A commercial solar array does not stop generating after 25 years. The average panel degrades by around 0.5% each year, so a system installed on day one is typically still producing roughly 87% of its original output twenty five years later. The real planning question for a Finance Director or Operations Manager is not whether the array survives that long. It is what happens to those panels, and what the business is required to do, once they are retired.
Twenty five years is a warranty milestone, not a shutdown date. Manufacturers guarantee a minimum output level to that point, commonly around 80 to 87.5%, because that is the threshold they are contractually comfortable defending, not the point at which the panel fails.
In practice, degradation is slow and close to linear rather than sudden. A panel losing half a percent of its output a year is still worth having at year 30, particularly against UK electricity prices that have risen well above general inflation over the past two decades. A rooftop array producing 85% of its original output at zero marginal fuel cost is still cheaper than buying from the grid.
Spirit Energy has been installing solar since 2010. None of those systems have needed decommissioning. They have needed routine maintenance, the odd inverter replacement, but the panels themselves are still on the roof and still generating sixteen years in.
Solar panels are classed as Waste Electrical and Electronic Equipment, Category 14, under the WEEE Regulations. That means a retired panel cannot go into a skip, general waste, or a scrap metal collection. It has to be collected by a licensed waste carrier and processed at an approved treatment facility.
For a commercial or business owned array, the business itself is generally treated as the producer under WEEE, rather than the panel manufacturer. In practice this means the legal duty to arrange compliant collection and disposal sits with the company that owns the asset, not with whoever originally supplied it. Getting this wrong risks fines and a failed audit trail, which matters increasingly to insurers and ESG reporting as much as to regulators.
The paperwork is straightforward once you know what to expect: a Waste Transfer Note at collection and a WEEE Evidence Note confirming treatment. Both should be kept as part of the business's Duty of Care record for the site.
This is where the hidden liability assumption tends to fall apart. Renewables distributor Segen launched a commercial recycling scheme in 2026 with published per panel pricing:
| Panel Size, M: | Price, £: (Excluding VAT) |
| Up to 2m Panel | £6.00 per panel |
| Over 2m Panel | £7.00 per panel |
On a 200 panel commercial rooftop array, that works out at roughly £1,200 to £1,400 for the panels alone, before removal labour and transport, which is a bounded and forecastable figure rather than an open-ended risk.
Recovery rates support the economics. Modern treatment facilities can recover 85 to 95% of a panel's material, including the aluminium frame, glass, silicon, and silver. The recyclable proportion of a typical panel sits at around 99% by weight. None of this changes the fact that removal from the roof, scaffolding, and site access will usually cost more than the recycling fee itself, so an end of life budget should weight labour ahead of material processing.
Not every business waits for panels to reach 25 years before acting. Repowering, replacing older panels with newer, more efficient ones while the array is still performing well, is increasingly discussed as an alternative to full decommissioning, particularly where roof space is fixed and output per square metre matters more than stretching an older system's last few percentage points of life.
Full decommissioning should be treated as a worst case outcome to avoid where possible, in favour of repowering or revamping an existing asset.
A business installing solar today is not creating a future waste problem. It is buying an asset with a well documented, gradual decline curve and a disposal process that is now priced, regulated, and routine. The panels degrade by roughly half a percent a year, the disposal cost per panel is published and modest, and the legal obligations are clear rather than open-ended.
The more useful question for an asset register is not what happens at year 25, but how the asset is performing now, and whether it makes sense to run it to end of life or repower it earlier.