Aiko has become the panel homeowners ask for by name, usually after reading that it is “the most efficient panel on the market”. This is the installer’s version of that story: what the panel actually is, the numbers that matter on a roof, what the long warranty guarantees and does not, and the honest answer to when a cheaper panel is the smarter buy. Every figure is from Aiko’s own published material or a named independent source, linked at the end.
What makes Neostar different
Every conventional solar cell has thin metal busbars running across its front face to collect the current. They are necessary and they are also a shadow: a strip of silicon under every busbar is not producing. Aiko’s ABC design, all back contact, moves every contact to the rear of the cell, so the whole front face is working surface and nothing sits between the sun and the silicon.
That is where the efficiency comes from. Aiko’s Neostar 2P rooftop modules reach up to 24.3% module efficiency, which is high for a residential panel, and it shows up on the datasheet as power: the Neostar 2P54 mono-glass module is rated 450 W to 485 W, and the 2P+ 54 dual-glass version 455 W to 475 W, in a 54-cell format that fits a domestic roof.
What that means on a West Midlands roof
The practical benefit is watts per square metre. A terrace with one usable slope and a chimney might take eight panels; with a 450 W-plus module that is 3.6 kWp, a system that covers a household’s daytime use, whereas with a lower-output panel the same eight spaces might fall short of 3 kWp. Nine Neostar panels on a semi-detached roof is 4.05 kWp.
What a 4 kWp array makes depends on where it is and which way it faces. The European Commission’s PVGIS tool, which models long-term yield from satellite irradiance data, puts a 4 kWp south-facing array at 35 degrees with 14% system losses at 3,839 kWh a year in Oldbury, 3,886 in Telford, 3,938 in Tamworth, 3,946 in Coventry and 4,002 in Worcester. The differences between towns are small; the difference between a south roof and an east roof is not, and shade from a chimney or a neighbour’s extension moves the figure more than any panel brand does. Our area pages for the Black Country, Worcestershire and Staffordshire carry those yields with their sources.
The warranty, read properly
Every panel comes with two warranties and they are routinely confused. The product warranty covers the panel as a manufactured object: delamination, cracked cells, a failed junction box. The performance warranty is a promise about output: the panel will still produce at least a stated share of its rated power after a stated number of years.
Aiko’s product warranty is 15 years. The performance warranty is 30 years: no more than 1% loss in year one and no more than 0.35% a year after that, which guarantees at least 88.8% of rated output at year 30. The useful comparison is the industry: the Jordan and Kurtz review of 1,920 published degradation rates found a median of 0.5% a year for photovoltaic modules, with crystalline silicon also at 0.5%. Over 30 years the median lands closer to 86%, Aiko’s floor is 88.8%. The gap is not dramatic in any one year; across the life of a roof it is real electricity, and more to the point it is a guarantee, with a company you can claim against.
Two honest caveats. A warranty is only as good as the company still existing in year 25, which is true of every brand and is why we fit established manufacturers. And the installer matters as much as the panel: a performance claim starts with someone measuring the array properly, and that is us, not a helpline.
When a cheaper panel is the smarter buy
On a large, clear, south-facing roof, a well-proven tier-one panel such as the JA Solar modules we also fit can reach the same system size as Aiko for less, and the saving is often better spent on a larger battery, which will do more for the bill than a few extra watts per panel. Aiko earns its premium when the roof is the constraint: a terrace, a hipped roof with short slopes, a chimney or a dormer in the way, or a household that wants the maximum from a modest footprint. If the brief is simply “the longest warranty you fit”, it is also the answer.
We quote both ways. An Aiko design and an alternative design, each with its modelled output and a fixed price, so the premium is a number on paper rather than a sales line. Our solar panel brands page sets out the three brands we fit and why, and the Aiko Neostar page has the full specification with sources.
Cost context, without inventing a price
We do not publish panel prices; they move with the market and the exchange rate and any figure on a blog post is wrong within months. Two public numbers frame the decision. The Department for Energy Security and Net Zero’s cost data for 2025/26 puts the mean installed cost of a 0 to 4 kW solar system in the West Midlands at £1,778 per kW, £1,628 per kW for 4 to 10 kW, a regional average across 21,961 installs that is useful as a sanity check and useless as a quote. And installing solar panels on a home is 0% VAT until 31 March 2027, after which the rate returns to 5%.
How we fit them
Green Tech Hub is MCS-certified for solar PV through NICEIC (NIC-600049), which is the certification your export tariff requires. Panels on a house are permitted development in almost every case under Part 14 of the General Permitted Development Order, provided they project no more than 0.2 m from the roof slope and sit no higher than the highest part of the roof; the survey confirms it for your house, including the conservation area rules. A system up to 3.68 kW is a G98 notification to the network operator; larger arrays, and any hybrid inverter above that size, need a G99 application, which we submit before work starts. Details of the process are on our solar panels for homes page.
Sources
- Neostar 2P54 and 2P+ 54 module ratings: Aiko, Neostar 2P54 Mono-Glass
- Up to 24.3% efficiency, n-type ABC cell technology: pv magazine, 7 February 2025
- Warranty terms, 15-year product and 30-year performance, 88.8% at year 30, 1% then 0.35% a year: Neostar datasheet (PDF)
- Median degradation 0.5% a year across 1,920 reported rates: Jordan & Kurtz, “Photovoltaic Degradation Rates: An Analytical Review”, Progress in Photovoltaics 21(1), 2013, doi.org/10.1002/pip.1182
- Modelled yields for a 4 kWp south-facing array at 35 degrees, 14% system loss: European Commission JRC, PVGIS 5.3
- Mean installed cost per kW by region and size band, 2025/26: DESNZ, Solar PV cost data
- 0% VAT on home solar installation to 31 March 2027: HMRC VAT Notice 708/6
- Permitted development for roof-mounted panels: GPDO 2015, Schedule 2, Part 14
- G98 and G99 thresholds: Energy Networks Association, engineering documents