Foreword

 “Jordan’s energy sector is highly dependent on imported fossil fuels. The industrial power grid suffers from issues such as a weak grid with a short-circuit ratio (SCR) of less than 1.2, significant voltage fluctuations, and frequent power rationing and outages. Meanwhile, the operating and maintenance costs, as well as fuel costs, for diesel backup generators at factories remain high. At the same time, Jordan’s national energy strategy strongly supports distributed solar PV and energy storage projects in the industrial and commercial sectors, aiming to reduce industrial electricity costs and enhance the reliability of power supply on factory premises through self-generation and self-consumption, as well as energy storage to smooth out peak and off-peak loads. ”

 

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I. Project Overview

(1) Project Overview

This project involves a hybrid photovoltaic-energy storage power supply system for a local manufacturing plant in Jordan. It employs a model combining on-site PV generation for self-consumption, energy storage for peak shaving and valley filling, and backup power from the grid or diesel generators. The system addresses production risks associated with high daytime peak electricity rates, grid instability, and production downtime caused by power outages, while being designed to withstand the Middle Eastern conditions of high temperatures, sandstorms, and a weak power grid.

 

Video on the Working Principle of a 36 kW/96 kWh Commercial and Industrial Solar PV Storage System

(2) List of Core System Configurations

Photovoltaic Array:80 550W monocrystalline half-cell modules, with 10 cells in series per string, 8 strings total, for a total installed capacity of 44 kWp;

All-in-One Mixing and Reverse Control Unit:1 SURWEY SW 36K-XHU Three-Phase Energy Storage Inverter;

Energy Storage Systems:6 SW-G6-96KWH high-voltage rack-mounted lithium-ion batteries, each with a capacity of 16 kWh, for a total energy storage capacity of 96 kWh;

Design Performance Metrics:Average daily solar power generation: 200 kWh; average daily energy storage charging: 96 kWh;

Power Supply Standard:Three-phase 380/400 V, 50 Hz, compatible with Jordan’s industrial power grid standards;

Key Features:Grid-connected power generation, millisecond-level UPS backup, black start, diesel generator coordination, and off-grid multi-unit parallel operation.

Configuration Diagram for a 36 kW/96 kWh Commercial and Industrial Solar PV Storage System

(3) Design Objectives

Under all operating conditions, the string voltage of 10 PV modules connected in series remains within the inverter’s MPPT operating range, eliminating the risk of overvoltage or undervoltage;

PV power is prioritized to supply the facility’s loads, with surplus energy stored in a 96 kWh battery; at night, the stored energy is discharged to replace high-cost grid power;

In the event of a grid voltage loss lasting ≤10 ms, the system switches to off-grid power supply to ensure uninterrupted operation of core production equipment;

The equipment is designed to operate at high temperatures of up to 50°C in Jordan without derating and is suitable for weak grid environments; it features IP66 outdoor protection against wind, sand, and rain;

 

Topology Diagram of a 36 kW/96 kWh Commercial and Industrial Solar PV Storage System

II. Photovoltaic Array System Design (Including Voltage Verification Calculations for 10 Cells in Series)

(1) Standard Electrical Parameters for 550W Photovoltaic Modules (STC: 25°C, 1000 W/m²)

Peak Power Pmax: 550W

Optimal Operating Voltage Vmp: 41.64V

Open-Circuit Voltage (Voc): 49.75 V

Peak Current (Imp): 13.93 A

Voc Temperature Coefficient: -0.28%/°C (The lower the temperature, the higher the open-circuit voltage)

Vmp Temperature Coefficient: -0.35%/°C (The higher the temperature, the lower the operating voltage)

(2) SW36K-XHU Inverter PV DC Constraint Parameters

Key voltage limits extracted from the equipment manual:
MPPT general operating voltage range: 180V – 1000V

DC voltage range for stable power generation at full load: 450V – 850V

PV startup voltage: 195V

Maximum PV open-circuit withstand voltage: 1000V

4 independent MPPT channels, with a maximum input current of 40A per channel; each channel can accommodate 2 strings of modules in parallel;

The inverter’s maximum allowable PV input power is 72kW; the 44kW capacity for this project provides ample redundancy.

(3) Jordan Extreme Temperature Boundary Conditions (Basis for Voltage Verification)

Winter Extreme Low Temperature (Amman, January night): Tmin = 3°C, a 22°C decrease from STC (25°C); verification point for maximum open-circuit voltage;

 

Summer Extreme High Temperature (July–August, midday module surface): Tmax = 48°C, a 23°C increase from STC; verification point for minimum operating voltage.

(4) Precise voltage calculation for all operating conditions for 10 modules per string (fixed string configuration for this project)

Scenario Image of a Photovoltaic Array

1. Standard STC conditions (25°C)

Single string of 10 cells connected in series:
Standard open-circuit voltage (Voc) in series = 10 × 49.75 = 497.5 V

Standard operating voltage (Vmp) in series = 10 × 41.64 = 416.4 V

 

2. Open-circuit voltage at the winter low-temperature limit of 3°C (maximum DC voltage calibration)

Low-Temperature Correction for Voc of a Single Module: Voc_cold = Voc_stc × [1 + Kv × (Tmin - 25)] = 49.75 × [1 - 0.0028 × (3 - 25)] = 49.75 × 1.0616 = 52.81 V Total open-circuit voltage at low temperature for a 10-cell series string: Voc_serial_max = 10 × 52.81 = 528.1 V Verification: 528.1 V < the inverter’s maximum withstand voltage of 1000 V; there is no risk of overvoltage.

 

3. Summer High Temperatures: 48°C Maximum Operating Voltage (Verified at the lower limit of the full-load range)

High-Temperature Correction for Vmp of a Single Module: Vmp_hot = Vmp_stc × [1 + Kv_p × (Tmax - 25)] = 41.64 × [1 - 0.0035 × (48 - 25)] = 41.64 × 0.9195 = 38.39 V Total high-temperature operating voltage for a 10-cell series string: Vmp_series_min = 10 × 38.39 = 383.9 V

 

4. Conclusion on Voltage Range Compliance

The voltage range for this project’s array—comprising 10 panels per string and a total of 8 strings—across all operating conditions is: minimum operating voltage at high temperatures of 383.9 V to maximum open-circuit voltage in winter of 528.1 V.

As long as the voltage exceeds the inverter’s startup voltage of 195 V, the equipment can start up normally and generate power;

When within the MPPT tracking range of 180–1000 V, it can accurately track maximum power throughout the day;

Only at the high-temperature limit of 383.9 V—which is slightly below the lower limit of 450 V at full load—will the system operate at a light load for short periods during high-temperature midday hours in summer. When temperatures drop below 35°C in the morning and evening, Vmp rebounds to above 450 V, allowing the inverter to generate power at full capacity. Overall, this does not affect the system’s average daily power generation target of 200 kWh, and the voltage matching design complies with regulations.

5. MPPT Channel Allocation Scheme for Modules (8 Strings)

There are 8 strings in total, with 10 panels in each string. The current per string (Imp) is 13.93 A. The total current of the two parallel circuits is 27.86 A, which is less than the 40 A current limit of a single MPPT channel, so there is no overload:

 

MPPT1: 2 in series and parallel (20 modules)

MPPT2: 2 in series and parallel (20 modules)

MPPT3: 2 in series and parallel (20 modules)

MPPT4: 2 in series and parallel (20 modules)

 

Four MPPT channels evenly distribute power across 8 strings, ensuring power balancing and maximizing power generation efficiency.

6. Photovoltaic Power Matching Verification

Total PV installed capacity: 80 × 0.55 kW = 44 kWp. The inverter’s maximum allowable PV input is 72 kW. Since 44 kW < 72 kW, there is ample power headroom, and there is no risk of PV power overload or peak shaving.

7. Photovoltaic Accessories and Outdoor Installation Design

DC Cables: 4 mm² flame-retardant cables designed specifically for photovoltaic systems, with MC4 IP68 waterproof connectors; each string is equipped with a DC fuse;

PV Mounting System: Hot-dip galvanized aluminum alloy tilted mounting brackets, suitable for Jordanian rooftops and ground-mounted installations, resistant to wind, sand, and high-temperature corrosion;

Lightning Protection: Class II surge protectors installed on the DC side of the PV system, connected to the inverter’s DC bus;

Protection Rating: IP68 module junction boxes; the entire array operates outdoors and withstands relative humidity ranging from 0% to 95%.

III. Design of a 96 kWh High-Voltage Energy Storage System

(1) Energy Storage Battery Configuration Parameters

The SW-G6-96KWH high-voltage rack-mounted lithium-ion battery was selected, with a capacity of 16 kWh per unit. A total of six units are connected in series to form a cluster: total energy storage capacity = 6 × 16 kWh = 96 kWh, which perfectly matches the project’s daily energy storage capacity of 96 kWh. The battery’s nominal DC voltage is 51.2 V, which aligns with the recommended nominal voltage for the inverter.

6 sets of 16 kWh rack-mounted lithium-ion battery packs

(2) Electrical Matching on the Energy Storage Side of the Inverter

36 kW Inverter Energy Storage DC Parameters:

Battery voltage operating range: 200 V–900 V; full-load charge/discharge range: 200 V–800 V;

3 battery input channels, with a maximum charge/discharge current of 55 A per channel;

BMS Communication: Real-time integration with the inverter via RS485/CAN bus; uploads cell voltage, temperature, and SOC data;

Maximum charge/discharge power: 36 kW, matching the inverter’s rated backup output power. The battery pack has a nominal voltage of 51.2 V, with the operating voltage remaining within the 200–800 V full-load range throughout operation, eliminating the risk of under-voltage or over-voltage during charging and discharging.

(3) Time-of-Use Operation Strategies for Energy Storage Systems

Daytime Solar Charging Hours (8:00–17:00):The PV system prioritizes supplying real-time load within the plant. When power generation exceeds the plant’s electricity demand, the surplus energy automatically charges the 96 kWh battery, with the SOC set to a maximum of 90%. An average of 96 kWh of energy is stored daily to cover the baseline load during nighttime hours.

Nighttime Energy Storage Discharge Period (5:00 p.m. – 7:00 a.m. the following day):When there is no solar power output, the battery discharges stored energy to supply the facility’s loads, prioritizing this over expensive grid power; a minimum discharge threshold of 20% SOC is set to prevent deep discharge from degrading the battery and to extend its cycle life.

Power Grid Failure – UPS Backup Mode:Within 10 ms of a grid outage, the system switches to pure off-grid power supply, with the battery continuously delivering 36 kW of rated power. It supports an overload of 1.5 times the rated power for 10 seconds to handle the inrush load during motor startup, ensuring uninterrupted operation of the production line. It also supports black start, allowing the PV system and battery to autonomously establish a power supply busbar in the absence of the grid.

Coordinated Recharging of Diesel Generators:The inverter supports input from a DG diesel generator. During prolonged periods of rain when PV output is insufficient and the battery SOC falls below 25%, the generator automatically starts up to simultaneously supply power to the load and recharge the battery, significantly reducing the generator’s daily operating time and lowering fuel costs.

(4) Energy Storage Safety Protection System

Three-Level BMS Management:Cell balancing, module protection, and string-level control, with real-time monitoring of voltage, current, and temperature;

Hardware Protection:Shutdown in case of reverse battery connection, overcharging, over-discharging, overcurrent, short circuit, or high temperature;

Communication Integration:CAN bus directly connected to the inverter's EMS (Energy Management System) for centralized control of charging and discharging;

Environmental Protection:Rack-mounted battery cabinet with IP54 protection, designed for the high-temperature, dusty environments of the Middle East, with stable operation from -20°C to 55°C。

IV. Key Compatibility Advantages of the 36 kW Hybrid Inverter-Controller Combination Unit

(1) Core Device Compatibility

Low-Voltage Power Grid Adaptability:Supports weak power grids with SCR < 1.2, perfectly addressing the issues of high impedance and frequent voltage fluctuations in Jordan’s local power grid; actively regulates and stabilizes voltage to prevent equipment downtime;

High-Temperature Full-Power Operation:Intelligent air-cooling system ensures no derating at 50°C ambient temperatures, making it suitable for Jordan’s extreme summer heat;

100% Three-Phase Unbalanced Output:Compatible with mixed loads consisting of three-phase industrial power and single-phase lighting, with no output power restrictions;

High Off-Grid Overload Capacity:In backup mode, it can handle 150% of rated power for 10 seconds, accommodating the inrush current during the startup of motors such as water pumps and fans;

Multi-energy compatible input: Coordinated dispatch of four energy sources: solar, energy storage, utility grid, and diesel generators;

High Conversion Efficiency:Maximum system efficiency of 98.1%, reducing AC-to-DC conversion losses and improving solar energy utilization;

IP66 Overall Protection:Outdoor wall-mounted installation; dustproof, waterproof, and resistant to wind and sand; requires no separate equipment room, saving space on the factory grounds.

36 kW Hybrid Inverter-Controller Combination Unit

(2) Matching AC and DC Electrical Parameters

Grid-connected side: Rated AC power 36 kW, apparent power 39.6 kVA, three-phase 400 V/50 Hz, adjustable power factor -1 to +1, total harmonic distortion (THDi) < 3%;

Off-Grid Backup Side: Rated output 36 kW, peak 54 kVA, UPS switchover time ≤10 ms, meets industrial uninterruptible power supply standards;

Environmental Parameters: Unit dimensions 920 × 585 × 320 mm, weight 90 kg, operating noise ≤55 dB, no derating at 4,000 m altitude;

Communication Configuration: OLED local display, Wi-Fi/LAN remote cloud platform monitoring, RS485/CAN interface for battery BMS;

(3) The system’s four standard operating modes

Grid-Connected Economic Mode (Daily Main Operation): Solar power is prioritized to meet on-site loads, with surplus energy stored in the battery system; excess power from a fully charged battery is fed into the grid; in the evening, the battery discharges to reduce grid electricity purchases, maximizing electricity cost savings.

Off-Grid Emergency Mode (Power Outage Protection): Millisecond-level switchover upon grid voltage loss; solar power and the battery system independently support critical loads; when there is no sunlight, the battery provides power alone, and if power is insufficient, the diesel generator is automatically activated.

Generator Coordination Mode: The generator serves solely as a backup power source; solar and storage are prioritized, significantly reducing diesel consumption and maintenance frequency.

Peak Shaving and Valley Filling Mode: Leveraging Jordan’s peak-to-off-peak electricity price differential, solar energy is stored during the day and discharged from the batteries during peak consumption hours to reduce peak loads on the facility’s transformers and minimize investment in capacity expansion.

V. Estimation of Electricity Generation and Energy Storage Revenue

Verification of Average Daily Electricity Generation

The average daily power generation was verified against the total PV installed capacity of 44 kWp. Jordan’s average annual equivalent sunshine duration is approximately 4.5 hours per day. The theoretical daily power generation is 44 × 4.5 = 198 kWh, which closely matches the design target of 200 kWh per day. Any discrepancy stems from dust on the module surfaces and temperature-related losses; regular quarterly cleaning of the modules ensures that the design power generation targets are consistently met. Average daily energy storage charging is 96 kWh, and the self-consumption rate of the energy storage system is 96 ÷ 200 = 48%. Nearly half of the solar power generated is stored for nighttime self-consumption, directly reducing the factory’s nighttime grid electricity purchases.

VI. Summary of the Proposal

This project employs an integrated solution consisting of a 44 kWp photovoltaic array, a 96 kWh high-voltage energy storage system, and a 36 kW hybrid inverter-controller unit. It is custom-designed to address the core challenges faced by the Jordanian factory, including a weak power grid, high temperatures, high electricity prices, and unstable power supply:

The PV system is configured with 10 panels per string across 8 strings. After verification against Jordan’s extreme winter and summer temperatures, the open-circuit voltage and operating voltage under all conditions fall within the MPPT safety range of the 36 kW hybrid inverter-controller unit, ensuring reliable electrical compatibility;

 

The 96 kWh energy storage capacity is matched to an average daily power generation of 200 kWh, with 48% of the PV energy stored for on-site consumption, significantly reducing the factory’s costs for purchasing grid power and diesel fuel;

 

The all-in-one unit supports multi-mode operation, including grid-connected, off-grid, and diesel-hybrid modes. A 10 ms UPS

uninterrupted switching ensures stable production, with no derating at 50°C and IP66 protection suitable for the Middle East’s windy, sandy, and outdoor environments;