Why is UK plug-in solar limited to 800W?
People will keep calling it the 800W limit, so I will too where it makes the article easier to find and understand. Technically though, the final UK specification sets the limit at 800VA continuous AC output.
That does not mean you are limited to 800W of solar panels. The final rules allow up to 2,000W of connected PV modules, which is why AC output, DC panel capacity and inverter clipping need separating properly.
Important: the new UK plug-in solar rules come into force on 27 August 2026. This explains the final specification now, but it should not be read as saying the new route is already in force before that date.
The short answer
The 800 figure limits what the plug-in solar product can continuously put onto the AC side of the house installation. It is not a blanket rule saying the solar panels themselves can only total 800W.
The final specification gives three figures worth remembering:
- 800VA maximum continuous AC output,
- 3.5A maximum continuous AC output current, and
- 2,000W maximum connected PV module capacity.
Think of it like this: the panels collect the energy; the inverter controls how much AC power can actually be supplied to the house. More DC panel capacity does not increase the permitted AC output.
Why does everybody call it 800W if the rule says 800VA?
Because with household solar equipment operating at a power factor close to 1, watts and volt-amperes can look almost identical in everyday discussion. But they are not technically the same unit. Watts describe real power and VA apparent power. The final UK document specifies 800VA.
So “800W plug-in solar” remains a useful search and everyday term, but when talking about the actual rule I would call it 800VA.
Why 3.5A and a 5A plug fuse?
The final specification also limits continuous AC output current to 3.5A. Plug-in solar is deliberately being kept as a small consumer-product category rather than becoming a socket-connected version of a full-size PV installation.
The specification also requires the manufacturer-supplied non-rewireable BS 1363 plug to be fitted with a 5A fuse. That is another reason not to take a separately purchased inverter lead, fit whatever fuse happens to be in it and assume it has become a compliant product.
Can I really have 2,000W of panels on an 800VA system?
Yes, the final UK specification permits up to 2,000W of connected PV module capacity. But that does not mean you can take any 800W inverter and randomly attach 2kW of panels.
The complete product still has to be designed and supplied for that panel arrangement. Voltage, current, MPPT range, connectors, thermal behaviour and the manufacturer's instructions still matter.
Example: a manufacturer could design a compliant product with four 450W modules: 1,800W DC of panel capacity while the inverter remains limited to 800VA AC. In weak light the extra panel area can help; in strong sun the inverter reaches its maximum and holds there.
What is inverter clipping?
Clipping happens when the panels could provide more DC power than the inverter can deliver on the AC side. If the panels could provide 1,100W at that moment but the inverter is limited to 800VA, its output stays at the permitted maximum.
Oversizing can still be useful in the UK because panels spend much of the year below their headline rating. More panel capacity can give earlier morning generation, better cloudy-weather output and longer useful generation later in the day.
So why not always fit the full 2,000W?
Because there is another figure people need to know: 960W.
The final IPS says that where connected PV module capacity exceeds 960W, professional assessment of the electrical installation should be considered.
960W is not another inverter limit. At 961W of panels the AC limit is still 800VA. The 960W figure is the point above which the government's specification recommends considering professional assessment of the existing electrical installation.
So a 2,000W DC / 800VA AC product can be within the product specification, but the guidance deliberately becomes more cautious as the DC array gets larger.
Does 2,000W of panels mean I can export 2,000W?
No. The plug-in product itself remains capped at 800VA AC. If your house is using less power than the inverter is producing, some of that generation may flow towards the grid, but the inverter cannot suddenly output 2kW AC because 2kW of panels are connected.
Export payment is a separate issue covered in the backfeed and export guide.
Is 800VA the same as the G98 3.68kW limit?
No. They are different limits for different things.
| Figure | What it means |
|---|---|
| 800VA / 3.5A | Maximum continuous AC output of the UK plug-in solar product category. |
| Up to 2,000W DC | Maximum connected PV module capacity in the specification. |
| 960W DC | Above this, professional assessment of the electrical installation should be considered. |
| 16A / 3.68kW per phase | The familiar G98 small-generation threshold. It does not make a 3.68kW plug-in solar product acceptable. |
See the G98 form guide for how the AC capacity appears on network paperwork.
Can I use two 800VA plug-in systems?
Do not assume two separate socket circuits automatically means two systems are acceptable. The final product specification discusses one device per final circuit, but the same document says current G98 network requirements restrict this to one device per household unless G98 is amended.
We cover that properly in the ring final, radial and socket circuit guide.
What about batteries?
The final UK plug-in solar IPS does not cover plug-in battery systems or plug-in solar products incorporating electrical energy storage. Do not assume an 800VA solar-only rule automatically covers a European balcony system with a battery added.
Read the plug-in battery storage UK guide.
Why has the UK chosen this size?
There is no magic electrical law saying 800 is the only number that could ever work. It is a policy and product-safety boundary intended to allow useful small generation while keeping the category tightly controlled: limited AC current, manufacturer-defined protection, supplied plug and lead, controlled mounting, circuit checks and network notification.
We no longer need to guess what the UK might copy from Germany because we now have a final UK specification.
Does an 800VA system actually save much money?
It can, but the inverter rating is not the most important number for savings. If your house normally uses 250W during the day, 800W of generation does not mean you save the cost of 800W every hour. Some may be exported unless you can move loads into the sunny period.
That is why base load and self-consumption matter. The home energy monitor and base-load guide explains how to measure it.
My take: the final numbers make much more sense once you stop treating “800W” as a panel limit. The UK is limiting the AC contribution to the house while allowing manufacturers to use more panel area to improve generation through poorer conditions. The 960W assessment recommendation is the bit I would not ignore on heavily oversized products.
Common questions
Is the UK limit 800W or 800VA?
The final specification says 800VA continuous AC output. “800W” will remain the common everyday/search term.
Can I have 2,000W of panels?
Yes, within a complete product designed and supplied for that arrangement. AC output remains limited to 800VA.
Do I need an electrician above 960W?
The specification says professional assessment should be considered above 960W connected PV capacity. It does not say 961W automatically makes an electrician a legal requirement.
Can an 800VA product include a battery?
Not under this IPS. Plug-in batteries and plug-in solar products incorporating storage are outside its scope.
Related guides
General guidance based on the final UK Interim Product Specification published in July 2026. Always follow the documentation supplied with the exact product you buy and the requirements applying at the time of installation.