Terra Pool.

Terra Pool was set up by two listed bitcoin miners, DMG Blockchain Solutions of British Columbia, Canada, and London-listed Argo BlockchainBlockchainBitcoin's shared record of every payment since 2009, stored in blocks that each link to the one before — which is what makes it a chain., which announced it in March 2021 as a pool powered only by clean energy. It started in December 2021 with the two companies’ own machines, mostly run on hydroelectric power, and opened to other miners in June 2022. Miners had to pass identity checks and show where their power came from, and the pool promised a yearly audit by an outside firm.

It was busiest in the first half of 2022, finding 30 or more blocks in a month at its peak. Each block paid its whole reward to one of the pool’s addresses, and the pool paid its miners from there. That reward is separate from the transactions confirmed inside the block. DMG says the pool’s software leaves out transactions linked to addresses on the US Treasury’s sanctions list.

At first members were paid according to the blocks the pool found, so their earnings rose and fell with its luck. In May 2022 Argo said its machines on Terra Pool had produced much less bitcoin than before, “primarily due to short-term probabilistic outcomes”, and that it was looking at other pools. Terra Pool found no block from August 2022 to January 2023, and its last came on 27 January 2024. DMG hasn’t closed it: the pool’s site still takes miners, now paying them for their work whether or not it finds blocks, but no block has carried its name since.