On the face of it, harnessing wind power to heat your house seems easy. In fact some of you might be doing it already, assuming you’ve got a wind farm somewhere on your local grid and you have an electric heat pump or — shudder — resistive heaters. But what if you want to skip the middleman and draw heat directly from the wind? In that case, wind-powered induction heating might be just what you need.

Granted, [Tim] from the Way Out West Blog is a long way from heating his home with a windmill. Last we checked, he didn’t even have a windmill built yet; this project is still very much in the experimental phase. But it pays to think ahead, and with goals of simplicity and affordability in mind, [Tim] built a prototype mechanical induction heater. His design is conceptually similar to an induction cooktop, where alternating magnetic fields create eddy currents that heat metal cookware. But rather than using alternating currents through large inductors, [Tim] put 40 neodymium magnets with alternating polarity around the circumference of a large MDF disk. When driven by a drill press via some of the sketchiest pullies we’ve seen, the magnets create a rapidly flipping magnetic field. To test this setup, [Tim] used a scrap of copper pipe with a bit of water inside. Holding it over the magnets as they whiz by rapidly heats the water; when driven at 1,000 rpm, the water boiled in about 90 seconds. Check it out in the video below.

It’s a proof of concept only, of course, but this experiment shows that a spinning disc of magnets can create heat directly. Optimizing this should prove interesting. One thing we’d suggest is switching from a disc to a cylinder with magnets placed in a Halbach array to direct as much of the magnetic field into the interior as possible, with coils of copper tubing placed there.

There’s no shortage of Geiger counter projects based on the old Soviet SBM-20 tube, it’s a classic circuit that’s easy enough even for a beginner to implement — so long as they don’t get bitten by the 400 volts going into the tube, that is. Toss in a microcontroller, and not only does that circuit get even easier to put together and tweak, but now the features and capabilities of the device are only limited by how much code you want to write.

Luckily for us, [Omar Khorshid] isn’t afraid of wrangling some 0s and 1s, and the result is the OpenRad project. In terms of hardware, it’s the standard SBM-20 circuit augmented with a LILYGO ESP32 development board that includes a TFT display. But where this one really shines is the firmware.

With the addition of a few hardware buttons, [Omar] was able to put together a very capable interface that runs locally on the device itself. In addition, the ESP32 serves up a web page that provides some impressive real-time data visualizations. It will even publish its data via MQTT if you want to plug it into your home automation system or other platform.

Between the project’s Hackaday.io page and GitHub repository, [Omar] has done a fantastic job of documenting the project so that others can recreate it. That includes providing the schematics, KiCad files, and Gerbers necessary to not only get the boards produced and assembled, but modified should you want to adapt the base OpenRad design.

This project reminds us of the uRADMonitor, which [Radu Motisan] first introduced in 2014 to bring radiation measuring to the masses. This sort of hardware has become far more accessible over the last decade, bringing the dream of a globally distributed citizen-operated network of radiation and environmental monitors much closer to reality.

Recently ESA published the results of a proof-of-concept study into monitoring marine litter using existing satellites, with promising results for the Mediterranean study area. For the study, six years of historical data from the Sentinel-2 satellite multispectral imaging  cameras were used, involving 300,000 images with a resolution of 10 meters. The focus was on litter windrows as common collections of litter like plastic, wood and other types of marine debris that float on the surface, forming clearly visible lines that can be meters wide and many times as long.

These were processed as explained in the open access paper in Nature Communications by [Andrés Cózar] and colleagues. As marine litter (ML) tends to be overwhelmingly composed of plastic, this eases the detection, as any ML that’s visible from space can generally be assumed to be primarily plastic litter. This was combined with the spectral profile of common plastics, so that other types of floating materials (algae, driftwood, seafoam, etc.) could be filtered out, leaving just the litter.

This revealed many of these short-lived litter windrows, with spot confirmation from ships in the area. Some of the windrows were many kilometers in length, with an average of around 1 km.

Although just a PoC, it nevertheless shows that monitoring such plastic debris from space is quite doable, even without dedicated satellites. As every day tons more plastics make their way into the oceans, this provides us with the means to at least keep track of the scope of the problem. Even if resolving it and the associated microplastics problem is still a far-off dream.

When comparing the efficiency of different wind turbine blade designs, [AdamEnt] found using a hair dryer wasn’t the best tool for the job. Enter his new 3D-printed wind tunnel.

After several prototypes, [AdamEnt] decided on a design that exploits slicer infill to create a flow straightener without having to do any tedious modeling of a lattice. Combined with a box on both ends of the straightener to constrain the flow, he has a more controllable air source with laminar instead of turbulent flow for testing his wind turbines.

The BLDC motor driving the air is attached to a toroidal blade of MIT fame. We get a little bit of the math behind calculating wind turbine efficiency and see a quick test of a blade placed next to the outlet of the air source at the end of the video.

If you’re planning on building your own wind tunnel, we’ve covered a few. We’ve even seen one that goes up to Mach 20, although that probably wouldn’t be useful for wind turbine design!

The use of concrete and steel have both become the bedrock of modern-day construction, which of course also means that there is a lot of both which ends up as waste once said construction gets demolished again. While steel is readily recyclable, the Portland cement that forms the basis of concrete so far is not. Although the aggregate from crushed concrete can be reclaimed, the remainder tends to end up in a landfill, requiring fresh input of limestone to create more cement. Now a team of researchers from the University of Cambridge claim to have found a way to recycle hydrated Portland cement by using it as flux during steel production in electric arc furnaces (EAFs).

Not only does this save a lot of space in landfills, it also stands to reduce a lot of the carbon dioxide produced during cement and steel production, which is primarily from the use of limestone for cement and lime-dolomite for steel. The details can be found in the open access paper in Nature by [Cyrille F. Dunant] and colleagues. Essentially reclaimed cement paste is mixed with some fresh material to form the flux that shields the molten steel in an EAF from the atmosphere. The flux creates the slag layer that floats on top of the molten steel, with this slag after cooling down being ground up and turned into cement clinker, which is then mixed to create fresh cement.

The process has been patented by Cambridge, who call the product ‘Cambridge Electric Cement‘, with the claim that if using low-carbon power sources for the EAF like hydro and nuclear, it would constitute ‘no emissions’ and ‘no landfill’ cement. We have to see how this works out on an industrial scale, of course, but it would definitely be nice to keep concrete and cement in general out of landfills, while cutting back on limestone mining, as well as questionable practices like adding heavy metal-laden fly ash as filler to concrete.

Thanks to [cscott] for the tip.

Amidst the push for more low-carbon energy, we see the demolishing of one of the pillars of electric grids: that of a careful balancing between supply and demand. This is not just a short-term affair. It also affects the construction of new power plants, investments in transmission capacity, and so on. The problem with having too much capacity is that it effectively destroys the electricity market, as suppliers need to make a profit to sustain and build generators and invest in transmission capacity. This is now the problem that Germany finds itself struggling with due to an overcapacity of variable renewable power sources (VRE) like solar and wind.

With a glut of overcapacity during windy and sunny days, this leads to prices going to zero or even negative. While this may sound positive (pun intended), it means that producers are not being paid. Worse, it means that when, for example, France buys German wind power for negative Euros via the European Electricity Exchange (EEX), it means that Germany actually pays France, instead of vice versa. The highly variable output of wind and solar also means a big increase in curtailment and redispatch measures to keep the grid stable, all of which costs money and drives up operating costs.

One suggested solution is to add more transmission capacity and more grid-level storage, but these scale poorly and are an economically dubious solution. Germany could also curtail its solar and wind generators, something which it currently avoids. Meanwhile, countries like Finland and France also integrate significant VREs on their grids, but with a strong base of hydropower and nuclear plants (both of which can load follow), which significantly reduces operating costs. Ultimately, some safe level of VRE grid integration will likely be found, alongside hydro and nuclear powerplants, including some with strong load-following capabilities like TerraPower’s Natrium. As we’ve mentioned before, this isn’t just a European problem.

While electricity generation has been the star of the energy transition show, about half of the world’s energy consumption is to make heat. Many industrial processes rely on fossil fuels to reach high temps right now, but researchers at ETH Zurich have found a new way to crank up the heat with a solar thermal trap. [via SciTechDaily]

Heating water for showers or radiant floor systems in homes is old hat now, but industrial application of solar power has been few and far between. Part of the issue has been achieving high enough temperatures. Opaque absorbers can only ever get as hot as the incident surface where the sun hits them, but some translucent materials, like quartz can form thermal traps.

In a thermal trap, “it is possible to achieve temperatures that are higher in the bulk of the material than at the surface exposed to solar radiation.” In the study, the researchers were able to get a 450˚C surface to produce 1,050˚C interior temperature in the 300 mm long quartz rod. The system does rely on concentrated solar power, 135 suns-worth for this study, but mirror and lens systems for solar concentration already exist due to the aforementioned electrical power generation.

This isn’t the only time we’ve seen someone smelting on sunlight alone, and you can always do it less directly by using a hydrogen intermediary. If you’re wanting a more domestic-level of heat, why not try the wind if the sun doesn’t shine much in your neighborhood?

Do you like your cup of tea to be cooled down to exactly 54 C, have a love for machining, and possess more than a little bit of a mad inventor bent? If so, then you have a lot in common with [Chronova Engineering]. In this video, we see him making a fully mechanical chime-ringing tea-temperature indicator – something we’d be tempted to do in silicon, but that’s admittedly pedestrian in comparison.

The (long) video starts off with making a DIY bimetallic strip out of titanium and brass, which it pretty fun. After some math, it is tested in a cup of hot water to ballpark the deflection. Fast-forward through twenty minutes of machining, and you get to the reveal: a tippy cup that drops a bearing onto a bell when the deflection backs off enough to indicate that the set temperature has been reached. Rube Goldberg would have been proud.

OK, so this is bonkers enough. But would you believe a bimetallic strip can be used as a voltage regulator? How many other wacky uses for this niche tech do you know?

Thanks [Itay] for the tip!