Electronics-Lab.com Blog

Stephen Evanczuk writes:

Energy-microharvesting applications such as wireless sensor nodes require periodic bursts of power well beyond that available in steady state from most ambient sources. In this respect, supercapacitors offer performance characteristics that are well suited for energy-harvesting environments. By combining supercapacitors with appropriate power and charge management circuitry, and using specialized devices from manufacturers including Linear Technology, Maxim Integrated Products, and Texas Instruments, engineers can exploit microharvesting techniques in applications with demanding peak power requirements.

Power Management ICs Simplify Integration of Supercapacitors in Energy Microharvesting Designs - [Link]

John Donovan writes:

Alternative energy sources deliver small amounts of power intermittently, and at times power levels may not match the needs of the applications that depend on them. Some form of energy storage is needed, though the solution will vary with the demands of the application. This article will examine various energy buffering solutions, including small form-factor batteries, thin-film batteries, and supercapacitors, highlighting both their specifications and the applications to which they are best suited.

Storage Alternatives for Energy Harvesting Applications - [Link]

Singapore-based fuel cell company Horizon announced that world’s first personal hydrogen station is now available in stores. The company is offering a small-scale hydrogen system consisting of a Minipak portable power device, Hydrostik cartridges and Hydrofill which enables you to safely generate your own hydrogen at home.

The Minipak produces electricity on the go and can be used as a universal charger for mobile gadgets. At its core is a passive air-breathing fuel cell converting hydrogen and oxygen into electricity. The Minipak can produce up to 2 W of energie. [via]

Get Your Own Personal Hydrogen Station and Fuel Cell - [Link]

Don Scansen writes:

Ambient light, thermal gradients, vibration/motion, or electromagnetic radiation can be harvested to power electronic devices. At the same time, all energy-harvesting-based systems need energy storage for times when the energy cannot be harvested (e.g., at night for solar-powered systems). Rechargeable batteries ‒ known as “secondary” cells to differentiate them from “primary” or single-use cells ‒ are usually specified for this task. This article will examine the various secondary cell technologies available to energy harvesting system designers looking for a cost-effective and powerful battery solution.

Primary and secondary batteries contain the same basic structure of a cathode, an anode, an electrolyte for moving charge between the terminals, and a means to separate them. Secondary cells are distinguished by the type of rechargeable chemistry employed, such as nickel-cadmium or lithium-polymer, or solid-state thin film.

Storage Battery Solutions for Energy Harvesting Applications - [Link]

Publitek European Ed writes:

Daylight harvesting is becoming increasingly important in the design and implementation of commercial lighting systems. Being able to integrate the natural light from windows with flexible, controllable sources of lighting helps improve the work environment and cut energy bills.

Being able to have closer control of the lighting systems in a commercial environment is a key element to this strategy and energy harvesting can play an important role. Being able to have flexible placement of control pads for a commercial lighting system is an important requirement as office space is regularly reconfigured as existing clients grow and change their requirements and new clients have new requirements.

Smart Lighting in the Enterprise - [Link]

Power plants and many industrial processes produce heat as a byproduct, as much as up to 50% of the initial energy input may be released as heat. What if we could store this waste heat for later use?

The most common form of thermal storage is in insulated water tanks, but water can only retain heat for a short period of time as it cools off gradually. Zeolite is a mineral that can store up to four times more heat than water can, but, unlike water, zeolite retains all of the heat for an unlimited period of time. Although these unique properties of zeolite are well known, it is only now that scientists of the German Fraunhofer Institute have succeeded in using the mineral to build a working thermal storage system. [via]

Store Thermal Energy Forever - [Link]

Don Scansen writes:

Untapped energy surrounds us. Transducers to convert various energy sources into electricity that can be put to useful work are relatively straightforward to understand and implement. However, harvestable energy sources are intermittent, or at least very inconsistent, in terms of output. Many can provide only a few microwatts. Putting these very low energy sources to use requires efficient charge control electronics designed for low power.

In terms of performance, one of the most attractive energy harvesting power management ICs (PMIC) on the market is the MAX17710G+T from Maxim, which was designed from the ground up for energy harvesting and extracting the greatest amount of energy possible from the transducer element. As a result, it offers class-leading performance for this application. The PMIC allows very simple, low-cost solutions for battery charging and protection. The MAX17710G+T will provide good battery charging performance for a wide range of ambient sources and conditions. Useful power is extracted from levels as low as 1 µW and 0.8 V. Coupled to a very small form factor MEC (micro energy cell), it is a powerful combination for a broad range of energy harvesting applications.

A Hands-on Look at the Maxim MAX17710 Energy Harvesting PMIC - [Link]

Double layer electrolytic capacitors already enable to replace backup batteries in many applications.

Modern high-capacity double layer capacitors (also known as supercapacitors) feature a very high energy/volume ratio, compared to usual electrolytic capacitors. Their capacity is so high, that they are able to replace backup batteries in many designs. On the market there are available miniature types as well as physically big types with capacities of tens to hundreds of Farads.

One of the biggest advantages of capacitors in comparison to batteries is their long lifetime, because their electrodes don´t undergo degradation neither after many thousands of cycles. On the other side, even modern batteries have a limited lifetime and a limited number of cycles, because energy storage in batteries is related to chemical changes of electrodes during charge/discharge (change from a solid to a liquid form, crystallization,…), what causes degradation of electrodes.
In our offer, you can find small “coin-type” double layer capacitors suitable for backup power supply of memories. For example a capacitor with a 1F (1000mF=1 000 000 uF) capacity charged at 5V can store energy of 12.5 Jouls (E=1/2*C*U²), what is 12.5 Wattseconds. This energy is in most cases sufficient to ensure a safe backup of memories at a voltage dropout. Such energy is also sufficient for a short time power supply of low power devices. This can be very useful for example for a safe write of data to EEPROM and a safe switch off of a device.

Supercapacitors instead of batteries? - [Link]

Don Scansen writes:

The viability of an energy harvesting application often depends on components that can efficiently extract very low levels of power at low current and/or low voltage, and deliver these to a storage battery or capacitor. The premise is simple: scavengers of ambient energy rely only on what they are given and what is available, sometimes more, sometimes less.

This self-evident truth places great importance on products such as step-up low voltage boosters, which are self-powered modules that convert a low DC voltage input to a higher AC or DC voltage output suitable for low-power energy harvesting applications using photodiodes, thermoelectric or electromagnetic generators as the input source.

Step-up Micropower Voltage Boosters Simplify Energy Harvesting - [Link]

Imagine if the next coat of paint you put on the outside of your home generates electricity from light—electricity that can be used to power the appliances and equipment on the inside.

A team of researchers at the University of Notre Dame has made a major advance toward this vision by creating an inexpensive “solar paint” that uses semiconducting nanoparticles to produce energy.

“We want to do something transformative, to move beyond current silicon-based solar technology,” says Prashant Kamat, John A. Zahm Professor of Science in Chemistry and Biochemistry and an investigator in Notre Dame’s Center for Nano Science and Technology (NDnano), who leads the research.

“By incorporating power-producing nanoparticles, called quantum dots, into a spreadable compound, we’ve made a one-coat solar paint that can be applied to any conductive surface without special equipment.” [via]

Nanoparticle paint generates electricity - [Link]