Every so often a message reaches our factory in Konya that makes the whole building smile: a photograph of a Solimpeks collector fitted in the early 2000s, still on its roof, still making hot water every morning.
We mention these systems almost in passing. When a customer asks how long a solar collector lasts, the honest answer is that units we built a quarter of a century ago are still in daily service. It is worth pausing on what that means. A collector installed in the early 2000s has stood through twenty-five rounds of frost and heatwave, and in many of the households it serves it has quietly outlasted a full generation of gas boilers — installed, worn out and replaced again while the panel on the roof kept working.
No moving parts, nowhere to hurry
There is no secret to the longevity — only engineering that respects how a flat-plate collector ages. The panel has no moving parts: an absorber, insulation, glazing and a frame, sitting still while the fluid does the work. What wears a collector out is slow chemistry and slow physics — ultraviolet light, thermal cycling, moisture, the heat of stagnation on a summer afternoon. Longevity is therefore decided years before installation day, in the choice of materials.
That is why the recipe has stayed deliberately consistent across our TSM thermosiphon and Wunder flat-plate lines: a selective coating on the absorber that keeps soaking up sunlight without surrendering it back as radiation; tempered solar glass that shrugs off hail and thermal shock; copper and aluminium joined with care, so dissimilar metals do not slowly corrode each other; insulation that holds its shape through thousands of heating cycles; and a frame sealed against decades of weather.
A little care goes a very long way
The owners of these veteran systems tend to have one thing in common: modest, regular care. Heat-transfer fluid checked and renewed when its frost protection fades, seals and fixings inspected now and then, the glass mostly left to the rain. That is nearly the whole list — our maintenance checklist covers it — and it is a fraction of what any fuel-burning appliance asks over the same years. For the engineering detail on lifespan, see how long solar collectors last.
What a collector like this gives its owner is easy to state: a quarter of a century of hot water with no fuel bill attached. Whatever it cost when it was fitted, it stopped being an expense a long time ago.
We have been building solar water heaters in Konya since 2001, and our collectors now work on roofs in 96+ countries. Somewhere among them are the panels that will be the 25-year stories of 2051.
Tell us about yours
If a Solimpeks collector from the early 2000s is still working on your roof, we would love to hear its story — a photo, the install year and a rough location are all it takes. Write to the Newsroom, and help us celebrate the collectors that refuse to retire.