Use case: energy and utilities

Precise timing for power grids

Power grids depend on GNSS timing because phasor measurement units across the network must synchronise their measurements of voltage, current and frequency, with accuracy measured in microseconds. GNSS receivers are comparatively low-cost, reliable and precise sources of that time. Because the power system is so important, the timing signal must also be resilient against interference.

Reference
UC-13
Technologies
  • Satellite navigation
Industry
Challenge
Connectivity, positioning and timing
Updated
Published by
LETO SPACE

01When you need it

Why grids need a common clock

Phasor measurement units (PMUs) measure the electrical conditions in a power system in real time: voltage, current, power and frequency. Grid operators use them to monitor and control the stability and reliability of the grid Source: EU Agency for the Space Programme (EUSPA), 26 May 2026EU Agency for the Space Programme (EUSPA)EU Space Market Report 2026, Issue 126 May 2026Open source (opens euspa.europa.eu). PMUs are deployed at nodes across the network, including remote locations, and they rely on accurate time synchronisation of their measurements Source: EU Agency for the Space Programme (EUSPA), 26 May 2026EU Agency for the Space Programme (EUSPA)EU Space Market Report 2026, Issue 126 May 2026Open source (opens euspa.europa.eu).

PMU shipments in 2025
just over 8,000
PMU shipments forecast for 2034
around 11,500
Measurements per second
up to dozens
Time source of many PMUs
GPS

These figures come from the EU Space Market Report 2026, which expects annual PMU shipments to keep growing as utilities expand wide-area monitoring, protection and control schemes Source: EU Agency for the Space Programme (EUSPA), 26 May 2026EU Agency for the Space Programme (EUSPA)EU Space Market Report 2026, Issue 126 May 2026Open source (opens euspa.europa.eu).

02Technology

How GNSS timing works in the grid

Besides position, satellite navigation delivers precise time. GNSS receivers are comparatively low-cost, reliable and high-precision timing sources that can be installed in large numbers across an intelligent grid Source: EU Agency for the Space Programme (EUSPA), 15 December 2020EU Agency for the Space Programme (EUSPA)Timing is everything: GNSS and the energy grids of the future15 December 2020Open source (opens euspa.europa.eu). Our page on what GNSS is explains the technology.

PMUs typically rely on GPS or another GNSS to synchronise their measurements Source: EU Agency for the Space Programme (EUSPA), 26 May 2026EU Agency for the Space Programme (EUSPA)EU Space Market Report 2026, Issue 126 May 2026Open source (opens euspa.europa.eu). The accuracy required is measured in microseconds, because protection and control applications need accurate timestamps and timely delivery of the data. State-of-the-art GNSS receivers meet these requirements Source: EU Agency for the Space Programme (EUSPA), 2024EU Agency for the Space Programme (EUSPA)EUSPA EO and GNSS Market Report, Issue 2, 20242024Open source (opens euspa.europa.eu).

Phasor measurement units (PMUs) typically take their time from GNSS, in many installations from GPS; Galileo could serve as an alternative or backup. The common time lets operators compare data from hundreds of PMUs in real time. Schematic drawing. Source: EU Agency for the Space Programme (EUSPA)

03Deliverables

What it enables

The digitisation of substations, which supports the spread of PMUs, has improved protection and control applications such as the following, and the quality of data synchronisation is key to them Source: EU Agency for the Space Programme (EUSPA), 2024EU Agency for the Space Programme (EUSPA)EUSPA EO and GNSS Market Report, Issue 2, 20242024Open source (opens euspa.europa.eu):

  • real-time modelling of the grid
  • fault analysis and fault localisation
  • wide-area monitoring across the network

Looking ahead, EUSPA expects GNSS timing receivers to enable real-time automatic control of intelligent grids, in which all energy market participants communicate with each other Source: EU Agency for the Space Programme (EUSPA), 15 December 2020EU Agency for the Space Programme (EUSPA)Timing is everything: GNSS and the energy grids of the future15 December 2020Open source (opens euspa.europa.eu).

04Overview

Resilience

Because the power system is important to our lives and economies, GNSS timing in the grid must be resilient against interference Source: EU Agency for the Space Programme (EUSPA), 15 December 2020EU Agency for the Space Programme (EUSPA)Timing is everything: GNSS and the energy grids of the future15 December 2020Open source (opens euspa.europa.eu). For PMUs, EUSPA names two options:

A second constellation. Galileo could provide an alternative or backup to GPS in PMUs Source: EU Agency for the Space Programme (EUSPA), 26 May 2026EU Agency for the Space Programme (EUSPA)EU Space Market Report 2026, Issue 126 May 2026Open source (opens euspa.europa.eu).

A backup time source. Precision Time Protocol (PTP) concepts are being explored as a backup, although some of them also rely on GNSS receivers Source: EU Agency for the Space Programme (EUSPA), 2024EU Agency for the Space Programme (EUSPA)EUSPA EO and GNSS Market Report, Issue 2, 20242024Open source (opens euspa.europa.eu).

Detecting jamming and spoofing, including with authenticated Galileo signals, applies to every GNSS-dependent operation and is covered under protecting GNSS-dependent operations.

05Limits

Limits

06Next steps

How we help

We help you find out where your grid depends on satellite time, specify accuracy, resilience and backup in requirements and procurement, and introduce the new set-up step by step.

More on implementation

To see who offers space-enabled solutions, use Spacegraph, our discovery platform.

07Use cases

Frequently asked questions

Q1Can Galileo replace GPS for grid timing?

Many PMUs still rely on GPS, and Galileo adoption in existing PMU infrastructure is still emerging. Galileo has, however, moved from a supplementary system towards a stronger alternative, and grid operators are beginning to invest in redundant timing such as multi-GNSS receivers Source: EU Agency for the Space Programme (EUSPA), 26 May 2026EU Agency for the Space Programme (EUSPA)EU Space Market Report 2026, Issue 126 May 2026Open source (opens euspa.europa.eu).

Q2What happens if the GNSS signal is jammed or spoofed?

GNSS signals can suffer interference, which is why timing for the power system must be resilient against it Source: EU Agency for the Space Programme (EUSPA), 15 December 2020EU Agency for the Space Programme (EUSPA)Timing is everything: GNSS and the energy grids of the future15 December 2020Open source (opens euspa.europa.eu). For PMUs, Galileo as a second constellation is gaining ground, and grid operators are beginning to invest in redundant timing solutions such as multi-GNSS receivers, terrestrial backup systems and network-based time distribution Source: EU Agency for the Space Programme (EUSPA), 26 May 2026EU Agency for the Space Programme (EUSPA)EU Space Market Report 2026, Issue 126 May 2026Open source (opens euspa.europa.eu). Detection, authenticated signals and backups for all GNSS-dependent operations are covered in our use case on jamming and spoofing.

Q3How do we start?

Start with an inventory: which devices in your substations and control systems take their time from GNSS, which receivers they use, and what happens when the signal is lost. From there we define requirements for accuracy, resilience and backup. Our consulting overview shows the path from the problem to operation.

Sources (3)

  1. EU Agency for the Space Programme (EUSPA), 26 May 2026EU Space Market Report 2026, Issue 1 (opens euspa.europa.eu)
  2. EU Agency for the Space Programme (EUSPA), 2024EUSPA EO and GNSS Market Report, Issue 2, 2024 (opens euspa.europa.eu)
  3. EU Agency for the Space Programme (EUSPA), 15 December 2020Timing is everything: GNSS and the energy grids of the future (opens euspa.europa.eu)

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