The world is full of “chaotic motion,” in other words, continuous but non-uniform types of physical excitation that are nevertheless pervasive and commonplace. Ocean waves are a naturally occurring example. So is the movement of people as they walk or run in everyday life. What almost all have in common is that they represent a nearly limitless source of energy if only a means could be found to convert them into a reliable form of electric power generation.
Methods of doing so have long been a focus of engineering research. A UK-based company has come up with something different: a single type of device that could be scaled to provide useful, usable power from a few watts to hundreds of kilowatts depending on the scale of the motion source.
The company is WITT Energy based in Plymouth in South West England and founded by a husband and wife team, Martin and Mairi Wickett. Their aim was to find a means of converting bi-directional movement to rotation. Their initial idea has now been embodied into the design for a device that goes by the name Whatever Input to Torsion Transfer (WITT). It is claimed to be one of the first ever practicable pieces of equipment with the potential to translate multiple degrees of motion – up, down, backwards, forwards and rotation about an axis – into a single output able to drive a generator to produce electricity. (Watch a video of the generator in action.)
The basic principle involves the use of pendulums that react to external movement. These drive a flywheel and gearbox that in turn drive a conventional generator. The potential benefits could be considerable.
The first is its potential scalability from a wearable device to something that could be mounted in a boat to exploit its pitching and rolling motions. Second, all of the essential working parts can be sealed inside a housing pierced only by the wires carrying the electric current, thereby making it resilient to damage from external forces. Another is that it could be able to produce power across a wide range of excitation – a marine device, for example, should continue to operate in storm conditions. It also would be flexible in operation and could be used to charge batteries if there was no immediate need for power or if the source of motion was intermittent.
The company’s commercial director Nicholas Gill says that the device has already won at least one award for innovation – the 2013 Gulfstream Navigator Award worth $100,000 made by the Ocean Exchange organization, an international venture that seeks to recognize environmentally friendly innovation with a potential for global application. He says the device is also attracting interest from the German conglomerate Schaeffler, which Gill says has agreed to work with WITT to help refine the concept. Both the Indian and U.S. defense departments also have expressed interest, he says.
The defense departments’ interest has been stimulated in part by the device’s potential to be built into a soldier’s backpack. Gill says this would enable the device to provide a means of constantly recharging the batteries used to power electronic equipment that military personnel now carry. He says that a WITT device weighing two pounds and capable of generating 10W of power could feasibly be developed and would be sufficient to meet military applications.
A prototype of such a device has been tested and, Gill says, has achieved a “peak power” output of 5W. Further lightweighting of almost all its component parts could help boost power output towards that target figure. Moreover, Gill says that the company could exploit the need for the pendulums to retain some weight by making them incorporate batteries, which would contribute “net zero weight” to the device.
That possible application is likely to be beaten into real use by a larger version of the concept that is capable of generating as much as 200W. WITT Energy is developing that device in cooperation with UK precision engineering operation Gibbs Gears. Gill says that this device is intended for marine use although the company has also recognized that fixed floating objects such as marker buoys present a potential market. A prototype is scheduled to appear by “the third quarter of 2016” with a market launch possibly in 2017, he says.
Gill says that by late 2015 the company will launch a crowdsourcing push that aims to bring in at least $1.1-4.5 million.