Case study · Industrial & manufacturing
Executive summary
Bostik SA manufactures adhesives and sealants across three sites in Durban, Cape Town and Johannesburg. Rather than three separate retrofits, the conversion was run as one programme under a single specification, removing an estimated 351,576 kWh a year, about 63% of the lighting load, and releasing an estimated 66.9 kVA of maximum demand. The programme paid back in an estimated 22 months.
351576kWh
Energy saved per year
(estimated)
63.0%
Reduction in lighting
energy (estimated)
22mo
Payback on the
retrofit (estimated)
362tCO₂e
Carbon avoided per
year (estimated)
66.9kVA
Maximum demand
released (estimated)
Figures are estimates derived from project close-out data and standard operating assumptions. They will vary with tariff, run hours and site conditions, and are indicative of this project rather than a guarantee of results on another site.
The project
A multi-site manufacturer has a problem a single-site one does not: three facilities in three provinces, each with its own maintenance history, its own contractor relationships and its own idea of what a replacement fitting looks like. Left alone, each site solves the same problem differently and the group ends up carrying three spares inventories.
The technical starting point was mercury-vapour high-bay lighting, which is among the least efficient installations still in service in South African industry. Mercury vapour has been withdrawn from manufacture in most markets, so a site running it is on a shrinking supply of replacement lamps as well as a large electricity account.
Operating hours varied widely by area: production running around the clock, stores and despatch on an eleven-hour weekday pattern, exterior lighting on sensors twelve hours a day, every day.
The three sites were assessed separately and specified together. Each facility got a design matched to its own areas and hours; all three drew on one fitting specification, so the group ended up with one spares inventory, one warranty position and one point of accountability.
The mercury-vapour high bays were replaced with 60 W LED high bays, a substitution that removes the great majority of the connected load at that position while raising delivered light, because mercury vapour depreciates severely across its life.
The programme was built on confirmed tariff and confirmed operating hours per area rather than on a blanket assumption, which is what allows a three-site result to be stated as a single number without averaging away the differences between them.
| Area | Legacy installation | Lamphouse specification |
|---|---|---|
| Production areas | Mercury-vapour high bays | LED high bay, 60 W |
| Stores, despatch and raw materials | Legacy fluorescent and discharge fittings | LED high bay and linear, specified per area |
| Exterior, on day and night sensors | Legacy discharge floodlighting | LED floodlighting |
Why it worked
Carried forward
Where a group holds lighting budgets at site level, the group-level result is unavailable until somebody consolidates them. The energy and carbon case is materially stronger at group level than the sum of the site cases, and it reaches a different decision-maker.
Supporting references
Tell us the areas, the hours they run, the lux you need to hit and your capex envelope. We'll come back inside the week with a design, a fitting schedule and a payback model.
Related: Industrial & manufacturing LED