Off-Grid Electricity And Hot Water From Scrap Wood

Cooking with charcoal is a fairly common human activity, as much as others have come to prefer fuels like propane and propane accessories for their outdoor, summertime grilling. Although it’s made from wood, it has properties that make it much more useful for cooking — including burning at a higher temperature and with more consistent burn rates. It can also be used as a fuel for generating heat and electricity, but since it’s not typically found lying around in the forest it has to be produced, which [Greenhill Forge] has demonstrated his charcoal production system in one of his latest videos.

The process for creating charcoal is fairly simple. All that needs to happen is for wood to be heated beyond a certain temperature in the absence of oxygen. At this point it will off-gas the water stored in it as well as some of the volatile organic compounds, and what’s left behind is a flammable carbon residue. Those volatile organics are flammable as well, though, so [Greenhill Forge] uses them to heat the wood in a self-sustaining reaction. First, a metal retort is constructed from a metal ammo box, with a pipe extending from the side and then underneath the box. A few holes are drilled in this part, and the apparatus is mounted above a small fire on a metal stand. With the fire lit the wood begins heating, and as it heats these compounds exit the pipe and ignite, adding further fuel to the fire. Eventually the small fire will go out, allowing the retort to heat itself on the gasses released from the wood alone.

To generate the hot water, [Greenhill Forge] has taken an extra step and enclosed the retort in a double walled metal cylinder. Inside the cylinder is a copper tube packed in sand, which harvests the waste heat from the charcoal production for hot water. In his test runs, the water in a large drum was heated to the point that the tubing he used for the test began to melt, so it is certainly working better than he expected.

After the retort cools, [Greenhill Forge] uses the charcoal in another process that generates about a days’ worth of electricity and hot water. It’s part of a complete off-grid system that’s fairly carbon neutral, since trees are an abundant renewable resource compared to fossil fuels. Heating with wood directly is still common in many cold areas around the world, with the one major downside being the labor required to keep the stove running. But we’ve seen at least one project which solves this problem as well.

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The Only Snail You Want In Your Garden Is A Seed-Starting Hack

As temperatures warm up in the Northern Hemisphere, one’s mind naturally turns to the outdoors and the garden — even if some of our gardens are still snow-covered. One secret to good gardening is that many of the plants we love take too long to grow if started from seed outside, at least in relatively temperate climes. There are a myriad of ways to grow seedlings indoors, and this new hack highlighted by [GrowVeg] looks like a great way to get started.

The idea apparently comes from the seedier side of Instagram, where [Farida Sober] has been popularizing it as a “seed snail”, a name they seem to have coined. The technique is very simple: take a sheet of something cheap that won’t disintegrate when moist like bubble wrap or cardboard, layer it with soil — up to 5 cm depending on your seed size — and you roll the whole thing up like a piece of sushi to produce the spiral shape that gives the hack its name. With a piece of tape to hold the roll, it’s just a matter of planting your seeds according to the packet directions. If that’s clear as mud, check out the video embedded below.

Once the seedlings have grown, it looks like it will be very easy to unroll the spiral and pluck them out to plant in the ground or bigger pots without overly traumatizing their roots, like we always do starting in flats. If it weren’t for those delicate roots, it certainly looks like the snail might save some space compared to, say, peat pots. Just remember that starting under the proper LEDs can make a huge difference to how quickly your seeds grow. No dirt? No problem — once sprouted, your plants can be made to grow hydroponically. For the really adventurous, there’s even aeroponics.

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The S2000 at a much lower altitude than 2000 m.

Wind Power Is Taking Off In China– All The Way To 2000 M AGL

2000 m above ground level (AGL), winds are stronger and much, much more consistent than they are at surface. Even if the Earth were a perfect sphere, there’d be a sluggish boundry layer at the surface, but since it’s got all these interesting bumps and bits and bobs, it’s not just sluggish but horribly turbulent, too. Getting above that, as much as possible, is why wind turbines are on big towers. Rather than build really big tower, Beijing Lanyi Yunchuan Energy Technology Co. has gone for a more ambitious approach: an aerostat to take power from the steady winds found at high altitude. Ambitiously called the Stratosphere Airborne Wind Energy System (SAWES), the megawatt-scale prototype has recently begun feeding into the grid in Yibin, Sichuan Province.

The name might be a bit ambitious, since its 2000 m test flight is only one tenth of the way to the stratosphere, but Yibin isn’t a bad choice for testing: as it is well inland, the S2000 prototype won’t have to contend with typhoons or other ocean storms. The prototype is arguably as ambitious as the name: its 12 flying turbines have a peak capacity of three megawatts. True, there are larger turbines in wind farms right now, but at 60 m in length and 40 m in diameter, the S2000 has a lot of room to grow before hitting any kind of limit or even record for aerostats. We’re particularly interested in the double-hull construction– it would seem the ring of the outer gas bag would do a good job funneling and accelerating air into those turbines, but we’d love to see some wind tunnel testing or even CFD renderings of what’s going on in there.

A rear view shows the 12 turbines inside the double hull. It should guide air into the gap, but we wonder how much turbulence the trusses in there are making.

During its first test flight in January 2026, the system generated generated 385 kilowatt-hours of electricity over the course of 30 minutes. That means it averaged about 25% capacity for the test, which is a good safe start. Doubtless the engineers have a full suite of test flights planned to demonstrate the endurance and power production capabilities of this prototype. Longer flights at higher capacity may have already happened by the time you read this.

Flying wind turbines isn’t a new idea by any means; a few years ago we featured this homemade kite generator, and the pros have been in on it too. Using helium instead represents an interesting design choice–on the plus side, its probably easier to control, and obviously allowing large structures, but the downside is the added cost of the gas. It will be interesting to see how it develops.

We’re willing to bet it catches on faster than harvesting wind energy from trees.

All images from Beijing Lanyi Yunchuan Energy Technology Co., Ltd.

 

Making Effective, Affordable Water Level Monitors

Water wells are simple things, but that doesn’t mean they are maintenance-free. It can be important to monitor water levels in a well, and that gets complicated when the well is remote. Commercial solutions exist, of course, but tend to be expensive and even impractical in some cases. That’s where [Hans Gaensbauer]’s low-cost, buoyancy-based well monitor comes in. An Engineers Without Border project, it not only cleverly measures water level in a simple way — logging to a text file on a USB stick in the process — but it’s so low-power that a single battery can run it for years.

The steel cable (bottom left) is attached to a submerged length of pipe, and inside the cylinder is a custom load cell. The lower the water level, the higher the apparent weight of the submerged pipe.

The monitor [Hans] designed works in the following way: suspend a length of pipe inside the well, and attach that pipe to a load cell. The apparent weight of the pipe will be directly proportional to how much of the pipe is above water. The fuller the well, the less the pipe will seem to weigh. It’s very clever, requires nothing to be in the well that isn’t already water-safe, and was designed so that the electronics sit outside in a weatherproof enclosure. Cost comes out to about $25 each, which compares pretty favorably to the $1000+ range of industrial sensors.

The concept is clever, but it took more that that to create a workable solution. For one thing, space was an issue. The entire well cap was only six inches in diameter, most of which was already occupied. [Hans] figured he had only about an inch to work with, but he made it work by designing a custom load cell out of a piece of aluminum with four strain gauges bonded to it. The resulting sensor is narrow, and sits within a nylon and PTFE tube that mounts vertically to the top of the well cap. Out from the bottom comes a steel cable that attaches to the submerged tube, and out the top comes a cable that brings the signals to the rest of the electronics in a separate enclosure. More details on the well monitor are in the project’s GitHub repository.

All one has to do after it’s installed is swap out the USB stick to retrieve readings, and every once in a long while change the battery. It sure beats taking manual sensor readings constantly, like meteorologists did back in WWII.

Electronic headstones. The first with an image of a circular lamp on a table. Text reads: "Halo Rise, Amazon, September 2022-August 2023, 0.9 years, Stopped offering cloud support (quick death)" Second is an image of a disassembled countertop appliance. Text reads: "Juicer, Juicero, March 2016-September 2017, 1.3 years, Change in business model/financial reasons" Third is an image of a black TV remote with the text: "Harmony Express, Logitech, April 2019-September 2020, 1.4 years, Stopped offering cloud support (quick death)"

Electronic Waste Graveyard Immortalizes Dead Electronics

Everyone here can think of a cloud-connected product that was killed because the company that made it stopped supporting it. While these corporations have forgotten their products, the US PIRG Education Fund has immortalized them in their Electronic Waste Graveyard.

With an estimated “130,000,000 pounds of electronic waste” produced since 2014, the amount of wasted resources is staggering. The advent of the cloud promised us reduced waste as lightweight devices could rely on remote brains to keep the upgrades going long after a traditional device would have been unable to keep up. The opposite seems to have occurred, wreaking havoc on the environment and pocketbooks.

Of course, we can count on hackers to circumvent the end of companies or services, but while that gives us plenty of fodder for projects, it isn’t so great for the normal folks who make up the rest of the population. We appreciate PIRG giving such a visceral reminder of the cost of business-as-usual for those who aren’t always thinking about material usage and waste.

If PIRG sounds familiar, they’re one of the many groups keeping an eye on Right-to-Repair legislation. We’ve been keeping an eye on it too with places like the EU, Texas, and Washington moving the ball forward on reducing e-waste and keeping devices running longer.

DIY, Full-Stack Farm Automation

Recently, [Vinnie] aka [vinthewrench] moved from Oregon to Arkansas to start a farmstead. This is a style of farming that focuses not just on a profitable farm where produce is sold at market, but also on a homestead where much of one’s own food is grown on the farm as well. Like any farm, though, it’s extremely hard work that takes a tremendous amount of time. Automation and other technology can make a huge impact in these situations, and [Vinnie] is rolling out his own software stack to help with this on his farm.

He calls his project the Pi Internet of Things, or PioT, and as its name suggests is based around the Raspberry Pi. Since this will all be outdoors and exposed to the extremes of Arkansas weather, everything built under the auspices of this project prioritizes ruggedness, stability, and long-term support, all while avoiding any cloud service. The system also focuses on being able to ride through power outages. The server side, called piotserver, uses a REST API to give the user access to the automation systems through a web interface

[Vinnie] also goes into detail about why existing systems like Home Assistant and Open Sprinkler wouldn’t work in his situation, and why a ground-up solution like this is more appropriate for his farm. This post is largely an overview of his system, but some of his other posts go into more detail about things like integrating temperature sensors, rainfall monitoring, controlling irrigation systems, and plenty of other farm automation tasks that are useful for any farmer or gardener.

We’ve also seen some other projects of his here like this project which converts a common AC sprinkler system to an easier-to-use DC system, and a DIY weather station that operates in the 915 MHz band. He’s been a great resource for anyone looking to have technology help them out with their farm or garden, but if you’re just getting started on your green thumb be sure to take a look at this starter guide as well.

The Many Questions And Challenges With DIY Hydroelectric Generators

The concept of building your own hydroelectric generator seems simple at face value: use gravity to impart as much force as possible onto a turbine, which spins a generator, thus generating electricity. If you’re like the bloke over at [FarmCraft101] trying to DIY this with your farm pond and a lot of PVC pipes, you may have some significantly more in-depth questions, especially pertaining to what kind of generator to use. This and other questions, some of which were raised after the previous video in which the first prototype generator was assembled, are answered in this follow-up video.

When you DIY such a hydroelectric system, you have a number of options when it comes to just the turbine design alone, with the Kaplan-style turbine being one of the most straightforward ones – especially if you use a fixed pitch instead of adjustable – but you can go pretty far in the weeds with alternatives. As for the sharp drop-off after the turbine in the used design, the technical term is a draft tube, which is actually more efficient in this kind of low head, high flow hydroelectric dam situation.

After getting his money back for the unusable ‘3 kW’ generator, there were three options left: try an EBay special, get a purpose-built one from a US company, or rewind an alternator stator for higher voltage output than the standard 12/24V. Ultimately option four was chosen, as in ‘all of the above’, so that comparison is coming upĀ  in a future video.

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