Perfecting The Solar Powered Web Server

October 8, 2018 by Tom Nardi 35 Comments

Running a server completely off solar power seems like it would be a relatively easy thing to do: throw up a couple of panels, tack on a charge controller and a beefy battery, and away you go. But the reality is somewhat different. Most of us hackers are operating on a relatively limited budget and probably don’t have access to the kind of property you need to put out big panels; both pretty crippling limitations. Doing solar on a small-scale is hard, and unless you really plan ahead your setup will probably be knocked out on its first cloudy day.

So when [Kris de Decker] wanted to create a solar-powered version of his site “Low-tech Magazine”, he went all in. Every element of the site and the hardware it runs on was investigated for potential power savings, and luckily for us, the entire process was written up in meticulous detail (non-solar version here). The server still does go down from time to time if the weather is particularly poor, but in general it maintains about 90% uptime in Barcelona, Spain.

The solar side of the equation is fairly simple. There’s a 50 watt photovoltaic panel charging a 12V 7Ah lead-acid battery though a 20A charge controller. With an average of 4 to 6 hours of sunlight a day, the panel generates 300 Wh of electricity in the best case scenario; which needs to be split between charging the battery and running the server itself.

As for the server, [Kris] chose the Olimex Olinuxino A20 Lime 2 in part because of it being open source hardware, but also because it’s very energy-efficient and includes a AXP209 power management chip. Depending on processor load, the Olimex board draws between 1 and 2.5 watts of power, which combined with charging losses and such means the system can run through two days of cloudy weather before giving up the ghost. A second battery might be added in the future to help improve the run time during low-light conditions, but for now its been working pretty well.

Perhaps the most interesting part of the whole project are the lengths to which the website itself was optimized to keep resource utilization as low as possible. Images are compressed using dithering to greatly reduce their file sizes, and the site eschews modern design in favor of a much less processor intensive static layout. There’s even a battery capacity display integrated into the page through some clever use of CSS. Even if you aren’t looking to set up your own sun worshiping website, there are tips here for building efficient web pages that could absolutely be put to use in other projects.

If you’re interested in solar projects, we’ve got you covered. From an open source charge controller to building DIY photovoltaic panels, there’s plenty of prior art you should find very…illuminating. Please clap.

Solar Power For Chernobyl’s Second Generation Of Electricity

October 7, 2018 by Roger Cheng 40 Comments

When featuring cool hacks repurposing one thing for something else, we prefer to focus on what we could get our hands on and replicate for ourselves. Not this one, though, as nobody else has the misfortune of being responsible for 2,000 square kilometers (772 square miles) of radioactive contaminated land like the government of Ukraine. Trying to make the best of what they have, they’ve just launched a pilot program working to put up solar power farms inside the Chernobyl Exclusion Zone.

This is sure to invite some jokes in the comments section, but the idea has merit. Thirty years of weather has eroded the worst aftermath of the Chernobyl explosion. That area is no longer immediately lethal and people have been making short visits. Spanning from safety inspectors, to scientists, to curious adventurers with questionable judgement making television shows. Supposedly, by following rules on what not to do, it’s possible to keep radiation exposure of a short visit down to the level experienced by frequent fliers. But that’s still too much radiation for long-term stay. That means no homes, office parks, or factories. No agriculture either, as plants and animals grown in the area should not be eaten.

So what’s left? That’s what Ukraine has been struggling with, as it tried to figure out something positive to offset the headaches of monitoring the area.

Well, next to the defunct power plant is the electric distribution infrastructure it used to feed into, and photovoltaic power generation requires little human oversight. Some maintenance will be required, but hopefully someone has worked out how to keep maintenance workers’ cumulative exposure to a minimum. And if this idea pans out, clean renewable energy would start flowing from the site of one of the worst ecological disasters of our era. That makes it a worthwhile hack on a grand scale.

[via Gizmodo]

Unmanned Sailboat Traverses The North Atlantic

September 7, 2018 by Bryan Cockfield 21 Comments

Sailboats have been traversing the Atlantic Ocean since before 1592, sailing through sunshine, wind, and rain. The one thing that they’ve all had in common has been a captain to pilot the ship across this vast watery expanse, at least until now. A company called Offshore Sensing has sailed an unmanned vessel all the way from Canada to Ireland.

The ship, called the Sailbuoy, attempted the journey last year as well but only made it about halfway before the mission was abandoned. This year, however, the voyage was finally completed, and this craft is officially the first unmanned ship to cross the Atlantic Ocean. The journey took about 80 days using sails and a small set of solar panels to drive the control electronics.

Using this technology, the company can investigate wave activity in specific areas of the ocean without having to send out a manned vessel to install a permanent buoy. The sailbuoy simply uses its autonomy to stay in a particular patch of ocean. There have been other missions that the sailbuoy has been tasked with as well, such as investigating the aftermath of the Deepwater Horizon oil spill in the Gulf of Mexico. With a reliable craft like this, it becomes much easier, safer, and less expensive to explore the ocean’s surface.

Thanks to [Andy] for the tip!

Quadcopter Ditches Batteries; Flies On Solar Power Alone

August 25, 2018 by Richard Baguley 34 Comments

It seems kind of obvious when you think about it: why not just stick a solar panel on a quadcopter so it can fly on solar power? Unfortunately, physics is a cruel mistress, and it gets a bit more complex when you look at problems like weight to power ratios, panel efficiency, and similar tedious technical details. This group of National University of Singapore students has gone some way to overcome these technical issues, though: they just built a drone that is powered from solar power alone, with no batteries or other power source.

Their creation is a custom-built quadcopter made with carbon fiber that weighs just 2.6kg (about 5.7lbs), but which has about 4 square meters (about 43 square feet) of solar panels. By testing and hand-selecting the panels with the best efficiency, they were able to generate enough power to drive the four rotors, and have managed to achieve altitudes of up to 10 meters. The students have been working on prototypes of this since 2012, when their first version could only generate 45% of the power needed for flight. So, reaching 100% of flight power in the demo shown below is a significant step.

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Before Sending A Probe To The Sun, Make Sure It Can Take The Heat

August 15, 2018 by Roger Cheng 61 Comments

This past weekend, NASA’s Parker Solar Probe took off for a journey to study our local star. While its mission is well covered by science literate media sources, the equally interesting behind-the-scenes information is a little harder to come by. For that, we have Science News who gave us a look at some of the work that went into testing the probe.

NASA has built and tested space probes before, but none of them were destined to get as close to the sun as Parker will, creating new challenges for testing the probe. The lead engineer for the heat shield, Elizabeth Congdon, was quoted in the article: “Getting things hot on Earth is easier than you would think it is, getting things hot on Earth in vacuum is difficult.” The team used everything from a concentrated solar facility to hacking IMAX movie projector lenses.

The extreme heat also posed indirect problems elsewhere on the probe. A rocket launch is not a gentle affair, any cargo has to tolerate a great deal of shock and vibration. A typical solution for keeping fasteners in place is to glue them down with an epoxy, but they’d melt where Parker is going so something else had to be done. It’s not all high technology and exotic materials, though, as when the goal was to verify that the heat shield was strong enough to withstand up to 20G of acceleration expected during launch, the test team simulated extra weight by stacking paper on top of it.

All that testing should ensure Parker can perform its mission and tell us a lot of interesting things about our sun. And if you got in on the publicity campaign earlier this year, your name is along for the ride.

Not enough space probe action for the day? We’ve also recently featured how creative hacking gave the exoplanet hunter Kepler a second lease on life.

Tiny Solar Energy Module (TSEM) Brings Big Performance

August 12, 2018 by Donald Papp 16 Comments

The Tiny Solar Energy Module (TSEM) by [Jasper Sikken] is not only physically tiny at one-inch square, but it is all about gathering tiny amounts of solar energy — amounts too small to be useful in a conventional sense — and getting meaningful work done, like charging a battery for later use. Elements that make this board easy to integrate into other projects include castellated vias, 1.8 V and 3.3 V regulated outputs that are active when the connected battery has a useful charge, and a low battery warning that informs the user of impending shutdown when the battery runs low. The two surface-mount solar cells included on the tiny board are capable of harvesting even indoor light, but the board also has connection points for using larger external solar cells if needed.

The board shows excellent workmanship and thoughtful features; it was one of the twenty Power Harvesting Challenge finalists chosen to head to the final round of The Hackaday Prize. The Hackaday Prize is still underway, with the Human-Computer Interface Challenge running until August 27th. That will be followed by the Musical Instrument Challenge before the finals spin up. If you haven’t started yet, there’s still time to make your mark. All you need is a documented idea, so start your entry today.

PTPM Energy Scavenger Aims For Maintenance-Free Sensor Nodes

August 1, 2018 by Donald Papp 13 Comments

[Mile]’s PTPM Energy Scavenger takes the scavenging idea seriously and is designed to gather not only solar power but also energy from temperature differentials, vibrations, and magnetic induction. The idea is to make wireless sensor nodes that can be self-powered and require minimal maintenance. There’s more to the idea than simply doing away with batteries; if the devices are rugged and don’t need maintenance, they can be installed in locations that would otherwise be impractical or awkward. [Mile] says that goal is to reduce the most costly part of any supply chain: human labor.

The prototype is working well with solar energy and supercapacitors for energy storage, but [Mile] sees potential in harvesting other sources, such as piezoelectric energy by mounting the units to active machinery. With a selectable output voltage, optional battery for longer-term storage, and a reference design complete with enclosure, the PPTM Energy Scavenger aims to provide a robust power solution for wireless sensor platforms.