Power is not energy
Power describes the rate at which equipment uses energy. A watt, written W, is a unit of power; 1,000 W equals one kilowatt, written kW. Energy accumulates over time. A kilowatt-hour, written kWh, is the energy associated with one kilowatt used for one hour. EIA’s measurement guide explains these units.
A machine drawing 3 kW for one hour and the same machine drawing 3 kW for ten hours have the same assumed power but different energy consumption. This distinction is essential when reading specifications and electricity bills. A power rating is not a daily energy total, and a rate per kWh is not a flat price for keeping a miner connected.
Start a planning sheet with four separate entries: miner power, operating hours, electricity rate, and site overhead. Write units beside every number. When a result looks surprisingly low or high, check whether watts were converted to kilowatts and whether the time period matches the question before changing the assumptions.
Process in three steps
- Define the load. Use a documented power assumption for the intended machine and operating mode. Label whether it is a nominal specification or a measured value.
- Choose the period. Estimate actual operating hours for a day, a 30-day month, or a 365-day year. State any assumed uptime and planned shutdowns.
- Apply the tariff. Multiply energy by the applicable rate, then account separately for charges or services that the simple energy calculation does not include.
The calculation is a planning tool. Its value comes from making assumptions visible, not from displaying many decimal places. If the power changes between operating modes, calculate each period separately rather than assigning one rate of consumption to the whole day.
Key vocabulary
- Power draw: The assumed or measured rate of electricity consumption in watts or kilowatts. Specify where the measurement is taken.
- Energy consumption: Power multiplied by operating time, expressed in watt-hours or kilowatt-hours when the inputs use those units.
- Electricity tariff: The supplier’s charging arrangement. Read the actual contract to identify energy rates and additional applicable charges.
- Efficiency: Power divided by hashrate for a given algorithm and operating condition. Lower power per unit of work can be useful, but does not settle total economics.
The Department of Energy’s electricity overview also distinguishes consumption over time from the electricity system supplying it. For mining, keep the site’s supply constraints and the billed consumption in separate parts of your assessment.
Read the whole electricity bill
An advertised energy rate may not describe the entire bill. Ask the supplier which fixed charges, demand charges, taxes, time-based prices, minimum commitments, or contract terms apply to your account. These are questions to investigate in your location, not charges that apply universally. Obtain the actual terms before entering a rate into a calculator.
If prices vary during the day, split your estimate into the relevant periods. For example, model the hours you intend to operate at each rate rather than averaging prices without weighting the hours. If you expect shutdowns during expensive periods, include the reduction in mining time as well as the reduction in energy cost.
Compare estimates with bills and meter readings after installation. Note whether the meter covers just the machine or a wider site. A whole-site bill cannot be attributed entirely to one miner unless the other loads are accounted for. Keep records so you can distinguish an input error from an operational change.
Cooling and electrical capacity
Mining equipment converts much of its electrical input into heat that the site must manage. Plan for ventilation or the cooling system specified by the equipment manufacturer. Any separately powered fans, pumps, or cooling equipment need their own energy assumptions. Do not silently treat a miner-only calculation as the total facility cost.
A site’s electrical suitability cannot be established from a profitability result. Ask a qualified electrical professional to assess the supply, circuits, protection, connectors, local requirements, and intended operating load. This page does not provide wiring instructions or a universal safe circuit size. Use the exact product documentation for equipment requirements; BITMAIN’s handling guidance is one manufacturer reference, not a specification for every miner.
Keep electrical capacity, temperature management, noise, and maintenance access on the site checklist. A financially attractive rate does not compensate for a location that cannot safely support the equipment or where operating conditions exceed the manufacturer’s limits.
Worked example
Hypothetical miner-only electricity cost
Assume 3,000 W of power and 90% uptime in a 24-hour day. Operating time is 24 h × 0.90 = 21.6 h.
Energy use is 3 kW × 21.6 h = 64.8 kWh. At an assumed USD 0.10/kWh, the energy charge is USD 6.48/day or USD 194.40 per 30 days.
The annual equivalent is 64.8 kWh multiplied by 365 days, or 23,652 kWh, costing USD 2,365.20 at the same assumed rate. This example assumes a constant draw while running and ignores standby consumption, cooling overhead, extra tariff charges, and repairs. It estimates cost, not revenue or profit.
Try the electricity cost calculator with these inputs, then change one assumption at a time. Compare full uptime with your realistic operating schedule and include separate site loads in your planning sheet.
Common mistakes
- Using watts as kilowatts. Convert 3,000 W to 3 kW before multiplying by hours and a rate per kWh.
- Counting only the miner. Identify cooling, networking, lighting, and other relevant loads instead of presenting miner energy as a complete site bill.
- Treating price as capacity. A low tariff does not establish that the supply, circuit, connectors, or location are suitable for the equipment.
Frequently asked questions
Is the most efficient miner always the best purchase?
No. Efficiency is one input. Purchase cost, condition, compatibility, site requirements, service arrangements, and the intended time horizon also matter. Compare machines using the same algorithm and consistent units.
Can I use a household socket?
Do not infer suitability from the socket’s appearance. Have the proposed installation assessed against the exact equipment requirements and local electrical rules by a qualified professional.
What should I learn next?
Continue with hardware to interpret specifications, or operations to connect electrical planning with cooling and monitoring. Use mining basics to review the wider operating model.