Bitfarms' (NASDAQ:BITF) bitcoin (BTC-USD) production fell nearly 10% to 481 in September vs. August due to a higher network difficulty as well as a shorter month and a brief farm outage, it said Monday. That figure it still up 57% from a year earlier.Nevertheless, with 229 megawatts of mining capacity expected to be developed by the end of 2022, "we are well positioned to further grow production in 2023.” said Ben Gagnon, chief mining officer of Bitfarms.The bitcoin (BTC-USD) miner's operating hashrate reached 4.2 exahash per second, up from 3.9 in August and 1.5 in the year-ago period.In an effort to free up more capital, the company said it sold 544 bitcoins (BTC-USD) during the month, generating proceeds of $10.66M. For Q3, it sold $3.8M worth of surplus miners to improve fleet efficiencies.It held 2,065 BTC in custody as of September 30, representing $40M based on a BTC price of $19.4K.Previously, (Sep. 19) Bitfarms tops 4 EH/s hashrate as production kicks off at Rio Cuarto warehouse.