Plug-in solar or proper rooftop panels: which should I get?
The short answer
They answer different questions. Plug-in is a cheap way to shave your daytime use. Rooftop is an investment in the house.
A plug-in kit costs a few hundred pounds, needs no electrician and no tariff change fee, but is capped at 800W and earns nothing for what you export. A rooftop system costs thousands, needs a Part P electrician and a £200 plus VAT tariff change, and pays 9.7p for every unit you send back.
Both are legal on the Isle of Man, and both need Manx Utilities’ written approval before you connect anything. Beyond that they have almost nothing in common, and choosing between them is mostly about how much roof you have, how much you want to spend and whether you own the place.
Side by side
| Plug-in kit | Rooftop or garden system | |
|---|---|---|
| Size limit | One unit per home, 800W or less | Up to 10 kW of export capacity, subject to network studies |
| Who fits it | You, into an existing socket | A Part P compliant electrician |
| Manx Utilities approval | Required, before you plug in | Required, before connection |
| Cost to apply | No charge at present | £200 plus VAT minimum for the tariff change |
| Paid for exports | No. Spare power earns nothing | Yes, 9.7p a unit on the Sustainable Generation tariff |
| Smart meter | Required | Not stated as a separate requirement |
| Batteries | No standalone batteries. Only as part of a compliant integrated kit | Hardwired storage is a separate connection matter with Manx Utilities |
| Planning permission | Check first in a conservation area | Needed for flat roofs, conservation areas and registered buildings |
| If you rent | Talk to your landlord. Manx Utilities recommends it | Realistically a job for the owner |
| Takes it with you when you move | Yes, with a fresh application at the new address | No |
The one number that decides it
A unit of electricity you use yourself is worth 29.5p, because that is what you would otherwise pay Manx Utilities. A unit you export is worth 9.7p if you are on the Sustainable Generation tariff, and nothing at all if you have a plug-in kit.
That is why a small system can do surprisingly well and a large one can disappoint. A plug-in kit is deliberately sized so that most of what it makes gets swallowed by the fridge, the router and the standing background load of a house, so very little of it is wasted. A big rooftop system on a house that is empty all day sends a lot of its best hours to the grid at 9.7p.
Neither is wrong. It just means the comparison is not simply “more panels is better”.
Which one fits you
Plug-in suits you if Lower cost
You rent, or you want to spend hundreds rather than thousands, or you have a balcony, a small yard or no suitable roof, or you want to take it with you.
Rooftop suits you if Bigger return
You own the house, you have an unshaded pitched roof, you are prepared for a quote-based job, and you want to cover a real share of the year’s electricity.
Wait if Not yet
Your roof is due to be replaced, you are moving within a year or two, or you are in a conservation area and have not yet asked Planning and Building Control.
Can you have both?
Not without asking first. Manx Utilities says that if you already have a solar PV or battery system, you should contact them in advance, because adding plug-in solar may require changes to your approved connection agreement. So it is not a flat no, but it is a conversation with them before you buy anything, not after.
Rules and rates from Manx Utilities’ plug-in solar page, its domestic tariffs page and its electricity network enquiry page, all read on 28 September 2026. Planning conditions from the Town and Country Planning (Permitted Development) Order 2025. We are an independent guide, not part of Manx Utilities.
Related guides
- Solar panels on the Isle of Man
- Home batteries and solar
- Is there a solar panel grant on the Isle of Man?
- How to choose a solar installer
Common questions
Is plug-in solar cheaper than rooftop solar?
Much cheaper to buy and to set up: hundreds rather than thousands, with no electrician and no tariff change fee. It is also far smaller, capped at 800W, and it earns nothing for exported power, so it saves less each year.
Can I get paid for exports with a plug-in kit?
No. Manx Utilities states that only hardwired equipment is eligible for the Sustainable Generation tariff, and that plug-in devices do not qualify.
Do both need Manx Utilities’ permission?
Yes. Any generation equipment connected to the Manx Utilities network needs written approval first, because Isle of Man legislation differs from UK legislation. The plug-in application is currently free; a rooftop system involves a tariff change charged at a minimum of £200 plus VAT.
I rent my home. Which can I have?
Realistically only a plug-in kit, and Manx Utilities recommends discussing it with your landlord before you buy. A rooftop system is a permanent alteration to the building and a change to the property’s electricity connection, so it is the owner’s decision.