Ahead of the rapidly approaching Ethereum Merge on Sept. 15, Ethermine, the world’s largest Ether (ETH) mining pool has unveiled a new staking pool for users. Notably, however, it is not available to United States miners

The new service, offered via Bitfly, enables Ethermine members to collectively stake their ETH and earn interest on top of their deposits. As little as 0.1 ETH, or $159 at the time of writing, is required to enter. However, the smaller the holding, the greater the fee. The platform is currently offering stakers an annual ETH interest rate of 4.43%.

At the time of writing, 393 ETH, worth roughly $626,000 at current prices, has been invested into Ethermine’s new pool.

Staking pools such as these hold significance, as they offer competitive interest rates and lower barriers of entry than solo staking as node operators, which requires at least 32 ETH, or around $51,000, to operate a node. In comparison to Ethermine’s interest rate, staking via the Ethpool on Bitfly as a node operator garners an annual interest rate of 4.6%.

The switch to offer to stake is something of a pivot for Ethermine which currently operates as a multi-currency mining pool, allowing users to mine ETH, Zcash (ZEC), Ethereum Classic (ETC), Beam (BEAM), Ravencoin (RVN) and Ergo (ERGO).

After the merge, ETH mining will be phased out as the network changes from a proof-of-work (PoW) mining model to a proof-of-stake (PoS) staking model.

At the time of writing, there are 222,657 active miners on Ethermine that account for a combined hash rate of 261.1 terra hashes per second (TH/s). After Sept. 15, the pool will only continue to support the PoW mining of ETC, RVN, ERGO and BEAM.

End of the mining era

Miner dashboards will have a Merge countdown clock and miners can keep mining ETH up until the timer hits zero.

ETH miners will soon be replaced with PoS validators, which could help cut the ETH network consumption by 99%.

However, some in the ETH miner community have pushed to keep the current PoW consensus mechanism because the shift will make their high powered and costly mining rigs redundant.

Other high-profile members of the crypto community have also been critical, arguing the changes will cause negative impacts beyond the loss of mining

Related: The Merge Q&A: A triumph for Ethereum — or a disaster waiting to happen?

The current PoW system is an energy-intensive process where miners harness large amounts of computer power to solve complex puzzles, validate transactions and earn ETH rewards.

Under the PoS model, participants or validators lock up set amounts of cryptocurrency in a smart contract on the blockchain; their stake helps secure and decentralize the network.