Merus Power

Merus® ESS
Energy Storage System

A high-power, fast-reacting, and reliable lithium-ion-based battery energy storage system fully designed and manufactured by Merus Power.

Merus® ESS, a robust BESS for long investment lifetime and high asset availability

Merus® ESS is designed for long investment lifetime, high asset availability, and fast deployment. Merus Power provides a complete one-stop-shop solution with full system integration, grid code compliance, and simulation models, ensuring the fastest time to market for your energy projects.

Built with Merus® PCS, the first TSO (Transmission System Operator) approved grid-forming BESS in the Nordics, Merus® ESS combines advanced grid support capabilities with proven reliability. Its integrated PPC (Power Plant Controller) and EMS (Energy Management System), developed in-house alongside the PCS, guarantee optimized performance and seamless operation.

Available in 5 and 10 MW AC block configurations, Merus® ESS offers the highest power on the market under a single MV transformer.

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Grid-forming capability

First TSO-approved grid-forming BESS in the Nordics

  • Integrated PPC/EMS design ensures seamless operation and eliminates integration issues.
  • Comprehensive simulation models (PSCAD, PSS®E, and DIgSILENT PowerFactory) support full system integration and grid code compliance.
  • Carefree operation with a guaranteed availability of 98%*.
  • Plug-and-play deployment enables fast and effortless installation on site.
  • Unlimited scalability with a customizable power-to-energy ratio.
  • Optimized efficiency achieved through a minimized number of MV feeders and high unit power.
  • Robust and durable design built on decades of expertise in power electronics and battery system engineering.
*with O&M agreement

Turnkey energy storage solutions built on partnership

At Merus Power, building a strong business case for energy storage starts with understanding each customer’s unique needs and investment goals. Our in-house experts in electricity markets, battery technologies, and power electronics work together to craft technically sound and economically viable solutions.

We analyze the customer’s energy profile, forecast market opportunities, and match the right battery technology to performance expectations and budget. Our deep experience in power electronics ensures seamless integration with existing infrastructure, enhancing efficiency and resilience.

This collaborative approach results in a flexible and future-ready solution, co-created with the customer for long-term value. From business case design to full system delivery, including installation, commissioning, and grid compliance, we handle the entire process. Long-term performance is secured through our Operations and Maintenance, as well as our trading services.

No prior expertise is needed. We make energy storage effortless.

Project development

Business case optimization

Turnkey technology delivery

Market access and trading services

Full life cycle O&M services

Comprehensive EPC deliveries

Our EPC deliveries can cover the entire scope of your energy storage project, from grid connection to commissioning. The scope of supply for Merus® ESS can include everything down the line from the grid connection point.

Typical delivery scope:

  • High voltage substation (if required)
  • Medium voltage substation (if required)
  • RMU network (if required)
  • Merus® ESS, including Merus® PCS and batteries with a tailored power-to-energy ratio
  • Civil works
  • Installations
  • Grid code compliance studies, simulations, and documentation

A practical project arrangement for a 30 MW / 36 MWh system with a Nordic climate battery shelter designed for battery containers or racks.

BESS technology designed and manufactured in Finland

Except for the batteries, the entire solution, from bi-directional inverters to proprietary system-level controls and Energy Management System (EMS), is designed and manufactured at our premises in Finland using innovative Merus® Technology. Thanks to its scalable, modular structure and easy configurability, our battery energy storage system can be tailored to meet each customer’s specific needs. Batteries are sourced from leading global suppliers with a focus on sustainability, energy efficiency, and optimal project performance.

Our Merus® ESS reacts to grid needs in less than 0.1 seconds using proprietary optical fiber control technology proven in our power quality portfolio. This ultra-fast response enables customers to access new electricity markets with simple software upgrades from our experts.

Merus® PCS — Power Conversion System

Backed by decades of experience in power electronics, we lead the way in grid-forming capabilities, helping clients stay ahead as new standards emerge across the Nordics. Thanks to our superior weather resistance and Arctic design, the system operates reliably even in -40°C temperatures, snow, and ice. As a European manufacturer, we have safety prioritized in every design, with durable and cybersecure systems built for long-term performance.

Customer benefits

  • Scalable and modular structure
  • Merus Power’s support and expertise throughout the device’s entire lifetime
  • Deep understanding of revenue stacking business models for energy storage systems through in-house trading and analysis team
  • Route to reserve markets with own trading and optimization system
  • Cost-effective and top-quality scalable solutions made with Nordic excellence in Finland
  • Over 15 years of experience in power quality and electrical engineering

Technical benefits

  • Reacts to the needs of the electric grid in less than 0.1 seconds
  • Merus® proprietary Technology utilizing optical fiber communication for control
  • Own Merus® Software Technology
  • Native outdoor design – can be placed outdoors, which means reduced cost of cooling and better operational efficiency
  • High operating voltage – better efficiency and reduced electrical installation needs
  • Full one-stop-shop, no scope gaps with energy storage procurement and operations – includes batteries, Power Control System, Battery Management System, Energy Management System, Operating & Maintenance, and trading to a seamless system

5 MW / 10-12 MWh BESS
at any MV voltage level with one MV feeder

10 MW / 20-24 MWh BESS
at any MV voltage level with one MV feeder

Note: The illustration of the layouts serves only as an example optimized for a longitudinal site deployment. The layout can be adjusted, for example, to a “box” layout depending on the site.

Industry-leading safety and security

At Merus Power, our battery energy storage systems are built for durability, resilience, and cybersecurity. Designed and manufactured in Europe, the Merus® ESS features a robust and redundant architecture that ensures continued operation even if individual components fail. The system withstands harsh conditions such as freezing temperatures and coastal climates, using heavy-duty components built for long-term performance.

We collaborate closely with fire departments and local authorities to meet the highest safety standards and apply best practices for critical infrastructure-level cybersecurity. As a Finnish market leader, we are committed to delivering solutions that are physically safe, digitally secure, and ready for the most demanding environments.

Get to know our BESS as part of an innovative Energy Community in Lempäälä, Finland.

Many different applications and operations

Wind and solar power

Optimizing production and providing ancillary (frequency regulation) and backup services.

Commercial and industrial applications

Reducing energy costs and earning new revenue streams.

Grid balancing

Stand-alone projects to provide ancillary services and other revenue streams.

Turbine-based generation

Increasing turbine lifetime and nominal production.

Distribution system operator

Securing power supply, improving power quality, and earning from ancillary markets.

Microgrid

Optimizing energy consumption and production, providing back-up and ancillary services.

Electric boilers

Joint operation to increase market revenues.

Dispatch

State of charge control

Grid forming

Droop control

Black start

Ramp rate control

Peak shaving

Frequency regulation

What sets Merus Power apart?

1. Finnish design and manufacturing

We design and manufacture our battery energy storage systems in Finland, including the Power Conversion System (PCS), bi-directional inverters, system-level controls, and the Energy Management System (EMS). Only the batteries are sourced externally. This gives us full control over quality, integration and reliability.

2. Ultra-fast response and grid-forming capability

Merus® ESS reacts to grid changes in less than 0.1 seconds thanks to proprietary fiber-optic control technology. This speed enables advanced grid-forming capabilities that go beyond typical market standards and are essential for supporting modern, dynamic power systems.

3. Own testing facility and end-to-end services

We operate our own 1 MW / 1 MWh energy storage system in Finland to test and validate new technology in real conditions. In addition to hardware, we offer complete services from project development and EPC delivery to operations and maintenance. We also provide our own MERUSCOPE™ platform for remote monitoring and trading, giving customers powerful tools to optimize their energy storage assets.

Merus® MERUSCOPE™

Remote Monitoring & Control Service and Electrical Market Trading Platform

Real-time monitoring

Remote monitoring service enables you to monitor the performance of your energy storage solution in real-time, providing insight into its health, status, and performance. This allows you to detect issues early and diagnose problems before they become critical, reducing downtime, and preventing costly repairs.

Predictive maintenance

Track the condition of your BESS over time and identify patterns that may indicate future issues. This allows you to perform proactive maintenance, replacing parts or making repairs before they fail, further reducing downtime and repair costs.

Remote control

Adjust the settings of your battery energy storage solution remotely, without the need for an onsite visit. This enables you to quickly respond to changing conditions and optimize your system’s performance without the need for expensive and time-consuming site visits.

Maximizing ROI

Performance monitoring over a long period of time optimizes the Return on Investment (ROI) of BESS by maximizing its uptime and efficiency, reducing downtime and repair costs, and ensuring that you get the most out of your investment. MERUSCOPE® follows the batteries’ cyclical usage and ensures that the manufacturer’s guarantee conditions are followed.

Trading and analysis service

In the Nordic region, Merus Power serves as your pathway to the market, equipped with proprietary trading software. Our market analysis service delivers the most current market insights and crafts trading strategies to optimize your Return on Investment (ROI).

Merus® Control Platform (EMS)

Merus Power’s in-house developed Energy Management System (EMS) controls all energy storage components and integrates distributed generation, flexible loads, and switchgear. It connects all assets to SCADA and cloud platforms for monitoring, offering very high integrability through fiber optics, hardwired signals, and Ethernet.

Get to know our BESS as part of a 21 MW wind farm in Northern Finland.

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Energy storage system supporting national frequency regulation

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Design data

Merus® ESS

Modular 1-5MW system

  • Modular Power Conversion System
    • Consists of 1MW independent power modules, installed up to 5MW per transformer winding
    • High efficiency (98.5% peak)
    • Both grid-following and grid-forming operation
    • DC-voltage up to 1500V
    • AC voltage connects to 600-800V

Connection point (PoC)

  • Medium (6-33kV) or High voltage (>100kV)

Installation environment

  • Fully outdoor suitable
  • -40℃ to +40℃

Merus® Control Platform (EMS)

  • High-level controller enabling >100MW integration
  • High-performance grid forming capability
  • Aggregated control of various energy storage subsystems at any voltage level

Battery type

  • LFP chemistry
  • C-rate 1-0,25C (1–4 hours)
  • 20 ft containers or standalone outdoor racks
  • Liquid-cooled

Safety and protection

  • Fire monitoring smoke and gas detection
  • Automatic alarm forwarding to fire department
  • Fire extinguishing gas or aerosol

Compliance

  • IEC-62933, Grid codes EU and UK, CE-label
  • UL9540A, IEC62619, UN38.3
  • Grid Code Compliance documentation, acceptance tests, and simulation models included in Merus project deliveries

Warranty

  • Standard 2 years, option up to 10 years
  • Flexible energy capacity warranty
  • Availability guarantee
  • Performance guarantee

Interfacing

  • Monitoring and control interface for 3rd party
  • IEC104, Modbus, MQTT, OPC

Footprint

  • 25–30 m2/MWh

Do you have any questions?

Please contact one of our salespeople with questions and inquiries.

Esa Lipsanen

Senior Sales Manager,
Energy Storage, Nordics

+358 45 263 1106 esa.lipsanen@meruspower.com

Håkan Nordlund

Senior Sales Manager,
Energy Storage, Scandinavia

+46701872844 hakan.nordlund@meruspower.com

Mika Laakso

Sales Manager,
Energy Storage

+358 40 1597 962 mika.laakso@meruspower.com

Roope Raisio

Manager,
Project Development

+358 44 596 0401 roope.raisio@meruspower.com

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