Indian Solar Energy Project Takes Home $100,000 IEEE Prize

The Empower a Billion Lives global competition aims to remove energy-access barriers

2 min read
Three people looking at a computer screen.
A family living in an off-grid village in Tanzania's Lake Zone region tests a converter for their solar home system made by Solaris
Photo: IEEE Empower a Billion Lives

THE INSTITUTE The IEEE Power Electronics Society (PELS) organized the Empower a Billion Lives (EBL) global competition to crowdsource ideas that could improve energy access in underserved communities. The competition’s solutions were aimed at addressing the energy-access needs of the 3 billion people living in energy poverty, including 1 billion people who have no access at all to energy services, as identified by the International Energy Agency.

“Energy access is an area where IEEE has the expertise and global reach and can review viable solutions to help de-risk market entry for solutions that will address the challenge,” says Deepakraj M. Divan, global steering chair of EBL.

Teams developed agnostic technology solutions using renewable and sustainable 21st-century technologies that were regionally respectful and had sound business plans that could be scaled up to address more people.

Solutions had to provide users with at least 200 watt-hours of electricity per day—an amount sufficient for a variety of activities beyond just providing lighting, such as cellphone charging, pumping water, running fans, milling, and refrigeration.

The competition consisted of an online round, a regional round, field-testing, and then the global final. More than 475 teams from 70-plus countries registered for the 2018 online round. They came from universities, companies, research labs, and nonprofit organizations.

The regional rounds included 82 teams selected from proposals submitted online. The sessions were held in Atlanta; Chennai, India; Johannesburg; Seville, Spain; and Shenzhen, China. The field-testing included the 23 teams that had won at the regionals. The field-testing of solutions was deployed in an area where there was no access to electricity and where people lived on less than US $1.90 per day.

 “The format of Empower a Billion Lives was helpful for the teams because they were able to interact with experts in the power electronics field,” says Mike Kelly, IEEE PELS executive director. “I think the feedback they received was invaluable in helping them further develop their solutions.”

The global final winner—selected based on the technology the team used, the project’s social impact, the business model, and field-testing data—was Solar Urja Through Localization for Sustainability, which collected the $100,000 grand prize. SoULS, founded at the Indian Institute of Technology Bombay in Mumbai, India, is an initiative that provides training and support for women to become entrepreneurs in the solar business.


The World Bank reports that more than 200 million people in India are not connected to the power grid.

The winning SoULS solution trains women and schoolchildren to assemble simple solar lamps that students bring home to use while studying at night. After constructing the lamps, the female entrepreneurs learn to assemble, install, and repair more sophisticated solar solutions. Hundreds of women who received the training now run factories.

“So far 700 women-led factories have opened up in 10 states serving 317 subdistricts and 40,000 villages,” Divan says. “One of the great advantages to this model is the money the women make stays within the community.”

Additionally, many of the women have opened up stores to offer villagers related products such as solar panels, DC appliances, batteries, and accessories.

The global final was made possible by funding from PELS, Vicor, ON Semiconductor, Southern Power, Kehua, Sungrow, and Texas Instruments. The IEEE Foundation provided partnership and support along with the Center for Distributed Energy at Georgia Tech.

The next EBL competition is scheduled to begin next year.

Jeremiah Daniels is a former intern for The Institute. Jane Celusak is a PELS project manager.

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The Inner Beauty of Basic Electronics

Open Circuits showcases the surprising complexity of passive components

5 min read
A photo of a high-stability film resistor with the letters "MIS" in yellow.
All photos by Eric Schlaepfer & Windell H. Oskay

Eric Schlaepfer was trying to fix a broken piece of test equipment when he came across the cause of the problem—a troubled tantalum capacitor. The component had somehow shorted out, and he wanted to know why. So he polished it down for a look inside. He never found the source of the short, but he and his collaborator, Windell H. Oskay, discovered something even better: a breathtaking hidden world inside electronics. What followed were hours and hours of polishing, cleaning, and photography that resulted in Open Circuits: The Inner Beauty of Electronic Components (No Starch Press, 2022), an excerpt of which follows. As the authors write, everything about these components is deliberately designed to meet specific technical needs, but that design leads to “accidental beauty: the emergent aesthetics of things you were never expected to see.”

From a book that spans the wide world of electronics, what we at IEEE Spectrum found surprisingly compelling were the insides of things we don’t spend much time thinking about, passive components. Transistors, LEDs, and other semiconductors may be where the action is, but the simple physics of resistors, capacitors, and inductors have their own sort of splendor.

High-Stability Film Resistor

A photo of a high-stability film resistor with the letters "MIS" in yellow.

All photos by Eric Schlaepfer & Windell H. Oskay

This high-stability film resistor, about 4 millimeters in diameter, is made in much the same way as its inexpensive carbon-film cousin, but with exacting precision. A ceramic rod is coated with a fine layer of resistive film (thin metal, metal oxide, or carbon) and then a perfectly uniform helical groove is machined into the film.

Instead of coating the resistor with an epoxy, it’s hermetically sealed in a lustrous little glass envelope. This makes the resistor more robust, ideal for specialized cases such as precision reference instrumentation, where long-term stability of the resistor is critical. The glass envelope provides better isolation against moisture and other environmental changes than standard coatings like epoxy.

15-Turn Trimmer Potentiometer

A photo of a blue chip
A photo of a blue chip on a circuit board.

It takes 15 rotations of an adjustment screw to move a 15-turn trimmer potentiometer from one end of its resistive range to the other. Circuits that need to be adjusted with fine resolution control use this type of trimmer pot instead of the single-turn variety.

The resistive element in this trimmer is a strip of cermet—a composite of ceramic and metal—silk-screened on a white ceramic substrate. Screen-printed metal links each end of the strip to the connecting wires. It’s a flattened, linear version of the horseshoe-shaped resistive element in single-turn trimmers.

Turning the adjustment screw moves a plastic slider along a track. The wiper is a spring finger, a spring-loaded metal contact, attached to the slider. It makes contact between a metal strip and the selected point on the strip of resistive film.

Ceramic Disc Capacitor

A cutaway of a Ceramic Disc Capacitor
A photo of a Ceramic Disc Capacitor

Capacitors are fundamental electronic components that store energy in the form of static electricity. They’re used in countless ways, including for bulk energy storage, to smooth out electronic signals, and as computer memory cells. The simplest capacitor consists of two parallel metal plates with a gap between them, but capacitors can take many forms so long as there are two conductive surfaces, called electrodes, separated by an insulator.

A ceramic disc capacitor is a low-cost capacitor that is frequently found in appliances and toys. Its insulator is a ceramic disc, and its two parallel plates are extremely thin metal coatings that are evaporated or sputtered onto the disc’s outer surfaces. Connecting wires are attached using solder, and the whole assembly is dipped into a porous coating material that dries hard and protects the capacitor from damage.

Film Capacitor

An image of a cut away of a capacitor
A photo of a green capacitor.

Film capacitors are frequently found in high-quality audio equipment, such as headphone amplifiers, record players, graphic equalizers, and radio tuners. Their key feature is that the dielectric material is a plastic film, such as polyester or polypropylene.

The metal electrodes of this film capacitor are vacuum-deposited on the surfaces of long strips of plastic film. After the leads are attached, the films are rolled up and dipped into an epoxy that binds the assembly together. Then the completed assembly is dipped in a tough outer coating and marked with its value.

Other types of film capacitors are made by stacking flat layers of metallized plastic film, rather than rolling up layers of film.

Dipped Tantalum Capacitor

A photo of a cutaway of a Dipped Tantalum Capacitor

At the core of this capacitor is a porous pellet of tantalum metal. The pellet is made from tantalum powder and sintered, or compressed at a high temperature, into a dense, spongelike solid.

Just like a kitchen sponge, the resulting pellet has a high surface area per unit volume. The pellet is then anodized, creating an insulating oxide layer with an equally high surface area. This process packs a lot of capacitance into a compact device, using spongelike geometry rather than the stacked or rolled layers that most other capacitors use.

The device’s positive terminal, or anode, is connected directly to the tantalum metal. The negative terminal, or cathode, is formed by a thin layer of conductive manganese dioxide coating the pellet.

Axial Inductor

An image of a cutaway of a Axial Inductor
A photo of a collection of cut wires

Inductors are fundamental electronic components that store energy in the form of a magnetic field. They’re used, for example, in some types of power supplies to convert between voltages by alternately storing and releasing energy. This energy-efficient design helps maximize the battery life of cellphones and other portable electronics.

Inductors typically consist of a coil of insulated wire wrapped around a core of magnetic material like iron or ferrite, a ceramic filled with iron oxide. Current flowing around the core produces a magnetic field that acts as a sort of flywheel for current, smoothing out changes in the current as it flows through the inductor.

This axial inductor has a number of turns of varnished copper wire wrapped around a ferrite form and soldered to copper leads on its two ends. It has several layers of protection: a clear varnish over the windings, a light-green coating around the solder joints, and a striking green outer coating to protect the whole component and provide a surface for the colorful stripes that indicate its inductance value.

Power Supply Transformer

A photo of a collection of cut wires
A photo of a yellow element on a circuit board.

This transformer has multiple sets of windings and is used in a power supply to create multiple output AC voltages from a single AC input such as a wall outlet.

The small wires nearer the center are “high impedance” turns of magnet wire. These windings carry a higher voltage but a lower current. They’re protected by several layers of tape, a copper-foil electrostatic shield, and more tape.

The outer “low impedance” windings are made with thicker insulated wire and fewer turns. They handle a lower voltage but a higher current.

All of the windings are wrapped around a black plastic bobbin. Two pieces of ferrite ceramic are bonded together to form the magnetic core at the heart of the transformer.

This article appears in the February 2023 print issue.