Time-of-Use Bitcoin Mining: How to Mine Only When Electricity Is Cheap

Electricity is the single largest ongoing cost in Bitcoin mining. For home miners, it can mean the difference between profitability and burning money. But most residential electricity plans are not flat-rate — they use time-of-use (TOU) pricing, where the cost per kilowatt-hour changes based on the time of day. Smart miners exploit this by running their ASICs at full power when electricity is cheapest and throttling or shutting down during expensive peak hours.

This guide explains how TOU mining works, which firmwares support scheduling, how curtailment functions at a technical level, and how much money you can save by aligning your mining schedule with your electricity rate.

What Are Time-of-Use Electricity Rates?

Time-of-use (TOU) pricing is an electricity billing structure where the rate per kWh varies based on the time of day, day of the week, and sometimes season. Utilities use TOU pricing to incentivize customers to shift energy consumption away from peak demand hours.

A typical TOU structure has two or three tiers:

• Off-peak: Lowest rates, usually overnight and weekends. This is when grid demand is lowest.
• Mid-peak: Moderate rates during shoulder hours (mornings, evenings).
• On-peak: Highest rates during afternoon hours when air conditioning and commercial demand peak.

The price difference between peak and off-peak can be dramatic — sometimes 3x to 5x or more.

Example Rate Schedules

To understand the savings potential, let us look at two real-world TOU rate structures.

Ontario, Canada (TOU Rates)

Typical US TOU (Summer Schedule)

In the US summer example, on-peak electricity costs more than 3x the off-peak rate. Mining during those peak hours at $0.25/kWh is almost certainly unprofitable for most ASIC models. But mining exclusively during the 15 off-peak hours at $0.08/kWh can be highly profitable.

The Math: How Much Can You Save?

Let us run the numbers for a typical home mining setup using the US summer TOU rates above.

Setup: Antminer S19 XP running at 3,010W (140 TH/s)

Scenario 1: Mining 24/7 at the Average Blended Rate

Scenario 2: Mining Only During Off-Peak Hours (15 hours/day)

Monthly savings: $204 (65% reduction in electricity costs)

Yes, you mine fewer hours. But the electricity cost drops so dramatically that your profit per hour of mining increases substantially. In many cases, mining 15 hours at $0.08/kWh is more profitable than mining 24 hours at the blended $0.144/kWh rate — because the peak hours were actually losing money.

How Curtailment Works

Curtailment is the technical term for reducing or stopping mining output in response to an external signal. In the context of TOU mining, curtailment means automatically throttling your miner when electricity enters a more expensive rate period.

There are several levels of curtailment:

Full Shutdown

The simplest approach: turn the miner completely off during peak hours and back on during off-peak. This is effective but has drawbacks — cold starts take time (the ASIC chips need to be re-initialized, autotuning may need to run again), and the thermal cycling from repeated on/off cycles can stress components over time.

Power Reduction (Throttling)

A more sophisticated approach: reduce the miner’s power consumption during mid-peak hours by lowering chip frequency and voltage. Instead of running at 3,010W, drop to 1,200W. You still mine (at reduced hashrate), but your electricity cost per hash drops significantly. This avoids cold starts and thermal cycling.

Ultra-Fast Curtailment

For demand response programs and real-time pricing, the speed at which a miner can curtail matters. LuxOS leads the industry here with sub-5-second curtailment — the miner can drop from full power to minimum in under 5 seconds by immediately reducing chip frequency and voltage. This is fast enough to participate in grid frequency response programs, which can generate additional revenue.

Which Firmwares Support Scheduling?

Not all firmwares make TOU mining easy. Here is how the major options compare:

The key distinction is between firmwares that require external scripting (you write a cron job or use a management platform) and those with built-in scheduling (you configure the schedule directly in the miner’s web interface).

Manual vs. Automated Approaches

The Manual Approach: Smart Plugs and Timers

The simplest TOU mining setup requires no special firmware at all:

1. Plug your miner into a heavy-duty smart plug or timer rated for the miner’s amperage.
2. Set the timer to turn power on during off-peak hours and off during peak hours.
3. Accept the thermal cycling and cold-start time as trade-offs.

This works, but it is crude. You lose hashrate during the startup period (5-15 minutes each cycle), you cannot throttle to a middle ground during mid-peak hours, and repeated hard power cycles stress the PSU and hash boards.

The Script Approach: API Calls on a Schedule

With firmware that exposes an API (BraiinsOS+, VNish, LuxOS), you can write scripts that adjust mining parameters on a schedule:

• A cron job on a Raspberry Pi or home server sends API calls to the miner at scheduled times.
• At 9pm (off-peak start): set power target to 3,010W.
• At 12pm (on-peak start): set power target to 0W (or 800W for eco mode).
• The miner throttles gracefully without a hard power cut.

This is more sophisticated but requires technical knowledge, a separate always-on device to run the scripts, and manual maintenance if your rate schedule changes.

The Built-In Approach: Firmware-Level Scheduling

The ideal solution is a scheduler built directly into the mining firmware. You configure your rate schedule once in the miner’s web interface, and the firmware handles everything automatically:

• Define rate periods with start/end times and days of the week.
• Assign a power profile to each rate period (full power, eco mode, sleep, or shutdown).
• The firmware transitions smoothly between profiles, ramping power up and down gradually to avoid thermal shock.
• No external devices, scripts, or management platforms required.

This is the approach D-Central is building into DCENT_OS — a cron-like scheduler with calendar-based profiles that runs entirely on the miner itself, with no external dependencies.

Advanced: Home Assistant Integration for Dynamic Scheduling

For miners who want maximum flexibility, combining firmware scheduling with Home Assistant opens up powerful automation possibilities:

• Dynamic rate import: Some utilities publish real-time rates via API. Home Assistant can pull these rates and send curtailment commands to the miner dynamically, rather than relying on a fixed schedule.
• Solar-aware scheduling: If you have solar panels, Home Assistant can monitor your solar production and adjust mining power to consume only your surplus generation — effectively mining with free electricity.
• Temperature-aware scheduling: In winter, override the TOU schedule to mine at full power when the house needs heat, regardless of electricity rate. The heating value offsets the higher electricity cost.
• Grid price signals: In deregulated markets (like ERCOT in Texas), real-time wholesale electricity prices can swing from $0.02/kWh to $9.00/kWh within minutes. Home Assistant automation can trigger instant curtailment when prices spike.

DCENT_OS is being designed with native MQTT support, which means Home Assistant can both monitor and control the miner in real-time — enabling all of these advanced scenarios without custom scripting.

Practical Tips for TOU Mining

Know Your Rate Schedule

Contact your utility or check their website for your exact TOU schedule. Pay attention to seasonal changes — many utilities have different summer and winter rate structures, with summer peak rates being significantly higher.

Calculate Your Break-Even Rate

Determine the maximum electricity rate at which your miner is still profitable. This depends on your miner’s efficiency (J/TH), the current hashprice, and your pool fees. Any rate period above your break-even rate should be a shutdown or minimum-power period.

Factor in Thermal Cycling

If you are doing full shutdowns, keep in mind that thermal cycling (repeated heating and cooling) can stress solder joints on hash boards over time. Throttling to a low-power eco mode is generally better for hardware longevity than hard on/off cycles.

Consider the Heating Value

If you are using your miner as a space heater in winter, the calculation changes. The heat output has monetary value (it replaces heating costs). During cold months, it may be worth mining during peak hours because the combined value of mined Bitcoin plus heating offset exceeds the electricity cost.

Monitor and Adjust

Your break-even rate changes as Bitcoin’s price and network difficulty fluctuate. Review your schedule monthly and adjust thresholds accordingly. Firmware with built-in profitability monitoring makes this much easier.

The Future: Fully Automated Economic Mining

The next evolution of TOU mining is firmware that handles everything automatically. Imagine a miner that:

1. Knows your electricity rate schedule (configured once or pulled from a utility API).
2. Monitors the current Bitcoin hashprice in real-time.
3. Calculates profitability per hour based on current conditions.
4. Automatically adjusts power output to maximize profit — mining at full power when profitable, throttling when marginal, and shutting down when unprofitable.
5. Factors in heating value during winter months.

No external platforms. No scripts. No manual schedule updates. Just set your electricity rate and your break-even preferences, and the firmware handles the rest.

This is exactly what D-Central is building into DCENT_OS — on-device economic intelligence that turns your miner into a profit-maximizing machine.

Frequently Asked Questions