compost.party

2026-04-14T00:00:00Z

compost is currently at a friends' place. They have some extra solar capacity while I (near) am too busy during the upcoming days to be able to properly take care of it. The suncycles just would't sync well, so thanks viernullvier for taking care!

Last weekend we hosted a session Cables of Resistance, and it turned into a really nice opportunity for many participants to network and talk about permacomputing and feminist servers. It was nice to establish new connections, thank you to all who took part in that!

2026-01-11T00:00:00Z

Happy new year!

Chaos Communication Congress ended up being kind of all over the place, sorry if we missed each other at the Feminist Server assembly. It was fun to see many people at the meetup!

There's now a zine that was prepared to describe this little habitat. Take a look at it if you like!

2025-12-25T00:00:00Z

if you're at 39c3, come say hi at the feminist server assembly!

2025-11-29T00:00:00Z

Hey gang, viernullvier here. I've been the designated guardian of compost.party for a few days and used the opportunity to play around with the solar power setup. My goal was to come up with a setup that is able to power the phone throughout the notoriously bleak Berlin winter while doing away with the need to unplug the panel every morning. TL;DR: We're not there yet, but I learned a lot along the way and have a couple of ideas for future improvements.

Of course, the hardware was again gathered in true compost fashion: I've been able to get hold of some outdoor-grade 40 W solar panels that have been decommissioned at my workplace as they are superseded by a new hardware generation. I also found a cheap second-hand solar charge controller for lead-acid batteries that has been sitting unused in an RV for some time. The hardware was completed by a couple of 12 V 5 Ah lead-acid batteries from someone's abandoned DIY residential solar battery project.

Before I took over compost duties, I've been dry-running the setup in my room for a few days while keeping an eye on the reported voltage. The first results were inconclusive: With one panel connected to three batteries in parallel, the controller was at least able to maintain the state of charge with the battery voltage fluctuating by about 0.2 V. I was a bit worried that this wouldn't be sufficient for actually powering the phone, so I wired up a second panel in parallel and used only two batteries (I assumed that fewer batteries will charge faster with the same charge current).

The results: Even though compost's reported battery level had been steadily sitting at 99% the whole time, the test was a failure. The phone was mostly running off the batteries, the solar power only delayed the battery discharge during daytime. At some point I even had to switch over to a second set of full batteries to prevent over-discharge. In the end, it turned out that the simple charge controller was not really fit for the purpose - and sure enough, infamous electronics youtuber Big Clive already did a thorough teardown of this very device.

In which way did it fail exactly?

The controller has no backfeed protection. At nighttime, the battery voltage was actually running through the the panels which acted as a large resistor, draining the battery. Two panels in parallel even decreased the resistance, making the problem worse.
The controller's USB outputs are hooked up directly to its internal voltage regulator, so they are always active and can not be switched off if the battery's state of charge is too low. It's possible to over-discharge the battery by using the USB outputs.
The controller is just a sophisticated switch. It doesn't do any voltage conversion in order to optimize the solar panel's output, so it is not able to charge the batteries at all in low-light conditions.

Where to go from here: While 1. could be fixed by adding blocking diodes in series to each panel and 2. could be circumvented with a 5 V buck converter on the properly switched 12 V output, I would prefer to keep the setup as simple as possible. I'd rather go with a different charge controller that already has the proper protections built in and supports maximum power point tracking in order to address 3. as well.

2025-11-13T00:00:00Z

compost is travelling again! it has been given into viernullvier's care while no one's home here for the next couple of days. It was placed into a bag and carried over on a bike, its new home is barely a kilometer away.

The site will be served through the cellphone network while we're gone, so please be gentle on the 1GB data plan.

2025-10-29T00:00:00Z

This work changes so much with the seasons. Keeping this running feels much more like tending to plants than it feels like conventional sysadmin work. Did it rain? Did something move, is everything still in place?

We are well into fall here in Berlin, which statistically means roughly half as much hours of sunshine as in summer, again halving to a total of 51 hours of sunshine in November. Empirically it means a lot of grey goo and rain. In addition to changes in weather patterns of course the days get shorter and the sun's position on the horizon stays lower. And this means that this daily dance of walking up the stairs into the attic, opening the door, unplugging the USB cable, waiting a couple of seconds to plug it back in, and checking the pixel soup on the broken display to make sure that things are running, has a different rhythm at the moment.

compost exists in a time and in a place. It is not like some hours of compute that you summon with a click in your AWS management console. Day jobs and other commitments decide when to leave the house and when to come back, and the environment decides what's possible in the first place.

Good mornings, like today's, look like this: The sun is shining and there's no wind. Shortly after 08:00 I climb up the stairs and open the door. I open the slanted window to the roof and pull in the panel to wipe off the morning dew. The panel is not the one we started with, it's a larger, foldable camping panel that was bought second hand, but like the other panel it degraded a lot since we first placed it outside. These camping panels use softer solar panels than those you often see on roofs, and they have a shorter lifespan, during which their surface gets increasingly worn down and they charge increasingly worse. Wiping off the dew means less light is refracted in odd ways and more can find its way to the panel. I prop it up outside again, hanging it down from the window, in a 45 degree angle facing the sun that is now high enough to reach over the roof on the left. I fix a gum strap on the closing handle of the window to hold everything in place and close it carefully. The panel's support is not very stable, but if there's still no wind blowing to fold the panel in onto itself, I turn around and check the pixel soup on the display. And maybe that's enough for the day.

2025-09-20T00:00:00Z

We have a new inhabitant, twilliability. Welcome!

The server is back in Neukölln after the intermezzo in ZKU, where excorp took care of it in August. It survived the way safely, but has had some issues finding back home comfortably.

The GSM experiment that we started has been quite the success. We hosted the server on the mobile cellphone network for about a month on a cheap data plan. The Gigabyte included in the plan was used up before the end of the month, so it had to be topped up after a couple of weeks, but the connection was very stable and availability was even better than we hoped. The battery drained a bit more quickly during that time, but it's still unclear to us if this is caused by the different kind of radio communication.

Putting compost back on the wifi caused the connection to be less stable. It's a known issue for this particular phone that the wifi modem is very picky about the kind of connections it accepts: 20 Hz bandwidth only, and only within the 2.4 GHz range. Small mismatches between the channel widths already cause it to stumble easily. We have seen many connection issues in the recent days that brought compost offline even though it was still running. We have set up a different access point that gives us a bit more control over its wifi settings and are hoping that this will improve stability.

And there's another thing that made it difficult to keep compost online: Since compost is back in its attic the existing charging issues seem amplified. This may be a sign that the solar panel has worn down. The plastic sheeting has a couple of scratches and some spots look like they have chipped off.

On one hand you have the point in time in the morning when the panel starts getting directly exposed to the sun. It's placed on a slanted, south-facing roof, and the moment arrives later in autumn and winter. This problem gets worse as the year continues and is increasingly hard to navigate with other obligations, leaving the house early in the morning for a day job and being present in meetings. On the other hand it can happen that a single cloud, a short drop in voltage, is already enough for the charging process to stop. Even with the currently mild autumn here in Berlin, and even if we sometimes walk up to the attic several times a day, it gets difficult to keep a steady charge. Maybe we need to swap out the panel at some point.

Did I already mention that the autumn here is nice and mild at the moment?

2025-09-14T00:00:00Z

We were at the Berlin permacomputing meetup today, where wellgedacht held a workshop discussing self-hosting and their Post-Platform Digital Publishing Toolkit. We printed some of our maintenance logs with a needle printer.

2025-08-10T00:00:00Z

Compost was down for several hours early in the morning today. As predicted in the previous maintenance log post, I was late getting back to the server on the previous day to unplug and replug. I had assumed I could do it anytime before the charge dropped too low but I realized later that I re-plugged it in too late in the day yesterday for it to develop a full charge before nightfall around 21:30. I awoke after a couple hours of sleep, just after sunrise, having had a premonition the battery might run out. Sure enough the battery had died in the previous couple hours. So I climbed up to the roof and re-plugged it in hoping for the best, seeing the charge hovering in the single digits finally, then went back to sleep. Several hours later and we seem to be okay. I think part of the issue was panel placement. While the panel received good sun during the morning it was in shadow in the evening. I moved the panel to a new position that should get an even amount of sun for much of the day, though the phone is a bit more exposed to the elements now.

2025-08-08T00:00:00Z

Added new log: excorp

And greetings from your guest server host excorp themself. Our little phone server was delivered yesterday by bike for some temp vacation caretaking while our regular hosts were away. After some careful scouting on site at the warehouse here in Moabit we found some little pocket on the roof that seemed like an ideal fit minus that it does rain a ton. The panel itself is waterproof and the phone was tucked into an unplugged refridgerator on the roof (for future parties), and the cables snaked inside. Will this withstand the elements? I do know that so far the solar panel loves our sun. The high since installed is at 99% battery!

But now let's talk about the other part of caretaking. I don't own any pets or have any offspring so am fairly free at night. In other words, I'm not worried about getting home to feed anybody, and can sometimes be out pretty late or even just stay up really late working on art or coding. Case in point, last night I went with friends to a concert at Gropious Bau, then hung at home with friends til late and so woke up very late today. When I got up, I checked the server. Oh shoot, 15% yikes. I raced up to the rooftop and unplugged and replugged the charging cable between panel and phone. Basically, my understanding is there's some glitch where once the sun returns and the panel starts feeling its rays it doesn't know to re-up until it's been un-plugged-re-plugged. Why? Dunno.

I wasn't sure at first if it was working. I went down and made breakfast (at noon) and kept checking the site to see the battery level. About 10 minutes later, phew, it was increasing. A couple hours later and we were back up to 90% and now we're at 99%, a big high from our 15% less than 6 hours ago!

Unfortunately (and fortunately!) I'm going out dancing really late tonight and I am really worried about whether I'll make it back home to do the unplug/replug dance. I guess I'm revealing my hand here but am hoping all will be well! Fingers quadruple crossed!

photo: rooftop with plants, seating and a certain hidden solar panel and phone