Solar category

Efficient Low-Cost Solar Energy Converter

Researchers at the École Polytechnique Fédérale de Lausanne and the Centre Suisse d’Electronique et de Microtechnique have invented a new device to store solar power while the sun’s not shining by converting it into Hydrogen. Although many current methods use the same approach to store energy, but this device rivals them in stability, efficiency and cost.

An effective and low-cost solution for storing solar energy © Infini Lab / 2016 EPFL


They combined commercially available components that have already proven effective in industry, such as Nickel, in order to develop a robust and effective system, that is  :made up of three interconnected, new-generation, crystalline silicon solar cells attached to an electrolysis system that does not rely on rare metals. The device is able to convert solar energy into hydrogen at a rate of 14.2%, and has already been run for more than 100 hours straight under test conditions.”

In order to develop this device, the researchers used layers of crystalline silicon and amorphous silicon to allow higher voltages. Thus, three cells in series generate a nearly ideal voltage for electrolysis.

“We wanted to develop a high performance system that can work under current conditions,” says Jan-Willem Schüttauf, a researcher at CSEM and co-author of the paper. “The heterojunction cells that we use belong to the family of crystalline silicon cells, which alone account for about 90% of the solar panel market. It is a well-known and robust technology whose lifespan exceeds 25 years. And it also happens to cover the south side of the CSEM building in Neuchâtel.”

This method, which outperforms previous efforts in terms of stability, performance, lifespan and cost efficiency, is published in the Journal of The Electrochemical Society. You can check the scientific paper here.


Arduino based sun tracking turret

Arduino Based Sun Tracker Turret

Sun tracker systems are widely used in solar panel setups to get maximum performance. You may want to use one in your personal solar panel setup. Now you can make your own with an Arduino, following the project that’s designed by RobotGeek Team and Wade Filewich.

Arduino based sun tracking turret
Arduino based sun tracking turret

Parts You’ll Need:

You should also upload the sketch in Arduino. So download it from GitHub –> desktopRoboTurretV3.

To upload the sketch in Arduino,

File → Sketchbook → desktopRoboTurretV3 → roboTurret3_solarTracker

Now click Upload.


Sun Tracker Turret Based On Arduino
Sun Tracker Turret Based On Arduino

Place the light sensors in correct position and wire them to Arduino accordingly. Any wrong positioning can generate strange behavior of the system.  Jumpers for the servos (pin 9, 10, and 11) are set to VIN, so that your servos function properly.

(NOTE: A 6V power supply will work just fine, and RoboTurret Kit includes one). Here is the chart of wiring:

Wiring list of servo and Arduino : Sun tracker
Wiring chart of servo,light sensor, potentiometer and Arduino : Sun tracker

There are two potentiometers. One is for controlling the speed of servos, and another is for controlling the sensitivity of sensors.

Set Up The Turret:

You should follow Desktop RoboTurret Assembly Guide to build the turret. After building, attach your sensors to the top plates as close to center as possible. Look at the picture:

Sensor Positions On Turret
Sensor Positions On Turret

The “+” shaped fins cast shadow on sensors. So, position of sensors should be correct else fins can’t cast shadow  on them accurately. Have a close view on sensor’s position:

Sensor position on turret : close lookup
Sensor position on turret : close view

While wiring through the plate, keep wires loose enough so that turret can move freely to aim at the Sun. At the back of the turret base, there is plenty of room to mount the two potentiometers.

The fins are 8 inches tall, which should be plenty to cast shadow on the sensors. I’ve used scrap cardboard for the fins, but you can use whatever material suits you best, so long as it is opaque and can throw a shadow.

Test It:

So, you finished the building process. Now let’s test it. Upload the code to Arduino and power up the system. Now hold a table lamp and move it. The turret should follow the movement. Adjust speed and sensitivity using the two potentiometers. Watch the video that demonstrates the system:

A very simple DIY solar-powered USB charger


Raj @ tipped us with his latest project. It’s a simple, but useful USB Solar powered charger able to charge a power bank or your smartphone.

Yesterday, I built a very simple DIY solar-powered USB charger for my TP-link 10400mAh USB Power Bank. All I needed was a 6V/3.5W solar panel and the TD1410-based 5V buck converter module. I bought both of them on Aliexpress for less than $8.

A very simple DIY solar-powered USB charger – [Link]

21.1% efficiency with Perovskite solar cells


Scientists have successfully developed a Perovskite solar call containing Cesium which has attained an efficiency of 21.1%, as well as a world record for reproducibility. by Denis Meyer @

In adding Cesium, the scientists at EPFL, let by Michael Saliba, have developed the first Perovskite compound with triple cations (Cs/MA/FA). These new films are more stable in hot conditions and less affected by fluctuations in environmental variables. They have confirmed efficiencies of 21.1%, and exit efficiency of 18% in operational conditions, even beyond 250 h.

21.1% efficiency with Perovskite solar cells – [Link]

SolarBoost – Make Your Own USB Solar Mobile Charger


SolarBoost is an open source smart interface that allows you to build your own powerful and portable solar charger for your phone and other mobile devices. It has two USB ports and can provide 5V @ 2A at each of them and is controlled by a 8-bit 32MHz Microchip PIC microcontroller. It is also equipped with various protection features like soft-start, over-temperature, over-charge, over-discharge, short-circuit and current limiter.

SolarBoost is the first open-hardware and open-source smart interface designed to give you the freedom and flexibility to make your own battery- and solar-powered power bank for charging cellphones, tablets, MP3 players, speakers, GPS navigators, and much more. Use it to also power your DIY electronics projects!

SolarBoost – Make Your Own USB Solar Mobile Charger – [Link]

Organic solar cells set new efficiency record


The German company Heliatek has developed new OPV multi-junction solar cells with an efficiency of 13.2%. This is a world record for organic solar cells.

Thanks to the excellent low light and high temperature behavior of the organic semiconductor, the electricity generation of the newly developed cells corresponds to the output of conventional solar cells with 16 to 17% efficiency when both are under real world conditions.

Organic solar cells set new efficiency record – [Link]