Merus Energy Storage Systems

Merus Energy Storage Systems (ESS), built on state-of-the-art-technology, are modular solutions in terms of output power and energy. A variety of operation modes and flexibility to connect to any voltage level make Merus ESS a preferred solution for complete electricity system value chain, starting from the generation. Particularly renewable energy integration, and from Transmission and Distribution (T&D) down to hybrid, island and microgrids. Built-in flexible design permits easy scalability to deliver customized solutions from few hundreds of kWh to several hundred MWh. Typical operation modes of Merus ESS are: frequency and voltage regulation, peak shaving and intermittent power support, including unique power quality modes.

In the micro grid applications, the core of Merus ESS is the modern Merus MCC Micro Grid Controller which measures various parameters from solar farm, wind farm, diesel generators or any other distributed power generator sources. Based on the micro grid loading requirement versus availability of distributed power sources, Merus MCC controller optimizes and prioritizes the overall power generation, resulting in lowest operational costs and maximum savings of fossil fuel. Other key building blocks of Merus ESS systems include Merus Power Conversion System (PCS) and energy storage system. Power System Solutions can provide a complete turnkey Merus ESS solution.

Functions and customer benefits

Key functions

  • Peak shaving

  • Ramp rate management

  • Power dispatch management

  • Spinning reserve

  • Voltage and frequency control

  • Power flow optimization

  • System stability improvement

  • Voltage control

  • Energy management for alternative sources

  • Black start functionality

  • Power quality compliance

Customer benefits

  • Reliable energy supply in real-time

  • Smooth integration of renewable energy

  • Balanced energy supply and demand

  • Uninterrupted power

  • Operational performance and reliability of the plant


Generation - Wind, solar and engine-hybrid power plants

  • Peak shaving

  • Ramp rate management

  • Energy shifting

  • Power dispatch management

Transmission and distribution grids

  • Spinning reserve

  • Frequency regulation

  • Power flow optimization

  • System stability improvement

  • Voltage control

Industrial and natural island grids, microgrids and hybrid systems

  • Energy management for alternative sources including solar, wind and fossil fuel plants

  • Black start functionality

  • Peak shaving

  • Power quality compliance

  • Voltage and frequency control

Operation Modes

Merus ESS state-of-the-art control and converter technologies enable real time ESS output control, providing unique operation features. Throughout its entire lifetime, the solution can operate in one or more of the operation modes shown in the matrix below within the range of installed energy and power capacity. With sufficient capacity of the energy storage media, Merus ESS can operate in one or any combination of the operation modes shown in matrix below.

Frequency regulation

MERUS ESS is capable of both charging and discharging, at the power level or levels, within the installed capacity or according to the preset operation mode combinations.

MERUS ESS can provide autonomous real-time frequency regulation based on the frequency measured from the Host Utility’s electric system. The frequency regulation mode can be used simultaneously with any other operation mode as shown in the matrix.

Peak shaving

In the peak shaving operation mode, Merus ESS is controlled to reduce peak power demand from the Host Utility feeder to which Merus ESS is connected. Merus ESS can be discharged at any power level within its capacity.

MERUS ESS performs autonomous real-time peak shaving based on the measured active power from the Host Utility’s electric system. The peak shaving mode can be used simultaneously with any other operation mode as shown in the matrix.

Intermittent power resource support – Microgrid

Merus ESS can be used as one of the main components of a microgrid. The solution has its own microgrid controller which can operate in grid-connected and island modes. The energy management philosophy is defined by the type and capacity of the integrated power generation.

A typical microgrid may include a combination of solar and diesel power, supplemented by the ESS, as well as various types of loads. These types of microgrids are usually controlled with economic optimization in mind. I.e. The priority may then be to minimize the operation hours of the diesel power plant, resulting in savings in fuel and wear and tear costs. The aim may also be to maximize the use of low cost energy provided by a solar plant.

How Merus ESS Works

Merus Power Conversion System (PCS)

Merus bidirectional state-of-the-art converters use 3-level NPC topology to enable low loss operation, high DC voltage and the best power quality performance thanks to optimized switching frequency.

DC voltage is available with a wide range spanning 600 – 4000Vdc. Bidirectional modules in various sizes are available starting from 50kVA up to 2000kVA, enabling the most cost-efficient solution for each customer-specific project up to hundreds of MWh, or even larger scales.

Battery energy storage

The battery energy system consists of battery modules connected in series to meet the required direct voltage level, typically 600-1500Vdc. The racks are connected in parallel to meet the needed energy capacity. One group of series-connected battery modules form the storage rack. Each rack can have its own battery management system (rack BMS) to manage the state of charge (SOC), state of health (SOH), voltage, current and temperature of each level of battery modules in the rack, as well as the control and protection.

Merus MCC controller for any applications

Merus MCC controller measures system voltages and currents and calculates the required PCS current based on measurements, active operation modes and battery status. It transmits reference current to PCS modules via a fiber optic link enabling real time ESS output control. Merus MCC controller uses modern compatible communication systems to send and receive status and operation mode settings with higher level operators such as a transmission system operator (TSO).

Merus MCC provides energy management for alternative sources including solar, wind and fossil fuel power plants. The fuel saving concept for micro grid operation optimization is provided. Merus ESS has a black start functionality, meaning it has the capability to form a standalone island mode grid, to which other power sources can be syncronized.

On-line monitoring and maintenance are available via an internet service provider.

Product Features

Merus ESS – UPQ – Energy storage with uninterrupted power supply

Merus ESS-UPQ is a unique solution that combines the benefits of various power quality systems in a single robust system. Among the other ESS features, Merus ESS – UPQ protects your grid against power interruptions, voltage sags and swells caused by upstream public grid.

Merus ESS-UPQ can seamlessly decouple the microgrid from grid-connected operation to islanded operation in case of a fault and reconnect to the grid automatically when the fault is cleared. Merus ESS-UPQ ensures the power quality in the microgrid in either operation mode.

Storage optimization – For specific customer need 

Merus ESS can be tailored to meet customer needs by choosing the storage type based on the intended usage. For example, peak shaving may occasionally require high power, whereas intermitted power resource support may require small power for a long period of time. If both operation modes are required in the same ESS, system design must be flexible. Merus ESS can be tailored to meet specific needs and designed with different energy storage media.

Technical Specifications

Merus ESS – type 1: Storage, PCS and transformer integrated in container.

Merus ESS – type 2: Storage, PCS and transformer integrated in container. Outdoor power transformer for utility.

Merus ESS – type 2: Storage, PCS and transformer integrated in separate containers. Outdoor power transformer for utility.

Contact Us

Power System Solutions | 250 Hogan Lane | Conway, AR 72034