Why Did We Abandon Inverters in Favor of an MPPT + 48V PoE Architecture?
For many involved in solar-powered smart street lighting, the default first step is to simply add an inverter.
This approach was perfectly acceptable during the era of standard street lighting.
However, today's "smart poles" are no longer merely "lights."
We recently re-evaluated the power supply architecture for a specific project.
The system configuration is as follows:
· 1000W Photovoltaic (PV) Modules
· 25.6V Lithium Iron Phosphate (LiFePO4) Energy Storage, with a capacity of 4.8kWh
· Hikvision TandemVu 32x AI PTZ Camera
· Total continuous load: approximately 276W
During the initial phase of the project, we adopted the traditional AC-based solution:
Battery → Inverter → AC 220V → Camera Power Adapter → DC
To be frank, there is nothing inherently wrong with this logic.
However, once the system went live, issues began to surface.
The first issue: The system was engaging in unnecessary energy conversions.
The essence of the traditional path is: DC → AC → DC.
Yet, internally, the AI PTZ camera ultimately operates on DC power.
In other words, the inverter's role here is to convert DC power into AC power, only for the camera's power adapter to convert that AC power back into DC.
Every such conversion results in energy loss.
Given that the strain on energy storage is already high during the night, layering these conversion losses on top significantly reduces the system's operational headroom.
The second issue: The power consumption of AI PTZ cameras has surpassed the levels typical of traditional surveillance equipment.
The TandemVu PTZ camera we utilized supports 32x optical zoom, ColorVu supplementary lighting, infrared night vision, PTZ motor control, and AI analytics.
Official specifications indicate that its peak power consumption can exceed 40W.
This figure approaches the power consumption range typically associated with small-scale telecommunications equipment.
In a nighttime scenario—when infrared illumination activates, the PTZ unit begins to move, and the battery voltage naturally dips—these three events often occur simultaneously.
If the inverter lacks sufficient instantaneous response capability, it can trigger camera restarts, network disconnections, or jerky PTZ movements.
Many projects suffer from the "works fine during the day, goes offline at night" syndrome; simply put, the root cause lies not with the camera itself, but with the underlying power supply architecture.
The third issue: 48V DC is rapidly emerging as the mainstream bus voltage standard for smart poles. An increasing number of devices are now beginning to support the PoE+, Hi-PoE, and 802.3bt standards.
The reasoning is straightforward: 48V DC is better suited for long-distance transmission—offering lower line loss—and makes it significantly easier to implement a unified, industrial-grade power supply for multiple devices.
This evolutionary logic closely mirrors the developmental trajectory of telecommunication base stations.
Based on these three factors, we have redesigned our system architecture:
Solar Panels → MPPT → 25.6V Energy Storage → DC-DC Boost Converter → 48V PoE Bus → AI PTZ Cameras / Network Switches / Communication Equipment
Yes, this configuration introduces an additional DC-DC boost module.
However, the overall conversion efficiency remains higher than that of inverter-based AC solutions.
More importantly, system stability has been significantly enhanced.
The most critical point is this: Smart poles are undergoing a fundamental structural transformation.
They are no longer merely lighting fixtures.
They are now evolving to simultaneously host AI cameras, LoRaWAN modules, 5G small cells, environmental sensors, edge computing units, and LED information displays.
In my personal view, the prevailing "streetlight power supply mindset" is shifting toward a "telecom-grade DC bus architecture."
Consequently, 48V DC is highly likely to emerge as the foundational voltage standard for the next generation of smart poles.
A question for the community: When working on off-grid smart pole projects, what power supply architecture do you typically choose—an inverter-based solution or a direct DC supply? We invite you to share your thoughts and discuss this in the comments section below.
Post time:May - 25 - 2026
