Reading your smart meter data | Switch to Octopus

Your smart meter records how much electricity and gas you use every half hour. That data is surprisingly useful once you know where to find it and what to look for. Most people never dig into it beyond glancing at their monthly bill, which is a missed opportunity.

The Octopus app

The simplest place to start. The Octopus Energy app (available on iOS and Android) shows your consumption broken down by day, with half-hourly detail if you tap into a specific day.

The data isn’t truly real-time. There’s typically a delay of 24 to 48 hours before half-hourly readings appear in the app. This is because the data travels from your meter through the DCC network, gets processed by Octopus’s systems, and then shows up in the app. For most purposes, a day’s delay doesn’t matter.

The app shows:

Daily electricity and gas consumption in kWh
Half-hourly electricity breakdown (visible when you tap a day)
Cost per day based on your tariff rates
Monthly totals and trends

If you’re on a time-of-use tariff like Agile or Go, the app also shows how much you consumed during cheap vs expensive periods, which helps you understand whether your usage patterns are actually saving you money.

The Octopus Home Mini

Octopus offers a small palm-sized device called the Home Mini, free for customers. Made from recycled ocean plastic, it connects to your smart meter via the HAN (Home Area Network) and to your home WiFi, sending usage data to the Octopus app every 10 seconds.

This gives you near-real-time electricity consumption in the app, far more responsive than the standard 24 to 48 hour delay for DCC data. The Home Mini also acts as a range extender for gas meters that struggle to communicate with the main communications hub. Over 200,000 homes now use one, and demand is high, so you may need to join a waitlist. Request one through the Octopus app or website.

The Octopus API

This is where Octopus really shines compared to other suppliers. They have one of the best customer-facing APIs in the UK energy industry, and it’s freely available to all customers.

With the API, you can programmatically pull:

Your half-hourly consumption data for both electricity and gas
Current and historical tariff rates (including half-hourly Agile prices)
Standing charges for your region
Account information and meter details

Octopus offers both a REST API and a newer GraphQL API. The REST API is straightforward and well suited to simple data pulls. The GraphQL API gives more flexibility for complex queries. To get started with either, you need your API key (found in the Octopus web dashboard under “Developer settings”) and your meter’s MPAN (electricity) or MPRN (gas).

The API documentation lives at developer.octopus.energy. It’s well written, with clear examples. We have a guide to the Octopus API basics if you want a quick overview before diving in. Even if you’ve never used an API before, it’s approachable.

Common uses for the API include feeding data into spreadsheets for cost analysis, building custom dashboards, integrating with home automation systems and creating alerts when usage exceeds a threshold.

Third-party tools and apps

Several third-party tools connect to your smart meter data, either through the Octopus API or through the DCC network directly:

Octopus Watch: An app designed specifically for Agile and Go customers. Shows upcoming Agile prices, lets you set price alerts and tracks your spending against the rates. Available for iOS and Android.
Bright app (by Hildebrand): Connects to your smart meter via the DCC (not Octopus-specific). Shows real-time and historical consumption. Works even if you switch away from Octopus. Free to use.
Loop: A free DCC-connected app that analyses your usage patterns, tracks costs and estimates whether you’d save on different tariffs. No physical device required.
Hugo Energy Pro: A paid app (£2.99/month) that connects via the DCC and offers detailed consumption analysis, appliance-level insights and multi-device management including EVs and solar.
Home Assistant: If you use Home Assistant for smart home automation, there’s an excellent Octopus Energy integration. It pulls tariff rates, consumption data and account information into your Home Assistant dashboard. You can build automations around it, like running the dishwasher when Agile prices drop below a threshold.
Emoncms: An open-source energy monitoring platform. Combine it with a CT clamp on your meter tail for true real-time monitoring, or feed it data from the Octopus API for cost analysis.

Understanding your electricity data

Once you have access to half-hourly data, here’s what to look for.

Your baseload: This is the amount of electricity your home draws constantly, even at 3am when everyone is asleep. Look at your lowest half-hourly readings overnight. A typical home has a baseload of 200 to 400 watts (0.1 to 0.2 kWh per half hour).

If your baseload is higher than 500W, something in your home is drawing power unnecessarily. Common culprits include old fridges and freezers, electric towel rails left on 24/7, aquariums, networking equipment and devices that don’t properly sleep.

Reducing your baseload by even 100W saves about 876 kWh per year. At current electricity rates, that’s over £200 a year. Worth investigating.

Peak vs off-peak split: If you’re on a time-of-use tariff, check what percentage of your consumption falls in the cheap window. On Go, you want most of your consumption between 00:30 and 05:30. On Intelligent Go, the window is longer: 23:30 to 05:30. On Cosy, you want it spread across the three off-peak windows. If your cheap-rate percentage is low, adjust your habits or schedules.

Seasonal patterns: Compare winter and summer consumption. Gas usage swings dramatically (from near zero in summer to 50-80 kWh per day in deep winter for a typical home). Electricity is more stable but still varies. Understanding your seasonal profile helps you estimate annual costs more accurately. Try the tariff comparison tool to see live rates on different tariffs for your area.

Understanding your gas data

Gas smart meter data is less granular than electricity. Readings arrive every 30 minutes, but gas consumption is reported in cubic metres, which the system converts to kWh using a calorific value.

Average UK gas consumption is about 12,000 kWh per year, though this varies enormously depending on property size, insulation and heating habits. In summer (May to September), a typical home uses perhaps 2-5 kWh of gas per day (hot water only). In January, that can jump to 50-80 kWh per day.

If you’re considering a heat pump, your gas consumption data gives you a good baseline for estimating how much electricity a heat pump would use. Divide your annual gas consumption by the expected COP (roughly 3 for an air source heat pump) to get an approximate annual electricity requirement for heating.

Half-hourly settlement and why it matters

The UK electricity market is in the process of moving to Market-wide Half-Hourly Settlement (MHHS). Migration started in late 2025 and is expected to complete by mid-2027. Once fully rolled out, every electricity meter point will be settled on actual half-hourly data rather than estimated profiles.

For you as a consumer, this means your half-hourly smart meter data becomes even more valuable. Suppliers will have stronger incentives to offer time-of-use tariffs that reward shifting consumption to cheaper periods. Octopus is already well ahead of the curve here with tariffs like Agile and Go, but MHHS should encourage other suppliers to follow suit, giving consumers more choice and more reason to engage with their data.

What’s normal?

As a rough benchmark: the average UK household uses about 8 to 10 kWh of electricity per day and 33 kWh of gas per day (averaged across the year). If your usage is significantly above these figures, your data will show you exactly when and where the consumption is happening.