Aiko vs LONGi vs DMEGC: an installer's honest take.

Last updated: 15 July 2026 · Written by the ECONEXIS team, MCS-accredited installers.

Most brand comparisons online are written by whoever has stock to shift. We install Aiko, LONGi and DMEGC panels week in, week out — all three aretier-1, 25-year-warranty panels we'd happily put on our own roofs. The real question isn't "which is best?" but "which is right for your roof and budget?" Here's how we actually choose between them.

Aiko — the space maximiser

Aiko's back-contact panels are the efficiency leaders of the three: all the electrical contacts sit behind the cell, so more of the panel's face collects light and the front is a clean, uniform black. In practice that means themost watts per square metre of roof — and the best shading tolerance of the three, because of how the cells are sectioned.

Choose Aiko when your roof is tight, awkward or partly shaded and every panel has to earn its place — or when the cleanest possible look matters. You pay a premium per panel; on a small roof that premium buys you output you literally can't get any other way.

LONGi — the bankable all-rounder

LONGi is one of the largest panel manufacturers on earth, and its Hi-MO range is what "safe pair of hands" looks like in solar: strong efficiency, tidy all-black options, and the financial scale that makes a 25-year warranty mean something. Banks and utilities buy LONGi by the gigawatt for a reason.

Choose LONGi when you want top-tier performance without the premium-brand price — the sensible default for most family roofs.

DMEGC — the value engineer

DMEGC is less of a household name but a serious manufacturer (it builds cells other brands put their names on). Its modern panels give up only a little efficiency to the others while costing noticeably less per watt — with the same 25-year warranty class.

Choose DMEGC when roof space is plentiful. If your roof fits 14 panels either way, paying for maximum efficiency buys you nothing — the money is better spent on a bigger battery or simply kept.

The rule of thumb we design by

• Small or shaded roof → Aiko: buy efficiency, it's the only way to more output.
• Typical roof, balanced budget → LONGi: the all-rounder.
• Big roof → DMEGC: buy panels, not bragging rights.

All three come in the 440–480W classes we typically fit, all three carry 25-year warranties, and your quote names the exact panel — never "tier-1 panel" with the brand to be confirmed later. If a quote won't name the panel, ask why.

Not sure which your roof calls for? That's literally what thefree custom design answers — panel by panel, with the brand and wattage written down, usually within 24 hours, anywhere across Bedfordshire, Hertfordshire, Buckinghamshire, Essex & Kent.

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