It was just shy of 120 years ago, when Nikola Tesla first attempted to beam power.
Since then, the idea of Wireless Power Transfer (WPT) has become something of a holy grail for physicists, governments, power companies and consumers alike. The more reliant we’ve become on electricity, the more reliance we’ve also placed on wires to conduct it. The UK National Grid alone is responsible for installing and maintaining around 9,000 km of overhead and underground power lines.
But is there a genuine alternative?
At QinetiQ, we think there might be.
What’s wrong with wires?
Aside from their aesthetic impact, power lines pose significant financial, environmental and access challenges. The cost of installing overhead power lines in the UK is around £4m per kilometre. For underground cables this rises to nearer £19m per kilometre. When we consider the global population and development growth, the future cost of wired power transmission is truly staggering. There’s also the cost of extracting the copper and other metals required, which shows no signs of abating in the face of increasing demand.
The future cost of wired power transmission is truly staggering.
Then we must consider the environmental impact. To date our access to copper and other conductors has been relatively unimpeded, but not without effects on local ecologies. As population demands increase, so the demands on these natural resources rises accordingly. This is in stark contrast to international efforts to reduce our global environmental footprint.
Finally, there are those inaccessible locations where wired power transfer is simply impossible, both geographically and practically. Beyond mountain ranges or in disaster zones, for example.
In effect, what we’re witnessing is the perfect electrical storm.
More countries are developing and adopting a renewable approach to energy, with an increasing need to deliver energy to power homes, businesses, and especially transportation networks. At the same time as this extraordinary exponential demand, our natural resources availability is decreasing.
We’re witnessing the perfect electrical storm.
So, it’s clear a workable alternative to the status quo could offer enormous benefits.
The search for the holy grail
The concept of WPT – transmitting power without wires – is widely understood. Toothbrushes, smartphones and razors can all be charged using wireless power. Trials with vehicles are also underway with manufactures like Nissan, Mercedes-Benz and Delphi. But these are all what we call ‘near-field’ examples. The technological uncertainties in this area are relatively easily overcome.
Transmitting power wirelessly over considerable distances – or ‘far-field’ wireless power transmission – presents significantly greater challenges.
The further power is beamed, the greater the likelihood of degradation. Absorption by the atmosphere and interference can all impact the strength of the power signal. Combine the need for safe operation and avoiding interference with existing systems, and the true nature of the obstacles becomes apparent.
However, we at QinetiQ are confident the complications surrounding wireless power, while challenging, are not insurmountable.
The complications surrounding wireless power are not insurmountable.
Since Nikola Tesla’s initial experiments in 1899, there have been limited attempts to beam far-field power. The furthest distance to date was achieved by the Jet Propulsion Laboratory at NASA. They successfully transferred 34kw over 1.6km with 82% efficiency. But that was in 1977 and since then, development has effectively stalled.
Challenging the power status quo
There are myriad reasons why wireless power transfer hasn’t progressed beyond near-field applications. A lack of any ‘burning bridge’ to prioritise WPT is among the primary causes of sluggish progress.
Additionally, many of the stakeholders in the benefits of WPT have worked disparately, often through well-intentioned funding considerations. The net result, however, has been to prevent complementary research and experimentation.
Then, there has been a fixation on specific frequencies without due consideration of the impact of operating at these frequencies on extant electrical infrastructure.
QinetiQ wants to challenge the status quo.
We want to promote a more collaborative approach to developing far-field WPT.
What’s next for wireless power transfer?
We believe QinetiQ is ideally placed to take on the future challenge of WPT. As well as unrivalled heritage in scientific discovery, our rich vein of partnerships has helped us deliver technical breakthroughs against seemingly impossible odds.
It is through this valuable network of partners across academia, industry and government that we hope to push back the boundaries of wireless power transfer.
If you would like to know more, please do email me: CDharper@qinetiq.com
We can imagine a world without wires.
But not without your help.