SMETS2 smart meters can measure both import and export. Here's why that matters for plug-in solar owners—and what to do if you haven't got one yet.

Plug-in Solar and the UK Smart Meter Rollout: What You Need to Know

When the UK government confirmed plug-in solar as legal in March 2026, one question kept coming up: can smart meters actually measure what you're exporting back to the grid?

The answer is yes—but with a caveat. Let's break down what smart meters do, why they matter for plug-in solar owners, and what you need to do if you haven't got one yet.

What SMETS2 Meters Can Do

Over the past decade, UK energy suppliers have been rolling out SMETS2 smart meters—the second generation of smart metering equipment. By early 2026, more than 85% of UK homes had a smart meter installed, and the rollout continues.

SMETS2 meters do something crucial: they record both your import (power you're buying from the grid) and your export (power you're sending back). They take half-hourly readings, which means your supplier can see exactly how much solar energy you're pushing out each 30-minute window.

This matters because when the Smart Export Guarantee (SEG) scheme becomes more widely available—potentially through a broader scheme in the coming years—meters that can't measure export are essentially useless. You'd have no verifiable record of what you've generated and sold back.

Why Export Measurement Matters for Plug-in Solar

Here's the practical bit: if you install a plug-in solar panel today and connect it to a standard grid outlet, your home is generating electricity. If you're feeding that back into the network, your energy supplier needs to know about it. Not for legal reasons (that's handled by your G98 notification to your DNO), but because:

Future SEG access: Most SEG schemes require MCS-certified installations. But as policy evolves, smaller schemes may emerge that do measure and reward self-installed systems. A meter that can't record export is worthless for this.
Accurate billing: Your import meter reading should not be inflated by power you've generated yourself. Export measurement prevents you overpaying.
Grid data: DNOs (Distribution Network Operators) and suppliers increasingly need granular data on where power is being generated and consumed. This helps them balance supply.
Future policy: The UK government is watching how Germany's 1M+ Balkonkraftwerk installations are performing. Export measurement is part of that picture.

Do You Have a SMETS2 Meter?

If your smart meter has a display that shows both import and export readings—or if your supplier's app shows export data—you've got a SMETS2 meter. If you're unsure, contact your supplier and ask: "Do my smart meter readings include export data?"

Most meters installed since 2023 are SMETS2. But older SMETS1 meters, or traditional mechanical meters, do not record export.

What If You Don't Have a Smart Meter?

This is important: you have the right to a free smart meter upgrade. Under UK energy supply regulations, your supplier must offer you a free installation.

If you're planning to install plug-in solar, request your smart meter upgrade now. Aim to have it fitted before your panels arrive—that way, you'll have a complete record of your usage and generation from day one.

When you call your supplier, be clear: "I'd like to upgrade to a SMETS2 smart meter that records export data." They'll arrange a free appointment.

How Smart Meters Interact with Plug-in Solar

Here's a real-world example. You install an 800W plug-in panel on a sunny Tuesday in June. Between 10 am and 11 am, your panel generates 600Wh. Your home is using 200Wh of that in real time (kettle, fridge, heating), and you're exporting 400Wh back to the grid.

Your smart meter records:

Import: 1,200Wh (you've still drawn this from the grid for other appliances)
Export: 400Wh (solar you're selling back)

Your supplier can now see this half-hourly breakdown and—if a SEG scheme is available—could eventually pay you for that export.

Without export measurement, the supplier would only see your import figure and have no proof of what you're generating.

Smart Meters and BS 7671 Compliance

Here's a question that sometimes comes up: does BS 7671 Amendment 4 require a smart meter?

The short answer is no. BS 7671 Amendment 4 (April 2026) sets safety standards—RCD protection, earthing, circuit capacity—not metering requirements. You can install plug-in solar legally without a smart meter.

But for future-proofing and to access export schemes as they develop, you'll want one.

Monitoring Your Generation Beyond the Meter

Many plug-in solar panels come with monitoring devices or smartphone apps. The Emporia Vue 3 is a popular choice (around £90)—it measures your whole-home energy in real time and can track solar export separately from your meter.

This gives you granular visibility of:

How much your panel is generating hour by hour
How much you're exporting vs. self-consuming
Your total household load
Potential savings

It's not a requirement, but it's a useful complement to your smart meter.

What Comes Next?

The BSI product standard for plug-in solar is expected in July 2026. Once retail-approved kits become available, suppliers will begin offering export schemes alongside them. Smart meters will be the essential infrastructure for measuring and paying for that export.

By then, having a working SMETS2 meter in place will be one less thing to worry about.

Summary

Over 85% of UK homes now have smart meters that can record export
SMETS2 meters are essential for future Smart Export Guarantee schemes
If you don't have one, request a free upgrade from your supplier
Smart meters aren't required by BS 7671 Amendment 4, but they're worth having
Monitor your generation independently with devices like the Emporia Vue 3

For more on plug-in solar safety and regulation, read our guide to BS 7671 Amendment 4.