) to charge a rechargeable battery (3)
- The solar charge controller also manages the distribution of energy from the battery to power a small, low-energy computer (8)
- The small computer (Raspberry Pi in this case) hosts software to serve webpages (making it a web server)
- The small computer is connected to the web and the web pages it hosts are accessible to visitors via a domain name (e.g. https://mysolarwebsite.com)
Managing intermittancy
The battery will not always have enough charge to run the computer, especially in wintertime when there is less daylight. So an additional step is needed to safely manage the supply of power to the computer, and to stop the computer from trying to boot when there isn’t quite enough energy available, which would result in a boot-shutdown-boot-shutdown loop. This is called Circuit Hysteresis.
- A programmeable microchip (see (6) in diagram) is used to monitor battery energy levels, safely shut down the computer when battery levels are getting low, and reboot the computer when the battery is sufficiently charged again. Without this, the computer would shut down abruptly when the battery runs out of charge, leading to possible corruption of its data: and it wouldn’t restart without human intervention
- The microchip uses a tiny amount of power, so it can be powered by the same battery which runs the web-server computer. It is unlikely that the battery will ever get so empty that it won’t be able to power the microchip. If it does, the microchip, unlike the Raspberry Pi computer, will be able to restart and continue where it left off, as soon as the battery has sufficient power.
I’ll write posts about each of the parts of the system in future how-tos.