DIY Solar Ebike Goes Around The World, We Hope

[Mark Havran] is on a mission to complete a solo trip around the world on his bicycle. For such a long and arduous trip, unsupported by anything other than what he and his bike can carry, he has devised a unique vehicle with everything he needs to accomplish his journey. This bike has plenty of things we’ve seen before, such as solar panels and an electric motor, but plenty of things that are completely novel as well.

For such long-distance trips, the preferred style of bike for most is a recumbent. This allows the rider to take a more relaxed position while riding and is much more efficient than an upright bike as well. [Mark]’s bike also uses a hub motor in the front wheel powered by a set of lithium ion battery packs. The bike also utilizes four solar panels with three charge controllers (to reduce the impacts of panel shading) laid out with three of the panels on a trailer and a single panel above the bike to give him some shade while riding. [Mark] also built solar tracking abilities into each of the two arrays, allowing the solar panels to automatically rotate around the trailer and bike to more efficiently capture sunlight than a statically-mounted set of panels would be able to. They can also be manually controlled in case of high winds.

From the video linked below, we can see a number of other added features to the bike that will enable it to make such a long trip. First, he is getting a new motor which has a number of improvements over his old one, which he put over 30,000 kilometers on. Second, there are some safety features that deserve a mention such as his lighting setup borrowed from emergency response vehicles, and even includes a fire extinguisher for any catastrophic electrical failures. Of course, if you aren’t optimizing your recumbent electric bike for long distance there are some other modifications you could make to it as well to improve its off-road abilities. Best of luck, Mark!

Continue reading “DIY Solar Ebike Goes Around The World, We Hope”

Suntracker Optimizes Solar Panels While Visualizing Sun’s Path

If you have solar panels, you want soak up as much sunshine as you can to get your money’s worth. If you don’t have space for a lot of panels, the next best thing is repositioning the panels to catch the most rays. For his entry into the Hackaday Prize, [Frank] built a gorgeous solar tracker prototype to both validate his theories and to serve as a learning platform.

A solar tracker’s purpose is — you guessed it — tracking the Sun’s location to determine optimal positioning for solar panels and other sun-seeking payloads. In the latest revision, [Frank]’s tracker follows the Sun’s azimuth angle, aka its horizontal movement.

The Sun’s path is represented along a ring of 32 red/green LEDs. It moves around the ring as a green LED, according to a real-time clock and a set of pre-determined solar positions stored on an SD card.

Two red LEDs show the sunrise and sunset azimuth angles, and a third LED indicates North as detected with a magnetometer and adjusted for local magnetic declination. In the center of the ring, a stepper motor drives an arrow that always points at the Sun LED. As the tracker is moved around, all the LEDs shift around the ring to follow their targets.

Though it already shines, we think this ongoing project has a bright future. Be sure to check out the demo video after the break.

Continue reading “Suntracker Optimizes Solar Panels While Visualizing Sun’s Path”

Self-Powered Sun Tracker Takes A Cue From NASA Solar Probe

Getting a solar array to track the sun has always been an interesting problem, and it has led to some complicated solutions. Controllers that use GPS and servos seem to be much in favor these days, but as this NASA-inspired sun tracker shows, the task needn’t be overly complex.

It’s pretty obvious from the video below that [NightHawkInLight]’s solar tracker is just a proof-of-concept for now, but it certainly shows promise. It’s based on NASA’s sun-skimming Parker Solar Probe, which uses sensors at the rear of the probe to maneuver the craft to keep sunlight from peeking around the sides of the shield. [NightHawkInLight]’s design simplifies that scheme even more, by using solar cells as the four sensors. The cells, mounted behind a solar shade, are directly connected to small gear motors that control azimuth and elevation. When a cell sees the sun, it powers the motor that moves the panel the right way to occlude the sun again, thereby cutting power to the motor.

[NightHawkInLight] mentions the obvious problem of what happens when the sun comes up and the array is pointing the complete opposite direction after the previous sunset, but we’re still not sure his solution – a larger array with tracking cells mounted further apart – will work. We’re also not sure how it will scale to larger arrays that need bigger motors to move. We’ve seen such arrays handled with more complicated trackers, of course, but we hope the simplicity of this design can be made practical for real-world use.

Continue reading “Self-Powered Sun Tracker Takes A Cue From NASA Solar Probe”

Hardware Store Goods And An Mbed Combine Help Solar Panels Track The Sun


If you have the space, and can build a tracking rig cheaply you’ll be able to get a lot more out of your solar panels. That’s because they work best when the sun’s rays are hitting them perpendicular to the surface and not at an angle. [Michael Davis] hit both of those stipulations with this mbed powered solar tracker.

At a garage sale he picked up an antenna motor for just $15. The thing was very old, but still wrapped in the original plastic. It’s beefy enough to move his panels, but he first needed a way to mount everything. After checking his angles he built a base out of wood and used galvanized water pipe as an axle. Cable clamps mate his aluminum angle bracket frame to the pipe. This frame holds the panels securely.

To track the sun he used two smaller cells which aren’t easy to pick out in this image. They are monitored by the mbed microcontroller which measures their output in order to point the assembly in the direction which has the most intense light. A couple of limit switches are included to stop the assembly when it reaches either side.

This technique of using small solar cells as the tracking sensors seems to work well. Here’s another project that took that approach.

Continue reading “Hardware Store Goods And An Mbed Combine Help Solar Panels Track The Sun”

Using Solar Cells To Track The Sun For Your Solar Cells (dawg)

This solar panel tracks the sun using solar cells. It’s a pretty interesting technique, and can be done on the cheap.

The rectangular panels are doing the actual energy harvesting. The circular modules seen below are solar cells from some landscaping lights. They’re being used as sensors to help judge if the device is aimed directly at the sun. We’ve already seen this type of thing done with a quartet of light dependent resistors. In this case, if the negative leads for both landscaping lights are connected, a voltage may be read from the positive lead of each panel. If you measure that voltage, and use a rotating stand to adjust the position until the readings balance, you can be assured that your array is getting the optimal amount of sunlight.

[Gtoal] had been trying to drive motors directly from the output lines of these panels without success. We’re sure there’s a simple analog comparator circuit which would facilitate this. Grabbing a small microcontroller is another option (and some chips have an analog comparator built in).

LED Sensor Solar Tracker

More of my EV kick coming through. A solar tracker is used rotate a solar panel to get optimum energy from the sun. This one uses LEDs as the light sensor and mosfets to drive the output to rotate on a single axis. He even reduced the duty cycle on the fets so no heatsink is needed. Mounting in a peanut butter jar keeps the circuit dry and allows the sun to shine through. (The designer sells these, but has circuits up on the site)