DEBUNKING USB-powered microwave story

[Original reporting! Not an echo!]

A UK tabloid story has set off a round of uncritical echoing of a ludicrous claim:

It is the world's smallest, portable microwave and can be powered via a link to the USB port on a laptop computer.

The turquoise device - called the Beanzawave - has been created in partnership with Heinz to allow workers tied to their desks to create a warm snack, or hot drink, to see them through the day.

I realize I am expecting too much for anyone in the echoing chain to say "But how is that possible?", as popularity wins over accuracy. But it's still a sad result.

For non-technical people, here's a short description of the problem:

Water takes a relatively large amount of energy to heat up (Microwave ovens typically use many hundred of Watts of power, 1100 Watts is common). USB ports supply very little energy (2.5 Watts of power). Without needing to do any complicated calculations, the scales just don't match.

So I mailed the company and asked them about this:

Dear Sirs

I am a blogger who has read the articles about the "Beanzawave", where supposedly a USB port powered device can heat a small food portion.

"Apart from its size, the key breakthrough is the use of a combination of mobile phone radio frequencies to create the heat to cook both on the outside and within in under a minute."

I don't understand what is meant by this. Even at 100% transfer efficiency, the total energy drawable in a minute from a USB port (which can supply around 2.5 Watts) is not enough to significantly heat even a small food portion.

Assuming that the news reports garbled whatever you were trying to say, would you be kind enough to clarify the idea?

[I received a prompt response]

The USB port is used for control purposes only. Oven is powered by appropriate sized Lithium-ion batteries, which can be mains supplied and/or recharged. It is the mobile phone frequencies that utilise prior long-term existing 900MHz (industrial) and 2450MHz (consumer) ISM approved microwave oven frequencies. I assure you we have sufficient power to effectively heat small type hand-snack food products.

Thanks your concern and interest ... Gordon Andrews

[end reply]

So, there you have it. With some big batteries and high efficiency, maybe they can make it work. But it's sure not going to be using just the power of the USB port.

Tell me again about how expert's blogs are going to rule the media world :-( (as opposed to the reality of "Blogs Falling in an Empty Forest")

Seth Finkelstein's Infothought blog (Wikipedia, Google, censorware, and an inside view of net-politics) - Syndicate site (subscribe, RSS)