Show HN: A tiny solar-powered server only awake during the day (witch.solar)
It's not a 24/7 website. Depending on the state of the battery, the server itself might run all night, but all the messages it receives during the day are deleted at sunset, and the messaging function itself is only active between sunrise and sunset. This is for two reasons:
1. Less usage of Solar Witch during the night conserves battery power.
2. I like the idea of websites which _aren't_ constantly available. Websites which have to sleep too. Websites living on servers which aren't somewhere in the cloud, but which are bound to a particular location, giving you a sense of where in the world they actually live.
Solar Witch is very much inspired by the solar-powered version of Low Tech Magazine (https://solar.lowtechmagazine.com/) and the not-always-online chatroom Gossips Cafe (https://gossips.cafe/), but at a far, far smaller scale.
PSA: Solar Witch is a teensy hand-written C server running on a teensy microcontroller attached to a teensy solar panel which can only handle one HTTP request at a time and may have buffer overrun issues due to my ineptitude with C. If it's gone down, please don't be surprised, and rest assured I'll hit the reset button soon! Solar Witch encourages patience.
99 comments
[ 2.9 ms ] story [ 150 ms ] threadPeople hugely overestimate the amount of firepower you need when you "go viral", presumably because more people read HN than post on HN so most will just never have tried, and even fewer people try without some preparation (you don't know for sure that it was unnecessary if nothing went wrong).
If one's pages don't require a lot of (pre)computation and you're not a huge destination on the web, things like load balancers, server clusters, etc. are a waste of time and money. But not using fancy tech is not what people here like to geek out on so...
Love it. Added to https://github.com/globalcitizen/taoup
Ideally so cheap that your ISP has a CDN and publishers pay nothing to get them to cache it, it's just included in your internet service. For some people things could even be cached temporarily at the building level.
SSDs are very fast and hardware acceleration exists. Why so we need such massive servers in a data center?
A movie is only 90 minutes. A single disk and some ASICs should be able to serve tens of thousands of people, if you could make dedicated hardware without all the stuff that's irrelevant for streams, just a bunch of cores with DMA going straight into crypto and out a bunch of Ethernet ports.
If we can make a tiny 10 gigabit swith with tons of ports in one rack, why can we not add some sticks of ram and do CDNs in hardware?
This begs the question if we could do the same with data centers: put them into hibernation during the night and move load to the sunny sites. Sure, latency would be higher, but it won't affect that many night-active people. Perhaps it's worth it to remove one use-case of energy storage?
(Yeah, the whole de-globalization and no-data-outside-my-backyard government movements speaks against this. Maybe there's some way around that.)
A lot of places experience the procession of the equinoxes. You wind up with the sun coming up after typical daytime working hours start and often setting after they end for part of the year. In places like Finland, this can mean a six-hour day in December. Some people may be different, but many expect things like Netflix and other entertainment options to work well in the evening. The details of solar power mean that less than 100% of daylight hours are useful for generation.
Further, the decreased usage of local data centers would have to be balanced against increased long-distance bandwidth usage and the corresponding increase in data center usage elsewhere. You would need to over-provision quite a few places relative to local demand to keep up their part in this follow-the-sun.
Let there be no doubt that your idea is interesting. It might not result in any desirable outcomes, though. Naively, it seems like it could get pretty expensive to turn one data center into four or five (with attendant solar farms) with a bunch of intercontinental high-bandwidth links to avoid having to store energy. It might work for some workloads, but seems sub-optimal for general-purpose use.
A more detailed financial analysis is of course possible and perhaps worth exploring! Adding wind, hydroelectric, geothermal, and nuclear power would make the whole thing far more workable. Or just use local energy prices.
Just thought I'd share because astronomy is cool!
Edit: Better link: https://www.gstatic.com/gumdrop/sustainability/247-carbon-fr...
Think this talk from Mike Christian covers it https://youtu.be/iO2z3ttlpi4
Also with something like this if it's using say a cellular or sat network you could drop it in the wilderness somewhere, a node that is hard to take down. Maybe some kind of Lorawan is more realistic but yeah something working remote/not on standard network provider. (but somehow is visible by http? hmm)
ESP01 modded has deep sleep capability so it would wake up, send an http request out, and then go back to sleep.
Example: https://www.rocksolars.com/products/rocksolar-weekender-port...
Should be enough to power a small router and a full Raspberry Pi 4 for a day, or a more minimalistic setup for several days.
I was just looking at small things like those garden night lights you can stake into the ground, has a solar cell on it.
Probably not going to work honestly about the outdoor light (need more solar cells). The voltage charging the battery has to be higher than the voltage of the battery. Also have to look at the current being drawn by each piece, when the radio goes on that causes a surge in current draw too. For the Pi Zero (non-W) something like 5V * 70-200mA say current so up to 1W needed * duration. The batteries could do that but the solar cell can't keep it topped off. Also yeah you need the charge controller, some diode to make sure voltage doesn't go back to the solar cells from the batteries... lead acid battery is "safer" to work with but BMS chips for lipos are pretty inexpensive. Need a voltage regulator to take your batteries and drop it down/keep it at 5V to keep the Pi happy.
There's probably way easier approaches to do this with regard to pre-made parts but yeah. I guess depends how much you want to learn/do yourself. I remember the first time I soldered a 2x16 LCD display there were micro shorts and it was smoking.
What I like about the capacitor idea and something low power like an ESP01 is it just accepts what the solar cells put in and that's it of course I still use a voltage regulator to put 3.3V to the ESP. Doesn't last as long as a battery but it's not as complex.
Anyway this guy made a solar-powered rc plane/charging it in midair pretty cool.
https://youtu.be/1OGrDvInUAY?t=701
That low price doesn't compare to a larger panel in efficiency, but the installation story is hard to beat.
these should be placed all over and come up with a good app to manage such.
these was that cheap card here a while back which had cell coverage for like 5 years and could send out some limited data per month...
that would be perfect marriage... typing with popcicle sorry for formatting
Have you by any chance read Stanisław Lem's The Invincible?
I'm with you. It reminds people that the internet is made up in people, not robots.
Being a little more human hasn't hurt B&H Photo, whose web site doesn't take orders on the sabbath.
https://solar.lowtechmagazine.com/2018/09/how-to-build-a-low...
They go into more detail on their github page:
https://github.com/lowtechmag/solar/wiki/Solar-Web-Design
> we found that dithered images can be stretched beyond their actual image size to emphasize its distinct aesthetic, and that these artifacts of compression can become an integral part of the design.
Attention, aesthetic, design. At no point do they even claim dithered PNG / GIF is smaller than a good JPEG. If it was, they wouldn't need to justify it as aesthetic.
What gets my goat is the motte-and-bailey. On the front page for lay people, it's a power-saving environmentalist stance. When we techies press them on it, they admit it's a graphic design fad.
My guess is that the server might use around the same power as a laptop (~50 W). Assuming a square meter patch of earth gets around 100 W (dependent on latitude/time of day), and assuming something like a 10% efficiency that works out to around 80 W (on average during sunlight hours)? So you're maybe getting 8 hours of server power per day from 10 hours of sunlight? Is that a reasonable ballpark estimate?
They're not efficiently designed usually, and there's probably a wiznet using another watt at peak. All in all, 1.2 to 1.5W would be my guess.
That is 36 watt hours per day for 24/7. We have, in a fairly dark ish winter, probably 2 hours of equivalent peak sun(Every square meter gets about 2KW per day of raw energy, which a good solar panel can get 18 to 25% of last I checked).
I would probably only want to by a 25W panel for this just for cost and size. That's about 1 square foot.
50Wh a day in those 2 hours. Lose half for non optimal placement, 25Wh a day. Lose 70% for cheap electronics, and another 70% in conversions with more cheap electronics(One can do way better for not that much more), and we should get about 12Wh per day.
This is, assuming it's not running full time and the Ethernet module has power save or sleep features, possibly enough to run all day if it's lightly used, but will almost certainly be enough for 6-8 hours. even a dark day.
If you are in Arizona in the summer you will of course be getting 3 to 4 times this. And if you have good electronics and placement you could probably double it again, but good electronics are hard because most MPPT controllers use 25mA sitting idle, you'll need a decent sized panel to keep up with idle loads.
I could also be wrong and they could be using an ESP32 with WiFi, or the Ethernet module could be better than I thought and use green ethernet modes for short range.
That would mean the power could be about a quarter to a half of what I imagined depending on load.
Of course, this doesn't account for the modem and other network gear in his place. But even then, an ESP32 can host it's own wifi, so if you just wanted a pure server for people right nearby, power usage can be very very low.
The local state unemployment office website will only let you complete some tasks during business hours.
When you’re unemployed it is a lot less amusing.
To make this extra awesome, combine it with an open wifi hotspot whose only purpose is to connect to the solar witch website. It could send you to the website as the sign on page.
Now, put the whole thing in a water proof case, mass produce, and place these high up in trees at parks. Now you have a super local and cool little cyberpunk autonomous data hangout.
There are a bazillion wifi hotspots everywhere, so noone would notice one more. Also, with no wires and not being visible from below, none would be any the wiser unless they randomly decided to connect to the open wifi hotspot.