ENNA Next becomes an active participant in balancing the Croatian electricity system

Zagreb, March 3, 2025 – ENNA Next has passed prequalification and become an active participant in balancing the Croatian electricity system, under the supervision of the Croatian Transmission System Operator (HOPS).

To ensure the safe and stable operation of the electricity system, it is crucial to constantly maintain a balance between electricity production and consumption. The primary goal is to keep the network frequency at 50 Hz, ensuring the proper operation of all connected devices, power plants, facilities, industrial systems, transmission and distribution infrastructure, and households.

Maintaining Balance in the Electricity System

In order to maintain the targeted frequency, HOPS manages power reserves that enable adjustments in production or consumption of energy. These reserves are used in cases of excessive consumption or production, or any imbalance in the system. ENNA Next, with its portfolio of electricity producers and consumers, actively participates in maintaining this balance (by either including or excluding its producers or consumers at any given moment, depending on the system's balance).

After receiving permission from the Croatian Energy Regulatory Agency (HERA) last year to provide aggregation services, ENNA Next has successfully passed prequalification to provide ancillary services for balancing the electricity system, including automatic (aFRR) and manual (mFRR) power reserves.

aFRR (Automatic Frequency Restoration Reserve) – The system automatically adjusts energy production or consumption within minutes, depending on frequency deviation. This reserve operates continuously to ensure network stability.

mFRR (Manual Frequency Restoration Reserve) – Activated manually when larger power adjustments are needed in the system. This reserve allows system operators to intervene precisely to maintain balance.

ENNA Next contributes to network stability with mFRR and aFRR services and is currently in the process of prequalifying technical units to further enhance this by incorporating power from renewable sources – such as solar plants, wind farms, biogas facilities, and battery storage systems.

Role of the Virtual Power Plant

In the process of balancing the electricity system, ENNA Next, as an aggregator, manages a Virtual Power Plant (VPP) that consolidates consumers (e.g., industrial plants, refrigeration or air conditioning units) and electricity producers (solar plants, wind farms, biogas facilities, cogeneration plants) through a digital platform, along with battery storage units. Through continuous communication with HOPS, ENNA Next optimizes energy production and consumption within the virtual power plant, contributing to the stability of the electricity system. At the same time, it provides additional revenue opportunities for VPP partners by participating in the ancillary services market.

ENNA Next invites all business entities – electricity producers and consumers – to join the virtual power plant and achieve financial and operational advantages. For more information, contact info@enna-next.hr.