마을 전체가 비트코인 채굴장이면 어떤 모습일까? 줄지어 이어진 컨테이너 박스 같은 곳에 대형 냉각기가 돌아가는 모습이 상상에만 그치지 않을 수도 있다.
인근에 수력발전소가 5개나 되서 전기료가 엄청 싼 곳. 이런 곳이 중국이 아닌 미국에 있다는 사실이 놀랍다. 미국 ‘중부 컬럼비아 분지’에 미국에서 전기료가 가장 싸고, 겨울의 찬 공기가 과열을 막아주기까지 하는 곳에 채굴자들이 몰려 있다. 그것도 비트코인의 광풍이 불기 전인 2012년부터 생성됐다.
비트코인 열풍이 불기 전에는 2달러 들여서 12달러에 팔수 있었으니 나쁘지 않은 장사였다.
이곳이 채굴 마을이 되기까지는 데이비드 칼슨이라는 인물의 역할이 크다. 그는 12 x 48 피트 크기의 조립식 나무 프레임 구조에 수백개의 고속 서버가 장착된 1메가 와트 이상의 전력을 소비하는 ‘기가 포드(Giga Pod)’를 설계하게 된다. 이론상으로 한달에 80개의 비트코인을 채굴하는 것이 가능한 구조다.
하지만 ‘사토시 나카모토’라고 알려진 미스터리한 비트코인 창시자가 채굴에 대한 보상의 룰을 변경해 프로그래밍 하면서 새로운 난관을 맞았다. 채굴에 대한 보상을 대폭 줄여나가는 전략이었다. 나카모토는 광부들이 네트워크의 장기 생존에 더 많은 돈을 투자하게 만들었다. 이 때문에 수익성은 떨어졌지만 채굴에 대한 열기는 사라지지 않았다. 그리고 이 난관의 해결책은 저렴한 전기료에 있다는 결론에 도달하게 된다. 그에 적격인 지역이 ‘중부 컬럼비아 분지’인 것이다.
여전히 채굴을 하고 있는 광부들은 지난 2월 비트코인이 6000달러까지 떨어졌을 때 심정이 어땠을까? 이들은 여전히 작년 크리스마스 전에 보였던 2만달러까지 오를 것이라고 믿고 있다. 다만 그게 ‘얼마나 걸릴지’만 문제라는 것.
이 마을에 관한 이야기는 비트코인 광풍과 더불어 돈다발을 들고 몰려든 일부터 각종 분쟁과 사건 사고를 동반하고 있다.
This Is What Happens When Bitcoin Miners Take Over Your Town
The attraction then, as now, was the Columbia River, which we can glimpse a few blocks to our left. Bitcoin mining—the complex process in which computers solve a complicated math puzzle to win a stack of virtual currency—uses an inordinate amount of electricity, and thanks to five hydroelectric dams that straddle this stretch of the river, about three hours east of Seattle, miners could buy that power more cheaply here than anywhere else in the nation. Long before locals had even heard the words “cryptocurrency” or “blockchain,” Miehe and his peers realized that this semi-arid agricultural region known as the Mid-Columbia Basin was the best place to mine bitcoin in America—and maybe the world.
The best mining sites were the old fruit warehouses—the basin is as famous for its apples as for its megawatts—but those got snapped up early. So Miehe, a tall, gregarious 38-year-old who would go on to set up a string of mines here, learned to look for less obvious solutions. He would roam the side streets and back roads, scanning for defunct businesses that might have once used a lot of power. An old machine shop, say. A closed-down convenience store. Or this: Miehe slows the Land Rover and points to a shuttered carwash sitting forlornly next to a Taco Bell. It has the space, he says. And with the water pumps and heaters, “there’s probably a ton of power distributed not very far from here,” Miehe tells me. “That could be a bitcoin mine.”
This bizarre process might not seem like it would need that much electricity—and in the early years, it didn’t. When he first started in 2012, Carlson was mining bitcoin on his gaming computer, and even when he built his first real dedicated mining rig, that machine used maybe 1,200 watts—about as much as a hairdryer or a microwave oven. Even with Seattle’s electricity prices, Carlson was spending around $2 per bitcoin, which was then selling for around $12. In fact, Carlson was making such a nice profit that he began to dream about running a bunch of servers and making some serious money. He wasn’t alone. Across the expanding bitcoin universe, lots of miners were thinking about scaling up, turning their basements and spare bedrooms into jury-rigged data centers.
But here, Carlson and his fellow would-be crypto tycoons confronted the bizarre, engineered obstinacy of bitcoin, which is designed to make life harder for miners as time goes by. For one, the currency’s mysterious creator (or creators), known as “Satoshi Nakamoto,” programmed the network to periodically—every 210,000 blocks, or once every four years or so—halve the number of bitcoins rewarded for each mined block. The first drop, from 50 coins to 25, came on November 28, 2012, which the faithful call “Halving Day.” (It has since halved again, to 12.5, and is expected to drop to 6.25 in June 2020.)
A few miles from the shuttered carwash, David Carlson stands at the edge of a sprawling construction site and watches workers set the roof on a Giga Pod, a self-contained crypto mine that Carlson designed to be assembled in a matter of weeks. When finished, the prefabricated wood-frame structure, roughly 12 by 48 feet, will be equipped with hundreds of high-speed servers that collectively draw a little over a megawatt of power and, in theory, will be capable of producing around 80 bitcoins a month.
More important, Nakamoto built the system to make the blocks themselves more difficult to mine as more computer power flows into the network. That is, as more miners join, or as existing miners buy more servers, or as the servers themselves get faster, the bitcoin network automatically adjusts the solution criteria so that finding those passwords requires proportionately more random guesses, and thus more computing power. These adjustments occur every 10 to 14 days, and are programmed to ensure that bitcoin blocks are mined no faster than one roughly every 10 minutes. The presumed rationale is that by forcing miners to commit more computing power, Nakamoto was making miners more invested in the long-term survival of the network.
Barely perceptible in the early years after bitcoin was launched in 2009, these adjustments quickly ramped up. By the time Carlson started mining in 2012, difficulty was tripling every year. Carlson’s fat profit margin quickly vanished. He briefly quit, but the possibility of a large-scale mine was simply too tantalizing. Around the world, some people were still mining bitcoin. And while Carlson suspected that many of these stalwarts were probably doing so irrationally—like gamblers doubling down after a loss—others had found a way to making mining pay.
Even in the recent price crash, the miners have maintained their upbeat attitude, in part because they’ve died this death a few times before. In February, a day after bitcoin’s price dipped below $6,000, I checked in with Carlson to see how he was dealing with the huge sell-off. In a series of long texts, he expressed only optimism. The market correction, he argued, had been inevitable, given the rapid price increase. He noted that mining costs in the basin remain so low—still just a little above $2,000 per coin—that prices have a way to fall before bitcoin stops being worth mining there. Carlson is, he told me, “100 percent confident” the price will surpass the $20,000 level we saw before Christmas. “The question, as always, is how long will it take.”