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Friday, April 28, 2017

Energous' Mid-Sized Watt Up Transmitter - Can It Get FCC Approval?

Reader Lord Stately-Wayne Manor asked me in comments on the last uBeam article:

Would you be willing to give your opinion on whether or not Energous will get FCC approval on their mid range soon? The CEO believes they have a clear path to approval and expects it to happen well before the end of this year. Any thoughts would be appreciated.

In brief - I don't think Energous mid/full range products as stated by the company will be able to be approved by the FCC in any manner, those that could be approved will emit such a low amount of power that they will not charge at any rate practical for consumer devices like phones. Any such approval would require a rewrite of existing regulations, and while I wouldn't put it past the current FCC to do stupid anti-consumer things, the fact that it would simply wreck any current WiFi signals and equipment means there is a massive, entrenched, business interest in making sure that does not happen.

As for the more detailed discussion, including some nerdy stuff since you literally can't analyze the situation without maths/physics/numbers/engineering:

I'll start by saying that the CEO of Energous has made a lot of claims over the years as to outcomes and timelines that are not met - the product promised is always some ways out, on the order of a year. Some call this the "Time to Carrot"(check Seeking Alpha for some good posts, and where I got the above image), which constantly moves forward and you never, ever get the carrot. Here in 2014 is him saying 2015 delivery. You may know of other companies that have promised deliveries of consumer product "by the end of the year" since, say, 2011, that have never materialized.

WATT started with a "full sized transmitter" which was the "~4m, multiple devices, multi-watt" version that no-one could explain with physics without cooking anyone around it. They claimed:

The strength of the charging drops off rapidly with distance; at the moment, 15 feet is the maximum range of the transmitter. At 5 feet, your gadget (actually, four of them at once) can receive a maximum of 4 watts. At 10 feet, it gets 2 watts; at 15 feet, 1 watt.

Which is a "holy crap 20W received we're going to get cooked" statement and had many eyebrows raised in "basic laws of physics" type ways. Quick question - what were uBeam's publicly stated specs before, and after, this announcement by Energous in early 2015?

Eventually Energous announced a 'mini' which at most emitted 300mW when in contact, so basically >10x worse charge rates and less useful than the already available Qi methods, along with a 'soon' medium and full sized which allowed time to carrot to remain at 18 months or so. Such a low charge rate and in-contact requirement, so it could be FCC approved, and allowed claims of "FCC Approval for Energous", but a pointless product.

Now Rizzone stated back in March 2017 he was confident over FCC approval. However - Energous' own filings with the FCC prove they can't get licensed under Part 18, read to the end where they literally say the rules have to change: 

Energous requests OET to interpret its ISM rules to enable WPT AAD conforming devices that satisfy the criteria specified in this Petition to qualify as Part 18 ISM... However, this can only happen if OET adopts a process that enables equipment manufacturers to secure equipment authorization.

How can the CEO argue it's coming when they admit that it can't be approved under current rules? Doesn't make sense to me, so let's dig more.

How about approval under Part 15 instead of Part 18? Part 15 is for "Low Power" so a problem there I think. In these FCC documents you will see that the FCC limit the 5.8GHz band that Energous use to 1W total if spread spectrum - take efficiency etc into account and you are looking at very long charge times (a couple of days to charge your phone if lucky?). If not spread spectrum then it's P=0.3e^2 where E is listed as 0.05 V/m so that's no more than 0.75mW, or to translate to practical implementation - it would take six months or more to charge your phone at 100% efficiency. I can't find the link but I believe Energous state their method is not spread spectrum, so that tells you how useful their method could be under Part 15.

So, basically, unless they either get the FCC to change the rules, in opposition to a vast entrenched business interest and wreck WiFi for everyone, or reduce their power output to the point where it is an utterly pointless product, then I just don't see FCC approval for their devices.

This doesn't even begin to cover the issues of safety or practicality of beamforming to a fine focus with your array is not much bigger than your wavelength. I go into lots of nerdy depth with it here.

One last piece of advice, and it comes from Warren Buffet - Don't invest in companies whose product you can't understand. If the engineers are arguing about the basics of the product working and laws of physics are being called into question, then just run...


  1. This was actually published on the 30th April 2017, I just changed the date as I wanted to keep my post from yesterday as the headline post on my blog when someone comes to it directly.

  2. What do u think about Ossia's Cota?

    1. I think they're facing the same physics, and same regulations, just at a different wavelength (2.4GHz frequency).

  3. So, how does this make the AirFuel alliance board? Liars too?