How much energy will the Bitcoin network eventually consume? A recent Bloomberg article stated that the Bitcoin network currently consumes about half as much energy as the Large Hadron Collider or enough to power 31,000 US homes. Even if the article is way off the mark, it is undeniable that the network's energy consumption (based on hash rate) goes up in direct proportion to the market price of a unit of the Bitcoin currency.

According to blockchain.info, the network is currently consuming 1,203.97 megawatt hours per day.

How much energy is the Bitcoin network expected to consume as the price of a bitcoin goes up from around $100 today to $1,000, $10,000, and so on?
The upper boundary for energy usage can be described with a function of the profit and energy costs. Miners won't ever pay more for energy than they get from profits. The actual energy usage formula will also have to count for the hardware costs.

The formula will look something like this :

max energy usage = (profit - hardware costs) / energy cost per unit
profit = exchange rate * generated btc
generated btc = transaction fees + block creation bonus


As you can see, the energy usage depends on the following factors:


Energy cost per unit (kWh)
Hardware costs
Block creation bonus (currently 25, some day 0)
Transaction fees (currently hardly relevant, some day very important)
Exchange rate


And, of course :


How much money the miners want to keep
Taxes?


[edit]

$10,000 a coin times 52560 (blocks per year) times 25 (coins per block) gives $13,140,000,000 mined USD a year. Yes, that's thirteen billion USD in mining profits. If we divide this by $0.20 per kWh, then the upper boundary for energy use will be 52,560,000,000 kWh (52 TWh), roughly 2/1000 of the total energy consumption of the USA. Of course, if we assume that 90% of the money goes to hardware and not energy, the actual energy usage will be more like 5TWh. (Link to the calculation)