Photovoltaic category

AEM10941 – Photovoltaic Energy Harvesting Power Management IC

E-peas’ photovoltaic energy harvesting IC solution – AEM10941 – is the next generation integrated energy management subsystem that extracts DC power from up to 7 cells solar panels to simultaneously store energy in a rechargeable element and supply the system with two independent regulated voltages. This allows product designers and engineers to extend battery lifetime and ultimately get rid of the primary energy storage element in a large range of wireless applications like industrial monitoring, home automation, wearables.

The AEM10941 harvests the available input current up to 125 mA. It integrates an ultra-low-power Boost converter to charge a storage element, such as a Li-Ion battery, a thin film battery or a super- or conventional capacitor. The Boost converter operates with input voltages in a range of 50 mV to 5V. With its unique cold-start circuit, it can start operating with empty storage elements at an input voltage as low as 380 mV and an input power of just 3 µW.

The low voltage supply typically drives a microcontroller at 1.8 V. The high voltage supply typically drives a radio transceiver at a configurable voltage. Both are driven by highly efficient LDO (Low Drop-Out) regulators for low noise and high stability.

more ->

Tiny Solar Energy Module (TSEM)

A 1 square inch PCB module with 2 tiny solar cells, a highly efficient Li-Ion charger and with 3.3V and 1.8V output by Jasper Sikken:

This is a 1×1 inch PCB module with two tiny solar cells, a highly efficient Li-Ion battery charger and with two regulated outputs (3.3V and 1.8V). It is unique because it is an easy to manufacture tiny module that other hackers can drop in their PCB design or bread board. Bessides it harvests enough power from indoor light to power a simple BLE or LoRa sensor.

The challenge is to design a TINY module that easily interfaces to other projects. I selected tiny surface mount solderable solar cells, a highly integrated energy harvesting IC, and left out the battery. The board has castellated vias so it can be surface mount soldered onto a mother PCB as well as soldered onto 0.1″ headers to be used in a bread board.

Tiny Solar Energy Module (TSEM) – [Link]

ATmega32U4-Based Synchronous MPPT Buck Solar Charger

You want to maximize the power output of your solar panel? Then you need a maximum power point tracking charge controller! Source files here.


  • Programmable with Arduino IDE
  • Input voltage: 15 – 22V
  • Output voltage: 1 – 14.4V
  • Simple MPPT (Maximum Power Point Tracking) solar charge controller for 18V solar panels
  • Proper buck converter topology, which increases the current on the output side, not just PWM
  • SparkFun Pro Micro 5V, 16MHz or 3.3V, 8MHz (3.3V recommended, more efficient)
  • ACS712 current sensor (5A version) on the output side
  • Voltage dividers for voltage measurement on panel and output side
  • Two N-channel MOSFETs, driven by IR2104 half bridge driver, inductor (synchronous buck converter)
  • Supplied by the panel voltage, so it can’t drain your battery during the night
  • Working frequency 31.5kHz
  • WARNING! This device is not intended to drive 5V USB devices directly. Do it at your own risk!
  • Always use a regulated 5V USB adapter on the output! Otherwise, voltage glichtes may damage your USB device!
  • This controller is COMMON NEGATIVE
  • Three operation modes: MPPT, CV, CC
  • SD card data logger for time, voltage and current. You can import the txt files in Excel
  • WARNING! Always adjust output voltage and output current limits according to your battery type!!
  • Efficiency between 84% and 92% (excluding board supply current of about 75mA)

ATmega32U4-Based Synchronous MPPT Buck Solar Charger – [Link]


High Efficiency MPPT Solar Charger

A 75 watt MPPT Solar Charger with tons of features. Efficiency > 97%, USB interface, data logging, 2 USB charging ports and much more…by Lukas Fässler

This is an open source project that I’ve been working on for several years now. From its modest beginnings it has evolved to a rather sophisticated device with a USB interface, powerful USB charging ports, a 20×4 character LCD, a rotary encoder with push button, precision measurement of everything from temperatures, voltages and currents. There are 4 switchable power outputs, a year’s worth of data logging with real time clock and calendar. It connects to a desktop app via USB where users can monitor and adjust every aspect as well as see what the charger did while they were away.

High Efficiency MPPT Solar Charger – [Link]

Hybrid solar panel can generate power fro rain too

Researchers Develop New Hybrid Solar Panel That Can Generate Power From Rain Too

The researchers at Soochow University in China, have published a paper on the hybrid device that is able to harness the power of sun and rain using a hybrid panel. By attaching a transparent nanogenerator to a silicon solar cell, researchers have designed a device that harvests solar energy in sunny conditions and the mechanical energy of falling raindrops in rainy conditions. The dual functionality of this hybrid panel may provide a way to collect energy with greater efficiency in the midst of constantly changing weather conditions.

Hybrid solar panel can generate power fro rain too
The hybrid solar panel can generate power fro rain too

The hybrid device consists of a conventional silicon solar cell and a Triboelectric Nanogenerator (TENG), which turns the mechanical energy of falling raindrops into electricity. Although previous research has shown that these two types of devices can be connected with an extra wire, in the new design the solar cell and TENG are integrated by sharing a mutual electrode.

The biggest breakthrough in this work is that an integrated generator composed of a solar cell and a TENG was demonstrated through sharing a mutual electrode,

Zhen Wen at Soochow University said,

Compared to previous work, the simple design of the mutual electrode reduces the number of functional layers, which greatly improves the output efficiency.

The mutual electrode not only results in a more compact design, but it also offers advantages to both the solar cell and TENG. In particular, the TENG protects the solar cell by acting as a waterproof barrier and prevents water from penetrating the silicon. The textured electrode surface also greatly overcomes unwanted reflection of light, enhancing light harvesting of the solar panel. The textured surface results in a greater contact area between the TENG and falling raindrops, which improves the overall performance of the nanogenerator.

Due to the unique design, it has advantages of being lightweight and having a high efficiency, The team is now designing a fiber-shaped device and expect to weave them together as a fabric. In near future, it is possible to fabricate such clothing that can generate electricity from sunshine and raindrops, and then use this electricity to power wearable electronic devices.

DC-DC converter starts up and operates from a single photocell

by Marian Stofka @

The bq25504 from Texas Instruments is a good candidate to become a milestone on the road to micro-power management and energy harvesting. A prominent feature of this IC is its ability to start up at a supply voltage as low as 330 mV typically, and 450 mV guaranteed. With an SMD inductor and a few capacitors and resistors, it forms a dc-dc converter with a high power efficiency that is unprecedented, especially in the ultralow-power region.

DC-DC converter starts up and operates from a single photocell – [Link]

Solar energy harvester IC that operates with indoor lighting

Saelig Company, Inc. ( has introduced the patented Sol Chip Saturn802 Energy Harvester IC – a unique photovoltaic (PV) cell which can produce output voltage levels of 0.75V, 1.5V, 2.25V, 3.0V, 4.5V, and 9V, which existing solar cells cannot do.  The maximum power which can be obtained in full daylight is around 10mW, or 55uW in office lighting, so the Saturn802 IC is targeted at low-power applications. The size of the die is approximately 1cm by 1cm, and the stable voltage levels are available from separate pins of the device.  The IC can be used with or without a back-up battery.

Sol Chip’s unique technology integrates solar energy conversion principles with very large scale integration (VLSI) techniques to produce a unique ambient light harvesting device that combines photovoltaic layer and microchip circuitry in layers on the same substrate.  Although solar cells have been around for a long time, with microchips being the mainstay of electronic devices, no company in the semiconductor industry has successfully integrated solar cells with standard chip manufacturing processes in a cost effective way.

The Sol Chip Energy Harvester allows designers to build low-powered products that can recharge themselves.  All that is needed is a small window in the product design or a transparent cover to allow light to reach the surface-mounted Saturn802 chip.  This eliminates the need for a battery in low power products, thus removing maintenance and environmental waste issues. Incorporating the Sol Chip Energy Harvester in product designs is ideal for hard-to-reach locations where battery use and routine replacement is inconvenient or prohibitively expensive.

Applications suited to the Saturn802 include wireless sensor networks, drip-irrigation systems, wearable electronics, smart city solutions like parking or security and utility meters, data loggers, shelf labeling, GPS emergency locators, animal tracking devices, GPS asset/container tracking,  autonomous environmental and pollution measurement devices, and RFID devices.   Saturn802 designs can operate continuously for more than ten years with no maintenance requirements.  In wireless products this also eliminates the significant costs and time associated with wiring connections for the deployed sensors, reducing system cost of ownership.

Forming an “everlasting battery”, the Saturn802 solar cells are available on an evaluation board, the Eval-802, allowing users to develop their own power regulation circuitry for handling differing light and load conditions.  For a ready-made solar solution using the Saturn802 cell, the SCP-2801 board provides all necessary circuitry to provide constant 24/7 output.

Made in Israel by Sol Chip Ltd., an innovative solar products manufacturer, the Sol Chip Saturn802 Energy Harvester IC and the SCP-2801 Evaluation Kit are available now from Saelig Company, Inc., Sol Chip’s authorized North American distributor.

Perovskite solar cells stabilized at 19% efficiency


Researchers at EPFL in Switzerland have found that adding large organic compounds called guanidinium (CH6N3+) into methylammonium lead iodide perovskite solar cells can provide stable power efficiency of 19%, approaching that of silicon cells. by Nick Flaherty @

The lab of Mohammad Khaja Nazeeruddin at EPFL Valais Wallis, with colleagues at the University of Cordoba and the Helmholtz Institute in Berlin, has discovered that they can improve the perovskite stability, overcoming what is known as the “Goldschmidt tolerance factor limit.” This is an indicator of the stability of a perovskite crystal, which describes how compatible a particular ion is to it. An ideal Goldschmidt tolerance factor should be below or equal to 1; guanidinium’s is 1.03.

Perovskite solar cells stabilized at 19% efficiency – [Link]


by Bryce Salmi @

The Radio Amateur Satellite Corporation, AMSAT, recently designated RadFxSat as AO-91 after its successful deployment from a Delta II rocket as a secondary payload to NASA’s JPSS-1. RadFxSat is the first of several AMSAT satellites which are flying a Maximum Power Point Tracker (MPPT) designed and built by Brent and I as a continuation of our Rochester Institute of Technology (RIT) senior design project. The story of the Fox-1 MPPT is a great example of how amateur radio is what you want it to be.


Grid-connected solar microinverter reference design

A PDF from Microchip on the theory behind inverter design connected to grip power.:

There are two main requirements for solar inverter systems: harvest available energy from the PV panel and inject a sinusoidal current into the grid in phase with the grid voltage. In order to harvest the energy out of the PV panel, a Maximum Power Point Tracking (MPPT) algorithm is required. This algorithm determines the maximum amount of power available from the PV module at any given time. Interfacing to the grid requires solar inverter systems to abide by certain standards given by utility companies. These standards, such as EN61000-3-2, IEEE1547 and the U.S. National Electrical Code (NEC) 690, deal with power quality, safety, grounding and detection of islanding conditions.

Grid-connected solar microinverter reference design – [Link]