Mapping The Depths With An Autonomous Solar Boat

July 23, 2023 by Tom Nardi 17 Comments

Ever look out at a pond, stream, or river, and wonder how deep it is? For large bodies of water that are considered navigable, it’s easy enough to pull up a chart and find out. But what if there’s no public data for the area you’re interested in?

Well, you could spend all day on a little boat taking depth readings and making your own chart, but if you’re anything like [Clay] you could build a solar-powered autonomous robot to do it for you. He’s been working on the boat, which he calls Gumption Trap, for the better part of a year now. If we had to guess, we’d say the experience of designing and building it has ended up being a bit more interesting to him than the actual depth of the water — but that’s fine by us.

The design of the boat is surprisingly economical, as far as marine designs go. Two capped four-inch PVC pipes are used as pontoons, and 3D printed brackets attach those to an aluminum extrusion frame that holds the electronics and solar panel high above the water. This arrangement provides an exceptionally stable platform that would be all but impossible to flip under normal circumstances.

Around the back of the craft, there’s a pair of massive 3D printed thrusters, complete with some remarkably chunky printed propellers. The lack of rudders keeps things simple, with differential thrust between the two motors enough to keep the Gumption pointed in the right direction.

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Listening In On A Deep-Space Satellite As It Returns Home

July 13, 2023 by Dan Maloney 1 Comment

We’ve covered dozens of projects about getting images of Earth’s weather straight from the source. It’s not too much of a trick to download images straight from our constellation of weather satellites, but what about space weather? We’ve got satellites for that too, of course, but to get a good look at the Sun, they’re out of reach of most homebrew ground stations.

That’s about to change, though, as STEREO-A returns to our neighborhood after a 17-year absence, making citizen science a reasonable proposition. The STEREO mission — Solar Terrestrial Relations Observatory — was launched in 2006 with a pair of satellites in heliocentric orbits. STEREO-B was lost in 2014 due to a navigational glitch, but STEREO-A has spent a lot of the intervening years watching the backside of the Sun relative to the Earth. As [Scott Tilley] explains, the satellite is now approaching inferior conjunction, where it will pass between the Earth and the Sun.

This close pass makes STEREO-A’s X-band deep-space beacon readily available to hobbyist-scale equipment, like [Scott]’s 66-cm dish antenna. The dish is mounted on an alt-az telescope mount for tracking, and sports a host of gear at the focus, like LNAs, filters, mixers, and an Ettus B200 SDR. It’s not a cheap setup, but compared to what’s usually needed to listen to STEREO-A, it’s a bargain. The process of demodulating and decoding the signals was a bit more involved, though, requiring not only SatDump and some custom code but also a lot of patience. The images are worth the wait, though; [Scott] shares some amazing shots of our increasingly active Sun as well as animations of recent sunspot activity.

If you’re interested in getting in on the STEREO-A action, you’d better get hopping — the satellite will only be in the neighborhood for a few more months before heading off for another pass around the back of the Sun.

Converting On-Grid Electronics To Off-Grid

May 11, 2023 by Dave Rowntree 54 Comments

Husband and wife team [Jason & Kara] hail from Canada, and in 2018, after building their own camper, sold up their remaining earthly goods and headed south. If you’re not aware of them, they documented their journey on their YouTube channel, showing many interesting skills and hacks along the way. The video we’re highlighting today shows a myriad of ways to power all the DC-consuming gadgets this they lug along with them.

LiFePO4 batteries are far superior to lead acid for mobile solar installations.

Their heavily modded F-550 truck houses 12kWh of LiFePO4 batteries and a 1.5kW retractable solar array, with a hefty inverter generating the needed AC power. They weren’t too happy with the conversion losses from piles of wall warts that all drained a little power, knowing that the inverter that fed them was also not 100% efficient. For example, a typical laptop power brick gets really hot in a short time, and that heat is waste. They decided to run as much as possible direct from the battery bank, through different DC-DC converter modules in an attempt to streamline the losses a little. Obviously, these are also not 100%

efficient, but keeping the load off the inverter (and thus reducing dependency upon it, in the event of another failure) should help stem the losses a little. After all as [Jason] says, Watts saved are Watts earned, and all the little lossy loads add up to a considerable parasitic drain.

One illustration of this is their Starlink satellite internet system consumes about 60W when running from the inverter, but only 28W when running direct from DC. Over the course of 24 hours, that’s not far off 1kWh of savings, and if the sun isn’t shining, then that 12kWh battery isn’t going to stretch as far.

There are far too many hacks, tips, and illustrations of neat space and power-saving solutions everywhere, to write here. Those interested in self-build campers or hacking a commercial unit may pick up a trick or two.

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Making Hydrogen With Solar Energy, With Oxygen And Heat A Bonus

April 27, 2023 by Lewin Day 66 Comments

Hydrogen is a useful gas. Whether you want to float an airship, fuel a truck, or heat an industrial process, hydrogen can do the job. However, producing it is currently a fraught issue. While it can be produced cleanly using renewable energy, it’s often much cheaper to split it out of hydrocarbon fuels using processes that generate significant pollution.

There are methods to generate hydrogen more efficiently, though, in a clean and sustainable process. that also produces useful heat and oxygen as byproducts. The key to the process? Concentrated sunshine.
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Self-Cleaning Tech Could Help Solar Panels Keep Efficiency Up

April 14, 2023 by Lewin Day 58 Comments

Solar panels are a special kind of magic — turning light into useful electrical energy. However, they don’t work nearly as well when they’re covered in dust, dirt, and grime. Conventional solutions involve spraying panels down with pure water, which is expensive and wasteful, or dry scrubbing, which can cause efficiency loss through scratching the panels. However, innovative new methods may offer useful solutions in this area, as shared by EETimes.

Researchers at MIT have explored the use of electrostatic methods to remove dust from solar panels. By creating a sufficiently strong electrostatic field, dust particles can be compelled to leap off of solar panels. The cleaning method requires no water and is entirely non-contact. It uses a motor system to pass a charged electrode past the surface of the panels, with the opposite charge applied to the panels themselves. This repels the dust from the panels and onto the moving electrode.

Other methods include the use of special “self-cleaning” glass manufactured with a laser etching technique. The method, referred to as Direct Laser Interference Patterning, or DLIP, creates microscopic features on the order of 300 nm to 30 um on the surface of the glass. The pattern creates a so-called “functional surface” from which dirt simply slides off. The laser-etched pattern has no negative impact on transparency.

If these ideas prove practical, expect them to take off quickly. Commercially viable technologies spread fast in the renewable space, as we’ve seen with the rapid uptake of floating solar farms in recent years.

Electric Volkswagen Adds Rooftop Solar

April 13, 2023 by Bryan Cockfield 46 Comments

Volkswagen has continually teased the release of a new Microbus in the same way that Duke Nukem Forever strung us all along in the 00s, but unlike the fated video game it seems as though Volkswagen is finally building a hip new van rather than continually teasing its release year after year. With the clunky name of I.D. Buzz, European drivers can expect to see them later this year while those in the North American market will have to wait until 2024. That release will have a camper-equipped option though, but you may also want to equip yours with some solar panels as well.

The German tuning shop ABT is behind this design, which adds 600 watts of solar fixed to the top of the van. The solar roof will generate electricity largely to power the van’s auxiliary systems and is being aimed at those who are looking to outfit this van as a camper and need something to power things like refrigerators, interior lighting, and various electronics while on extended stays. There is also some mention of a 1000 watt option but with the limited space available on the roof may involve a side panel of some sort.

ABT is also noting that this system can be used to extend the driving range and, while technically true, don’t expect to be driving an I.D. Buzz on entirely solar power unless you’re willing to let it sit to charge the battery for days at a time. Like other solar installations on vehicles we’ve seen from various ingenious builders, the lack of real estate available on passenger vehicles limits their use largely to auxiliary electrical loads, but it can be possible to drive a vehicle on solar energy alone with the right design.

There’s Cash In Them Old Solar Panels

April 12, 2023 by Bryan Cockfield 82 Comments

The first solar panels may have rolled out of Bell Labs in the 1950s, with major press around their inconsistent and patchy adoption in the decades that followed, but despite the fanfare they were not been able to compete on a price per kilowatt compared to other methods of power generation until much more recently. Since then the amount of solar farms has increased exponentially, and while generating energy from the sun is much cleaner than most other methods of energy production and contributes no greenhouse gasses in the process there are some concerns with disposal of solar panels as they reach the end of their 30-year lifespan. Some companies are planning on making money on recycling these old modules rather than letting them be landfilled. Continue reading “There’s Cash In Them Old Solar Panels” →