green hacks

767 Articles

Using Old Coal Mines As Cheap Sources Of Geothermal Heat

April 11, 2023 by 33 Comments

For as much old coal mines are a blight upon the face of the Earth, they may have at least one potential positive side-effect. Where the coal mine consists out of tunnels that were drilled deep into the soil, these tend to get flooded by groundwater after the pumps that keep them dry are turned off. Depending on the surrounding rock, this water tends to get not only contaminated, but also warmed up. As the BBC explains in a recent video as a follow-up to a 2021 article, when the water is pumped up for decontamination, it can be run through a heat exchanger in order to provide heat for homes and businesses. Continue reading “Using Old Coal Mines As Cheap Sources Of Geothermal Heat” →

A red Tesla Model 3 converted into a pickup truck with a black lumber rack extending over the roof of the cab sits in a grey garage. A black and silver charging robot is approaching its charging port from the right side attached to a black cable. The charging bot is mostly a series of tubes attached to a wheeled platform and the charging connector itself is attached to a linear actuator to insert the charging device.

Truckla Gets An Open Source Charging Buddy

April 11, 2023 by 11 Comments

More than three years have passed since Tesla announced its Cybertruck, and while not a one has been delivered, the first Tesla truck, Truckla, has kept on truckin’. [Simone Giertz] just posted an update of what Truckla has been up to since it was built.

[Giertz] and friend’s DIT (do-it-together) truck was something of an internet sensation when it was revealed several months before the official Tesla Cybertruck. As with many of our own projects, while it was technically done, it still had some rough edges that kept it from being truly finished, like a lack of proper waterproofing or a tailgate that didn’t fold.

Deciding enough was enough, [Giertz] brought Truckla to [Marcos Ramirez] and [Ross Huber] to fix the waterproofing and broken tailgate while she went to [Viam Labs] to build Chargla, an Open Source charging bot for Truckla. The charging bot uses a linear actuator on a rover platform to dock with the charging port and is guided by a computer vision system. Two Raspberry Pis power handle the processing for the operation. We’re anxious to see what’s next in [Giertz]’s quest of “picking up the broken promises of the car world.”

If you want to see some more EV charger hacks, check out this Arduino-Based charger and the J1772 Hydra.

Continue reading “Truckla Gets An Open Source Charging Buddy” →

The UK’s ST40 Spherical Tokamak Achieves Crucial Plasma Temperatures

April 11, 2023 by 23 Comments

As the race towards the first commercially viable nuclear fusion reactor heats up, the UK-based Tokamak Energy has published a paper on its recent achievements with its ST40 spherical tokamak. Most notable is the achieving of plasma temperatures of over 100 million Kelvin, which would put this fusion reactor firmly within the range for deuterium-tritium fusion at a rate that would lead credence to the projection made by Tokamak Energy about building its first commercial fusion plants in the 2030s.

The ST40 is intended to provide the necessary data to construct the ST80-HTS by 2026, which itself would be a testing ground for the first commercial reactor, called the ST-E1, which would be rated at 200 MWe. Although this may seem ambitious, Tokamak Energy didn’t come out of nowhere, but is a spin-of of Culham Centre for Fusion Energy (CCFE), the UK’s national laboratory for fusion research, which was grounded in 1965, and has been for decades been involved in spherical tokamak research projects like MAST and MAST-Upgrade, with STEP as its own design for a commercial fusion reactor.

The advantage offered by spherical tokamaks compared to regular tokamaks is that they favor a very compact construction style which puts the magnets very close to the plasma, effectively making them more efficient in retaining the plasma, with less power required to maintain stable plasma. Although this makes the use of super-conducting electromagnets not necessary, it does mean that wear and tear on these magnets is significantly higher. What this does mean is that this type of tokamak can be much cheaper than alternative reactor types, even if they do not scale as well.

Whether or not Tokamak Energy will be the first to achieve commercial nuclear fusion remains to be seen. So far Commonwealth Fusion’s SPARC and a whole host of Western and Asian fusion projects are vying for that gold medal.

How Simple Can A Wind Generator Get?

March 9, 2023 by 12 Comments

As the world has moved towards sustainable energy sources over the last few years, it’s increasingly common to be close to a wind turbine. The huge turbines visible on the horizon from where this is being written are the upper end of the scale though, and along comes [Robert Murray Smith] with the opposite, probably the simplest and smallest wind turbine we’ve seen.

His use of a 3-phase motor from a CD-ROM drive as the generator isn’t particularly unexpected, these motors are ubiquitous and readily generate power when spun up. A simple 3-phase rectifier and a capacitor delivers a DC voltage that while the ready availability of switching converter modules should be relatively easy to turn into something more useful.

The clever part of this hack lies then in the rotor, it’s not the propeller-style bladed affair you might expect. Instead he takes a CD, as it’s the obvious thing to fit on a CD motor, and glues a piece of Tyvek on top of it. This is cut to form four flaps which make a rudimentary but effective turbine when the wind comes from the side. It’s beautifully simple, and we wish we’d thought of it ourselves. The whole thing is in the video below the break, so take a look.

Maybe this won’t solve the green energy requirement on its own, but we’ve shown you far larger fabric turbines in the past.

Continue reading “How Simple Can A Wind Generator Get?” →

A Ground Source Heat Pump From An Air Conditioner

March 7, 2023 by 39 Comments

When it comes to lower-energy home heating, it’s accurate in all senses to say that heat pumps are the new hotness. But unless you happen to work with them professionally, it’s fair to say their inner workings are beyond most of us. Help is at hand though courtesy of [petey53], who made his own ground source heat pump for his Toronto house using a pair of window-mounted air conditioning units.

Continue reading “A Ground Source Heat Pump From An Air Conditioner” →

Screenshot from the presentation, showing the datalogger product image next to the datalogger specs stated. The specs are suspiciously similar to those of a Raspberry Pi 3.

Reclaiming A Pi-Based Solar Datalogger

March 4, 2023 by 7 Comments

There’s quite a few devices on the market that contain a Raspberry Pi as their core, and after becoming a proud owner of a solar roof, [Paolo Bonzini] has found himself with an Entrade ENR-DTLA04DN datalogger which – let’s just say, it had some of the signs, and at FOSDEM 2023, he told us all about it. Installed under the promise of local-only logging, the datalogger gave away its nature with a Raspberry Pi logo-emblazoned power brick, a spec sheet identical to that of a Pi 3, and a MAC address belonging to the Raspberry Pi Foundation. That spec sheet also mentioned a MicroSD card – which eventually died, prompting [Paolo] to take the cover off. He dumped the faulty SD card, then replaced it – and put his own SSH keys on the device while at it.

At this point, Entrade no longer offered devices with local logging, only the option of cloud logging – free, but only for five years, clearly not an option if you like your home cloud-free; the local logging was not flawless either, and thus, the device was worth exploring. A quick peek at the filesystem netted him two large statically-compiled binaries, and strace gave him a way to snoop on RS485 communications between the datalogger and the solar roof-paired inverter. Next, he dug into the binaries, collecting information on how this device did its work. Previously, he found that the device provided an undocumented API over HTTP while connected to his network, and comparing the API’s workings to the data inside the binary netted him some good results – but not enough.

The main binary was identified to be Go code, and [Paolo] shows us a walkthrough on how to reverse-engineer such binaries in radare2, with a small collection of tricks to boot – for instance, grepping the output of strings for GitHub URLs in order to find out the libraries being used. In the end, having reverse-engineered the protocol, he fully rewrote the software, without the annoying bugs of the previous one, and integrated it into his home MQTT network powered by HomeAssistant. As a bonus, he also shows us the datalogger’s main PCB, which turned out to be a peculiar creation – not to spoil the surprise!

We imagine this research isn’t just useful for when you face a similar datalogger’s death, but is also quite handy for those who find themselves at the mercy of the pseudo-free cloud logging plan and would like to opt out. Solar tech seems to be an area where Raspberry Pi boards and proprietary interfaces aren’t uncommon, which is why we see hackers reverse-engineer solar power-related devices – for instance, check out this exploration of a solar inverter’s proprietary protocol to get data out of it, or reverse-engineering an end-of-life decommissioned but perfectly healthy solar inverter’s software to get the service menu password.

AGES Of Renewable Energy Storage

March 3, 2023 by 26 Comments

As society transitions toward renewable energy sources, energy storage inevitably comes to mind. Researchers at the University of Illinois at Urbana-Champaign have found one way to store renewable energy that re-purposes existing fossil fuel infrastructure.

While geothermal electricity generation shows a lot of promise, it’s currently limited to a select few areas where hot rock is close to the Earth’s surface. Advanced Geothermal Energy Storage (AGES) stores energy underground as heat and recovers it later, even in places without high subsurface temperatures. For this study, the researchers located an old oil well and instrumented it with “flow meters, fiber optic
distributed temperature sensing (DTS) cable, surface pressure and temperature gauges, and downhole pressure and temperature gauges to monitor the thermal and hydraulic changes during the injection test.”

This field study found that AGES system efficiency could be as high as 82% and yield an “economically viable” levelized cost of electricity (LCOE) of $0.138/kWh. Using existing deep hole infrastructure speeds up site selection and deployment of AGES when compared to developing on an undisturbed location, making this a very interesting way to deploy grid-scale storage rapidly.

We’ve covered reusing fossil fuel infrastructure before as well as challenges and unusual solutions to the energy transition if you’re looking for more about what might be on a future smart grid.