Plug-in solar panels — also called balcony solar or portable solar — became legal in the UK on 15 April 2026. If you have been searching for information on them, you have probably noticed there is a lot of confusion about what is actually allowed, how much they cost, and whether they are worth it.
This article covers the facts: the new legal framework, real costs, realistic savings, who they are for, and — critically — when a proper rooftop system is the better investment.
Depth of Light now installs balcony solar in Milton Keynes
MCS certified hardwired install — fully compliant with BS 7671 Amendment 4 and the new G98 framework. From £800 fully installed.
Balcony Solar ServiceWhat are plug-in solar panels?
Plug-in solar (also marketed as balcony solar, portable solar, or micro-solar) refers to small solar systems designed for people without access to a suitable roof. The typical setup is two solar panels — each around 400W — connected to a microinverter that converts DC power from the panels into AC power usable in your home.
They are designed for:
- Balconies — panels mounted on railings or wall brackets facing south
- Gardens — panels on ground-mounted frames or fence-mounted
- Window ledges — flat panels propped at an angle on a south-facing ledge
- Flat roofs — accessible areas where standard roof mounting is not viable
Systems must be under 800W to fall within the permitted framework. That is a hard limit under the current rules — two 400W panels is as large as the compliant plug-in category goes.
In Germany and the Netherlands, these systems have been common for years. The UK was late to legalise them. That changed on 15 April 2026.
Are they legal in the UK?
Yes — since 15 April 2026, when BS 7671 Amendment 4 came into force. This is the amendment to the UK Wiring Regulations that created a legal pathway for plug-in solar systems. Before that date, connecting any unauthorised generation device to a UK domestic supply was a breach of wiring regulations, regardless of size.
However, there is an important distinction between legal and fully standardised.
What is currently the compliant route?
Right now, the fully compliant installation method is:
- Installation by a CPS-registered electrician (Competent Person Scheme)
- Hardwired connection to a dedicated circuit at your consumer unit — not a socket plug-in
- G98 DNO notification — your electrician notifies your Distribution Network Operator that generation is being connected
The phrase “plug-in” is actually a bit misleading at this stage. DIY socket plug-in — where you literally plug the microinverter into a standard 13A socket — is not yet fully compliant under UK rules. A BSI product standard is expected in July 2026 that will define safety requirements for socket-connected plug-in systems. Until that standard is published, the hardwired route via a qualified electrician is the correct path.
In short: Plug-in solar is legal since 15 April 2026, but the fully DIY socket route is not yet standardised. The compliant path today is hardwired installation by a CPS-registered electrician with G98 notification. The BSI product standard expected in July 2026 should enable fully compliant socket connections.
How much do they cost?
The hardware for a typical 2-panel 800W system — two 400W panels plus a microinverter — costs around £500. Several brands are entering the UK market from Europe (where these products have been sold legally for years), and prices are likely to fall further once the BSI product standard is published and retail distribution scales up.
The compliant installation cost on top is roughly £200–£400 for a CPS-registered electrician to hardwire the system to a dedicated circuit at your consumer unit. The exact cost depends on how far the cable run is, whether any remedial work on the consumer unit is needed, and your location.
| Cost item | Typical price |
|---|---|
| 2 × 400W panels + microinverter (hardware) | £500 |
| CPS electrician — hardwired install + G98 notification | £200–£400 |
| Total (compliant installation) | £700–£900 |
Note that 0% VAT does not currently apply to plug-in solar systems in the same way it applies to full rooftop installations. VAT treatment for these small systems is still being clarified — check with the supplier before purchase.
How much do they save?
An 800W system in the UK generates roughly 650–800 kWh per year, depending on your location, the orientation of the panels, and how much shading affects them. Milton Keynes is reasonably well-placed in terms of UK solar irradiance.
At the current standing rate of 24.67p per kWh, that works out to approximately:
The savings figure assumes you actually use the electricity the system generates rather than exporting it unmetered. If you are out during the day and the system is generating but you are drawing nothing, much of that generation will go to the grid without payment. This is one of the key limitations — covered below.
Who are plug-in solar panels for?
The honest answer is a fairly specific audience:
- Renters who cannot make structural changes to the property and want some reduction in their electricity bill
- Flat owners who have no roof access but have a south-facing balcony or garden space
- People with no suitable roof — north-facing, heavily shaded, or structurally unsuitable roofs
- People testing solar before committing to a full rooftop system — though this is a fairly expensive way to test it given the limited ROI
- Lower-usage households where even £160–£200/year is meaningful in proportion to overall consumption
If you fall into one of those categories, plug-in solar is now a legitimate option in the UK. If you do not — if you own your home and have a reasonable roof — keep reading.
The limitations you need to know
Plug-in solar systems have some real constraints that the marketing tends to gloss over.
No battery integration
An 800W plug-in system cannot connect to a home battery. The power it generates is fed directly into your home circuit and consumed immediately or exported. You cannot store excess generation for evening use. This significantly limits how much of the output you actually benefit from — if you are at work during the day, the panels may be generating while your consumption is near zero.
No Smart Export Guarantee (SEG) payments
To receive SEG payments for exported electricity, you need a smart meter and a metered G98 connection. Most plug-in solar setups are not configured for export metering, so any surplus you generate and export goes to the grid without compensation. You are effectively giving it away.
Limited impact on high-usage households
If your household uses 4,000+ kWh per year (typical for a 3–4 bedroom house with multiple occupants), an 800W system generating 650–800 kWh covers roughly 15–20% of that consumption at best. The saving is real but modest. A full rooftop system sized properly for your household would cover 40–60% of consumption and then some.
Planning considerations
Panels on balconies, external walls, or free-standing frames in gardens may require planning permission in some cases — particularly on listed buildings, in conservation areas, or where the installation would be visible from a public highway. Permitted development rights generally cover small-scale solar, but this is not universal. Check with your local authority if you are unsure.
Tenancy restrictions
Even though you may be renting, a hardwired installation still requires landlord consent because it involves work on the consumer unit. Some landlords will agree; many will not. The socket-only route (which would not require consumer unit work) is not yet standardised — so renters face a practical catch-22 until the BSI standard is published in July 2026.
When does a proper rooftop system make more sense?
For most homeowners with a suitable roof, the comparison is stark.
The numbers for Milton Keynes homeowners
For homeowners in Milton Keynes, a 5kWp rooftop system saves £800–£1,000 per year — versus £160–£200 from a plug-in system. Over 10 years, that difference is £6,000–£8,000. The maths almost always favour going full rooftop if you own your home and have a suitable roof.
Here is when a proper rooftop solar system is clearly the right choice:
- You own your home. You can make the structural changes and you will benefit from the long-term return.
- You use more than 3 kWh/day. At that level of consumption, a properly sized rooftop system makes a material difference to your bill. A plug-in system does not.
- You want to charge an EV at home. You need a properly sized system to generate enough surplus to charge a car. An 800W plug-in will not make a meaningful contribution to EV charging.
- You want battery storage. Battery storage connects to a rooftop system, not to a plug-in. If you want to store solar energy for evening use, you need a full installation.
- You want backup power. Some battery systems can provide power during grid outages. That requires a full system — not a plug-in.
- You want the best long-term ROI. A 5kWp rooftop system typically pays back in 6–8 years at current rates, then generates free electricity for 20+ years. A plug-in system returns a fraction of that value over the same period.
To understand what a rooftop system would cost and save for your specific property, use our free solar calculator. It gives you a realistic estimate based on your roof size, location, and energy usage — not a generic ballpark figure.
Is your home suited to rooftop solar?
Get a personalised estimate based on your roof, usage, and location. It takes 2 minutes.
Use Our Free CalculatorFor context, here is how plug-in compares to a full rooftop system on the numbers that matter:
| Plug-in (800W) | Rooftop (5kWp) | |
|---|---|---|
| Annual generation (MK, UK avg) | 650–800 kWh | 4,500–5,000 kWh |
| Annual saving (self-consumed) | £160–£200 | £800–£1,000 |
| Battery integration | No | Yes |
| EV charging contribution | Minimal | Significant |
| SEG export payments | Very unlikely | Yes (with smart meter) |
| Hardware + install cost | £700–£900 | £7,000–£10,000 |
| Payback period | 4–6 years | 6–9 years |
| Saving over 20 years | £3,200–£4,000 | £16,000–£20,000+ |
The payback periods are comparable. The total return is not. That gap is even larger if you add a battery storage system or qualify for any grants and incentives.
Plug-in solar is a legitimate entry point for people who have no other option. For homeowners with a suitable roof, it is the expensive, low-return version of something you could do properly for 10–12 times the savings.
Frequently asked questions
Are plug-in solar panels legal in the UK?
Yes, since 15 April 2026, when BS 7671 Amendment 4 came into force. The current compliant installation route is via a CPS-registered electrician with a hardwired connection to your consumer unit and G98 DNO notification. DIY socket connection is not yet fully standardised — the BSI product standard expected in July 2026 will address that.
How much do plug-in solar panels cost in the UK?
The hardware for a 2-panel 800W system costs around £500. Add £200–£400 for compliant installation by a CPS-registered electrician and G98 notification, and a fully compliant setup comes to £700–£900. Hardware-only costs will likely fall once the BSI standard is published and retail supply scales.
How much can plug-in solar panels save per year?
An 800W system generates roughly 650–800 kWh per year in the UK. At 24.67p per kWh, that is £160–£200 per year. Payback on a fully installed compliant system is typically 4–6 years. The savings are real but modest — roughly one-fifth of what a proper rooftop system saves.
Do plug-in solar panels need planning permission?
In most cases no, but it depends on the property. Listed buildings and some conservation area properties may require consent. Permitted development rights generally cover small solar installations, but ground-mounted frames and balcony mounts can sit in a grey area. Check with your local authority if your situation is not straightforward.
Can I get SEG payments from a plug-in solar system?
Very unlikely. Smart Export Guarantee payments require a smart meter and a metered G98 connection. Most plug-in systems are not set up for export metering. Surplus electricity you do not use in real time goes to the grid without compensation.
Who should get a rooftop solar system instead of plug-in?
Anyone who owns their home and uses more than 3 kWh per day should look at a proper rooftop system. A 5kWp rooftop installation in Milton Keynes saves £800–£1,000 per year — five times more than a plug-in system. Add battery storage and the savings increase further. Plug-in solar is for renters, flat owners, or those with no suitable roof — not for homeowners with a south-facing roof and realistic appetite for proper ROI.
If you own your home, get a proper quote first
If you own your home and have a suitable roof, a proper solar installation will almost always give you better returns than a plug-in system. Get a free survey from our MCS certified team — we cover Milton Keynes and all of Buckinghamshire.
Use our solar calculator for a quick estimate, or call us on 07516 762540 and we will talk you through what makes sense for your property. No pressure, no sales script — just straight advice on whether solar is the right move for you and what size system your usage justifies.
If plug-in solar genuinely is the right fit for your situation, we will tell you that too. We install rooftop systems — we have no interest in selling you something that does not stack up.