Case study · Education
Executive summary
Bishops is a full campus: pre-prep, prep and senior schools, boarding houses, sports facilities and grounds, lit across a working day that starts before assembly and ends long after the last practice. The full-facility LED conversion took an estimated 231,904 kWh a year out of the estate, a reduction of about 66%, and released an estimated 55 kVA of maximum demand. On South Africa's grid that is roughly 239 tonnes of CO₂e avoided a year, with the work paying for itself in an estimated 32 months. All figures on this page are estimates.
231904kWh
Energy saved per year
(estimated)
66.1%
Reduction in lighting
energy (estimated)
32mo
Payback on the
retrofit (estimated)
239tCO₂e
Carbon avoided per
year (estimated)
55.0kVA
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 school estate is a harder lighting problem than its budget suggests. It is not one building but many, built in different decades to different standards, and the lighting in each was specified for what that decade could buy. Classrooms, boarding houses, halls, corridors, sports lighting and grounds all sit on the same meter and all age at different rates.
The financial constraint is the real one. Independent schools fund capital works from fee income and reserves under a governing body that has to weigh a lighting upgrade against a science block or a bursary. A proposal that cannot show where the money comes back does not get past the first meeting.
And the work could not interrupt teaching. A campus has a hard calendar: term time is untouchable, holidays are short, and anything left half-finished on the first day of term is a problem in front of parents.
The estate was surveyed as a whole rather than building by building, because the savings case only closes when the long-hours areas are included. Corridors, boarding houses, external and security lighting run far more hours than classrooms do, and they are routinely left out of school lighting proposals because they are not where the pupils are.
The conversion was scoped as a full-facility upgrade, so no legacy islands were left behind to be handled at a later date and at a later price. Phasing followed the school calendar, with the disruptive work taken in holiday windows and the balance staged around teaching.
The case put to the governing body led on payback rather than on lumens. At an estimated 32 months, the upgrade is funded by the saving it produces, which is a materially different conversation from asking for capital.
Why it worked
Carried forward
Lead with payback, not with lux, when the decision sits with a governing body. The technical case wins the specification; the payback case wins the budget, and the budget meeting happens first.
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: Commercial & office LED