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.

Continue reading “Converting On-Grid Electronics To Off-Grid” →

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.
Continue reading “Making Hydrogen With Solar Energy, With Oxygen And Heat A Bonus” →

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” →

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 Arya Voronova 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.

A white longtail cargo bike sits on grass with fenced-in planters behind it. The bike has a basket made of black metal tubes on the front and a passenger compartment behind the rider seat for children made of similar black metal tubes. A white canopy is above the passenger compartment and a solar panel sits atop the canopy.

Solar Powered E-bike Replaces Car Trips

February 7, 2023 by Navarre Bartz 20 Comments

E-bikes can replace car trips for some people, and adding a solar panel can make the fun last longer. [Luke] did some heavy modifications to his RadWagon to make it better, stronger, and faster than it was before.

The first step was replacing the stock 750 W controller with a 1500 W model to give the motor twice the power. [Luke] plans to replace the motor if it gets fried pushing too much juice, but is planning on just being careful for now. To stop this super-powered ride, he swapped the stock mechanical discs out for a hydraulic set which should be more reliable, especially when loading down this cargo bike.

On top of these performance enhancements, he also added a 50 W solar panel and maximum power point tracking (MPPT) charge controller to give the bike a potential 50% charge every day. Along with the OEM kid carrier and roof, this bike can haul kids and groceries while laughing at any hills that might come its way.

Checkout this other solar e-bike or this one making a trip around the world for more fun in the sun.