Electricity is hot

Cutting-edge power technologies that are poised to provide advantages over conventional approaches include fewer wires, higher power, longer life, smaller size, lower cost, faster recharge and more green.

Wireless electricity: Power cords and disposable batteries are becoming passé with the emergence of wireless power transmission. Although metal can interfere with the power transmission and there are efficiency problems to overcome, great strides are underway. For example, WiTricity’s wireless power transfer technology provides direct wireless power to devices within range of the WiTricity power source, eliminating the need for batteries. It also automatically and wirelessly charges rechargeable batteries, whether the device is in use or at rest, which avoids battery replacement. The technology is being embedded in OEM products designed for mid-range distances (from a centimeter to several meters) and can transfer milliwatts to several kilowatts of power. It uses magnetic near-field energy transfer, which wraps around certain metallic obstacles, and is being developed to be fully compliant with applicable magnetic field and electromagnetic radiation regulations.

Fulton Innovation’s eCoupled technology provides cordless charging of wireless devices. eCoupled-enabled devices are already on the market and new solutions are being co-developed with OEMs. For instance, Fulton is working with partners that want to be able to recharge laptops and run systems from as far as 30 feet away. Other OEMs are manufacturing power tools, flashlights and tables with built-in charging stands. The technology combines near-field inductive coupling with microprocessor communications and control to match the power needs of the electronic device dynamically.

A pocket-size hydrogen fuel cell charger from Horizon Fuel Cell Technologies, called MiniPak, is expected to be available in 2010. It’s a universal charger and power extender for any USB device, including communications equipment, surveillance cameras and GPS devices. It stores hydrogen gas as a safe solid in small refillable cartridges. Because it releases water vapor instead of air pollutants and contains no mercury or lead, it’s environmentally favorable. The device’s high energy storage capacity makes low-cost energy readily available.

Storage innovations: Nanotechnology is opening doors in the development of energy storage devices. Stanford University scientists recently turned ordinary paper infused with nano ink into highly conductive batteries and supercapacitors. The ink, made of carbon nanotubes and silver nanowires, sticks strongly to fibrous paper. The paper batteries and supercapacitors are durable, lasting an order of magnitude longer than lithium batteries, and cost much less. They’re also lighter and less bulky, more efficient and physically flexible. The technology shows promise for energy storage and as flexible electrodes for any electrical device. Paper supercapacitors might be particularly useful for electrical vehicles such as lift trucks, which depend on quick transfer of electricity. Building a GPS sensor into the nano-wiring adds inexpensive location tracking.

Maryland NanoCenter researchers at the University of Maryland discovered a new way to store electrical energy from renewable sources. They sought a device that captures and accumulates large amounts of energy from sources like solar and wind, delivers it at high power on demand and recharges rapidly. The result is electrostatic nanocapacitors, which provide higher power and faster recharge than lithium ion batteries and higher energy density than both electrochemical and electrostatic capacitors. The nanodevices being developed for mass production will likely resemble thin panels that can be layered to increase capacity.

Unusual sources: Did you know trees produce electrical power naturally? MIT researchers found that placing one electrode in a plant and the other in surrounding soil records an electrical potential of as much as 200 mV. A team of University of Washington researchers have since managed to run a custom circuit entirely off tree power, followed by a custom boost converter to take the tree’s low incoming voltage and store it to produce greater output. The converter generated 1.1 V, which is sufficient to run low-power sensors.

The kinetic energy of motion is another potential electricity source. City College of New York researchers are working to generate auxiliary power by harvesting and converting otherwise wasted energy from airflow using piezoelectric materials. Piezoelectric strips produce less noise and vibration than windmills and require less maintenance, but the energy output is much lower. The power generated could be sufficient to run batteries and small electronic devices within vehicles, or sensors in remote locations.

E-mail Contributing Editor Sheila Kennedy, managing director of Additive Communications, at [email protected].