Every time​ a bitcoin ‘miner’ is successful they create for themselves 12.5 new bitcoins, currently worth around $60,000. If they don’t succeed, they can have another go roughly ten minutes later – all day, every day. It isn’t surprising, therefore, that despite the sharp fall in bitcoin’s dollar price in 2018 there is still a lot of mining going on. You can try mining on your laptop, but don’t get your hopes up. Nowadays, to have a serious chance of winning the prize you need a specialised computer system – ideally, hundreds or thousands of computers, linked together in a network. The world’s largest ‘mine’, run by a subsidiary of the Chinese company Bitmain in the high desert of Inner Mongolia, has more than twenty thousand machines.

Bitcoin mining uses a lot of electricity. Each individual machine consumes about two kilowatts, around the same as a domestic electric heater. It’s a big headache to keep a warehouse packed with thousands of machines cool enough to stop them breaking down. A paper in the energy research magazine Joule in May 2018 estimated that bitcoin mining globally was consuming at least 2.5 gigawatts, almost as much as the country of Ireland in its entirety, implying that each individual bitcoin transaction required, on average, between two hundred and three hundred kilowatt hours of electricity. That’s equivalent to leaving a heater running full-blast for four days or more. Given that most bitcoin transactions are tiny by the standards of global finance, it’s strikingly profligate.

Mining was the way bitcoin’s original designer, the unknown figure who goes by the name Satoshi Nakamoto, sought to solve the basic problem of any electronic currency: how to make sure that a user doesn’t spend the same unit of currency more than once.1 Since the vast majority of pounds, dollars and euros are also now electronic, the problem isn’t unique to bitcoin. The way it is usually solved is by keeping a centralised record of transactions, with tight controls over who can amend or add to the record. That, for example, is how your bank does it.

Satoshi didn’t want to do it that way. Even though we don’t know the designer’s real identity (they might, perhaps, be a group of people, not a single individual), it is clear from the paper that originally proposed bitcoin in 2008, and from the emails in which Satoshi discussed it, that he was familiar with – and may have been part of – a strand of thinking in computer science that combined technical sophistication with fears about the invasion of privacy and a libertarian distrust of centralised authority. Bitcoin isn’t a company; it isn’t even an organisation in any full sense. It is a software system. Satoshi seems to have done all the initial programming. The system was then refined by other programmers, many of whom worked on the same voluntary basis as, for example, those who contribute to and police Wikipedia. Those programmers seemed – and many of them still seem – strongly committed to Satoshi’s vision. A decade later, the central features of the bitcoin system remain almost entirely unchanged.