A decade of solar street light tenders has taught buyers one thing: the wattage on the box predicts very little about the light on the road in year four. The specification sheet is changing accordingly.

What Used to Decide a Tender

Rated power, lumen output and unit price. Those three numbers were easy to compare and easy to print. They were also easy to manipulate: a lamp labelled 100W might draw 60W, and a lumen figure might be measured once, at the ideal temperature, with a fresh battery.

What Decides One Now

1. Runtime at realistic conditions. Full brightness hours plus dimmed hours, with the battery derated for local temperature.
2. Cycle life and replaceability. A pack rated above 6,000 cycles, accessible without dismantling the head.
3. Sealing method. Separate gaskets per compartment and threaded cable glands, not a single perimeter seal.
4. Spare-parts commitment. Written availability for the warranty period, including drivers and sensors.
5. Installation time. Units per crew day, bracket compatibility with existing poles.
6. Dimming profile control. Lockable settings for urban compliance and energy management.

Why This Shift Is Happening

Because maintenance budgets are now visible. A municipality that installed cheap lamps five years ago is facing a replacement wave, and the finance department has started asking why the first purchase did not include serviceability.

Distributors feel it too. A lamp that fails in warranty costs them a return, a labour visit and a reputation. A lamp that can be repaired with a module costs them ten minutes.

How to Write the New Spec

A practical tender can include the new metrics without becoming unreadable. Ask for a runtime table at three temperatures, a cycle-life figure with the test condition, a sealing drawing, a spare-parts price list and the number of units a two-person crew can install per day. Those five items fit on two pages and eliminate most of the ambiguity that leads to disputes later.

What Suppliers Should Do

Publish the boring numbers: derated runtime, cycle life at temperature, sealing design, spare-part list and installation time. Buyers who understand the category will reward that transparency, and the ones who only compare unit price were never going to be long-term customers.

“Show me the part that fails first and the price of replacing it. Then we can talk about watts." — Procurement officer, municipal lighting

The spec sheet is not getting longer. It is getting more honest.