Base Station Solar Overlay Solutions combine the clean, renewable nature of solar energy with the high power requirements of communication base stations, offering significant advantages and broad application prospects.

Core Features:

• No interruption to the existing power supply
• Integration of photovoltaic power generation units into the existing power supply infrastructure via DC coupling
• Priority use of solar energy to power the load

I. System Components

The Base Station Solar Overlay system primarily consists of a photovoltaic array (solar panels), a solar controller (such as an MPPT controller), a renewable energy battery bank, photovoltaic mounting brackets, and power distribution cables. Together, these components form a highly efficient, intelligent, and reliable closed-loop green energy system. The system architecture is designed to balance power generation efficiency, operational safety, and ease of maintenance, ensuring a stable power supply in a wide range of complex environments.

II. Operating Principle

• Solar Energy Harvesting: The photovoltaic array (solar panels) generates direct current (DC) when exposed to sunlight.
• Power Conversion: A maximum power point tracking (MPPT) controller efficiently converts the DC power generated by the photovoltaic array and regulates the output voltage and current to match the power requirements of the communication base station.
• Energy Storage: The converted electrical energy is first supplied to the communication base station, while the excess is stored in a battery bank for use during periods of no sunlight or during peak power demand.
• Intelligent Monitoring: The system is equipped with remote monitoring capabilities, enabling real-time monitoring of the solar power system’s operational status and power output to ensure stable operation and efficient power supply.

III. Solution Features

This solution has proven its stability and adaptability in a variety of complex environments. Whether in densely populated urban areas, remote regions without grid power, or on communication towers with limited space, it enables efficient deployment and stable operation.

• High Efficiency and Energy Savings: By adopting a direct DC power supply mode, the solution avoids the AC-DC conversion losses of up to 15% found in traditional AC systems. The overall link efficiency is ≥95%, with a maximum measured efficiency of up to 98.3%. A typical site can save approximately 2,920 kWh of electricity annually, with power generation gains increasing by 10%–30% compared to AC solutions.
• Cost Reduction: Annual electricity costs per site can be reduced by up to 12,000 yuan, with a payback period of approximately 5.5 years; this period is further shortened when combined with local subsidies. No grid connection permits are required, and the deployment process is simplified, significantly reducing regulatory transaction costs.
• High Reliability: Under daylight conditions, the system can maintain power supply during grid outages; when combined with energy storage, it can sustain operations for over 3.5 days during cloudy or rainy weather. Field tests show a reduction of over 80% in emergency power generation needs, significantly lowering the risk of station outages and ensuring continuous network operation.
• Outstanding Environmental Benefits: A single station equipped with 18 SPV modules is estimated to generate 7,671 kWh annually, equivalent to a reduction of 4.374 tons of carbon dioxide emissions; taking a province-wide project in Liaoning as an example, annual carbon emissions can be reduced by 267,000 tons, making a significant contribution to the environment.
• Easy Installation and Strong Adaptability: The retrofitting process can be completed without power outages and is compatible with existing power systems from various manufacturers and models. Suitable for various installation scenarios, including rooftops, tower facades, and ground-mounted racks, offering high deployment flexibility.
• Strong Policy Alignment: The “self-generation for self-consumption” model is not subject to grid connection approval restrictions. It meets the Ministry of Industry and Information Technology’s target requirement of over 30% PV coverage for new base stations, aligns with the national policy direction for distributed energy development, and facilitates rapid, large-scale deployment.

IV. Application Scenarios

The Base Station Solar Overlay system is suitable for various communication base station scenarios, including macro base stations, micro base stations, and 4G/5G base stations. This system demonstrates its unique advantages particularly in remote areas where the national power grid is unavailable or power supply is unstable. Through a smart energy consumption model of “self-generation and self-consumption with local consumption,” this solution effectively reduces reliance on the grid and provides stable and reliable power support for communication base stations.

V. Classification of Specific Solutions

1. Classification by Installation Scenario and Space Utilization

Rooftop Stacking Solution

• Applicable Scenarios: Macro base stations and aggregation nodes located on the rooftops of standalone equipment rooms or atop server racks.
• Features: Utilizes idle space on the existing roof of the equipment room to install PV modules. This is the most traditional form of stacking, with relatively simple construction; however, installation capacity is limited by roof area and load-bearing capacity.

Tower/Mast Stacking Solution

• Applicable Scenarios: Urban densely populated areas, land-constrained regions, and outdoor cabinet sites without independent equipment rooms.
• Features: Photovoltaic modules are installed vertically or at an angle on the body of communication towers, support poles, or aesthetic covers (i.e., “minimalist tower stacking”).
• Advantages: Does not occupy additional ground or rooftop space, addressing the “lack of available land” challenge in urban areas; vertical installation offers good wind resistance and is less prone to dust accumulation.

Facade/Wall Stacking Solution

• Applicable Scenarios: Vertical surfaces such as equipment room exterior walls, site perimeter walls, and noise barriers.
• Features: Utilizes vertical building surfaces surrounding the site to install PV panels as a supplementary energy source.

2. Classification by Electrical Coupling Method

DC Coupling / Direct DC Stacking

• Principle: The direct current (DC) generated by the PV system is directly converted into the standard -48V DC required by communication equipment via a DC stacking controller (DC/DC converter) and fed into the site’s DC busbar.
• Features:
• Highest efficiency: Eliminates energy losses from the “DC-AC-DC” secondary conversion process.
• Easy to Implement: No need to alter the existing AC power supply architecture; it connects directly in parallel with the switching power supply system, offering “plug-and-play”
• Mainstream Choice: Currently the most common approach in energy-saving retrofits for communication base stations.

AC Stacking Solution (AC Coupling)

• Principle: PV power is converted to AC via an inverter, fed into the site’s AC distribution panel, and then converted to DC via a rectifier module to power the load.
• Features: Suitable for large sites or scenarios requiring simultaneous power supply to AC loads such as air conditioning; however, efficiency is slightly lower than DC coupling when powering purely communication-related loads.

3. Classification by System Function and Evolutionary Goals

Basic PV Stacking Solution

• Objective: Purely to save electricity.
• Components: PV modules + PV stacking controller.
• Logic: Uses PV power when sunlight is available and automatically switches back to grid power when it is not. Primarily reduces electricity costs (OPEX).

PV + Storage Stacking Solution

• Objective: Energy savings + enhanced backup power.
• Components: PV + lithium-ion battery/PV stacking controller + smart energy management system.
• Logic: PV power is prioritized for loads, with excess electricity stored in lithium batteries; during grid outages, power is supplied by the batteries. This enables “peak shaving and valley filling” (charging during off-peak hours using low-cost grid power or PV, and discharging during peak hours) and extends backup runtime.

PV-Storage-Diesel/PV-Storage-Grid Integrated Solution (Hybrid Integrated Solution)

• Objective: Maximum sustainability and high reliability (Commonly used in areas with power shortages or high-energy-consumption 5G sites).
• Components: PV + Energy Storage + Intelligent Dispatch System (may include a diesel generator interface).
• Logic: The EMS intelligently dispatches four energy sources: PV, storage, grid (utility power), and diesel (generator).