[gandalfian]

In Uk, If an old (rare) mechanical meter the meter will go backwards, the ideal. If a dumb digital meter the meter will simply pause counting up. If a smartmeter again the import reading will pause but a separate export reading will count up, for which you get no credit or debit but its nice to know. Ideally as battery prices drop you end up buying a battery that soaks up any surplus for later and so you don't lose any back to the grid. If you pay up for a commercially installed solar you can get paid for what you export but with plug in solar you just give it away.

[DamonHD]

In the UK as a consumer you can (always AFAIK) get a smart meter for free, and your retail supplier is required to offer you a non-zero rate (the "Smart Export Guarantee") for what you export back to the grid. That can be as high as about half the rate to import.

[gandalfian]

To get paid for export you will nearly always need an MCS number to show it was installed by accredited professionals. Doing it yourself, or by your local electrician or plug in solar is not something they accept. It's a bit of a racket, but in practice pay up for the professional install or no export payments.

[megak1d]

I’m guessing this will almost certainly change once this comes in. Historically you’d need an MCS cert as a proxy for a safe/valid solar install (electrically safe I mean, followed regs etc). Now the regs say anyone can have plugin solar there’s no reason to stop consumers getting export tariffs.