New Energy Module for SatCom Systems Validated in the IRIS2 LEO-1200 Scenario

October 2, 2025

digital illustration of Earth with connectivity lines and the word 6G

As satellite networks grow and demands for global connectivity rise, optimizing energy in Low Earth Orbit (LEO) constellations becomes critical – in terms of both performance and sustainability.

The past spring and summer, Magister Solutions collaborated with Veera Klemettinen, a Master’s student from the University of Jyväskylä, to explore these topics. Her Master’s thesis focuses on the energy intake and consumption of LEO communication satellite constellations.

A key outcome of this thesis work was the design and implementation of a new energy module to Magister’s C-DReAM simulator. The module was evaluated through an IRIS2 LEO-1200 simulation scenario, utilizing the publicly available estimations and information about the planned European satellite constellation.

LEO communication satellites constantly need energy to provide reliable connectivity

Sustainability and energy efficiency are central priorities across industries, and the space and satellite sector is no exception. For Low Earth Orbit (LEO) satellite constellations, understanding energy intake and consumption is critical to ensuring both reliable operations and sustainability.

LEO satellite constellations are increasingly being utilized for providing internet connectivity, offering low latency thanks to their proximity to Earth. These constellations are at an altitude of 300 – 1500 km above Earth. They have an orbital period of 90 – 120 minutes and due to their constant motion, they are deployed in constellations to achieve continuous global coverage.

LEO constellations face unique challenges due to their rapid orbital movement and the global demand for continuous internet connectivity. Communication satellites operating in LEO constantly need energy to keep providing reliable connections.

However, due to eclipse periods and the changing orientation of satellites, the availability of solar energy varies through the orbit. The energy required for serving different service areas in the communication mission also causes variations in satellite energy needs.

Additionally, developments such as Inter-Satellite Links (ISLs) and regenerative satellites have increased the intelligence required of satellites, which increases power consumption. Ideas have also been proposed for using satellites for distributed, resilient processing, which demands more energy.

New energy module for estimating the energy use of SatCom systems

The thesis aimed to answer how the energy intake and consumption of LEO communication satellite constellations can be modelled in orbit. This was achieved by designing and implementing a new simulator component to the C-DReAM satellite constellation simulator.

With the designed energy module, users can model solar energy generation based on different parameters – for example, orbital position, sunlight conditions, solar panel orientation, and efficiency. There is also a model for energy consumption based on the downlink data transmission’s power and volume.

The energy module can estimate the energy intake and energy consumption of different communication satellite constellation scenarios. It can also be used for testing how different configurations of the solar panels and communication payloads affect energy intake and consumption.

Performance assessment of the module in the IRIS2 LEO-1200 constellation

The IRIS2 system architecture (IRIS2 – 5G-NR NTN Multi-Orbit Satellite Communications System, The 3GPP Newsletter, Issue 10, June 2025, p. 27)

The designed component was tested by simulating the IRIS2 satellite internet constellation, which is a new constellation planned by the European Union. It’s estimated to be deployed by 2030.

The IRIS2 initiative aims to establish a secure, resilient satellite communication network, strengthening European digital sovereignty, competitiveness, and societal progress.

Since the full technical details of the constellation are still under development, we utilized the information and estimations that were publicly available at the time of conducting these simulations.

IRIS2 is expected to be a multi-orbital constellation with satellites in different Low Earth (LEO) and Medium Earth orbits (MEO). It’s planned to consist of around 290 satellites in total; 264 in LEO at an altitude of 1200 km, 10 or more in LEO at an altitude of 600 km, and 18 in MEO at an altitude of 8000 km.

For evaluating the operation of the designed energy module, we decided to focus on simulating the constellation of 264 satellites in LEO-1200.

Evaluating energy module accuracy and opportunities for future development

The parameters chosen for the simulation scenario were estimates of the real values of the IRIS2 LEO-1200 constellation. Although the simulation results are predictive, they can be used to evaluate the accuracy of the designed energy module.

Based on the results achieved, the energy consumption modelling works as intended. For example, results suggest that around 20% of satellites in the constellation are in eclipse and 80% in sunlight, which is consistent with the literature consulted in the thesis research.

Towards more detailed modelling of energy intake and consumption

While the module fulfils its intended purpose, it currently uses a simplified approach, not accounting for factors like the temperature and time degradation of the solar panel.

The model for energy consumption could be developed by including more detailed modelling of the payloads, such as ISLs and other subsystems, the solar panel systems, and their degradation of efficiency. The results could be compared to real constellation data.

Estimating satellite energy consumption is challenging due to variations in satellite size and operational states. In this version, the communication payload energy use is approximated according to the downlink service needs in the simulation scenario.

We’d like to thank Veera for her excellent work on the thesis and energy module, as well as the Magisterians who provided support throughout the project. We’re excited to continue refining this feature to support more comprehensive satellite energy modelling in future scenarios.

Master’s Thesis: Energy intake and energy consumption of a LEO communication satellite constellation (Veera Klemettinen, 2025)

C-DReAM – Satellite Constellation Simulator