As the energy input source for the entire system, this project selected high-efficiency photovoltaic modules with a power output of 645 W per module. Key parameters per module are as follows: open-circuit voltage (Voc) = 44 V, maximum power point voltage (Vmpp) = 39 V, maximum power current = 18 A, short-circuit current = 19 A, and module dimensions = 2382 mm × 1134 mm × 30 mm.

To meet the system’s 6 kW rated load requirement, the complete configuration consists of 11 photovoltaic modules of the same specifications. First, the power calculation is performed:
Total peak power: 7.095 kW, which exceeds the system’s 6 kW rated load and provides ample power redundancy. This design fully accounts for issues such as overcast conditions during the South American rainy season, dust and sand obstruction, and long-term power degradation of the modules. Even under poor sunlight conditions, the PV array can still stably output sufficient electricity to ensure the system’s baseline power generation.

Based on the SW-6.2KW-48V device specifications: MPPT operating voltage range 100–450 VDC, maximum PV open-circuit voltage 500 VDC, and startup voltage 100 VDC. In this configuration, 11 modules are connected in series. The voltages are calculated as follows:

Total voltage at the maximum power point after series connection

Total open-circuit voltage after series connection

Analysis of Matching Rationality

The operating voltage after series connection is 429 VDC, which falls within the inverter’s MPPT operating range (100–450 VDC). The inverter can normally track the PV maximum power point, ensuring photovoltaic conversion efficiency;

The total open-circuit voltage is 484 VDC, which is below the inverter’s maximum voltage rating of 500 VDC; the equipment operates safely with no risk of overvoltage;

The string voltage is well above the inverter’s 100 VDC startup voltage, ensuring the equipment starts normally under typical sunlight conditions.

In summary, the configuration of 11 PV modules connected in series fully matches the voltage parameters of the SW-6.2KW-48V inverter, and the wiring scheme is reasonable and feasible.

From a wiring perspective, the voltage of a single PV module is compatible with the charging requirements of a 48V DC energy storage system. The single-string wiring structure is simple, effectively reducing line losses and the probability of failure. Additionally, these solar panels offer excellent weather resistance, including UV and hail resistance, making them suitable for South American outdoor environments characterized by high temperatures, frequent sandstorms, and significant diurnal temperature fluctuations. They are unlikely to develop cracks or experience significant power degradation over the long term. The 11 panels occupy a moderate amount of space, making them suitable for common installation locations such as residential rooftops and courtyard awnings, and facilitating future cleaning, maintenance, and operations.

The average effective daily sunshine duration in the area is 5 hours. Daily power generation is calculated directly based on the total panel power and the duration of sunshine: Formula: Daily power generation (kWh) = Total peak panel power (kW) × Effective daily sunshine duration (h)
The daily power generation is approximately 35.48 kWh, which is essentially in line with the preset value of 35 kWh and is sufficient to meet the round-the-clock electricity needs of a typical South American household.

During daylight hours when sunlight is abundant, the photovoltaic array absorbs solar energy and converts it into direct current (DC). A portion of this power is supplied directly to the household’s real-time loads, while excess energy is continuously stored in the lithium-ion battery bank. If the photovoltaic generation is insufficient to support instantaneous high-power loads, the system automatically draws on battery storage or connects to the utility grid to supplement the power supply, achieving intelligent coordination among the photovoltaic system, energy storage, and the utility grid.

Designed for the 120V/240V dual-voltage split-phase power system commonly used in South America, this split-phase inverter can flexibly switch between output voltages, making it perfectly compatible with a wide range of local household appliances. It eliminates the need for additional voltage conversion equipment, thereby simplifying the system configuration. As a hybrid inverter, it supports both grid-tied and off-grid operation modes: When the grid is supplying power normally, the system operates in hybrid mode, prioritizing power from the solar array and storing excess energy; during extreme power shortages, the grid provides supplemental power, reducing reliance on the utility grid and saving on electricity bills; In the event of a grid outage, voltage abnormalities, or line maintenance, the inverter can automatically switch to off-grid mode within milliseconds, switching to power supplied solely by the lithium-ion battery pack to ensure the continuous operation of critical household loads, meeting emergency power needs in regions of South America with unstable power grids.

The device integrates a high-efficiency MPPT charge management module that precisely tracks the maximum power point of photovoltaic modules, achieving a photovoltaic tracking efficiency of up to 99%; It also features built-in multi-layer circuit protection against overcurrent, overvoltage, undervoltage, ground fault, and overheating, ensuring rapid response to circuit anomalies and establishing a robust safety barrier for the entire AC/DC circuit system. The device comes equipped with dust-proof components and intelligent air-cooling, and supports lithium battery BMS communication, Wi-Fi, RS485, and dry contact interfaces, enabling remote monitoring and making it suitable for smart home applications in South America.

This wall-mounted lithium-ion battery uses high-end lithium iron phosphate (LiFePO₄) cells with a cycle life exceeding 8,000 cycles. Under typical shallow charge-discharge conditions for residential photovoltaic energy storage, the battery experiences slow capacity degradation and can provide stable operation for over twenty years. Its service life far exceeds that of traditional lead-acid batteries and standard lithium-ion energy storage batteries, offering significant long-term cost advantages. Its electrical parameters are highly compatible with PV arrays and 48V inverters. With a continuous charge/discharge current range of 0–120A and a smooth charge/discharge process, it effectively protects both the battery cells and downstream electrical equipment. The battery is equipped with multiple communication interfaces—including RS232, RS485, and CAN—enabling interconnectivity with inverters and smart energy management systems to upload real-time operational data and facilitate intelligent monitoring and control.

In terms of environmental adaptability, the battery operates within a temperature range of -20°C to 60°C and at a relative humidity of <95%, making it suitable for the climates of most tropical and temperate regions in South America. It is designed for altitudes below 4,000 meters, covering the majority of residential areas in South America. The wall-mounted design is compact and does not require a separate battery cabinet; it can be installed on indoor walls or in storage rooms, saving space while providing protection against dust and theft. The battery system incorporates comprehensive protection against overvoltage, undervoltage, overload, short circuits, and overheating. In the event of a fault, it quickly cuts off the circuit to eliminate safety hazards and ensure the safety of household electricity use.

The entire system operates intelligently throughout the entire process without the need for manual intervention:
During daylight hours with ample sunlight: The photovoltaic modules prioritize generating electricity to directly supply household loads, and any excess energy is automatically stored in the 48V wall-mounted lithium-ion battery pack;

When sunlight weakens or during cloudy or rainy weather: As photovoltaic power generation decreases, the system automatically switches to power supply from the lithium-ion battery;

Excessive load demand: When combined power from solar and storage is still insufficient, the inverter automatically connects to the utility grid toa supplement power and balance the load;

Utility power outage: The inverter disconnects the grid connection within milliseconds and switches to pure off-grid storage power to ensure basic electricity supply;

Grid restoration: The system automatically switches back to hybrid mode, simultaneously using solar power to recharge the battery.

The entire system features a smooth, closed-loop energy flow, with intelligent coordination among solar power, energy storage, and the grid, truly achieving the design objectives of self-generation for self-consumption, storing surplus electricity, and providing emergency backup power.

The system features separate wiring for the DC and AC sides: The DC side uses dedicated PV cables, paired with DC circuit breakers, reverse connection protection devices, and surge protectors to guard against lightning strikes and voltage surges; the AC side is equipped with an AC distribution panel and ground-fault circuit interrupters (GFCIs) to standardize indoor electrical circuits. All wiring ports are treated with waterproof insulation, and the outdoor PV junction boxes feature a sealed design, making them suitable for South America’s rainy and humid climate.

The PV modules are mounted on wind-resistant, corrosion-resistant aluminum alloy racks, whose tilt angle can be adjusted based on local latitude to maximize solar energy utilization; wall-mounted batteries are installed in well-ventilated, dry indoor areas, away from fire sources and standing water, to extend equipment lifespan. The entire system consists of mature, industrial-grade products with a low failure rate.

Routine maintenance is simple, requiring only periodic cleaning of dust from the PV panels and inspection of wiring connections. Additionally, the system offers excellent scalability; when future load increases occur, PV panels of the same model or 48V lithium-ion battery packs can be added directly without modifying the core inverter, ensuring convenient upgrades.

This 6kW residential grid-connected split-phase photovoltaic energy storage system employs a unified 48V DC architecture. Eleven 645W photovoltaic modules connected in series provide a voltage that is perfectly matched to the SW-6.2KW-48V inverter, ensuring optimal parameter alignment and safe, stable operation. The system generates approximately 35.48 kWh of electricity per day, fully meeting the electricity needs of local households and offering outstanding cost-effectiveness.

The solution is deeply tailored to the current state of South American power grids, climatic conditions, and residential electricity consumption habits. It features a storage battery with an ultra-long cycle life of 8,000 cycles, ensuring exceptional durability. Leveraging a high-efficiency inverter and long-life storage battery, the system offers dual capabilities for both grid-connected power savings and off-grid emergency power supply. With comprehensive safety protections and convenient installation and maintenance, it is an economical, practical, and durable residential clean energy solution suitable for a wide range of residential properties across South America.