Plug in solar

QrizB

IIRC the study the government commissioned concluded it would be adequately safe across a range of typical domestic wiring configurations. I think that included single-direction type AC RCDs.

(I would check the report myself but it's not convenient right now.)

tfhnota

Will any energy retailers step up and offer payments for export or will it be the same cartel thinking? Smart meters can measure the export so technically should not be a problem despite the "need" for an export MAN for the full installs.

Scot_39

my ihd just dropped back to 20W after the FF had it at 70W - for much of the day in summer even 800W would have plenty of excess if went for such a system.

Sure its been mentioned above - but on subject of export and its voltage level push potential -

Do these mini invertors also have a voltage cap to protect grid limits - a cut off set near 253V (230V+10% iirc)

QrizB

Do these mini invertors also have a voltage cap to protect grid limits - a cut off set near 253V (230V+10% iirc)

Generically, yes.

Re. the UK-approved ones, yes it's part of the Interim Product Specification (by reference to G98).

QrizB

There's an interesting snippet towards the end of the Guardian article:

https://www.theguardian.com/money/2026/jul/23/uk-households-free-install-plug-in-balcony-solar-panels

Rob Hallifax, a co-founder of Windfall Energy, said the new legislation could also pave the way for plug-in batteries in British homes. The government is reportedly considering plans to bulk buy the devices and distribute them to low-income homes, according to the i Paper.

Had anyone heard anything specific about the government looking into supplying plugin batteries to low-income homes? Or is this speculation?

A large, distributed virtual power plant made up from tens of thousands of 5kWh batteries could be a huge help towards grid balancing.

Ildhund

It's apparently one of several proposals being studied. The article that broke the news yesterday is behind a paywall, but there's a reasonably accurate rehash here: Government to hand out free plug-in batteries - The Eco Experts. Watch this space, I think.

tfhnota

Not really viable until sodium batteries have ramped up to cheap production status, otherwise too much fire risk to put them indoors, but having a huge distributed battery storage (and solar) ain't a bad idea. Octopus are also bulk buying, presumably direct, for next year and they are always keen to up-price things so they have free money to hand them out to the welfare wallahs. Sodium should force battery prices down by at least twenty percent a year, possibly a lot more.

NedS

The Octopus batteries, announced recently, are rebranded Fox ESS units and are both lithium-based.

Other similar stackable 2kWh plug-in units are launching at retail prices around £700. However, these are unlikely to be legal as plug-in units in the UK this year.

Qyburn

https://forums.moneysavingexpert.com/discussion/comment/82078446#Comment_82078446

I think the intention is that products should be designed so they don't cause issues. From the Interim Product Specification

"The device shall be designed such that it does not adversely affect the operation of upstream
residual current devices. Any smooth DC residual current to the mains shall not exceed 5 mA
under normal operating operation and relevant fault conditions. Compliance shall be
demonstrated through testing at maximum apparent power output."

lohr500

https://forums.moneysavingexpert.com/discussion/comment/82079647#Comment_82079647

I must confess that I have lost the plot with all the discussions about RCD's.

I thought one concern was over the reverse flow of "clean" AC through non bi-directional RCD's and the damage this may cause to the tripping system, resulting in a failure to trip in a genuine overload condidion.

I'm not sure how the plug-in inverter design would know if its output was solely supporting demand from the property or if it was feeding power back to the grid. But I'm no expert on this.