Aiko makes the most efficient mainstream panel you can readily buy in the UK, and its shading performance is genuinely better than conventional alternatives rather than merely marketed that way.
It also carries a price premium, has a warranty structure that varies by model in a way almost nobody explains, and has been in the UK market only since late 2023 — so there is very little long-term field data.
Here is the honest version from someone who fits them.
What ABC actually means
Aiko's cells are All Back Contact: the electrical contacts sit entirely on the rear of the cell, so there are no busbars or gridlines shading the front face.
That is not marketing. Removing the front-side metalisation genuinely frees up active cell area, and it is why Aiko's efficiency figures sit at the top of the mainstream market. The current Neostar 3 generation runs at 24.3% to 24.8% module efficiency, against roughly 22.5% to 23.3% for the mainstream N-type TOPCon panels most installers fit.
For a typical UK roof, that difference means you fit perhaps one or two fewer panels for the same output, or get meaningfully more output from a roof that was always going to be full.
The range
Neostar is residential, Comet is commercial at 655–690 W, Stellar is utility scale.
Within Neostar the model codes tell you what you are getting. AIKO-A485-MCE54Mw reads as 485 W, and in the series naming an S means all-black with a black backsheet, a P means black frame with a white backsheet, and a + means dual-glass.
Current residential wattages run roughly 460 W to 555 W depending on cell count and glass type.
Verified figures for a Neostar 3 at 485 W:
- Module efficiency 24.3%
- Dimensions 1762 × 1134 × 30 mm, about 2.0 m²
- Weight 21.1 kg mono-glass, 24.2 kg dual-glass
- Temperature coefficient of Pmax −0.26%/°C
- Degradation ≤1% in year one, then ≤0.35% a year
- 30-year performance warranty ending at 88.85%
The warranty split nobody mentions
This is the single most misreported thing about Aiko in UK marketing, and it will cost you if you get it wrong.
The performance warranty is consistent: 30 years, ending at 88.85% of rated output.
The product warranty is not consistent. Depending on series and generation it is 15 years (extendable to 20 or 25), 25 years, or 30 years. The S series generally carries the longer product warranty; the P series is commonly 15 years extendable.
Sources genuinely conflict on this — Which? records Aiko's product warranty as a range of 12 to 25 years, Aiko's own page for one model says 15 extendable to 25, and installer documentation for another says 30. We could not find a single consolidated Aiko UK warranty document that resolves it.
So: check the product warranty against the exact model code on your quote. If an installer quotes "Aiko, 30-year warranty" without a model number, they are either quoting the performance warranty and calling it the product warranty, or they do not know. Either is a reason to ask more questions.
The shading claims, examined
Aiko's headline claim is much better partial-shading performance. The evidence is real but needs reading carefully.
In TÜV Nord flash testing with a single cell masked, Aiko reports retaining around 95% of power under light cover and about 70% under full single-cell cover, against a TOPCon reference at roughly 90% and 40%. Aiko also states its 475 W Neostar passes TÜV Rheinland's partial-shading Class A, which requires no more than 5% additional power loss across three different mask patterns.
Two honest caveats. First, this is manufacturer-commissioned testing — independent verification is thin. Second, and more practically, Aiko's own documentation concedes that covering half a panel triggers bypass diodes regardless of cell technology.
So the ABC advantage is real for small obstructions: a flue, an aerial, a satellite dish, a pole, dappled shade along an edge. It is not a solution for a chimney shadow crossing a third of the array through the afternoon, and it is not a substitute for optimisers or microinverters where you have genuine structural shading.
If someone tells you Aiko panels mean you no longer need to worry about shading, they are overselling. If you have a flue or an aerial clipping one or two cells, they will measurably outperform a conventional panel.
Handling, on the roof
The practical advantage nobody writes about: the mono-glass modules weigh around 21 kg, roughly 3 kg lighter than several comparable panels. Over a day of carrying modules up a ladder on a two-storey property, that is a real difference, and it reduces the risk of a drop.
Dual-glass is 24.2 kg, which is a noticeably different proposition for a two-person in-roof install.
The frame is 30 mm anodised aluminium over 3.2 mm tempered glass. Worth knowing that 30 mm is thinner than the 35 mm frames common on some rivals, with static load ratings of 5400 Pa front and 2400 Pa back. On an exposed, high-wind site we would factor that into the mounting design rather than treat all panels as equivalent.
Junction box is IP68 with three bypass diodes and Stäubli MC4-EVO2A connectors. No problems reported.
Reliability — what we can and cannot say
No known issues. Which? lists none. The installer reviews that exist report no installation problems or field failures.
But be clear about what that means: it is an absence of negative evidence, not positive evidence of long-term reliability. Aiko signed its UK and European distribution agreement with Segen in October 2023. There is simply not enough UK field history yet to say how these panels behave at year ten.
Aiko claims its ABC construction reduces microcrack risk by over 60%. That is the manufacturer's own figure.
What they cost
Trade pricing in November 2026 runs roughly £0.17 to £0.26 per watt ex-VAT for the module alone — around £170 to £260 per kWp. In-stock examples: a Neostar 3S+ 480 W dual-glass at about £96, a 3P+ 540 W at around £99 to £105.
Retail sits between roughly £113 and £165 inc VAT per panel depending on output.
Against JA Solar and Longi, Aiko carries a premium of roughly 10% to 50% per panel. Whether that is worth paying depends entirely on your roof. On a large, unshaded, south-facing roof where you can fit as many panels as you want, it usually is not — a cheaper TOPCon panel will give you the same kWh for less. On a small, awkward or partially obstructed roof where every square metre counts, it frequently is.
One practical warning: stock churn is real. On the day we checked, most Generation 2 model codes were out of stock across the main distributors, with only a couple of Generation 3 lines held in depth. If a quote specifies an exact Aiko model code, confirm availability before you rely on the delivery date.
MCS listing — check the model
Important, and routinely glossed over. We were able to confirm one Aiko module in the MCS Product Directory directly: the AIKO-A630-MAH72Mw at 630 W, certified by TÜV Rheinland and valid to May 2030.
We could not independently confirm Neostar models in the directory — though the directory holds over 340,000 records and a single certificate commonly covers a family of models, so absence from a quick search proves nothing either way.
For your installation to be MCS certified, the product must be MCS listed. Ask your installer for the MCS certificate covering the exact model code on your quote. Any competent installer will have it to hand. We will.
Our verdict
Aiko Neostar is an excellent panel and the right choice on constrained or lightly shaded roofs where efficiency per square metre genuinely matters. The shading performance is real within its limits. The build quality is good and the weight is a practical advantage.
Where we would not specify it: large unshaded roofs with room to spare, where a cheaper panel delivers the same annual yield for less, and very exposed high-wind sites where we would rather have a heavier frame.
Where we would want you to ask questions: the product warranty for your specific model code, and the MCS certificate for it.
We install Aiko alongside other manufacturers across Milton Keynes, Buckinghamshire, Bedfordshire, Oxfordshire and Northamptonshire, and we will tell you honestly when a cheaper panel is the better buy for your roof.