Octopus Agile + Home Assistant 2026: Automate cheap electricity in the UK

Pairing Octopus Agile with Home Assistant turns half-hourly electricity pricing into automatic savings.

TL;DR — the five-minute version

Install the community Octopus Energy integration by BottlecapDave via HACS — it's the de-facto standard and Octopus themselves recognise it as the one. Then build three automations, in this order, to capture most of the savings:

1. Shift the dishwasher / washing machine / tumble dryer to the cheapest two-hour window — £4–£7/month saved.
2. Charge your home battery or EV only below a price threshold (e.g. 10p/kWh) — £15–£50/month, often more.
3. Push a phone notification when tomorrow has a slot below 5p or a negative slot — lets the household run hot tubs, ovens or showers on nearly-free electricity.

Agile publishes tomorrow's rates every afternoon between ~4pm and 8pm, capped at 100p/kWh per slot. Against the April 2026 price cap (~25p/kWh standard rate), cheap slots are routinely 2–5× cheaper. Negative ("plunge") slots pay you to use electricity.

At-a-glance: the three day-one automations

The catch is obvious. You have to actually move your usage into those cheap windows, and nobody sensible is going to stand in the kitchen at 3am to start the dishwasher. That is exactly what Home Assistant is for: it reads tomorrow's prices the moment Octopus publishes them, picks the cheapest slots, and tells your appliances, battery or EV charger when to run.

Why Agile exists and how the pricing works

Most domestic tariffs hide the wholesale market behind a fixed unit rate. Agile does the opposite. Octopus takes the half-hourly wholesale price, adds a small margin and some network costs, and passes that straight through to you. Each afternoon — typically between 4pm and 8pm, most often closer to 4pm — Octopus publishes the unit rates for the next 24 hours. From that moment you know exactly what every half-hour slot until the following end-of-day will cost. Individual rates are capped at 100p per kWh to protect customers from extreme wholesale spikes.

Two things make Agile interesting for a smart home. First, the spread is enormous: cheap slots in the small hours can be four or five times cheaper than the early-evening peak between 4pm and 7pm. Second, the window is predictable. Once tomorrow's prices drop, you have the whole evening to plan. A Home Assistant instance with the Octopus Energy integration installed pulls those prices in as sensors, which means any automation you can dream up can make decisions based on them.

Setting up the Octopus Energy Home Assistant integration

Octopus does not publish its own Home Assistant integration, and there is no core-bundled Octopus integration. The de facto standard — the one essentially every Agile household uses — is the community Octopus Energy integration by BottlecapDave, installed via HACS. Octopus themselves have publicly estimated that the vast majority of their Home Assistant–driven API traffic flows through it. The integration is comprehensive: Agile rates, standing charges, consumption data if you have an Octopus Home Mini, intelligent dispatch data for Octopus Intelligent Go, cheapest-window calculations via the companion Target Timeframes integration (a separate HACS install that consumes data from the main Octopus Energy integration to surface the cheapest N-hour continuous window), and helpers for peak avoidance. It is actively maintained — new releases land most months — but worth knowing that it is a community project, not an Octopus product.

To install it:

1. Add HACS to your Home Assistant instance if you do not have it already.
2. In HACS, search for Octopus Energy and install the integration by BottlecapDave.
3. Restart Home Assistant.
4. Go to Settings, Devices and Services, Add Integration and search for Octopus Energy.
5. Enter your API key (available from the Developer section of your Octopus Energy online account) and your account number.

Within a few minutes you will see sensors for your current rate, the next rate, today's and tomorrow's rates as attributes, and — if you configure them — target-timeframe helpers that mark themselves as "on" during the cheapest continuous window you specify.

Three Octopus Agile Home Assistant automations worth building on day one

If you do nothing else with Agile and Home Assistant, build these three. They are the ones that actually move the bill.

Shift the dishwasher, washing machine and tumble dryer

The pattern is simple. Create a target-timeframe helper for a two-hour window. When the helper flips on — meaning you are inside the cheapest continuous two-hour block of the next 24 hours — trigger the appliance to start.

How you trigger it depends on the appliance. Modern Bosch, Miele, Samsung and LG machines support delayed start, and most have Home Assistant integrations — Miele has an official core integration, Samsung and LG are reachable via SmartThings and LG ThinQ, and Bosch machines work through the Home Connect community integration. Older or simpler machines can be power-cycled with a smart plug, but only if the appliance resumes cleanly from a cold start — check the manual, because a few models will sit with error lights after a power loss.

Realistic savings: you might save 15-25p per cycle versus an average rate, across five to seven cycles a week. Call it £4-£7 a month. Not life-changing on its own, but it is genuinely set-and-forget.

Charge a home battery or EV only when Agile is cheap

This is the single highest-value automation on Agile. An EV charger or a home battery moves serious kilowatt-hours, so every penny of difference per kWh matters.

The pattern: charge during slots below a threshold (say 10p per kWh), and never charge during slots above another threshold (say 20p per kWh). For a home battery automation using GivEnergy, Fox ESS, Pylontech or Tesla Powerwall, Home Assistant can send the charge command directly to the inverter. For EV charging, a Zappi, Ohme or other HA-compatible charger can be switched between Eco and Boost modes based on current price.

If you are on Octopus Intelligent Go rather than Agile — worth considering specifically for EV owners — the charger schedules itself, and the community integration exposes Octopus's smart-charge windows as sensors so other automations can react to them.

Realistic savings on Agile: £15-£50 a month for most households, more if you have both a battery and an EV on the same cheap slots. See the EV charging guide for the specifics.

Notify on cheap or negative slots

Some loads you would never automate, but would happily run manually if you knew the electricity was almost free. Hot tubs. Electric showers for a deep-clean cycle. Sunday-roast-sized oven sessions. Tumble dryers for the bedding nobody planned for.

Create an automation that sends a phone notification whenever tomorrow's prices include a slot below 5p per kWh, or any negative slot at all. It is low-tech and surprisingly engaging — once the household starts seeing "cheap slot 2-3pm tomorrow" notifications, behaviour shifts on its own.

The edge cases Agile users actually hit

Once the basics are running, the next wave of problems appears. Home Assistant handles all three of these gracefully, but you have to know to ask for them.

Peak pricing between 4pm and 7pm. On cold, still winter evenings, Agile can spike to 40-50p per kWh for a handful of slots. Any flexible load running in those slots wipes out a chunk of your overnight savings. Write a blanket automation that turns off or defers non-essential loads — hot-water immersion, pool pumps, towel rails, dehumidifiers — whenever the current rate exceeds a threshold you set.

Plunge pricing. The opposite problem, and more fun. When prices go negative — Octopus calls it "plunge pricing" — you want to actively consume electricity you would otherwise skip. Boost the hot water tank to a higher setpoint. Drop the freezer a couple of degrees. Top the battery up to 100%. Run the dehumidifier. Every kWh you absorb during a plunge slot is money back on the bill.

Day-ahead uncertainty. Because prices only publish once a day, any schedule you set before 4pm is working on incomplete information. Build your automations so they re-run the moment new prices arrive, not on a fixed clock. The community integration fires an event when tomorrow's rates land, which is the right trigger to hang re-optimisation off.

What can break

Agile automation is powerful, but it is not fit-and-forget. Here is what goes wrong in practice.

The community Octopus integration has broken several times over the years when Octopus changed their API. It is always fixed quickly — usually within a day or two — but during that window your price sensors may go stale, and automations that depend on them will fall back to whatever last known state they had. If that state was "cheap, run everything", you get an awkward bill. Build your automations with a safety check: if the price data is more than a few hours old, do nothing.

Heat-pump schedulers, EV charger apps, and battery inverter apps all have their own built-in logic, and they will happily fight your Home Assistant automations if you let them. Pick one source of truth per device. If Home Assistant is running the Agile logic, put the inverter or charger into a dumb mode and let HA drive it.

Smart plugs that power-cycle appliances are a quiet risk. Some dishwashers and washing machines do not resume cleanly from cold start; a few will need a manual reset on the panel after losing power mid-cycle. Test each appliance once, deliberately, before you trust an automation to run it at 3am.

And finally, Home Assistant itself needs updates. The Octopus integration needs updates. HACS needs updates. Cloudflare tunnels need keeping alive. None of it is hard, but none of it is zero either, and all of it has to happen for the savings to keep landing.

Who Agile is right for — honestly

Agile is not for everyone. Octopus themselves will tell you this.

Agile works well if: you have an EV, a home battery, or both. You have flexible appliance use and can shift laundry and dishwashing off peak. You have a home office and can time-shift discretionary loads. You have solar with a Smart Export Guarantee arrangement and can soak up cheap grid electricity when your panels are quiet. You are willing to pay attention, or willing to put Home Assistant in charge of paying attention for you.

Agile works badly if: most of your usage is daytime and inflexible — children home from school, electric cooking at 6pm, no overnight loads. You do not have smart appliances or delayed-start functionality. Your household runs on a strict routine that happens to align with peak pricing. In those cases, a fixed tariff or one of Octopus's other smart products (Octopus Go for EV owners on fixed overnight windows, Octopus Cosy for heat-pump owners, Octopus Intelligent Go for smart-charge EVs) may genuinely beat Agile on total cost. Note that Octopus Go and Cosy moved to 6-month fixed deals with £25 early-exit fees in March 2026, so switching between them is no longer costless (Intelligent Octopus Go is unaffected — no minimum term, no exit fee). Octopus Flux is currently paused to new customers due to volatile wholesale prices — existing Flux customers still have it, but new sign-ups are temporarily unavailable.

Before you switch, pull a month of half-hourly consumption data from your smart meter (the energy savings overview walks through this) and model it against historical Agile prices. Tools like Octoprice and energy-stats.uk do this for free. If the modelled Agile bill beats your current tariff by more than 10%, it is worth the switch. If it is within 10% either way, the admin overhead probably is not worth it unless you genuinely enjoy the optimisation.

The honest conclusion

Octopus Agile and Home Assistant together are the closest thing the UK energy market currently offers to a genuinely smart home. The savings are real, the automations are achievable, and the integration ecosystem is mature enough that you can be up and running in an afternoon.

The ongoing cost is attention. API changes, integration updates, the occasional 3am automation that misfires because an appliance did not resume state — none of it is crushing, but it adds up to a few hours a month for anyone running this stack themselves. If you want the savings without signing up to be your own smart-home sysadmin, that is exactly where habbb's managed Home Assistant service fits in: we keep the integration current, the backups running and the tunnel up, so the automations you build on top of it stay working. Like a boiler service — we keep what you have working. Adding a new radiator is a separate job.

Either way: if you are on Agile and you are not yet letting Home Assistant make the decisions, you are leaving money on the table every single night.

What changed in the April 2026 update

• Added a TL;DR at the top: the five-minute version with integration name, automation priority, and expected savings per tier.
• Added an at-a-glance table of the three day-one automations with savings and risk markers.
• Title reframed to include "2026" and the direct query match for octopus agile home assistant plus the UK qualifier.
• Confirmed pricing references against the April 2026 Ofgem cap (~25p/kWh) and the March 2026 structural changes to Octopus Go / Cosy / Intelligent Go (6-month fixes + £25 exit fees) and Flux (closed to new customers).