Monitoring4 May 20267 min read

Smart Meter App vs Solar Panel App: Which Should You Use for Monitoring?

Your supplier app shows billing data. Your inverter app shows generation. Here's how to use both together for a complete picture of your plug-in solar performance.

🇬🇧This article is relevant for the UK market

Two Apps, Two Jobs

When you install plug-in solar, you'll likely end up with two apps on your phone that both claim to show your energy data. They're measuring different things, and understanding the distinction prevents confusion.

Your supplier app (Octopus, OVO, E.ON, British Gas, etc.) shows data from your SMETS2 smart meter: total household import, export, half-hourly usage, costs, and standing charges. This is your billing reality — what you're paying and getting paid for.

Your solar/inverter app (EcoFlow, Anker, APsystems, Hoymiles, etc.) shows data from your panels: current generation in watts, daily production in kWh, inverter status, and potentially battery state of charge. This is your generation reality — what your panels are doing.

Neither alone tells the full story. Together, they're powerful.

What Your Supplier App Tells You

Half-hourly import — this is your consumption minus solar self-consumption. On sunny days, you'll see a clear dip during daylight hours. The deeper the dip, the better your self-consumption.

Half-hourly export — if the export register is enabled, you see how much surplus solar you're sending to the grid. This is what you get paid for under SEG.

Cost tracking — how much you're spending per day, per week, per month. Compare to pre-solar periods to see your actual saving.

Usage patterns — which hours you use the most. This informs load-shifting decisions.

The supplier app does not tell you how much your panels generated, what your self-consumption percentage is, or whether your panels are performing correctly.

What Your Inverter App Tells You

For EcoFlow STREAM owners, the EcoFlow app shows:

  • Real-time generation — current output in watts, updated every few seconds
  • Daily/monthly production — total kWh generated, with historical charts
  • Battery state — if you have a Delta 2, current charge level and charge/discharge rates
  • System health — inverter status, error alerts, firmware updates

The inverter app does not tell you your total household consumption, what you're paying, or how much you're importing from the grid.

Using Both Together

The real insight comes from combining the data:

Self-consumption rate = (Generation from inverter app − Export from supplier app) ÷ Generation × 100

Example: your EcoFlow app says you generated 3.5 kWh today. Your supplier app shows 0.8 kWh export. Self-consumption = (3.5 − 0.8) ÷ 3.5 = 77%.

Savings calculation = Self-consumed kWh × import unit rate + Exported kWh × SEG rate

From the example above: (2.7 × £0.245) + (0.8 × £0.06) = £0.66 + £0.05 = £0.71 saved today.

Performance monitoring — if your inverter app shows consistently lower output than expected for the conditions (check PVGIS data for your location), something may be wrong: shading, dirt, or a faulty panel. The supplier app alone wouldn't flag this.

What If You Don't Have an Inverter App?

Some simpler micro-inverters (like basic Hoymiles or no-name units) don't have an app. In that case:

The Ideal Monitoring Stack

For complete visibility:

  1. SMETS2 smart meter → billing data, export tracking, half-hourly patterns
  2. Inverter/solar app → real-time generation, system health
  3. Optional: energy monitor → individual appliance usage, CT clamp precision

This gives you everything you need to maximise savings without any guesswork.

Related Reading

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