Bitcoin Has a Dirty, Dirty Secret

Bitcoin’s algorithm dictates that after a certain number of tokens are created, more work is required for the next batch, said James Butterfill, the head of research and investment strategy at ETF Securities in London who has been studying cryptocurrency markets.
Using estimates of electricity prices and the rising speed with which calculations must occur, Butterfill estimates the marginal costs of each bitcoin will more than double from $6,611 in the fourth quarter to $14,175 in the second quarter of 2018. At the start of 2017, the cost was $2,856. With costs rising, there’s a greater risk for miners should prices tumble. Not all cryptocurrency mining is dirty. Computers in Iceland get power from geothermal plants. Even in China, some are clustered around hydroelectric facilities in Sichuan and Yunnan.