Hacker News Reader

Comment by tommynicholas | Hacker News Reader

That is an excellent idea, doesn't your phone continue to use power after it's done charging? This wouldn't produce a ton of Bitcoin but it would be an opportunity for a net-positive outcome from a cost perspective which is clever.

View on HN

No, phones don't use power after they're done charging (they might trickle-charge[1], but that uses a fraction of the power). That would either destroy the battery or heat up your phone to spend that energy.

[1] https://en.wikipedia.org/wiki/Trickle_charging

How is it net-positive from a cost perspective? From what I remember, 21 takes a large cut of the Bitcoin "mined" and you'll spend far more on electricity than you'll get in return for Bitcoin.

I assuming chargers were eating energy after the phone was done charging, if they're not then this wouldn't be energy positive and isn't as exciting.

The energy that idle chargers use up is negligible, and even then, it's not as if you can just turn that into computational power. You'd still need to consume (significantly) more energy to mine.

You're right indeed. 21's mining chip does give a negative ROI, even in areas where electricity is very cheap.

Why would anyone buy a $400 mining chip that costs more in electricity than it produces in bitcoins, when they can just buy $400 worth of bitcoins? Beats me...

Because they aren't paying for the electricity?

Reply on news.ycombinator.com