Just a quick brain dump: more and less useful things you can do with the components of an old electric wheelchair (usually two 24 V DC geared electric motors of 200-400 W each, a motor controller, and batteries).

  • Telepresence robot for tele-farming. The robot would have a video camera and a high resolution still image camera. It would carry PV panels to recharge itself, so would never get completely stuck (but may only be able to move a few hundred meters per day). The robot can be used to inspect the farms and growing conditions for remotely giving advice to smallholder farmers in developing regions. Also, it could allow consumers from so-called developed countries to explore the farms and village where their products come from, without having to travel there. As part of a P2P food monitoring scheme like the Fairdirect Label (which I co-developed), the telepresence robot would allow customers to check whether the farming conditions are as stated.
  • Telepresence robot for “visiting” friends and relatives.
  • Remote gardening robot. So you can grow your food in one place even when living a nomadic life. The robot for this would look like a portal robot, driving above a row of plants.
  • Weeding robot. Would use deep learning based image classifiers to identify weeds.
  • Irrigation robot for gardening.
  • Robotic parcel delivery in a village. Would be a simple line following robot, with a network of lines on sidewalks in the village.
  • Toolsharing robot for multiple villages. At 7-10 km/h it’s realistic to let the robot move tools on demand in an area of 5 km diameter (6-8 villages). Delivery time would be at most one hour (going to the village 5 km apart, and coming back). It could be a simple line-following robot, with lines on the ground between villages.
  • Pulling a trailer with load.
  • Solar powered autonomous vehicle. This is more like an art project: an autonomous robot that is left to travel alone forever.
  • Firewood collecting robot.
  • Street sweeper robot. Of course autonomous.
  • Street graffitti robot. CNC painting on the street and other large surfaces. ith spray paint cans, chalk or other means.
  • Telepresence robot for the public. Would be put in some interesting location, like an abandoned industrial area, a refugee camp, or a war zone. It would be controlled by anyone on the Internet who is interested in driving it for a time.
  • Animal herding robot.
  • Open source StreetView mapping robot. In contrast to normal StreetView, it would collect 360° pictures in a grid every 5-10 cm. This allows to fluidly visualize moving from anywhere to anywhere (while keeping eye distance from the floor, of course).
  • Soil mapping robot for agriculture.
  • Autonomous mini library. It would drive around in a city by itself and offer books to anyone who wants them.
  • Sutonomous mini sales cart.
  • Snow pattern maker. Some people create huge, nice geometric patterns in snow by walking them. This would be more efficient.
  • Autonomous terrace farming robot. It would probably be tracked for that purpose.
  • Fertilizer robot. In organic gardening that would mean urine and compost.
  • Load carrying robot that follows a person. Using an optical beacon attached to the person.
  • Drink and food server for a restaurant.
  • Self-driving battery power tool carrier and charger.
  • Storage management robot. Carrying pallets or boxes to storage workers, like Amazon does it in their storage areas.
  • Robotic load carrier for mountain villages. It would move slowly but autonomously between villages. For villages in Nepal which are still often only connected by footpaths, this could be an interesting and economical new logistics infrastructure.
  • Vacuum cleaner robot for indoors.
  • Trash collecting robot for cleaning up outdoors.
  • Camera rig robot.
  • Childrens’ toy car. They will love it.
  • Remote surveillance robot for guarding a place. WIth cameras and LED lamps attached.
  • Advertising carrier robot. To be used in pedestrian areas etc..
  • Segway type vehicle. Quite suitable as there are two independently powered wheels normally.

To approach any of these ideas, or your own of course, have a look at some of the more interesting devices people already created out of electric wheelchair parts:

Finally, here are some good technical explanations about how to add remote control to an electric wheelchair:

So I just finished another little project: my new entrance ladder. Ok, let's say it's finished except for a layer of paint, as always. All paint jobs pile up for when I have no urgent needs and will start to care how things actually look 😛

2016-06-02.EntryLadder.1600x1200

This shows the truck's right side, with the door to the living area open. The new ladder is hooked for storage to the inside of the door and will only be in use (means hooked below the door) when the truck parks on the roadside or otherwise in confined spaces where the normal stairs cannot be used. Or, like now, where the normal stairs exist only in pieces laying around …

The reason I'm writing this is to illustrate how a few pieces of trash and a few hours of time, mixed in the right way, can become useful items for everyday use. Here are the ingredients:

  • ladder hooks on door: self-made, bent to shape from 3 mm stainless steel; originally this was a broken bumper bar at the truck's box body that I had to cut off, so it's free …
  • blue mounting plate: leftover pieces from big aluminium 2 mm metal sheets that I bought from the junkyard to create door and window frames; originally all this were commercial signs at a MOT station; maybe back then I paid 0.40 EUR for the amount used here?
  • steel ladder: basically free trash, since I cut it out from the leftover back part of a tractor trailer that I had to shorten for a friend
  • lower holder: tool holder from the wooden leftover body of a 1953 firefighter truck which I burned one winter in the wood stove of my truck
  • hooks below door (not shown): bent from 5 mm steel that came as a leftover 20 cm slice of a MAN truck frame
  • nuts and bolts below door (not shown): stainless steel nuts and bolts I sorted from a 5 kg package of mixed overstock material I bought on eBay for 20 EUR … let's say these are 0.20 EUR again all together
  • rivets: seven are found by sorting a big free bucket of nuts and bolts; five are bought (0.20 EUR each?); one of them I shortened because I did not have the right length at hand (how to? remove pull pin, cut off a bit of the rivet head, put in pull pin, remove grate with file)
  • PU sealing agent: used as glue behind the blue base plate and lower holder; bought, used amount might be worth 1 EUR
  • cutting and sanding disks: I used a 125×1 mm angle grinder cutting disk half, and a 125 mm sandpaper disk half … together about 1.40 EUR
  • electricity: the sun did not send me an invoice yet

Which makes for a total monetary investment of 4.00 EUR, or 4.55 USD. I'm still ok with that amount 😀

Of course I could also have bought an entrance ladder. Why didn't I? For one thing, it is difficullt to find something that fits here (I looked once, and only found fitting ones from yachting accessory for at least 100 EUR). And then: While this might be uneconomical in monetary terms for me now, I am learning and getting better at building my own stuff. It's an investment into the future, because I discovered that building your own stuff grants you a form of freedom. How so? Because you can always build some simple, useful items you need, and this way you can always cover some of your needs without a paid job. Just free trash and free time needed. Now what if we could build everything we need from trash? Would we still fear "unemployment"? Would we still accept hiearchies in the workplace, strict time regimes, uninhabitable and ugly offices, bad pay?

With projects like these, I'm exploring how much freedom there is in free trash. I know about efficiency issues with DIY building, the need for automation and so on. But it's just the start, and so far I cannot even see the end: open source tech solutions are getting more powerful every day. (Have a look at EarthOS if you are not convinced yet, it's my collectionf of "open source solutions for everything in life".)

So this is my home now, a 4×4 ex-firefighter truck from 1976. Bit older photo, but from the outside it still looks like this. Except it has a licence plate, means it's street legal now. It's misssing some creative lettering though. I plan to write "UM" on it's side in big black letters one day, to confuse some gangstas. I think they call it mimikri in the animal kingdom, and it's perfectly legal there laugh

2015-09-09 19.51.22.1024x768

For introducing you to this little beast called "Erwe", know this: I have just this place to live and work now and these 9 m² just fit me (ceiling is 1 cm above my head). But I own this one, which is a relief: no rent, no interest, just a bit of vehicle tax. And while I say I live in it, don't expect a living room. It's more meant to be an expedition truck for the decades to come laugh So, you'll find lots of waterproof boxes instead of furniture, more truck tools than kitchen tools, and even a beautiful aluminium carpet (pictured below). Not sure where my expeditions will go and what my tasks will be – currently it looks like I want to go to the Balkans or Southern Italy and see what I can understand and do about the refugee situation there. More ideas are always welcome.

For the moment, my life in this setup works like this (going along the images):

gallery2013-08-13 18.57.49.1024x1365

(1) Say it is winter, so fire up the wood stove first thing in the morning and go to bed for 20 min more until it's all heated up. Not much wood (or free pine cones laugh) needed, since I live in a former deep freeze box used for fish. Insulation is 10 cm PUR foam all around, equivalent to 20 cm styrofoam. In German winter, I needed a bit more than one Eurobox (60×40×30 cm) of wood per week.

2016-05-29.Coffee.2.1024x768

(2) Make hot water and have a coffee. Coffee machine is very simple yet, so not for coffeephiles for the time being … still looking for an oversized version of these stovetop espresso machines somewhere …

2016-05-29.WorkshopMode.2.1024x768

(3) Put "bed" into workshop mode. Toolboxes are normally stored under the bed, in the middle of the four used Zarges A10 aluminium boxes on which the mattress rests. That seems like a strange choice for a bedframe, but I store everything in stackable boxes here so that moving without the truck to another place for longer is just about shipping my stuff on one pallet (ca. 80 EUR with a trucking company within Germany, or ca. 300 EUR half around the world in a container as LCL). Also note my little assortment of "clubbing utensils" visible to the right, fixed handy right next to the door for personal security. There's a large MagLite flashlight, basically the only heavy item you may carry when opening the door at night and find police in front (which I expect to happen a lot while travelling). And a bamboo stick, as used by the friendly Nepal Armed Police forces cheeky I brought it from Kathmandu last year, after the earthquake made our garden wall fall on the poor bamboos.

2016-05-29.NoBatteryTool.3.1024x768

(4) Work on some "home improvement" or "workshop improvement" project. One of my latest projects was creating "sun powered" 24 V power tools, as shown. I do not use an inverter to make 240 V AC from my 24 V DC solar system (because inverters are only ~85% efficient, quite expensive when sizing them for powertools – and worse, they break, and they produce electricity unsafe to touch … while my 24 V DC is safe for all my DIY purposes). So instead, I selected a series of cordless power tools with input voltage that fits for my 24 V DC, like the Milwaukee V28 series shown here. Then bought a defective replacement battery on eBay (ca. 7-12 EUR), removed the LiIon cells from it and connected a cable to plus and minus instead. Plug it into the socket and it will work – no need to connect the temperature sensor (the central pin). Just make sure your sockets are fused, and the fuses can take 35 A – the circular saw draws 800 W max., angle grinder 500 W max., power drill I have to see, did not use it above 150 W so far). If you want to replicate this, also note the cable and plug. Cable is 4 mm² copper cable, of which the cheapest and most available solution is buying speaker cable, and the plug is not a normal 12 V / 24 V cigarette lighter plug as they can's stand more than 12 A – instead I use SpeakON STX series plugs from PA / music equipment, which can stand 40 A normally and 70 A when using all four pins and a special cascading fuse setup ­– also these plugs are rainproof and made from sturdy aluminium, I really like them.

2016-05-29.MyMeal.1024x768

(5) Have a meal right in the middle of your home construction site mess and wonder if it will ever be a "normal" place to live. Just in that last unsuspecting picture, there are some more not-so-normall things to observe when you look closely:

  • I might find a bench vise next to the food. Perfectly normal here. Because it is not fixed, it can move. I mounted it on a small base plate and it likes to move around a lot …
  • There are two boxes of small drills and milling bits for a rotary tool that I found, fixed and converted to be "sun powered" as well. Just use any adjustable 24 V DC-DC notebook adapter fitting for the input voltage of the rotary tool, and make a power tip adapter from an exchangeable tip of the notebook adapter which you don't need for your own notebook …
  • Then ther's my own notebook, and if you look closely to the back left of it, you see a DC plug that has been tampered with. I had to make my own DC tip because it was impossible to buy a 24 V DC-DC converter coming with the right tip … . But it works flawlessly now, means it's a "sun computer" (minuscle s!).
  • There's a PUR foam insulation block I use in the window over the winter and also as an improvised curtain in the evening. It helps, but I should cover it with something pretty I guess frown
  • There's a wood stove with an orange metal belt made from the roof of an old street roller, keeping it to the wall.
  • Fork and spoon are used ones from German Army, produced sometime in the mid 1960s. Very sturdy, available for cheap on eBay, and they can be neatly arranged for transport when travelling with a backpack.
  • There's a battered table that is at least 35 years old (I know becaus it's from my childhood … hehe), now featuring a line of holes at the back by which it holds on to the grid hole system I use in the truck (compatible with OpenStructures and Gridbeam).

Hope you enjoyed being introduced to some of the not-so-normal objects in my home … many more waiting in the line, it's literally full of them here. As you saw, I rather build something from trash metal or pre-owned stuff than spending money to buy it. And srsly, I don't care how these things look, just that they work, don't break, and don't cost much. To me, every alternative is so much better than forced labor in a nonsensical fulltime job just to have money for buying shiny new things.

Powerline is a technology for transmitting data over the AC grid. All devices provide an RJ45 Ethernet plug (and some also wifi and USB), so they support client devices of all operating systems. Basic configuration of encryption is likewise OS independent, as nearly all of them use a "pairing" button for that. However, to set the encryption key manually, to make more detailed settings, to read out speed statistics and to update the firmware most come with configuration tools that only work under Windows.

So, can we find a device that can be fully managed under Linux, ideally with free software? After a long search, this turns out to be a simple task. Just use any device that supports the Homeplug AV or Homeplug AV2 standard, and manage it with Open PLC Utils, a free software full-featured management tool developed by AV/AV2 chipset maker Atheros. It  allows full device configuration, info reading and upgrading for all INT6000/6300/6400/AR7420 devices, even tampering with the parameter set in the firmware. The only alternative are DS2 chipset based devices, since at least most of them can be fully configured via a built-in web interface (such as the COMTREND Powergrid 9020, their most modern device). However, a tool like Open PLC Utils is preferred here since it effectively replaces a part of the DS2 management software with free software, allowing scripting, modifications etc., and is more powerful in general.

Recommendable devices

It is said that it does not matter so much in terms of connection speed and quality which exact device you choose, as long as you choose the right chipse. Here, we focus on the Homeplug AV chipsets (INT6000, INT6300, INT6400) and there on the most modern one (INT6400). We avoid the Homeplug AV2 chipsets because they seem not yet mature (see below) and the DS2 chipsets because they are not as readily configurable under Linux.

Recommendation for Germany: Speedport Powerline 100. The best recommendation is so far: Telekom Speedport Powerline 100. It has the INT6400 chipset (most modern one for the Homeplug AV 200 Mbit/s devices), and it is dirt cheap (ca. 20 EUR incl. shipment for a pair of them, via ebay.de) because Telekom made Germany awash with these devices. It also is good quality, since it is a whitelabel product from well-known French brand LEA Networks – see also the very detailed test on tomsnetworking.de (in German). One can use the LEA-made software tool SOFTPLUG for settings beyond simple pairing for encryption, but it runs only under Windows. It is not needed however, as the free software tool Open PLC Utils can likewise be used, also running under Linux.

Discussion of alternatives: Devolo dLAN AVsmart+. These devices are quite nice, as they have an extended status display on the device – compare the manual. They are also readil available in used condition on eBay, but not as dirt cheap as the Speedport Powerline 100. However, they use the older INT6000 chipset [source], leading to a third less speed in long-range applications [source].

Discussion of alternatiives: COMTREND PowerGrid 9020. This is not a Homeplug AB/AV2 device, but uses the non-interoperable DS2 chipset. Reviews on Amazon are good. However, it can be fully managed under Linux as all settings are available within a web interface, as argued for and against above. The Powergrid 9020 is the most modern Powerline device of Madrid-based manufacturer COMTREND so far, and avaible in UK and Europe type plug versions. The UK plug versions are very readily available online, as they are provided by UK based large ISP Britich Telecom (BT) to their customers. The Europe plug versions are quite hard to find though (but here are some). Also see the installation guide and the  full manual.

Discussion of alternatives: Homeplug AV2 devices. There are the even more modern 500 Mbit/s Homeplug AV2 devices (using the AR7420 etc. chipsets), however as of 2014-09 this generation of technology seems to not be mature still, often suffering from connection breakdowns, low throughput, the devices running hot etc. (as judged from reviews on Amazon). So we avoid them here, also because they are still more expensive on the second-hand market. But your priorities and mileage may vary. They also can be fully managed with Open PLC Utils.

Linux software for powerline adapters

While Open PLC Utils is clearly the winner, the following list is all the Linux-based powerline software I came across:

  • Open PLC Utils. As said, clearly the winner: full-featured and free software.
  • Faifa. A manufacturer independent, free software Homeplug AV/AV2 utility for Linux. Allows low-level functions such as control frame dumps. Considered to be the successor to the older plconfig utility, see below.
  • plconfig. An older, simple Linux based configuration utility. For download on Github. Superseded by Faifa now.
  • dlanlist, dlanpasswd. Open source software that can be downloaded and compiled under Linux and is meant to list (and set the password of) Devolo dLAN devices. Since these conform to the Homeplug AV/AV2 standard, the software might be used to also configure other devices, after some simple modifications.
  • devolo Cockpit. A large configuration softwre for Devolo dLAN devices. Seemingly not available as a source version, so adaptations to other devices are not possible.
  • Intellon device manager for 3.x firmware (Windows software). Allows full management of INT6x00 chipset devices when using a 3.x firmware version, incl. editing firmware parameters. Its use is described in this article.
  • Intellon device manager for 4.x firmware (Windows software). In contrast to the version for 3.x firmwares, this does not support full management of the of INT6x00 chipset devices any more.

Background information

The following in-depth articles provide relevant background information about Powerline technology and their successful use:

Modding and hacking powerline adapters

At 10 EUR for a used device or less, powerline adapters are so cheap that they offer themselves to several non-standard uses. At least teh following come to mind:

  • Powerline noise filters. Devices that include an AC plug with noise filter (such as the SpeedportPowerline 100 recommended above) are the cheapest option to use them as frequency filters to prevent contamination of the 50 Hz frequency from other digital devices, mobile phone chargers etc..
  • Powerline bridge. It is also possible to create a simple bridge by connecting two of them with a crossover Cat5e cable (or a bridge device in between, if necessary). This should allow crossing phase boundaries in the home cabling, if necessary.
  • VDSL P2P modem replacements. And then, of course, these cheap devices are a natural candidate for creating a cheap DIY replacement for pairs of VDSL modems (usually 150 EUR per piece!). It works by connecting twisted phone wire to the signal (via soldering) before it gets modulated on the AC mains power. It is possible to use this for transmitting data over several hundred meters at least.

 

This applies for example when you want to add a photovoltaics installation to your campervan, expedition vehicle, garden hut, off-grid house or similar. For having enough electricity year-round from photovoltaics alone, battery size and module size have to be properly dimensioned.

The best tool I found for this is the European Commission JRC's PV potential estimation utility. There, use the last tab "Stand-alone PV".

Note that that the tilting angle of the solar panels is important in winter. Differences of up to ca. 30° from the optimum have no large effect, but above that they get quite important. So having an angle of 0° (flat panels) while you should have an angle of 74° (Germany in winter for example) means you get only about 25% of the power you would get at a 74° angle. You can calculate the exact numbers for this with the SunAngle calculator.

Disclaimer due to legal implications: The following is not to be understood as legal or tax advice. I just document what I found out by my own research for myself, not intending that you try to do it likewise. There is no warranty for adequacy, correctness, or anything else.

As a practicioner of a voluntary simplicity lifestyle (and yes, I love tech), I am troubled with the German health insurance legislation. Self-employed people like me pay public health insurance fees for a so-called “fictional minimum income” even if they don’t earn that or (like me) don’t even want to earn that. So my propoportional pay for health insurance was way higher than the regular percentage. I have to do something about this, and here’s the list of possible solutions I found. It’s a complex issue, like everything in German society laugh

The problem for self-employed people really started in 2009-01-01, when a law came into effect that required plain everybody living in Germany to have health insurance [§ 193 Abs. 3 S. 1 VVG], which depending on ones job type and status would be public or private health insurance [source]. Simply having no health insurance is no longer possible – you can only cancel health insurance when showing that you just switch the insurer, and an insurer will require you to also pay aftwerwards for your uninsured times when taking you in.

The problem gets even more severe because the public health insurers have a rigid and merciless scheme of encashment, some essentially threatening legal enforcement when being 9 days behind the payment’s due date, and even sending toll collectors for seizing. They tell such people they can always apply to German Jobcenter for the Hartz IV public benefit money, but as you all know, your life (life quality) is over once you enter into that … . So this kind of health insurance is essentially a humiliating and stressing experience, which is another reason why I find ways to work around this.

Normal health-insurance fees for self-employed in Germany

The normal fees for self-employed persons, from 2015 on, are:

  • 14.6% normal health insurance rate
  • + 0.9% additional health insurance rate (de: “Zusatzbeitrag”) – in principle charging this or not can differ between health insurers based on competition, but in reality it does rather not …
  • + 2.35% for old-age care insurance [source]; was 2.05% in 2014
  • + 0.25% for old-age care insurance when not having children [source]
  • = 18.1%

When being self-employed, they have to be paid from a fictional minimum income of at least 1417.50 EUR as of 2015, even if not making that (so called “Mindestbemessungsgrundlade”, earlier called “fiktives Mindesteinkommen” or “virtual minimum income”, regulated in SGB V §240 (4); you calculate it for every year as 0.5 × Monatliche Bezugsgröße, using the value for West Germany). And even this is a variant “for self-employed persons in need”. This fictional minimum income tends to be increased by 40-50 EUR a year, or about 3%: much higher than current inflation or wage increase, making the situation even worse year by year. Now on to solutions:

Ways to reduce health-insurance fees for self-employed in Germany

As of 2014-11, sorted by adequacy, the best solution first.

  1. Side-job self-employment without other income. As of 2015, this results in health insurance and old-age care insurance minimum fees of (combined) 171.05 EUR/month (calculated as 945 EUR × 0.181, which assumes the 0.9% Zusatzbeitrag and a childless person). It is the same rate as for all other “voluntary” members of German public health insurance, which is a way to look up the current fee for this category, which is often not published elsewhere. The 945 EUR is the “virtual minimum income”, itself calculated as (1/3) × Monatliche Bezugsgröße [source], in 2015: (1/3) × 2835 EUR = 945 EUR. When exceeding this virtual minimum income (also called “Allgemeine Mindestbemessungsgrundlage” – source), the insurance fees increase proportionally.
    Since a change in the self-imposed rules of health insurers (“Gemeinsames Rundschreiben der Träger der gesetzlichen Sozialversicherung vom 11.06.2013: Grundsätzliche Hinweise zum Begriff der hauptberuflich selbstständigen Tätigkeit“) to determine the self-employment status of people, which became effective 2013-07-01, this setup is quite simple and reliably to achieve and is the preferred option.
    This status and fee is granted if the self-employment is not considered as ones main job. As per the rules referenced above, this required a second major source of income that is at least 83.33% (100 of 120 parts) of the income from self-employment [source, section 3.2.3]. However, starting around 2015 some health insurers started to regularly accept people as side-job self-employed without them having a different “main source of income”, simply because they were reporting to work part-time (it worked this way at least up to 30 hours weekly). I assume this is the new official regulation now, so there is no need to look for another “main source of income”.
  2. Side-job self-employment while listing a different main source of income. In case the previous proposal of not listing any other income does not work out for you to be considered side-job self-employed, you may read on about this proposal for creative ideas to have the required different “main source of income”. (It’s simpler to just try another health insurer though, most should now use the guidelines on which the first proposal above is based).
    So: If you need to show a different “main source of income”, this requires a second major source of income that is at least 83.33% (100 of 120 parts) of the income from self-employment [source, section 3.2.3]. This figure is however just for orientation, so it’s better to err on the safe side and have a second source of income that is larger than ones income from self-employment – which we’ll use below. The simplest and safest way to prove such a second source of income is if it is contained in ones income tax statement under “other income”. So if possible with no or minimal income tax implications, it makes sense to “voluntarily” list all other sources of income in ones income tax declaration, even if not required as they are income tax exempt (like fees below the 720 EUR honorary office exemption limit, profit from Bitcoin speculation after a holding period of a year etc.). In addition, ones income from self-employment should not exceed 673.75 monthly (25% of monatliche Bezugsgrößesource) if taking >30 hours weekly, or more relaxed values for less time invested, or else the health insurer will regularly assume that ones self-employment is the main source of ones income. This can be challenged as per these rules (section 3.2.3) by proving that ones second source of income is the major one, but again, it’s simpler and better to err on the safe side.
    Now how to have that “major source of income” beyond your self-employment? Here are some creative options, and there are many more:

    • Donations for private projects. This is quite a wild construction, but sounds reasonable to me. Here is how it works: if you do a non-commercial hobby project, making carefully sure that it does not make a gain, this is not a company, but a private project. So if you collect donations for this, for example via crowdfunding, they are private income, to be stated under “other income” in your income tax statement. You just have to make sure that you don’t profit personally (by buying food etc.), as that would make the project profit oriented, part of your company. Use all the donations for the project itself, and collect receipts to prove it. It is not difficult to collect a few thousand Euros a year in donations for a project with collective benefits that you would have liked to work on anyway. Think open source, open content, open hardare etc.. Even better, since in-kind donations have to be stated with their monetary value in an income tax statement, you can also use moneyless crowdfunding (like on Makerfox). Collecting donations in-kind should be even much simpler than collecting monetary donations, as money is always scarce for the 99%. In effect, you would add donation income on top of your monetary income, and the effect is both reducing your health insurance, increasing your spendable monetary income, and enabling you to work on what you love to do anyway (with the donations).
    • Profit from private sales. As a solo entrepreneur, it is still possible to sell private goods at the same time, also with a profit [source]. It must be in the scale of private wealh management, not a professional activity itself though. Profit from this would be stated in the “other income” section of your income tax statement, and that is what we want. See Wikipedia on Privates Veräußerungsgeschäft for details. To increase your “other income”, you may want to report even profits that are income exempt due to a holding period of a year or longer (of your Bitcoins etc.). The benefit with here is that one can realize any desirable amount of gain on demand, depending on how much other income one needs, and under the condition that one holds profitable assets.
    • Honorary office fees offset by donations. I did not fully think this through, but there is an option (called Aufwandsspende) how people in a honorary office can make donations from what they would be entitled to get (expense remuneration, honorary office fee etc.). So no money has to flow, as it increases your income and your expenses at the same time, but the recipient organization legally must have the liquidity to pay the fees. The expenses are even tax-deductible donations up to 20% of the stated income.
    • Personal gifts. This is quite an elegany solution if you know a donor 🙂 Because donations have high income tax exemption limits [source] and would be in your “other income” section. They must be unconnected to your business activity, of course, and not require something in compensation from you. (So unfortunately, it is not legally permissive to agree to “gift back” every other year.)
    • Mini job. A mini job (≤450 EUR/month) does not come with its own health insurance, but can still serve as your other major sourcee of income to prove that your self-employment is not your main job.
    • Spouse’s income. [source, example]
    • Housewife as a job. Stating that ones main job is “housewife” [discussion]. It would be quite similar to stating that ones other major income is support from ones spouse.
    • Credit. A credit from somebody; just an unproven wild idea though.
    • Proof by necessity. Or maybe you can try to explain to your insurer that you get these by getting non-cash benefits from friends and relatives or other supporters (like free food & stay for volunteer services) or that you get these means of subsistence by being modest and forgoing them – just say that they have to assume that the majority of means has to come from another source because nobody can live from what you live 😉 But that’s just a wild guess, you’d have to try.
    • Grants, awards, prize money. This is not a workable option because: all grants, award and prize money that are connected to what you do professionally as a self-employed person have to be entered into your income tax statement as business turnover [source]. So they won’t appear under “other income”. Only if the award is paid for ones personality, it would be non-business income. But for example all awards that have an application process are usually assumed to be connected to professional activity [source]. So they are income-taxable business income even though most awards are not VAT taxable [source].
  3. Go abroad and use a travel health insurance. For this to work, it seems one has to leave the European Union and also cannot go to several other countries with which Germany has some health insurance related association agreement. Because when staying there and still having the regular residence inside Germany, one still has to pay German health insurance fees and will not be “let out” of German compulsory health insurance. The list of the countries where such an agreement exists is here – it is for pensioners’ health insurance, but probably applies also to other cases (to be confirmed, though).
  4. Emigrate to a country with a national health system. This simply means, go abroad and also have your registered permanent residence there abroad. Then, one has nothing to do any more with the German health insurance system, instead paying into the one at ones location. And by selecting a country with a national (that is, tax subsidized) health system, this is much cheaper. For example, Italy or UK. It can be a bit complicated still to leave German compulsory health insurance since you will have to show a follow-up insurance (b/c you still reside in the EU) and the new insurance may require a confirmation of canceling your old one (which you cannot get before getting the new one …), but it can be worked out somwhow.
  5. Foreign national health insurance while in Germany. This is possible if that public or private foreign health insurance covers your medical needs while you are in Germany. Because then, you have fulfilled the need to have a health insurance within Germany.
  6. Foreign national health insurance abroad. This may be a public or private insurance scheme. Some countries like Spain have astonishing low fees for private health insurance, compared to German levels.
  7. Midi-job plus mini-job plus side-job self-employment. This is the ultimate way of low health insurance fees when living inside Germany and being self-employed. Namely, for 7.6% of 450.01 EUR (which is the employee’s part of the 14.9% rate without sick pay). Which is 34.20 EUR per month, and the employer will pay approx. the same again. The monthly earnings possible with this scheme are: ca. 412 EUR net income from the midi job (2013 numbers), 400 EUR net income from the mini job, and 800 EUR net income from side-job self-employment. Because if your self-employment is a side job, you don’t have to pay health insurance for that part of your work, but for your midi job employment instead. The incom from self-employment is calculated from a yearly average, and only 18 hours per week of worktime are allowed for it to be a side job (to-do: source for this).
  8. Employee job plus side-job self-employment. As an employee, you pay no additional health-insurance fee at all for a side-job self-employment (see however the conditions for this above). So in most cases, this will result in lower total fees, even when including the other social security fees you’ll pay then.
  9. Self-employed with bulking up by public benefits (“Aufstocker”). This is done by approx. 1.4 million people in Germany, see Wikipedia on Aufstocker. In general, public benefits will bulk up what people do not earn in a month to secure their minimum for existence. It can include to have the health insurance paid by the state benefits, and in pratice can be a kind of “unconditional basic income”. But like all kinds of public benefits, this is really the last variant to choose.
  10. Self-employed person “in need”. In German, “bedürftiger Selbständiger”. Self-employment can be your main job then. This rate is the one I mentioned above: 14.9% of 1347.50 EUR virtual minimum income for health insurance, 2.3% of that for pension care insurance. Taken together, ca. 232 EUR as of 2013. This rate was introduced 2007-04-01, and was a progress at that time as before that the minimum fee was about 300 EUR.
  11. Sue the government for the law that calculates health insurance fee based on a virtual minimum income. You’d sue against SGB V §240 (4). This has, in my view, no or very little chance for success because this case was basically decided by the highest court in Germany (BVerfG) in their decision of 2001-05-22 – 1 BvL 4/96. I read through that court decision, and newer changes in law seem to not affect their reasoning.
  12. Time-series combination of these solutions. The most flexible way is, of course, to use the solution from the above list that is most adequaate for you at any given time. Note that you can switch between rates of the same public health insurer as often as you like – switching insurers is only possible every 18 months though.

Keywords (for Germans searching in German): Krankenversicherung als Selbständiger, Krankenversicherung nebenberuflich selbständig, günstige Krankenversicherung selbständig

This is quite some stuff to work through, because everything in Germany is complex 😀

Travel health insurance or the foreign national health insurance?

This will depend on the legislation in that country, and on what type of job status you will have there. For example for Spain, when being employed or self-employed there, you have to be part of the Seguridad Social public health insurance system and pay fees there (though only ca. 50 EUR monthly) [source]. If you want to avoid that and still want to work, you may have have your business registered in your country of origin and only work telecommute jobs – should generate no problems, though I have no experience with that so far.

When not being part of the foreign national health insurance system, you can get insurance from a private health insurer – either a regular rate that covers also costs abroad, or a specialized travel health insurance (which will be cheaper in nearly all cases).

Selecting an adequate insurer

I have no experience with any of the below, but they'd be the first I would look into.

Travel health insurances:

  • Auslandsreiseversicherung der HANSEMERKUR Reiseversicherung. As offered by Mawista GmbH as an intermediate, for example. The special thing about them is that this insurance is possible for up to 5 years in a row, while most other insurers only have a max. duration of one or three years. Costs are a bit higher though, normally 59 EUR monthly (18 – 65 years, without U.S. and Canada).

How to re-enter German health insurance

Once returning to Germany, you have to re-enter the German health insurance system (except you can keep your existing health insurance, which is for example normally possible with travel health insurances for 6 – 12 weeks a year). Here are several options how to re-enter the system, by adequacy:

  1. As self-employed person: "voluntarily insured member" in public health insurance. This is generally the most recommendable variant. However, public health insurers have to accept you only if you have enough pre-existing health insurance time (de: Vorversicherungszeit). They might still accept you if not, but it's not guaranteed by law. If they do not accept you, you would have to enter private health insurance, given the obligation to have health insurance while in Germany.
    The required pre-existing health insurance time is 24 months within the last 5 years [SGB V §9 (1) 1.] This refers to times in the public health insurance only [source], but that should be confirmed again. So when going abroad after 24 or more months of public health insurance, you can stay 3 years without caring about re-entering. To keep your right to re-enter while staying abroad after that, you can re-enter as a voluntarily insured member without entitlement to benefits (because you are abroad). This will cost you about 40 EUR monthly – 2695 EUR * 10% * 14.9% as of 2013 [SGB V §240 (4a), compare Bezugsgröße]. I guess this is what public health insurers usually call "prospective entitlement insurance" (de: Anwartschaftsversicherung). They usually want to tell you to get that type of insurance immediately when going abroad, but that's only needed after three years as reasoned for above.
  2. As non-employed person. Even without entitlement to become again voluntarily insured in a German public health insurance, you can enter it by leveraging the very law that obliges everybody in Germany to have health insurance since 2009. For that, you have to cancel your self-employment when coming back to Germany, and not take on an employee job either. This makes you a person with obligation to get public health insurance according to SGB V §5 (1) 13. a), and any public health insurance has to take you in. This is sometimes called "Versicherung der ansonsten Nichtversicherten", "Auffangsversicherung" or "Bürgersicherung" in Germany. The rate is the same as for other voluntarily insured members, ca. 130 EUR monthly.
  3. As employee. This is the simplest case, as all employees are obligatorily insured in the German public health insurance. However, former self-employed people won't like this 😉
  4. Other options. See the publication "Mitgliedschaft in der gesetzlichen Krankenversicherung nach Auslandsrückkehr" by German Ministry of Health.