Power Your Home With A Water Battery

October 8, 2021 by Matthew Carlson 69 Comments

I’ve stated it before on Hackaday but one of the most interesting engineering challenges posed to me this year was “how could you store enough energy to power a decent portion of a home for several hours without using batteries, all while staying within the size of a typical suburban plot?” [Quint Builds] attempts something up that alley by using solar power to pump water up onto his roof and later releasing it for power generation. (Video, embedded below.)

Earlier [Quint] had built a water collecting system using his gutters and a bell siphon but wasn’t satisfied with the overall power output. Using the turbine he had created for that system, he put a 55-gallon drum on top of his roof with the help of some supporting structures. We’d like to advise the public to consult a professional before adding a large heavy weight on top of your roof, but [Quint] forges ahead after studying his trusses and determining it to be a risk he is willing to take. A solar panel runs a small pump that pumps water from a reservoir up to the top of the roof when the sun shines with a float switch in the roof barrel stopping the motor once it’s full. A valve at the bottom allows water to spin the turbine and fill back into the bottom reservoir, forming a closed loop. There were a few snags along the way with prototype circuits not being fully contacted and the motor needing water cooling, an issue fixed by a custom CNC’d heat sink. The fixes for the various issues are almost as entertaining to see as the actual system itself.

It’s incredible to see lights come on powered by water alone but also sobering to realize just how much water you’d need to power a typical home. Perhaps if [Quint] upgrades, he can swap out the small motor for a larger 3D printed water pump.

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Green Roofs Could Help Improve Solar Panel Efficiency

September 20, 2021 by Lewin Day 83 Comments

There’s been a movement in architecture over the past couple of decades to help tie together large urban developments with plant life and greenery. We’ve seen a few buildings, and hundreds more renders, of tall skyscrapers and large buildings covered in vegetation.

The aesthetic is often a beautiful one, but the idea is done as much for its tangible benefits as for the sheer visual glory. Naturally, there’s the obvious boost from plants converting carbon dioxide into delicious, life-giving oxygen. However, greenery on the roofs of buildings could also help improve the output of solar installations, according to a recent study from Sydney, Australia.

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Tracking Maximum Power Point For Solar Efficiency

September 19, 2021 by Bryan Cockfield 45 Comments

In days of yore when solar panels weren’t dirt cheap, many people (and even large energy companies) used solar trackers to ensure their panels were always physically pointed at the sun to make sure they harvested every watt of energy possible. Since the price of panels has plummeted, though, it’s not economical to install complex machines to track the sun anymore. But all solar farms still track something else, called the Maximum Power Point (MPP), which ensures that even stationary panels are optimized for power production.

While small MPP trackers (MPPT) are available in solar charge controllers in the $200 range that are quite capable for small off-grid setups, [ASCAS] aka [TechBuilder] decided to roll out an open source version with a much lower price tag since most of the costs of these units are in R&D rather than in the actual components themselves. To that end, the methods that he uses for his MPPT are essentially the same as any commercial unit, known as synchronous buck conversion. This uses a specially configured switch-mode power supply (SMPS) in order to match the power output of the panels to the best power point for any given set of conditions extremely rapidly. It even works on many different battery configurations and chemistries, all configurable in software.

This build is incredibly extensive and goes deep into electrical theory and design choices. One design choice of note is the use of an ESP32 over an Arduino due to the higher resolution available when doing analog to digital conversion. There’s even a lengthy lecture on inductor core designs, and of course everything on this project is open source. We have also seen the ESP32 put to work with MPPT before, although in a slightly less refined but still intriguing way.

Thanks to [Sofia] for the tip!

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Rugged Solar Generator Packs A Punch

September 7, 2021 by Dave Rowntree 29 Comments

Hackaday Prize 2021 entrant [Philip Ian Haasnoot] has been building a well-polished power bank. But this is no ordinary little power bank the like you would throw in your rucksack for a day out. No, this 2.5 kW luggable power bank is neatly encased in a tough, waterproof Pelican 1550 case, and is suitably decked out with all the power sockets you could possibly need for a long weekend of wilderness camping and photography.

Testing the hand-built 18650 based battery bank — Boy, that’s a lot of tab welding

This box sports USB-C and USB 3.0 connectors for gadget charging, as well as 12 VDC cigarette lighter and XT-60 ports for high-drag devices. Also it provides a pair of 120 VAC sockets via an integrated inverter, which at 1.5 kW could run a small heater if you were really desperate, but more likely useful to keep your laptop going for a while. Now if only you could get Wi-Fi out in the desert!

[Philip] doesn’t actually talk much about the solar panels themselves, but we know the box contains a 600 W MPPT boost converter to take solar power in, and feed the LiPo battery pack in the correct manner.

The battery pack is custom-made from salvaged and tested 18650 cells, as you would expect, which we reckon took an absolute age to make by hand. The whole project is nicely finished, and looks like something we’d be happy to throw in the back of the car before heading out into our local wilderness.

As [Philip] says in the project description, it’s a tough job to carry enough power and keep all his drones, cameras and lighting equipment charged, not mention helping prevent the campsite occupants from freezing overnight during the chilly Arizona nights.

Many power bank designs have graced these fair pages over the years, like this rather polished build, and long may they continue to do so.

Spiffy Summer Project Sources Solar Sounds From Scraps

August 17, 2021 by Ryan Flowers 8 Comments

[Gijs Gieskes] has a long history of producing electronic art and sound contraptions, and his Zonneliedjes (sunsongs) project is certainly an entertaining perpetuation of his sonic creations. With the stated goal of making music from sunlight, the sunsongs most prominent feature is solar panels.

Although It’s not clear how the photons transform into the rhythmic crashes and random beep-boop sounds, the results are quite satisfying. We have a strong suspicion that the same principals that turn random junk into BEAM robots are at work, maybe with some circuit bending sprinkled on for good measure. One detail we were able to glean from a picture of the device he calls “mobile” was a 40106 oscillator, which [Gijs] has used in previous projects.

The construction style that [Gijs] uses reminds us of the “Manhattan” construction style the amateur radio homebrewing community favors. Squares of copper PCB are glued directly to the back of the solar cells and the circuits are built atop them. Looking carefully at the pictures we can also see what look like cutoff leads, suggesting a healthy amount of experimentation to get the desired results, which we can all relate to.

Be sure to check out the video after the break, and also [Gijs] website. He’s been hacking away at projects such as these for a very long time, and we’ve even featured his projects going back more than 15 years. Thanks for the continued hacks, [Gijs]. We look forward to seeing what you come up with next!

If the terms “BEAM robotics” and “circuit bending” are unfamiliar to your ears (or if a refresh is due), be sure to check out our recent re-introduction to BEAM robotics and our classic “Intro to Circuit Bending” to get acquainted. Continue reading “Spiffy Summer Project Sources Solar Sounds From Scraps” →

Solar Display Case Is A Portable Triple Monitor Setup

August 15, 2021 by Lewin Day 10 Comments

They say once you start using twin monitors on the desktop, you’ll never want to go back. It’s even worse when you upgrade to three or more. However, it can be difficult to take such a set up on the road. Desiring better productivity on the go is what spurred [Brian Whitsett] to develop the Solar Display Case to solve this problem.

The Solar Display Case aims to pack three 17″ full-size monitors into a portable waterproof case. Brian has already built a prototype, which puts the monitors on folding arms so that they can be quickly stowed or deployed when needed.

The build also relies on solar power to charge batteries, in order to make the solution as portable as any laptop or other hardware you may be using with it. It’s no good having three mains-powered monitors sitting in the field with no AC power, after all. [Brian] aims to use a flexible solar panel to make the most of the surface area of the deployed assembly, for maximum power generation.

It’s a great project, and one we’d love to see fleshed out to the fullest. Imagining a briefcase that folds out into a triple-monitor workstation is exciting, and it looks like [Brian] is well on the way to making it a reality.

Wireless Earbuds Charge Themselves

August 11, 2021 by Bryan Cockfield 20 Comments

As more and more ports are removed from our smart devices, it seems that we have one of two options available for using peripherals: either buy a dongle to continue to use wired devices, or switch to Bluetooth and deal with perpetually maintaining batteries. If neither of these options suits you, though, there’s a third option available as [befinitiv] shows us in this build where he integrates a tiny solar panel to his earbud case to allow them to automatically charge themselves.

To start, he begins by taking apart the earbud case. For those who still haven’t tried out a set of these, they typically charge only when placed inside of their carrying case, which in his case also contains a small battery itself. Soldering wires directly to the battery allow for the battery to charge without as much electrical loss as he would have had if he had connected to the USB pins on the circuit board. Even then, the cell only generates a single volt so he needs a 5V boost converter to properly charge the battery. That came with its own problem, though, as it wouldn’t fit into the case properly. To solve that issue, he desoldered all of the components and deadbugged them together in order to fit the converter into a much smaller space without having to modify the case in any other way.

With all of that done and the small solar cell attached to the case, [befinitiv] has a smart solution to keep his wireless earbuds topped up without having to carry cables or dongles around every day. We’ve seen plenty of interesting solutions to the problem of various electronics manufacturers removing the ubiquitous 3.5 mm headphone jack too, and not all of them have dealt with this problem without certain other quirks arising as a result.

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