The procurement problem
Competitive price-based tendering creates systematic pressure towards the lowest purchase price. This is rational from the perspective of a single budget line. But for street lighting — a capital asset with a planned service life of 20 to 25 years — the purchase price is typically one of the smaller cost components over that period. Optimising for it at the expense of the larger components is a structural misalignment between procurement method and actual outcome.
EN 13201-5, the European standard for road lighting energy performance, provides a framework for comparative assessment using the Power Density Indicator (PDI) and Annual Energy Consumption (AEC). The EU public procurement directive and national implementing legislation in most member states permit lifecycle cost as an evaluation criterion alongside or instead of purchase price. It is an available method, not a mandatory one — the contracting authority decides whether and how to weight it.
Total cost of ownership over 20 years
A complete lifecycle cost calculation for a street lighting installation includes five main categories:
- Purchase price — capital cost at delivery, including installation labour, equipment, and traffic management. Typically 15–25% of 20-year total cost of ownership.
- Energy cost — by far the largest component over a 20-year service period. Every 1 lm/W improvement in installed efficacy compounds over thousands of operating hours. A luminaire specified at 150 lm/W rather than 130 lm/W delivers meaningful long-term energy savings that dwarf a modest difference in purchase price.
- Planned maintenance cost — periodic inspection, optical cleaning, and scheduled group replacement. For a well-specified luminaire in a benign environment, this cost is predictable and manageable. For an under-specified luminaire in a harsh environment, it escalates.
- Unplanned replacement cost — this is the line item most commonly omitted from purchase-price comparisons, and frequently the most significant. Each unplanned intervention requires a maintenance vehicle, access equipment, traffic management, and the administrative overhead of permits and scheduling. In road applications, where lane closures are required, the cost of a single unplanned visit can exceed the original purchase price of the luminaire itself.
- End-of-life disposal — decommissioning, waste management, and recycling. Smaller in absolute terms, but relevant when comparing products with different material compositions.
In practice — a simplified illustrative example
- "Luminaire A" and "Luminaire B" below are entirely hypothetical examples used to illustrate the principle. They are not based on real products, tenders, or actual price data.
- Luminaire A costs 20% less at purchase, but requires replacement at approximately year 12 in a coastal environment due to housing corrosion and seal failure.
- Luminaire B costs more at purchase but is designed for the full planned service period of 20+ years.
- Calculated over the full period, Luminaire B is almost always less expensive in total — because a field replacement rarely costs only the price of a new luminaire. Crew, access equipment, traffic management, and administrative overhead add substantially to the event cost.
What purchase-price comparisons routinely miss
A tender that evaluates only purchase price consistently misses the items that matter most over time. How long the luminaire will actually last in a specific environment is one question. How quickly the housing material will degrade in coastal or de-icing salt conditions is another. What level of planned maintenance is needed to reach the claimed service life is a third. And what conditions need to be written into the specification to hold the supplier accountable for those claims is a fourth.
The indirect costs that rarely appear in a tender comparison but typically carry the most weight in practice are maintenance vehicle and access equipment costs for reaching the luminaire, traffic impact during lane closures, the administrative burden of permits and scheduling, and the future maintenance budget that must be reserved now even if the expenditure falls years away.
A lifecycle cost analysis framework
Structuring an LCC calculation for a public procurement requires a small number of key inputs. The transparency of these assumptions is as important as the calculation itself — assumptions that favour one product can be adjusted to favour another, so the inputs should be stated explicitly and applied consistently to all options being evaluated.
Key inputs for a street lighting LCC:
- Service life assumption — stated in years, with the environmental conditions to which it applies (corrosion category, coastal proximity, de-icing salt exposure).
- Replacement probability over the period — probability of one or more unplanned replacements within the assessment period, based on stated service life and any available field data.
- Energy cost — current electricity price in €/kWh or local currency, plus a projected escalation rate over the assessment period.
- Maintenance interval and labour rate — planned inspection cycle, cleaning schedule, and current crew and equipment costs per visit.
- Unplanned replacement event cost — full-loaded cost of a single unplanned intervention including crew, vehicle, traffic management, and administration.
What to ask manufacturers
Several specific questions give a more useful basis for comparison than the standard data sheet specification:
- What is the stated service life, and under what specific environmental conditions does that claim apply?
- What planned maintenance does the luminaire require to achieve that service life?
- Is spare parts availability committed for the full service period, and for how long after production discontinuation?
- What does the housing warranty cover versus the component (driver and LED module) warranty? These are often different periods and different scopes.
Practical guidance for municipal procurement
Where procurement rules permit, requiring suppliers to submit a lifecycle cost calculation alongside their purchase price forces the conversation about service life, maintenance requirements, and total cost of ownership into the tender process itself. The calculation need not be complex to be useful — a transparent, consistently applied model that quantifies the main cost components is more informative than an opaque price comparison.
For installations in coastal environments, marine zones, or locations with significant de-icing salt use, including an explicit corrosion resistance clause in the specification — with a stated minimum service life in those conditions — provides a basis for accountability that a simple purchase price cannot.
The principle applies regardless of manufacturer: calculate over the full period, not just the invoice.