TL;DR:

  • If you have a SMETS2 smart meter, the Hildebrand Glow IHD or the free Loop app can show live and historical usage data at no cost.
  • Clamp-on monitors like the Shelly Pro EM give circuit-level breakdown for around £50–£80 and work offline with Home Assistant.
  • Whole-house monitors pay for themselves within months by identifying standby waste and badly-timed high-draw appliances.

Knowing your household’s electricity consumption in real time changes how you use energy in a way that estimated monthly bills simply cannot. Studies consistently show that households with real-time energy monitors reduce consumption by 5–15% — not by doing anything complicated, just by seeing the numbers and making small behavioural changes. In 2026, the UK has several good options at every price point.

What Energy Monitors Actually Show You

A home energy monitor typically shows:

  • Live consumption in watts or kilowatts, updating every few seconds
  • Cost per hour at your current tariff rate
  • Daily, weekly, and monthly totals so you can spot trends
  • Historical comparison — is this month’s usage up or down versus last year?

More advanced monitors add appliance-level detection, solar export tracking, EV charging monitoring, and integration with smart home platforms. Which features you need depends on what you’re trying to understand.

Option 1: Smart Meter IHD Upgrades (Free)

If you already have a SMETS2 smart meter installed, you have access to half-hourly usage data via the Data Communications Company (DCC) network — and two services make excellent use of it at no cost.

Loop is a free app (iOS and Android) that connects to your SMETS2 meter via the DCC and shows live usage, historical data, and comparison with similar homes. Loop provides personalised tips based on your actual usage patterns and can track estimated savings from behaviour changes. For most users with a smart meter, Loop is the first thing to install — it costs nothing and requires no hardware.

Hildebrand Glow offers both a free app similar to Loop and a physical IHD (In-Home Display) that plugs into the wall and shows live data on a colour screen without needing your phone. The Glow IHD (around £35–40) pulls data directly from your smart meter via Zigbee — no internet required for the live display. The accompanying app adds historical analysis and export options. For households that want a visible display in the kitchen without picking up a phone, the Glow IHD is the most practical low-cost option.

Limitation: Both services depend on your smart meter’s Zigbee communications module working correctly. Some smart meters have this disabled by their supplier, or the signal doesn’t reach through thick walls. If Loop can’t connect after a few days, contact your supplier.

Option 2: Clamp-On Monitors (£30–£150)

Clamp-on current sensors fit around your incoming mains cable (or around individual circuit cables) and measure current flow without any electrical work. They’re the right tool if you don’t have a smart meter or want more granular circuit-level data.

Efergy Engage (around £30–50) is one of the simplest: a clamp fits around one of the two mains cables in your consumer unit, a transmitter sends data wirelessly to a display unit, and an app shows historical usage. Setup takes about 10 minutes. Accuracy is good for whole-house monitoring, and the app includes tariff settings for accurate cost calculations.

Shelly Pro EM (around £60–80) is the choice for home automation enthusiasts. It installs in the consumer unit and measures two circuits independently, with accuracy to ±0.5%. It connects to your Wi-Fi and integrates natively with Home Assistant, MQTT, and Shelly’s own cloud. If you have solar panels, it can monitor both import and export simultaneously. The data stays local if you want it to — no cloud dependency required.

Sense Home Energy Monitor (around £250) takes a different approach: it uses machine learning to identify individual appliances by their electrical “fingerprint.” Over several weeks, Sense learns to distinguish your fridge, washing machine, EV charger, kettle, and other devices by how they draw power. The appliance-level breakdown is genuinely useful for identifying energy hogs. Sense is US-designed but supports UK single-phase installations.

Option 3: Circuit-Level Monitoring (£100+)

For a full picture of where electricity goes in your home, circuit-level monitoring measures each individual circuit breaker separately. This shows you exactly how much your immersion heater, underfloor heating zones, EV charger, and appliance circuits cost to run.

Emporia Vue 2 (around £100 for 16 circuits) is widely used in the US and increasingly available in the UK via importers. It clips current transformers around each circuit breaker in your consumer unit and reports to a cloud app. The setup takes a couple of hours but the result is a complete breakdown of every circuit’s consumption.

For UK-native solutions, electricians can install sub-metering hardware (Schneider Electric, Carlo Gavazzi) at higher cost but with professional-grade accuracy — relevant for households with EV chargers, heat pumps, or solar where accurate sub-metering matters for tariff calculations or grant compliance.

Integrating with Solar and Heat Pumps

If you have solar panels, a monitor that tracks both import from the grid and export to the grid simultaneously shows your actual self-consumption rate — the share of your solar generation you’re using in your home versus exporting at the lower SEG rate. Improving self-consumption (by shifting dishwasher and washing machine use to midday) can be worth £100–300/year on a typical solar installation.

Heat pumps show their COP (coefficient of performance) in real-world conditions only when you can measure both electricity consumption and heat output. An energy monitor on the heat pump circuit plus a heat meter (flow rate × temperature differential) gives you real COP data, which is useful for verifying performance and identifying maintenance issues before they become expensive.

Getting the Most from Your Monitor

The biggest mistake is installing a monitor and then ignoring it. The insights come from:

  1. Establishing a baseline — what does your home consume on a typical weekday with everyone out? That’s your floor: everything running even when you don’t think you’re using electricity.

  2. Identifying standby waste — plug loads in idle state. Common culprits: games consoles on standby (80–150W), old broadband routers, desktop PCs in sleep mode, satellite TV boxes.

  3. Shifting high-draw loads — if you’re on an Agile, Go, or Intelligent Octopus tariff, seeing when your dishwasher, washing machine, and EV charger run, and whether that aligns with cheap-rate periods, shows you exactly how much you’re saving (or not) from tariff optimisation.

  4. Verifying improvements — insulation, draught-proofing, and appliance upgrades all have measurable impacts. A monitor tells you whether your new heat pump is actually using less electricity than your old boiler, week by week.

For most UK households with a SMETS2 smart meter, starting with the Loop app costs nothing and answers 80% of questions. For those who want circuit-level detail or offline local data, a Shelly Pro EM at around £60–80 is the most capable mid-range option.