BTC: US Industrial Electricity Price (EIA)
The average price US industrial customers paid for electricity each month, for the whole country and the states with large bitcoin mining sites, in US dollars per megawatt-hour, from the US Energy Information Administration.
Why use it. Power is a miner's largest cost. The industrial tariff is what a site pays without a special contract, and the gap between states shows why mining gathers where power is cheap. How to read it. Each line holds a month's average for every day of that month. Set it against Energy Hashprice: a site paying more for power than its machines' energy hashprice mines at a loss. The EIA publishes each month about two months after it ends, so the newest months are not there yet.
Calculation. Monthly average retail price of electricity to industrial customers (EIA series ELEC.PRICE.<state>-IND.M, cents per kWh) × 10 = USD per MWh, held for each day of its month, from January 2014. Read from the EIA's bulk electricity file, checked daily. Large miners often pay less through negotiated contracts, demand-response credits or their own generation: the industrial average is a benchmark, not what any miner pays. US Energy Information Administration, bulk electricity data (public domain), read by CryptoKeyhole.