I'll run some better numbers tomorrow for a fixed distance / size, but intuitively, eliminating the "tracking a phone from 5M away" requirement dramatically expands the use cases.

The writeup I linked has a good argument against the feasibility of wireless power for a TV:

> A typical large, flat-screen TV (eg. [42]) will draw about 60 watts. Since a TV is usually mounted in one place, some of the limitations get easier, but not all - if the TV is two feet (60 cm) from the wall, and the receiver is 40% efficient, that's still about 80% losses. To transmit 300 watts at 0.3 W/cm^2, one has to have a 1,000 cm^2 transmitter, a bit over a foot on each side (31.6 cm). One could make the transmitter smaller (100 cm^2, or 4 inches/10 cm across) by increasing the intensity to 165 dB, a level that causes burns "almost instantly" (from Question #7), but that seems unwise. Since most power outlets are near the floor, and the TV probably isn't, one would still have to run a cord to the transmitter. And uBeam takes 240 watts of electricity, about a dozen light bulbs' worth, and dumps it into the air for no real reason. That's not good for the environment. Or the power bill. Or the air conditioning - all that heat makes the room hotter.

So, a startup in a closed system with no product or source of revenue will dissolve into entropy. But a startup with continual funding from VCs can remain as long as the influx of cash continues.

Anyway, there's nothing about thermodynamic limitations in the section about the TV. The author is making several exaggerated statements that are easily refuted to make the TV suddenly possible... Let's focus on the wasted energy (240W or a dozen light bulbs!) to make the point:

* Assume a 48" LED[1] that uses 31W and suddenly you're only wasting 120W.

* His 80% loss figure is a holdover from his calculations about the phone -- cut this in half and you're at 60W of waste heat. (You should be able to achieve a nearly perfect perpendicular 'connection' between transmitter/receiver for a fixed TV).

So far, we're delivering 30W of power and wasting 60W as heat -- not ideal

* If you plan for a worst-case of 8-hrs straight of watching TV and plan on a battery backup, you could get away with delivering 10W to the TV and only wasting 20W as heat which is eminently reasonable.

The "physically impossible" claims are greatly overstated (for non-phone charging use cases).

[1] - https://www.energystar.gov/index.cfm?c=most_efficient.me_tvs...

Until our houses are powered by 100% renewable energy, any technology that sacrifices more than half the input energy just so someone doesn't have to see an extension cord should be banned by law.

There's a big difference between 30% efficient now and 90% efficient in the future, and "it's never going to get any better than this"

Actually, I take it back. That's not fair -- according to their investors they don't have any intention of only making phone chargers;

> And the truth is that Team uBeam doesn’t want to stop at phones. With the explosion of “wearables’ wouldn’t it be nice if you didn’t have to charge your watch, fitness tracker or noise-canceling headphones? What about if elderly people never had to ask a relative or healthcare worker to change the batteries on their hearing aids? The practical uses for uBeam technology is limitless.

Or the company themselves;

> With wires virtually eliminated, TVs can sit in the middle of a room cord-free and light fixtures will become “stick-on” without the need for routed power.

<--Original post-->

That's fair, but it sure seems like the obvious path to getting cell phone charging to work is to get a fixed object charging to work -- at which point, if they'd hired any bizdev people, they'll sell the hell out of the fixed object systems to anyone and everyone.

It's just striking to recollect the many complaints about only easy, derivative ideas being funded when a hard idea with tons of applications is being derided in such an intense fashion.

I'd rather they fund 10 uBeams that could yield useful insights or pivots than 0.

When uBeam say they're going to make wires a thing of the past, I will remain skeptical until they have a product on a shelf that I can buy. Until then I am as excited about their wireless power transmission as I am by any other startup in the same space - it's a great idea, but it needs to be seen.