This is one of the questions I get most often, and it has a genuinely confusing answer right now. The short version: the regulations say one system per household. The product spec says one per ring circuit. Those are different things, and the gap between them matters if you have a larger home.
What the rules actually say
SI 2026/848 limits installations to one certified plug-in solar device per household under the socket-connection route. The Interim Product Specification (IPS v2) behind it allows one device per final ring circuit, but carries a note that G98 overrides this with a stricter one-per-household cap until G98 is amended. The current live answer is: one system per household, regardless of how many ring circuits your house has.
The IPS v2 drafters wrote the one-per-ring-circuit rule because it is technically defensible. An 800W inverter adds less current to a ring main than a toaster. Two inverters on two separate ring circuits is still within what the wiring can handle. The G98 restriction is a grid-level constraint, not an electrical safety one. DESNZ explicitly noted that G98 will need amending to unlock the per-circuit allowance. That amendment has not happened yet.
The hardwired route for multiple systems
The one-per-household restriction applies specifically to the socket-connection route under SI 2026/848. A hardwired installation by a CPS-registered electrician on its own dedicated circuit at the consumer unit is not governed by the socket-connection rules. A two-storey house could have a hardwired system at the consumer unit for the ground floor and another for the first floor, provided the combined AC output stays within the G98 3.68kW simple-notification threshold.
Two EcoFlow STREAM Ultra X units hardwired on separate dedicated circuits: combined output 2.4kW — well within the 3.68kW G98 threshold. An electrician would install Type B RCD protection on each circuit, submit a G98 notification covering the total, and both systems run legally.
When will the per-circuit rule unlock?
When G98 is amended. There is no confirmed timeline. DESNZ noted the amendment is needed but gave no date. Given the pace of the regulatory process so far — SI 2026/848 itself took from the March 2026 announcement to August 2026 to come into force — a G98 amendment in early 2027 is plausible but not guaranteed.
For everything about the August 2026 regulations see our regulations article. For how hardwired installations work and the Type B RCD requirement, see our Type B RCD article.