Batteries not included: How small-scale energy harvesting will power the future

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Back from the future

Much earlier in this article we discussed the media hubbub surrounding the U of Bedfordshire’s radio-wave harvesting model. We’ve since learned that Ben Allen and his team are but one of scores of such teams worldwide working on a variety of small-scale ambient energy harvesting technologies.

“When you need watts and the harvesting device is generating mere nanowatts or microwatts, a huge gap clearly exists.”

Yet most of those concepts are still a long way from being fully prime time. Indeed, there’s no shortage of people who claim certain approaches to micro energy harvesting will never be a seriously viable solution. Mosey on over to spots such as the Physics Forum, for example, where you’ll find a gaggle of hyper-scientific types pontificating on the subject – many with less than favorable conclusions.

The primary issue is, as we covered earlier, rather weak source material. When you need watts and the harvesting device is generating mere nanowatts or microwatts, a huge gap clearly exists. This gap can be closed some with further technological (harvesting) advances, by pairing multiple technologies together, or by keeping a dedicated energy storage device (battery) of some description permanently in the equation. But all of these solutions add to the bulk, the complexity, the cost, and the R&D time.

Moreover, the notion that any of the technologies or combination of technologies we’ve featured will completely replace traditional power in high-draw devices (flashlights, tablets, smartphones, etc.) is fanciful at best.

And in the interim, other already entrenched technologies continue to evolve – solar power arguably being the best example. Large-scale solar applications are now commonplace, but small-scale solar is already here – and seemingly doing just fine. One need only explore the sheer number of solar-equipped radios and flashlights and even battery chargers currently on the market to see how many companies have already jumped in the game.

But in a world that chews through power like a dog through a juicy steak, there’ll clearly be an increasing need for “alternative” power that doesn’t rely on the sun (or the wind) – even if those solutions are augmentative to traditional sources, or to each other. Considering that each of these technologies is apparently suited to such a wide variety of applications – and when taken as a group seem to cover virtually all the bases – we see a bright long-term future for those who can best adapt their ideas across the spectrum.

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