Solar panel battery management

BMS, Battery Management System, is a mandatory component of a LiFePO4 battery system because lithium batteries are sensitive to over-current and over- and under-voltage. The BMS is supplied by the battery cell manufacturer and is already integrated into the battery container.

What does BMS do?

• protects battery cells from overcharging
• protects battery cells from excessive discharge
• calculates the state of charge level of the battery cells
• monitors the battery temperature
• monitors the health and safety of batteries by checking for loose connections and internal shorts.

To effectively manage a hybrid park (solar park + batteries) and profitably participate in the energy market, smart solutions and partners are needed:

• Aggregator: Your gateway to the energy market, consolidating output and simplifying market participation.
• Balance Responsible Party (BRP): Guarantees energy balance in the grid, ensuring stability and avoiding penalties.
• PPC (Power Plant Controller): The park’s hardware “brain” that manages output and battery operations in real-time.
• EMS (Energy Management System): Smart software that optimizes battery and solar park schedules based on exchange prices and consumption, ensuring maximum benefit measurable in euros.

These components and partners work together so that your solar park yields maximum revenue, complies with regulations, and is always under control.

When selecting an energy storage system, it is crucial to comprehend the technical parameters that influence the system’s actual performance, profitability, and reliability.

• Battery Power (kW): Indicates the maximum power at which the battery can be charged or discharged.
• Battery Capacity (kWh): Indicates how much energy can be stored in the battery.

In addition to these basic indicators, the following parameters are critically important for LFP (Lithium Iron Phosphate) batteries, ensuring maximum efficiency and reliability:

• High Efficiency: Up to 98% Round-Trip Efficiency (RTE) ensures minimal energy loss during charging and discharging.
• Maximum Utilization: Achieving up to 100% Depth of Discharge (DoD) and over 6000 cycles (approximately 16 years of lifespan) provides maximum available energy and a long service life.
• Fast Response and Safety: Ultra-fast response (e.g., for participating in reserve markets) and ultimate chemical stability ensure the system’s safety and quick operational readiness.
• Grid Stability and Revenue: Batteries support the grid (FCR, aFRR, mFFR) and enable earning additional revenue from providing grid services.
• Comprehensive Management: Minimal maintenance requirements and full service from commissioning to long-term operation ensure flawless BESS system performance.

LFP batteries are the market’s best solution for safety, profitability, and seamless grid integration.

Historical data on electricity consumption can be found in Elektrilevi’s self-service. It is possible to save hourly data for the previous 12 months. Based on this, a graph can be created that shows the average electricity consumption per hour for the entire year.

Optimum battery power = average consumption per hour per year.

Optimum battery capacity = 2 to 4 times the average hourly consumption.

• Battery charging takes place at night during the cheapest hours.
• The battery is discharged during the daytime and evening hours when the price is the highest.

The greater the capacity, the greater the energy saving potential.

A battery used in the frequency reserve market should have a relatively high capacity compared to the battery capacity. A 1C rating (power = capacitance) is ideal, but a 0.5C rating (power = ½ capacitance) is also suitable.

Such a configuration allows the battery to be quickly charged or discharged in the most efficient manner according to the offers made on the frequency market and their activation by the system operator. The battery participating in the frequency market is kept at a 50% capacity level, because in this way the battery can be quickly used both in the direction of consumption and production according to the needs of the frequency market.

By choosing a modular energy storage system, it is possible to start with a smaller configuration and easily expand it later according to needs.

Energiapartner offers:

• DC-coupled storage solutions, where the battery inverter is integrated with the PV inverter.
• AC-coupled solutions, where the storage solution has a separate inverter.

Typically, DC-coupled solutions have power ratings in the range of 30-200kW, while AC-coupled solutions are for 200+kW.