How the system services market works, and why it exists.

Your Battery Earns Revenue by Stabilising the Grid

When you invest in a ZynexGroup battery, it earns money by providing system services — helping keep Denmark's electrical grid in balance. The grid relies on an invisible, delicate equilibrium: every watt of power produced must be consumed in the exact millisecond it is generated. The grid itself cannot store energy. Think of it as a massive scale that must stay perfectly level at all times. Your battery helps keep that scale balanced, and grid operators pay for this service.

Provision of Inertia Has Evolved From Synchronous to Inverter Based

Historical sources of inertia:

Traditionally, inertia in the power system has been provided by large synchronous generators, which store kinetic energy in their rotating masses. During a disturbance, this stored energy is released almost instantly, slowing the rate of frequency decline (Rate of Change of Frequency, RoCoF) and giving PFR and other Frequency Control Ancillary Services (FCAS) time to respond. As the NEM shifts to renewable energy, fewer synchronous generators are online, which reduces the system's inherent inertia and increases the risk of rapid frequency changes that could lead to instability.

Non-generating sources of inertia:

As synchronous generators are displaced by renewable energy sources, grid operators are turning to alternative equipment to help stabilise the frequency. Synchronous condensers, also known as syncons, which replicate the rotating mass and magnetic field of traditional generators, provide physical inertia to resist sudden changes in frequency. Although they do not generate power, they offer a hardware-based solution to support grid stability during disturbances.

New inverter-based sources of inertia:

Grid-forming batteries are playing an increasingly important role in maintaining power system stability as traditional sources of inertia decline. These advanced inverter-based resources can establish and regulate grid voltage and frequency, a function once provided by synchronous generators. A key feature of grid-forming operation is the ability to provide synthetic inertia, where active power is rapidly injected in response to frequency changes. This fast response helps limit the frequency nadir following disturbances, enhancing stability in low-inertia conditions. Grid-forming battery systems can provide controllable, instantaneous active power through emulated inertia responses, helping to constrain frequency nadir in power systems with fewer synchronous generators.

Why the Grid Needs Your Battery More Than Ever

Historically, heavy fossil-fuel power plants provided natural stability — their spinning turbines acted like a flywheel, absorbing sudden changes. As Denmark transitions to wind and solar, this mechanical stability is disappearing. The grid is becoming more sensitive to sudden changes in weather and consumption. This is not a future problem — it is happening now, and it is why system services are the primary revenue source for battery installations.

Source visual: Energinet. The graph is included here because it illustrates the broader structural pressure that creates demand for balancing and reserve services.

System Services: What Your Battery Actually Does

To keep the grid balanced, the Transmission System Operator (Energinet in Denmark) purchases "system services" — contracts with flexible assets that stand ready to respond when the grid needs help. Your battery is one of these assets. When the grid signals that it needs support, your battery responds within milliseconds. This is the core service that generates your revenue. ZynexGroup bids your battery into these markets every day.

Two-Way Flexibility: Up and Down Regulation

The grid fluctuates in both directions, and your battery handles both:

Up-Regulation: When the grid needs more power (e.g., a cloud covers a solar park), your battery discharges energy. This is the higher-paying direction.

Down-Regulation: When the grid has too much power (e.g., a storm produces excess wind energy), your battery absorbs the surplus.

This two-way flexibility is what makes batteries uniquely valuable. If the grid frequency deviates too far from 50 Hz, safety systems trigger blackouts — your battery helps prevent that.

Speed Matters: The Hierarchy of Response

System services are divided by speed. Some grid instabilities need an immediate reaction for a short burst — like a sprinter catching a falling glass. Others need sustained response over hours — like a marathon runner. Your battery excels at the fast services, which are also the best-paid. The ZG-261 can go from standby to full output in under 1.3 seconds — a level of precision that conventional power plants cannot match.

Operational sequence

In practice, value is created through a simple causal sequence. An imbalance occurs, a signal is issued, the battery responds, and the service is delivered into the balancing structure.

Imbalance occurs

A deviation appears in the system and the grid needs corrective action.

Signal is issued

The balancing layer requests a response from available flexible assets.

Battery responds

The battery charges or discharges within the required response window.

Grid is stabilised

The response helps restore operational balance in the system.

Service is delivered

The technical response becomes part of the economic value delivered through the market.

Why Batteries Are the Best Asset for System Services

Different assets can provide system services, but batteries are uniquely suited. A battery acts as both a consumer and a generator — it can seamlessly switch between absorbing and releasing power. It does not permanently consume the energy; everything it absorbs is stored and released back when needed. This bidirectional capability, combined with millisecond response times, is why system services are the primary revenue driver for ZynexGroup installations — not peak shaving, not arbitrage.

The Giant Synchronized Machine

To understand the energy market, you must first understand the physical map. An electrical grid is not just wires; it is a single, synchronized machine. When countries connect their grids, they form a "synchronous area." Imagine a massive system of interlocking gears. Every power plant and battery in that area must spin at the exact same speed—50 Hz. If one country's gear slows down, it physically pulls on the rest of the network.

Europe's Two Main Grids

Europe is not one single machine. It is divided into several separate, massive synchronous areas. The two main ones are the Continental Europe area (connecting Germany, France, Spain, Poland, and most of mainland Europe) and the Nordic area (connecting Norway, Sweden, and Finland). These two massive grids operate independently and are not synchronized with each other.

The Trading Layer: Nord Pool and PICASSO

On top of this physical infrastructure sits the financial layer: the markets where energy and system services are actually traded. For example, Nord Pool is the leading power market in Europe where the raw electricity is bought and sold day-to-day. Meanwhile, platforms like PICASSO are European-wide balancing platforms where the Transmission System Operators trade the flexible "system services" we discussed earlier. The physical grid moves the electrons; the market platforms move the money and the dispatch signals.

The Danish Anomaly: DK1 and DK2

Usually, a country sits comfortably inside a single synchronous area. Denmark is the exception. Geographically, Denmark sits exactly on the fault line between the Continental and Nordic grids. This physically splits the country in two. West Denmark (DK1) is synchronized with Germany and the rest of Continental Europe. East Denmark (DK2) is synchronized with Sweden and the Nordic grid.

Neighboring Maturity

This split makes the Danish grid inherently complex to operate within. While our neighbors—Germany to the south and Sweden to the north—have highly mature markets for Battery Energy Storage Systems (BESS), Denmark has lagged behind. In Germany and Sweden, high deployment volumes over the years have created streamlined integration processes and clear operational frameworks for system services.

The Documentation Bottleneck and Price Oligopoly

The primary reason Denmark lacks this maturity is regulatory friction. Implementing a BESS project in Denmark requires navigating a notoriously strict, localized documentation and approval process based on EU regulations. This compliance barrier is so demanding that only a very small number of early players have successfully achieved grid approval. This lack of competition has created an oligopoly, allowing a few suppliers to dictate the market and charge artificially inflated prices for BESS hardware and integration.

Breaking the Bottleneck: The ZynexGroup Approach

This is the specific bottleneck ZynexGroup is engineered to solve. Our objective is to master the entire chain—from the raw hardware architecture to the complex EU documentation and grid compliance protocols. By internalizing the expertise required to navigate Denmark's rigid approval process, we remove the friction, break the price oligopoly, and bring BESS deployment down to its true, scaled cost.

Site-Specific Investment Analysis

Because the exact capability of a BESS depends entirely on your specific grid connection and your daily consumption rhythm, no two business cases are identical. By analyzing your facility's historical data and grid connection parameters, ZynexGroup engineers calculate the exact hardware configuration needed and provide an objective investment report for your site.

The Cost and Delay of New Grid Connections

If you want to build a large, standalone battery park today, you run into an immediate physical and financial wall: the grid connection. Establishing a new, high-capacity connection from the local Distribution System Operator (DSO) is extremely expensive. Furthermore, because the public grid is already under massive pressure, getting this new connection approved and physically built can currently take up to seven years in Denmark.

The Grid Connection as an Unused Commodity

However, industrial facilities and commercial buildings already have high-capacity grid connections installed. A grid connection is a physical commodity. In many cases, the full two-way potential of this infrastructure lies underutilized. Instead of waiting years and paying heavily for a new connection, ZynexGroup utilizes your entire existing grid connection to deliver System Services alongside your normal operations.

Where site-level value comes from

The value does not come from one single mechanism. It is created through the interaction between market access, physical site conditions, and optional operational benefits.

System services participation

The primary commercial value comes from participating in balancing and reserve services that require fast flexible response.

Connection capacity already in place

Existing site infrastructure can make participation more practical than building a new standalone grid connection.

Operational continuity

Depending on configuration, the system can also contribute to resilience and outage protection at the site.

Industrial facility with steady power consumption

Predictable Consumption and Up-Regulation

If your facility has a steady, predictable power consumption, that is an advantage. Industrial sites typically operate on Type C grid connections, which allow them to export the exact same amount of power to the grid as they are permitted to consume. On the market, up-regulation (giving power to the grid) pays significantly better than down-regulation. When the grid requires up-regulation, the battery can instantly take over powering your facility while simultaneously exporting power back to the grid. From the grid's perspective, the power you stopped pulling and the power you are exporting combine into one larger up-regulation delivery. Therefore, a site that actively consumes power can mathematically deliver a larger up-regulation volume.

Grid connection sized for matched import and export

Building for Your Connection

Because the battery is placed behind your existing meter, it must respect the physical limits of your current cables. You cannot simply connect an oversized standard battery; the hardware must fit the exact size of your electrical "pipe." ZynexGroup builds modular installations, allowing us to configure the precise kilowatt capacity required to perfectly match your site's specific electrical threshold, ensuring you do not pay for unusable hardware.

Crane installing modular BESS units sized to the facility grid connection

Future Bottlenecks and Grid Deficits

The need for these local safety nets and flexible assets is mathematically guaranteed to grow. According to Energinet's projections, the physical grid is struggling to handle the mass electrification of transport and heating. At the same time, EU targets mandate 70% renewable energy by 2030 and 100% by 2050. This means the heavy, rotating mass of old power plants will continue to disappear right as our electricity needs peak. This combination directly leads to more severe grid bottlenecks and a higher risk of physical power outages in the future.

2030

2050

Securing Against Power Outages

Beyond balancing the public grid, the battery can also act as a physical shield for your own building. The installation can optionally be equipped with a Static Transfer Switch (STS) to secure your facility from blackouts. In the event of a total grid failure, this switch safely disconnects your facility from the public network and flips your building over to battery power, keeping sensitive production and IT equipment running safely. This backup capability operates in parallel with System Services, meaning it does not interfere with the battery's standard market operation.

Frequently asked questions about system services

Why are batteries relevant for system services in Denmark?

Batteries can react extremely quickly to frequency deviations and provide flexibility in both directions, which makes them well suited to system services in a more volatile power system.

Are system services the only source of value in a battery project?

No. System services are the primary revenue source in ZynexGroup's model, but the battery can also support backup power, peak shaving, and optimization of onsite generation.

Why does grid capacity matter so much?

Available grid capacity determines how large a battery solution can realistically be installed and operated without conflicting with the facility's core operations.

See what your existing grid connection could unlock.

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