Every mining calculator on the internet asks you for one number: your electricity price in pence per kWh. On a fixed tariff that is fine. On a wholesale-linked tariff it is close to meaningless, because you do not have an electricity price. You have forty-eight of them, and they change every day.
Octopus Agile republishes its rates every afternoon for the following day, tracking the wholesale market in half-hourly blocks. Here is what that looked like in Eastern England today.
| Cheapest half hour | 13.77p per kWh |
| Median | 26.47p per kWh |
| Most expensive half hour | 44.87p per kWh |
A single day spanning 13p to 45p. If you plugged the median into a calculator you would conclude that mining is hopeless. If you plugged in the minimum you would conclude it is fine. Both are wrong, because the real question is not whether mining pays on average. It is which specific half hours it pays in, and whether you can be switched on for those and off for the rest.
The right question is not "is this coin profitable?" It is "how many of today's forty-eight windows clear my break-even, and can I automate the switching?"
The shape of the day
Agile pricing follows a fairly reliable pattern. The overnight trough runs roughly 11pm to 6am, when demand collapses and wind generation often keeps running — this is where the cheap half hours live. A modest daytime plateau follows. Then the evening peak between 4pm and 7pm, when Agile applies its highest pricing and rates can double or triple.
For mining, the practical consequence is that you are running a night shift. Six or seven hours in the small hours, off for the rest. Which is fine for a rig, since nobody needs it to be quiet at 3am, and the ambient temperature is lower too.
Negative pricing
Occasionally — usually windy nights in spring and autumn, when generation exceeds demand — wholesale prices go negative and Agile follows. You are paid to consume electricity.
In those half hours a mining rig has no cost at all. Its revenue is whatever it earns plus whatever you are being paid to draw the power. These windows are the single best argument for having a rig ready to switch on, and they are entirely invisible to any calculator using an average rate.
They are also not frequent enough to build a business on. A handful of hours a month in a good month. Treat them as a bonus rather than a plan.
Regions matter more than people expect
Agile pricing varies by DNO region — fourteen of them across Britain, each with its own rates reflecting local distribution costs and grid constraints. The spread between the cheapest and most expensive region is routinely several pence per kWh, which on a marginal coin is the difference between profitable windows and none.
If you are reading a mining guide written by someone in Scotland and you live in London, their numbers do not transfer. Our calculator asks for your region for exactly this reason.
Automating the switching
Knowing which windows pay is only half of it. Being awake at 2:30am to switch on is not a viable strategy, so the rig needs to respond to price automatically.
The mechanics are straightforward. Octopus publish tomorrow's rates through a free public API with no authentication required. A script can pull them each afternoon, compare against your break-even, and drive a smart plug or a mining client's own scheduling. Plenty of people already do this for EV charging and immersion heaters; a rig is no different.
Two cautions. Frequent power cycling is harder on hardware than continuous running, so switching every half hour is a false economy — better to identify contiguous blocks and run those. And if you are on Agile primarily to charge a car or run a heat pump, a mining rig competing for the same cheap windows may cost you more in displaced charging than it earns.
Does it change the answer?
Honestly, usually not. Today's cheapest half hour was 13.77p and the best break-even across the coins we track was Monero at 12.55p. Even the single cheapest slot of the day did not clear it.
But it changes the answer far more often than a flat-rate calculation suggests, and on a marginal coin it is the difference between "never" and "six hours a night". That is worth knowing before you write mining off entirely — or before you leave a rig running through a 45p evening peak because a calculator told you the daily average looked fine.
Octopus Agile rates for Eastern England (region A), retrieved live on 14 August 2026 from the public Octopus Energy API. Break-even figures assume typical tuned hardware, a 1% pool fee, and exclude hardware depreciation and tax.