Can you make a spectrometer for your home lab all from materials you have sitting around? We might not believe it from a less credible source, but this MIT course does indeed build a spectrometer from foam board using two razor blades as the silt cover and a writable CD as the diffraction grating. The coolest part is removing the metal backing of the CD.
Hackaday reader [gratian] tipped us off about the course available from MIT courseware called Nanomaker. It boils down some fairly complicated experiments to the kind one can do in the home lab without involving thousands of dollars of lab equipment. The whole point is to demystify what we think of as complicated devices and topics surrounding photovoltaics, organic photovoltaics, piezoelectricity and thermoelectricity.
Spectrometers are used to analyze the wavelengths of a light source. Now that you have a measurement tool in hand it’s time to build and experiment with some light sources of your own. Here you can see an LED that is the topic of one of the course labs.
If you have a bit of background in chemistry this is a good step-by-step guide for getting into these types of experiments at home. It reminds us of some of the really cool stuff [Jeri Ellsworth] was doing in her garage lab, like making her own EL panels.
Continue reading “Bring Doping, Microfluidics, Photovoltaics, and More Into the Home”
Solar panels are an amazing piece of engineering, but without exactly the right conditions they can be pretty fickle. One of the most important conditions is that the panel be pointed at the sun, and precise aiming of the panel can be done with a solar tracker. Solar trackers can improve the energy harvesting ability of a solar panel by a substantial margin, and now [Jay] has a two-axis tracker that is also portable.
The core of the project is a Raspberry Pi, chosen after [Jay] found that an Arduino didn’t have enough memory for all of the functionality that he wanted. The Pi and the motor control electronics were stuffed into a Pelican case for weatherproofing. The actual solar tracking is done entirely in software, only requiring a latitude and longitude in order to know where the sun is. This is much easier (and cheaper) than relying on GPS or an optical system for information about the location of the sun.
Be sure to check out the video below of the solar tracker in action. Even without the panel (or the sun, for that matter) the tracker is able to precisely locate the panel for maximum energy efficiency. And, if you’d like to get even MORE power from your solar panel, you should check out a maximum power point tracking system as well.
Continue reading “Two-Axis Solar Tracker”
This solar monitoring project was entered in The Hackaday Prize and didn’t make the semifinal cut, but it is worth featuring on the site because we think that it is pretty cool. The idea started all the way back in May of 2013 when [Michel] was planning to attempt to bring his house totally off the grid in an effort to become as independent from the local Utility company as possible. After a bit of calculating, he figured out that the solar cells on the roof could potentially provide about 80% of the power needed, which of course took into account the lack of sun during the winter months in his area.
[Michel] posts a lot of the technical details on the Hackaday.io page and lists the components that were required to set up this system. At night, a lighting mechanism shows whether the building is being run off of the Photovoltaic (PV) System or if it is getting power from the grid. He states in the projects logs why it is important to monitor the solar cells and provides some amazing graphs of the data that was recorded through the energy-intelligence platform that he integrated into his home. An example can be seen posted below. A few quick specs of the project include the solar field being made of 16 solar modules providing 4300 Wp (Watts – peak) of electrical power. The system comes with a comprehensive remote control as well. We like this idea a lot. Now, would you install something like this up on your own home or office? Let us know in the comments.
This project is an official entry to The Hackaday Prize that sadly didn’t make the quarterfinal selection. It’s still a great project, and worthy of a Hackaday post on its own.
Continue reading “Extrinsic Motivation: Off-grid Solar System Monitoring Solution”
Drone technology is driving the aerospace industry as companies trip over each other trying to develop the next big thing. Here’s a good example of what we’re talking about. Lasers can no be used to keep a UAV in the air indefinitely. The trick is to add an array of photovoltaic cells specifically tuned to an IR laser’s wavelength. A ground system then directs a high-intensity laser beam onto the aircraft’s cell array to transfer energy while in flight.
After the break you can catch a video from a trade show where a Lockheed Martin employee describes the successful testing of such a system. But there’s a lot more information available in the white paper (PDF) which Laser Motive has released. They’re the folks behind the technology who have teamed up with LM to implement the system. The laser unit on the ground can track a UAV visually, but there is also a method of using GPS coordinates to do so in the case of overcast skies.
Continue reading “Laser power system keeps UAVs flying indefinitely”
[Michael Ossman] wrote in to show off his newest project. He calls it the Firefly cap, which we think is something of a play on words. You can see that it serves as the cap of a Mason jar, but it also uses a supercap instead of a rechargeable battery.
Posts about firelfly jars go way back. And [Michael] mentions that a similar firefly project was his first embedded project. The concept uses LEDs suspended in a jar. When a light detector senses the target level of darkness, the lights inside begin to twinkle like their insect namesakes.
We like this design for two reasons. It’s aimed at collecting light in an indoor environment so you don’t have to worry about placing it in the sun. And it uses a super capacitor instead of a battery so this should truly keep going and going without wearing out the energy storage components. We also like the fact that although this is a Kickstarter project, everything you need to build your own is already available at the Github repository.
[Mathieu] was interested in using more solar cells for his everday electronics. He looked around but couldn’t find much information about using pholovoltaic for small indoor devices. We remember hearing some of the same things from [Dave Jones] in one of his EEVblog installments from a few years ago which looked at solar calculators; the only indoor solar gadget we can think of.
The quest for knowledge was on and [Mathieu] decided to build this indoor solar cell test platform. It’s a stable piece of hardware that allows him to run reliable tests in many different conditions. It’s designed to compare two identical cells. One is charging the Lithium cell, the other is driving a load directly. A second battery powers the platform separately from the solar circuits so that it can be used as a data logger. He collects, dumps, and graphs info from his test runs, then discusses his findings. We won’t spoil it, but the results are not great. Mostly you need sunlight to get real results as it’s just so much more powerful than artificial lighting.
Here’s a photovoltaic cell that can be printed onto paper. The manufacturing technique is almost as simple as using an inkjet printer. The secret is in the ink itself. It takes five layers deposited on the paper in a vacuum chamber. But that’s a heck of a lot easier than current solar cell fabrication practices. In fact, is sounds like the printing process is very similar to how potato chip bags are made. This is significant, because it could mean a fast track to mass production for the technology.
It isn’t just the easy printing process that excites us. Check out the video after the break where a test cell is placed on top of a light source while being monitored by a multimeter. It’s been folded like a fan and you can see a researcher sinch up the cell into a small form for storage. It’s a little counter-intuitive; for instance, you wouldn’t want to make a window shade out of it because it would have to be down during the day to get power. Be we think there’s got to be some great use for these foldable properties. Continue reading “Printable solar cells that can be folded up when not in use”