Weird Energy Storage Solutions Could Help The Grid Go Renewable

November 29, 2022 by Lewin Day 122 Comments

We’re all familiar with batteries. Whether we’re talking about disposable AAs in the TV remote, or giant facilities full of rechargeable cells to store power for the grid, they’re a part of our daily lives and well understood.

However, new technologies for storing energy are on the horizon for grid storage purposes, and they’re very different from the regular batteries we’re used to. These technologies are key to making the most out of renewable energy sources like solar and wind power that aren’t available all the time. Let’s take a look at some of these ideas, and how they radically change what we think of as a “battery.”

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Better Air Quality Sensing With CO2

November 21, 2022 by Bryan Cockfield 19 Comments

Measuring air quality, as anyone who has tried to tackle this problem can attest, is not as straightforward as it might seem. Even once the nebulous term “quality” is defined, most sensors use something as a proxy for overall air health. One common method is to use volatile organic compounds (VOCs) as this proxy but as [Larry Bank] found out, using these inside a home with a functional kitchen leads to a lot of inaccurate readings. In the search for a more reliable sensor, he built this project which uses CO2 to help gauge air quality.

Most of the reason that CO2 sensors aren’t used as air quality sensors is cost. They are much more expensive than VOC sensors, but [Larry] recently found one that was more affordable and decided to build this project around it. The prototype used an Arduino communicating over I2C to the sensor and an OLED screen, which he eventually put in a 3D printed case to carry around to sample CO2 concentration in various real-world locations. The final project uses a clever way of interfacing with the e-paper display that we featured earlier.

While CO2 concentration doesn’t tell the full story of air quality in a specific place, it does play a major role. [Larry] found concentrations as high as 3000 ppm in his home, which can cause a drop in cognitive function. He’s made some lifestyle changes as a result which he reports has had a beneficial impact. For human-occupied indoor spaces, CO2 can easily be the main contributor to poor air quality, and we’ve seen at least one other project to address this concern directly.

Making A Do-It-Yourself Sand Battery

November 21, 2022 by Maya Posch 96 Comments

Storing energy can be done in many ways, with the chemical storage method of a battery being one of the most common. Another option is a thermal battery, which basically means making something hot, and later extracting that heat again. In this video by [Robert Murray-Smith] the basic concept of a thermal battery that uses sand is demonstrated.

By running a current through a resistive wire that’s been buried inside a container with sand, the sand is heated up to about 200 °C. As [Robert] points out, the maximum temperature of the sand can be a 1000 °C or more. Because sand doesn’t boil like water, the total amount of energy stored in sand is correspondingly higher.

Extracting the thermal energy can be done rather inefficiently using the demonstrated Peltier element. A Stirling engine, or steam generator and turbine, would get a lot more energy out. Either way, the thermal battery itself is made using just plain sand, which makes it an attractive DIY target to tinker with.

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Go Fly A Kite

November 13, 2022 by Bryan Cockfield 17 Comments

Harvesting energy from the wind has been a commercially viable way of generating clean energy for around three decades now. Wind turbines are a reliable, proven technology but they do have some downsides, one of which is that since there’s more wind higher above the ground this usually means tall, expensive towers. There is a way around this problem, though, which is using kites to generate energy instead of a fixed turbine.

While kite generators aren’t a new idea, [Benjamin] has been working on this kite generator which has a number of improvements over existing kite generators. Like other kite generators, this one uses a tether to spin a generator which is located on the ground. But while this is similar to other kite systems, this prototype has a much simpler design and sweeps a much larger area while in flight. It also has an autopilot with multiple independent steering systems, which [Benjamin] says will allow it to stay in flight for months at a time provided there is enough wind. If there isn’t, it can land reliably, and launching it is relatively fast and simple as well.

While kites do have some obvious downsides compared to fixed turbines including a single point of failure at the tether and a large amount of cleared area to operate, they have plenty of advantages as well. They’re smaller, simpler, require no complicated yaw system, and can be easily maintained on the ground. In fact, it’s possible to build very simple kite generators out of nothing more than a hobby kite and some readily-available electrical components.

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Scratch Built Wind Turbine Makes Power And Turns Heads

November 11, 2022 by Ryan Flowers 31 Comments

If you’ve ever aspired to live off the grid, then it’s likely that one of the first things you considered was how to power all of your electrical necessities, and also where to uh… well we’ll stick to the electrical necessities. Depending on your location, you might focus on hydroelectric power, solar power, or even a wind turbine. Or, if you’re [Kris Harbor], all three. In the video below the break, we get to watch [Kris] as he masterfully rebuilds his wind turbine from scratch and reconfigures his charging solution to match.

The Rotors Are Built With a 3d Printed Rotor Jig

A true hacker at heart, [Kris] has used a everything from 3d printing to broken car parts in order to build his new wind turbine. The three phase generator is constructed from scratch. A hand wound stator is held firmly between two magnetic rotors, where 3d printed jigs hold the magnets in place.

A CNC cut backing plate holds everything together while also supporting the automatically furling vane that keeps the entire turbine from self destructing in inclement weather. A damaged wheel hub from [Kris]’ Land Rover provides the basis for a bearing so that the entire turbine can turn to face the wind, and various machined parts round out the build. The only things we didn’t see in the build were hot glue and zip ties, but we remain hopeful. Continue reading “Scratch Built Wind Turbine Makes Power And Turns Heads” →

A man and a woman stand at opposite ends of a wooden-framed bicycle. It has 20" tires and a long, black seat. A rack extends over the front tire for carrying small items.

Plywood Bicycle Makes Frame Building More Accessible

November 4, 2022 by Navarre Bartz 37 Comments

Bike frames are simple on the surface, but can quickly become complicated if you want to fabricate one yourself. Brazing and welding tend to be less common skills than knowing how to bolt things together, so [Arquimaña] has brought us the OpenBike to make the process accessible to more people.

An open-source set of files designed for CNCs and 3D printers, the OpenBike uses readily available materials like sheet plywood to make a sturdy, if unconventional-looking, bicycle. Like many other consumer goods, most bike frames are currently built in Asia. This allows for economies of scale, but removes locals from the design process. By using simpler tools, OpenBike allows for more local direction of what features might be needed for a particular region.

Shifting even a small portion of trips to more active forms of transport is an important part of lowering carbon emissions, so making bikes a more attractive means of transportation is always welcome. What might be important in one region might be superfluous and expensive in another (multiple gears in a hilly region, for example). OpenBike could be especially useful as a way to rapid-prototype different feature sets for a particular region before committing to a more traditional frame-building technique for larger batches of bikes.

If you want to see some other bike hacks, why not check out this extending bicycle, this steampunk recumbent trike, or these bike hacks from around the world?

via Yanko Design

Breakers for the system on a DIN rail, with markings like 48V and 24V and 12V and so on on the bottom, and two hefty devices of some kind on the bottom, probably MPTT controllers, with hefty wires running from them.

Low-Voltage DC Network Build Incited By Solar Panels

November 2, 2022 by Arya Voronova 56 Comments

Nowadays, some people in Europe worry about energy prices climbing, and even if all the related problems disappear overnight, we’ll no doubt be seeing some amounts of price increase. As a hacker, you’re in a good position to evaluate the energy consuming devices at your home, and maybe even do something about them. Well, [Peter] put some solar panels on his roof, but couldn’t quite figure out a decent way to legally tie them into the public grid or at least his flat’s 220V network. Naturally, a good solution was to create an independent low-voltage DC network in parallel and put a bunch of devices on it instead!

He went with 48V, since it’s a voltage that’s high enough to be efficient, easy to get equipment like DC-DCs for, safe when it comes to legal matters concerned, and overall compatible with his solar panel setup. Since then, he’s been putting devices like laptops, chargers and lamps onto the DC rail instead of having them be plugged in, and his home infrastructure, which includes a rack full of Raspberry Pi boards, has been quite content running 24/7 from the 48V rail. There’s a backup PSU from regular AC in case of overcast weather, and in case of grid power failures, two hefty LiFePO4 accumulators will run all the 48V-connected appliances for up to two and a half days.

The setup has produced and consumed 115kWh within the first two months – a hefty contribution to a hacker’s energy independence project, and there’s enough specifics in the blog post for all your inspiration needs. This project is a reminder that low-voltage DC network projects are a decent choice on a local scale – we’ve seen quite viable proof-of-concept projects done at hackercamps, but you can just build a small DC UPS if you’re only looking to dip your feet in. Perhaps, soon we’ll figure out a wall socket for such networks, too.