Solar power is a great source of renewable energy, but has always had its limitations. At best, there’s only 1,000 Watts/m2 available at the Earth’s surface on a sunny day, and the limited efficiency of solar panels cuts this down further. It’s such a low amount that solar panels on passenger cars have been limited to menial tasks such as battery tending and running low-power ventilation fans.
However, where some might see an impossibility, others see opportunity. The World Solar Challenge is a competition that has aimed to show the true potential of solar powered transport. Now 30 years since its inception, what used to be impossible is in fact achieved by multiple teams in under one tenth of the original time. To keep competitors on their toes, the rules have been evolving over time, always pushing the boundaries of what’s possible simply with sunlight. This isn’t mainstream transportation; this is an engineering challenge. How far can you go in a solar car?
Continue reading “World Solar Challenge: How Far In A Solar Car?”
About four years ago, [Russell Graves] created what was, to him, the ultimate work-from-home environment: an off-grid office shed. The shed might look a bit small, but it’s a considerably larger workspace than most people in an office are granted. Four years later, in the middle of a global pandemic, working from home has become much more common and [Russel] shares some thoughts on working from home and specifically reflects on how his off-grid, solar powered shed office (or “shoffice” as he likes to call it) has worked out. In short, after four years, it rocks hard and is everything he wanted and more.
Its well-insulated plywood walls let him mount monitor arms and just about anything else anywhere he wants, and the solar power system allows him to work all day (and into the night if he wants, which he doesn’t) except for a few spells in the winter where sunlight is just too scarce and a generator picks up the slack. Most importantly, it provides a solid work-life separation — something [Russell] is convinced is critical to basic wellness as a human being.
That’s not to say an off-grid solar shed is the perfect solution for everyone. Not everyone can work from home, but for those who can and who identify with at least some of the motivations [Russell] expressed when we covered how he originally created his office shed, he encourages giving it some serious thought.
The only thing he doesn’t categorically recommend is the off-grid, solar powered part. To be clear, [Russell] is perfectly happy with his setup and even delights in being off-grid, but admits that unless one has a particular interest in solar power, it makes more sense to simply plug a shed office into the grid like any other structure. Solar power might seem like a magic bullet, but four years of experience has taught him that it really does require a lot of work and maintenance. Determined to go solar? Maybe give the solar intensity sensor a look, and find out just how well your location is suited to solar before taking the plunge.
As the world has become more environmentally conscious, we’ve seen an uptick in projects that monitor or control home energy use. At a minimum one of these setups involves a microcontroller and some kind of clamp-on current sensor, but if you’re looking for resources to take things a bit farther, this Raspberry Pi energy monitoring system created by [David00] would be a great place to start.
This project includes provides software and hardware to be used in conjunction with the Raspberry Pi to keep tabs on not just home energy consumption, but also production if your home has a solar array or other method of generating its own power. Data is pulled every 0.5 seconds from a MCP3008 ADC connected to up to
five six current sensors to provide real-time utilization statistics, and visualized with Grafana so you can see all of the information at a glance.
While [David00] has already done the community a great service by releasing the hardware and software under an open source license, he’s also produced some absolutely phenomenal documentation for the project that’s really a valuable resource for anyone who wants to roll their own monitoring system. He’s even offering hardware kits for anyone who’s more interested in experimenting with the software side of things than building the PCB.
Home energy monitoring projects are certainly nothing new, but the incredible advances we’ve seen in the type of hardware and software available for DIY projects over the last decade has really pushed the state-of-the-art forward. With so many fantastic resources available now, the only thing standing between you and your own home energy monitoring dashboard is desire and a long weekend.
Custom weather stations are a common enough project these days, especially based around the ESP8266. Wire a sensor up to the MCU, power it up with an old phone charger, and you’re half way there. But if you want something that’s going to operate remotely on the long term, you’ve got to put a little more thought into it.
Which is exactly what [BuckarewBanzai] did for his solar powered Raspberry Pi weather station. With an industrial NEMA-rated enclosure, a beefy 35 watt photovoltaic panel, and enough lead-acid battery capacity to keep the show going for days, this build is certainly more robust than most. Some might call it overkill, but we think anyone who’s ever deployed hardware outdoors for more than a few days knows you can never be too careful when Mother Nature is involved.
To keep the 18 Ah battery topped off, [BuckarewBanzai] is using a 10 amp Wanderer charge controller. It sounds as though he burned through a few lesser models before settling on this one; something to consider for your own off-grid projects. An LM2596 regulator is then used to provide a stable 5 V for the Raspberry Pi.
In addition to the BME280 environmental sensor that picks up on temperature, humidity, and pressure, there’s also a AS3935 lightning sensor onboard which [BuckarewBanzai] says can pick up strikes up to 40 kilometers away. All of this environmental data is collected and stored in a local SQLite database, and gets pushed offsite every five minutes with a REST API so it can be visualized with Grafana.
Critics in the audience will no doubt pick up on the solderless breadboard located in the center of the weather station, but [BuckarewBanzai] says he’s already on the case. He’s working on a custom PCB that will accept the various modular components. Not only should this make the station more reliable, but he says it will cut down on the “spaghetti” wiring. Though for the record, this is hardly the worst offender we’ve seen in that department.
If you’re out in the wilderness, having plenty of electricity on hand is a blessing. Eschewing fossil fuels, [LithiumSolar] is, as their name suggests, a fan of other technologies – undertaking the construction of a 3.5kWh solar generator that’s rugged and ready for the outdoors.
The build starts with 18650 lithium-ion cells sourced from a recycler, packed inside obsolete modem battery packs. After harvesting 390 cells, the best 364 are chosen and assembled into plastic holders to create a 14S26P configuration. A spot welder is employed to weld the pack together, with XT60 connectors used as the main bus connectors, albeit in a very non-standard configuration. Balance leads are hooked up to a 14S battery management system, to keep things in check. The huge pack is then installed inside a stout Craftsman toolbox, along with a MPPT solar charger module, and a 1500W inverter for output.
The build video is a great resource for anyone interested in building custom 18650 packs or battery solar power systems. [LithiumSolar] does a great job of clearly explaining each step and the reasons for part selections along the way. Of course, in a neat dovetail to this project, we’ve even seen solar-powered spot welders before – which would be useful if you need to replicate this build out in the field somewhere. Video after the break.
Continue reading “Building A Serious Solar Inverter Battery Pack”
Air quality is one of those problems that is rather invisible and hard to grasp until it gets bad enough to be undeniable. By then, it may be too late to do much about it. But if more people were interested in the problem enough to monitor the air around them, there would be more innovators bringing more ideas to the table. And more attention to a problem usually means more accountability and eventual action.
This solar-powered particulate analyzer made by [rabbitcreek] is a friendly way to take the problem out of the stratosphere of ‘someday’ and bring it down to the average person’s backyard. Its modular nature makes it fairly simple to build, and the conch shell enclosure gives it a natural look. That shell also cleverly hides the electronics, while at the same time allowing air and particulates to reach the sensor. If you don’t like the shell enclosure, we think the right type of bird feeder could protect the electronics while allowing airflow.
[rabbitcreek] attached a sizeable solar panel to the shell on a GoPro mount so it can be adjusted to face the sun. The panel charges a Li-Po battery that gets boosted to 5V. Every two hours, a low-power breakout circuit wakes up the Feather ESP32 and takes a reading from the particulate sensor. [rabbitcreek] can easily see the data on his phone thanks to the Blynk app he created.
Why limit this to your yard? Bare ESP32s are cheap enough that it’s feasible to build a whole network of air quality sensors.
Bringing a product to market is not easy, if it were everyone would be doing it, and succeeding. The team at Pycno is in the process of launching their second product, a modular solar powered IoT unit called Pulse. It’s always interesting to get an inside look when a company is so open during the development process, and see how they deal with challenges.
Pycno’s first product was a solar powered sensor suite for crops. This time round they are keeping the solar part, but creating a modular system that can accept wired or wireless connections (2G/3G/4G, WiFi, LoRa, GPS and Bluetooth 5) or modules that slide into the bottom of the unit. They plan to open source the module design to allow other to design custom modules, which is a smart move since interoperability can be a big driving factor behind adoption. The ease of plugging in sensors is a very handy feature, since most non-Hackaday users would probably prefer to not open up expensive units to swap out sensors. The custom solar panel itself is pretty interesting, since it features an integrated OLED display. It consists of a PCB with the cutout for the display, with solar cells soldered on before the whole is laminated to protect the cells.
Making a product so completely modular also has some pitfalls, since it can be really tricky to market something able to do anything for anybody. However, we wish them the best of luck with their Kickstarter (video after the break) and look forward to seeing how the ecosystem develops.
When a large community develops around a modular ecosystem, it can truly grow beyond the originator’s wildest dreams. Just look at Arduino and Raspberry Pi. We’re also currently running a contest involving boards for the Feather form factor if you want to get in on the act. Continue reading “Modular Solar-Powered IoT Sensors”