Recently the Winklevoss twins said that Bitcoin could easily skyrocket to a 400 billion market cap.
And that a 1 trillion market cap, was also a possibility.
http://money.cnn.com/2015/01/27/investing/bitcoin-winklevoss-twins-gold/

I'm not taking it to serious but it got me wondering:

What would such a market cap mean, in terms of hash power, and electricity consumption?
Not even sure what the electricity consumption of BTC equals to today.
A small/medium/large sized city?
Would such a market cap lead to equal power consumption of a small country?
What would the computing power needed for such a market cap, equal to?

The last thing we need now is a bitcoin bashing, but it would be an interesting blogpost.

Satoshi once said:
“When Bitcoins start having real exchange value, the competition for coin creation will drive the price of electricity needed for generating a coin close to the value of the coin.”

After the next block halving:
12.5 btc/block X 6 blocks per hour X 24 hours per day X 365 days = 656,000 btc a year

Let's say there are 15 million btc by then, so a $1 trillion market cap means about $65k/btc

$65,000 X 656,000 = $42.6 billion a year worth of electricity.

My electricity costs about $0.15/kWh but let's say bitcoins are mined in a places with cheaper power, $0.10/kWh. That's 426 billion kWh or 426,000 gWh.

So, according to http://en.wikipedia.org/wiki/List_of_countries_by_electricity_production, that would fall between the electricity production of the United Kingdom and South Korea.

As a side note, with a limit of 3 transactions per second, or 1800 per block, 12.5btc ÷ 1800 = 0.007 btc and at $65k/btc that is $451 per transaction to keep the network secure.

Now imagine a few million coloured coins representing cars or stocks are added on top of that. You need more hashrate to protect that as well or somebody will double spend your car. But you can't reward miners with colored coins...