Short answer: replacing high-pressure sodium street lights with LED typically cuts lighting energy by more than half, and by about two thirds with night-time dimming. Cities that cannot fund the upgrade use savings contracts, where a partner installs the lights and is repaid from the savings over about seven years, or PPPs that add solar generation and maintenance. The baseline audit and the savings measurement decide whether either works.
Street lighting is often one of the largest electricity bills a city pays, and many cities in Africa and Asia also carry thousands of lights that no longer work. That combination is why retrofit and PPP projects are multiplying.
Key numbers
- India’s Street Lighting National Programme has replaced over 13 million street lights with LED, saving about 8.8–9.0 billion kWh a year. Its contracts run about 7 years and typically guarantee around 50 % energy savings.
- Kenya’s Eldoret solar street lighting PPP (about KSh 3.45 billion) was approved for contract negotiation in April 2026: around 12,000 new LED lights, 90 high masts, refurbishment of 2,271 broken lights and a 3 MWac solar plant with battery storage.
1. Energy saved: a worked example
| Per 1,000 lights, 11.2 hours a night | 150 W sodium (about 170 W with ballast) | 75 W LED | 75 W LED, 50 % after midnight |
|---|---|---|---|
| Average power | 170 W | 75 W | about 55 W |
| Energy per year | about 695 MWh | about 307 MWh | about 225 MWh |
| Saving against sodium | – | about 56 % | about 68 % |
| Lamp life | typically 24,000–30,000 h (lamp changes every few years) | 50,000 h or more to 70 % lumens | |
Our own calculation, with dimming applied for 6 of the 11.2 hours. Multiply the saved megawatt-hours by the local tariff to get the annual saving; add avoided lamp replacements and crane visits for the maintenance saving. A 75 W LED replaces a 150 W sodium lamp only if the optics suit the existing pole spacing; check it with a lighting calculation, as in our lighting class guide.
2. Four ways to pay for it
| Model | How it works | Suits |
|---|---|---|
| Direct purchase | City or road agency buys and installs through a tender | Funded budgets, donor projects |
| Energy savings contract | Partner finances and installs LEDs; city repays from guaranteed savings over about 7 years | Metered grid lighting with reliable bills |
| Availability PPP | Private partner finances, builds and maintains; paid for lights working to standard | Large programmes with maintenance problems |
| Solar or hybrid PPP | As above, plus solar generation and storage replacing grid supply | Unreliable grid, high tariffs, as in Eldoret |
3. What owners and lenders check
- Baseline audit: how many lights, their wattage, how many work, hours of operation, and whether lighting is metered or billed on estimates. Unmetered lighting makes savings hard to prove.
- Savings measurement: metered before and after, or an agreed method such as IPMVP. Guarantees without a measurement method lead to disputes.
- Lighting performance: the target class and uniformity after retrofit, measured on site, not just wattage.
- Payment security: escrow accounts, deductions at source or guarantees, because partners are repaid over years.
- Maintenance scope: response times, spare stocks and who replaces stolen or damaged lights. Uganda’s review of its USMID programme recommended at least three years of maintenance in the contract.
- Controls: dimming profiles and remote monitoring, which raise savings and show failures quickly.
- Handover: condition of the assets at the end of the contract and the remaining warranty.
4. Grid LED or solar?
Where the grid is reliable and lighting is metered, grid LED with dimming gives the lowest life-cycle cost; Uganda’s USMID review reached that conclusion for urban roads. Where power cuts are frequent, tariffs are high or new roads have no supply, solar wins: stand-alone solar lights for streets and estates, or a central solar plant with storage, as Eldoret plans. Many programmes mix both. Our all-in-one vs split guide covers the solar options.
FAQ
How much energy does an LED street light retrofit save?
Typically 50–60 % against high-pressure sodium, and about two thirds with night-time dimming, depending on the wattages replaced.
How can a city upgrade street lights without upfront capital?
Through an energy savings contract or a PPP, where a partner finances the upgrade and is repaid from savings or availability payments over several years.
What is the payback of an LED retrofit?
It depends on the tariff and the wattages replaced. India’s programme repays the investment from savings over about seven years, including maintenance.
Can existing poles be reused?
Usually, if they are structurally sound. The LED optics should be chosen for the existing spacing and mounting height; see our pole spacing guide.
How we help
We supply LED street lights, solar street lights and high masts to contractors and PPP partners. Send us the existing light inventory and the target class; we will propose replacement luminaires with IES files and the energy comparison.
Sources: Energy Efficiency Services Limited, Street Lighting National Programme, and Government of India statements (2025); Kenya National Treasury PPP progress status report (10 April 2026) and Kenyan press on the Eldoret project; Uganda MLHUD technical study on public lighting (2024); IPMVP measurement and verification protocol. The energy example is our own calculation. Related: high-mast specification, warranty.