1. Project Overview

This project comprises a DC-coupled photovoltaic plus energy storage system deployed in Bulgaria. It implements multiple energy management strategies, including self-generation for self-consumption, surplus electricity feed-in/off-grid, peak shaving and valley filling, and off-grid backup power. The system supports flexible configuration, enabling or disabling functions according to actual user requirements.

2. Project Specifications

Applications

The system supports four typical application scenarios:

Scenario 1: PV + storage for self-consumption, with surplus electricity permitted for sale to the grid (requires disabling grid-side metering restrictions to allow electricity sales);

Scenario 2: PV + storage for self-consumption, with surplus electricity prohibited from feeding into the grid (requires enabling grid-side metering to block electricity sales);

Scenario 3: Peak Shaving and Valley Filling – Utilising electricity price differentials to charge during off-peak periods and discharge during peak periods to reduce electricity costs;

Scenario 4: Off-Grid Backup Power – Switching to off-grid mode during grid failures to ensure continuous power supply to critical loads.

Note: Specific functions should be enabled based on the customer’s actual circumstances.

Installed Capacity

Photovoltaic component: Equipped with 3 MPPT photovoltaic controllers;

Energy storage system: Total power 100 kW, total capacity 215 kWh;

Grid connection/switching unit: 2 x 200 kVA static transfer switches (STS).

Primary Equipment

PCS (Power Conversion System), STS, MPPT

BMS (Battery Management System)

Air Conditioning System

Electricity Meter

3. Project Advantages

Multi-functional integration: A single system supports four core functions—self-generation for self-consumption, surplus power management, peak shaving and valley filling, and off-grid backup power—accommodating diverse electricity demands;

Flexible Configuration: Operational modes switch via software settings without hardware modifications, facilitating customisation to user requirements;

High-Reliability Equipment Selection: Critical components utilise industry-leading brands to ensure long-term stable system operation;

DC-Coupled Architecture: Enhances energy conversion efficiency from PV to storage while reducing system losses;

Localised Adaptation: Designed for Bulgaria’s grid policies and tariff mechanisms to maximise economic returns and energy autonomy.