Editorial owner: MCL Solar Knowledge Center. Technical scope: Final sizing must be verified against the selected model, site coordinates, climate data, and contract documents. Last updated: July 16, 2026.
Key takeaways:
- Choose the architecture from site constraints, not from a universal ranking.
- All-in-one systems simplify installation; split systems provide more freedom for panel, battery, and luminaire sizing.
- Compare daily load, worst-month solar resource, thermal conditions, maintenance access, wind loading, and verified test reports.
- The correct choice is project-specific and must be confirmed in the PI or sales contract.
All-in-one and split systems defined
An all-in-one solar street light integrates the luminaire, controller, battery, and usually the solar panel into a compact assembly. A split system places major components separately so their size, orientation, and service access can be optimized independently.
Project selection matrix
| Decision factor | All-in-one | Split system |
|---|---|---|
| Installation | Fewer field connections and faster assembly | More wiring and installation control |
| Energy sizing | Limited by the integrated housing and panel format | Greater freedom for panel and battery capacity |
| Panel orientation | Usually linked to the luminaire or bracket geometry | Can be optimized separately for the site |
| Thermal management | Compact packaging requires careful heat evaluation | Battery and electronics can be located separately |
| Maintenance | Module replacement can be quick when parts are accessible | Individual components are easier to isolate and replace |
| Typical use | Paths, local roads, parking areas, and standardized programs | High-load, long-autonomy, or highly customized road projects |
Energy and climate checks
Calculate the daily load from each dimming period and any continuous camera or communications load. Size the battery from required autonomy, usable depth of discharge, discharge-path efficiency, and temperature derating. Size the photovoltaic array from worst-month peak sun hours and explicit system losses. Autonomy and post-rain recovery charging must be checked separately.
Optical and structural checks
Do not select a system from watts or a beam-angle label alone. Use the model-specific IES or LDT file and a DIALux calculation that states road width, pole height, spacing, overhang, tilt, maintenance factor, average illuminance, uniformity, and glare or TI where applicable. Structural review must use the design wind speed, projected areas, pole geometry, and foundation conditions.
Procurement checklist
- Model number and rated LED input power
- Model-specific LM-79 or equivalent photometric report
- Battery chemistry, rated Wh, test method, and traceability
- Controller charging profile, protections, and conversion efficiency
- Ingress-protection reports for each relevant enclosure
- Installation drawing, service method, and spare-parts plan
- Standard system warranty of 5 years; any extension stated in the PI or sales contract
Limitations
No architecture is best for every climate or road. A final recommendation requires site coordinates, operating profile, target lighting class, installation geometry, wind data, and the exact proposed model.
Add serviceability and change control to the comparison
Installation time is only one part of the all-in-one versus split decision. The procurement review should also compare battery access, controller replacement, optical options, panel orientation, heat exposure, theft risk, spare-parts strategy and the effect of a component change on the approved configuration.
For lifecycle comparison, state which parts can be replaced in the field, which tools are required, whether sealed modules must be returned, and how long compatible spares will remain available. These questions often matter more than a small difference in initial installation labor.