Open-Source Solar Modules

As the price of solar panels continues to fall, more and more places find it economical to build solar farms that might not have been able to at higher prices. High latitude locations, places with more clouds than sun, and other challenging build sites all are seeing increased green energy development. The modules being used have one main downside, though, which is that they’re essentially a black box encased in resin and plastic, so if one of the small cells fails a large percentage of the panel may be rendered useless with no way to repair it. A solar development kit like this one from a group called Biosphere Solar is looking to create repairable, DIY modules that are completely open source, to help solve this issue.

The modular solar panel is made from a 3D printed holster which can hold a number of individual solar cells. With the cells placed in the layout and soldered together, they are then sandwiched between a few layers of a clear material like acrylic or glass with a seal around the exterior to prevent water intrusion. Since the project is open-source any number of materials can be used for the solar cell casing, and with the STL file available it’s not strictly necessary to 3D print the case as other manufacturing methods could be used. The only thing left is to hook up a DC/DC converter if you need one, and perhaps also a number of bypass and/or blocking diodes depending on your panel’s electrical layout.

The project is still in active development, and some more information can be found at the project’s website. While the “recyclability” of large-scale solar farms is indeed a problem, it’s arguably one which has been overblown by various interests who are trying to cast doubt on green energy. A small build like this won’t solve either problem anytime soon, so the real utility here would be for home users with small off-grid needs who want an open-source, repairable panel. It’s a great method to make sure solar technology is accessible and repairable for anyone that wants it, and in a way this approach to building hardware reminds us a lot of the Framework laptops.

Kites Fill Electricity Generation Gaps

Looking at a wind turbine from first principles, it’s essentially a set of wings that generate lift in much the same way an airplane wing does. Putting the wings on a rotor and calling them “blades” is not a huge step away from that. But there’s no reason the wing has to rotate, or for that matter be attached to a fixed platform, in order to generate electricity. Anything that generates lift can be used, and this company is demonstrating that with their kite-powered wind generators.

Like other wind energy producers that have used kites to generate electricity, this one is similar in that the kite is flown in a figure-8 pattern downwind where it can harness energy the most efficiently, pulling out a tether which is tied to a generator. When fully extended, it is flown to a position where the wind doesn’t strike the kite as strongly and the tether is reeled in. Unlike other kite generators we’ve seen, though, this one is offered as a turnkey system complete with battery backup and housed in a self-contained shipping unit, allowing it to be deployed quickly to be used in situations where something like a diesel generator would be impossible to get or where the fuel can’t be obtained.

The company, called Kitepower, does note that these aren’t replacements for traditional wind turbines and would be used more for supporting microgrids. There are still some advantages to using kites over fixed turbine blades though: kites can reach higher altitude where the wind is stronger, and they require less materials for a given amount of energy production, often making them even more environmentally friendly and possibly more economical as well. Surprisingly enough, kites can also be used to generate energy even in places where there’s no wind at all.

Solar Chimneys: Viable Energy Solution Or A Lot Of Hot Air?

We think of the power we generate as coming from all these different kinds of sources. Oil, gas, coal, nuclear, wind… so varied! And yet they all fundamentally come down to moving a gas through a turbine to actually spin up a generator and make some juice. Even some solar plants worked this way, using the sun’s energy to heat water into steam to spin some blades and keep the lights on.

A solar updraft tower works along these basic principles, too, but in a rather unique configuration. It’s not since the dawn of the Industrial Age that humanity went around building lots of big chimneys, and if this technology makes good sense, we could be due again. Let’s find out how it works and if it’s worth all the bluster, or if it’s just a bunch of hot air.

Continue reading “Solar Chimneys: Viable Energy Solution Or A Lot Of Hot Air?”

Monitoring Energy Use And Saving Money

On the surface, the electric grid might seem like a solved piece of infrastructure. But there’s actually been a large amount of computerized modernization going in the background for the past decade or so. At a large scale this means automatic control of the grid, but for some electric utility customers like [Alex] this means the rates for electricity can change every hour based on demand. By keeping an eye on the current rate, you can extract the most value from these utilities.

[Alex] is located in the United Kingdom and has an energy provider whose rates can change every half hour. This information is freely available well enough in advance to download the data and display it visibly in with a NeoPixel LED ring around a clock. The colors displayed by the LEDs represent an increase or decrease in price for the corresponding time and allow him to better plan out the household’s energy use for the day. The clock uses a TinyPICO ESP32 module to gather the data and handle the clock display. A second wall-mounted device shows real-time energy readings for both gas and electricity using two old analog voltmeters modified to display kilowatt-hours.

While not everyone has a utility which allows this sort of granularity with energy pricing, having one can make a bit of a difference as electricity rates under this system can sometimes go negative. [Alex] estimates that using these two displays to coordinate his energy usage has saved around £50 a month. Even if your utility offers minimal or no price adjustments for time-of-use, it’s still a good idea to monitor energy use in your home. Here’s a fairly comprehensive project that does that without modifying any existing wiring.

Bending Light To Fit Technology

Solar power is an excellent way of generating electricity, whether that’s for an off-grid home or for the power grid. With no moving parts maintenance is relatively low, and the downsides of burning fuel are eliminated as well. But as much as it’s revolutionized power generation over the last few decades, there’s still some performance gains to be made when it comes to the solar cells themselves. A team at Stanford recently made strides in improving cell efficiency by bending the properties of sunlight itself.

In order to generate electricity directly from sunlight, a photon with a specific amount of energy needs to strike the semiconductor material. Any photons with higher energy will waste some of that energy as heat, and any with lower energy won’t generate electricity. Previous methods to solve this problem involve using something similar to a prism to separate the light out into colors (or energies) that correlate to specific types of cells calibrated specifically for those colors. This method does the opposite: it changes the light itself to an color that fits the semiconductor material. In short, a specialized material converts the energy from two lower-energy photons into a single higher-energy photon, which then strikes the solar panel to create energy.

By adding these color-changing materials as a layer to a photovoltaic solar panel, the panel can generate more energy with a given amount of light than a traditional panel. The major hurdle, as with any research, is whether or not this will be viable when produced at scale, and this shows promise in that regard as well. There are other applications for these materials beyond photovoltaics as well, and the researchers provide an excellent demonstration in 3D printing. By adding these color-change materials to resin, red lasers can be used instead of blue or ultraviolet lasers to cure resin in extremely specific locations, leading to stronger and more accurate prints.

Harvesting Mechanical Energy From Falling Rain

Collecting energy from various small mechanical processes has always been something that’s been technically possible, but never done on a large scale due to issues with cost and scalability. It’s much easier to generate electricity in bulk via traditional methods, whether that’s with fossil fuels or other proven processes like solar panels. That might be about to change, though, as a breakthrough that researchers at Georgia Tech found allows for the direct harvesting of mechanical energy at a rate much higher than previous techniques allowed.

The method takes advantage of the triboelectric effect, which is a process by which electric charge is transferred when two objects strike or slide past one another. While this effect has been known for some time, it has only been through the advancements of modern materials science that it can be put to efficient use at generating energy, creating voltages many thousands of times higher than previous materials allowed. Another barrier they needed to overcome was how to string together lots of small generators like this together. A new method that allows the cells to function semi-independently reduces the coupling capacitance, allowing larger arrays to be built.

The hope is for all of these improvements to be combined into a system which could do things like augment existing solar panels, allowing them to additionally gather energy from falling rain drops. We’d expect that the cost of this technology would need to come down considerably in order to be cost-competitive, and be able to scale from a manufacturing point-of-view before we’d see much of this in the real world, but for now at least the research seems fairly promising. But if you’re looking for something you can theoretically use right now, there are all kinds of other ways to generate energy from fairly mundane daily activities.

Continue reading “Harvesting Mechanical Energy From Falling Rain”

Formation Flying Does More Than Look Good

Seeing airplanes fly in formation is an exciting experience at something like an air show, where demonstrations of a pilot’s skill and aircraft technology are on full display. But there are other reasons for aircraft to fly in formation as well. [Peter] has been exploring the idea that formation flight can also improve efficiency, and has been looking specifically at things like formation flight of UAVs or drones with this flight planning algorithm.

Aircraft flying in formation create vortices around the wing tips, which cause drag. However, another aircraft flying through those vortices will experience less drag and more efficient flight. This is the reason birds instinctively fly in formation as well. By planning paths for drones which will leave from different locations, meet up at some point to fly in a more efficient formation, and then split up close to their destinations, a significant amount of energy can potentially be saved. Continue reading “Formation Flying Does More Than Look Good”