Bitcoin mining consumes as much energy as a country about the size of Malaysia each year

The Kentucky boom comes as environmentalists campaign to limit the spread of bitcoin mining, which consumes as much energy as a country about the size of Malaysia each year, according to estimates from Cambridge University.

BELFRY, Kentucky: In a ravine deep in the Appalachian mountains, Warren Rogers stands on the ruins of an abandoned coal-washing plant that used to prepare hundreds of tons of the fuel a day for transport through the tiny town of Belfry, Kentucky.

His construction crews have been putting in 10 to 12-hour shifts through the winter, retrofitting the old site to power a new kind of extractive operation: mining the digital currency bitcoin.