ACER’s updated unit investment indicators show rising energy infrastructure costs that call for closer monitoring

ACER publishes its report on unit investment cost (UIC) indicators for energy infrastructure, updating the reference values last published in 2023. 

What are UIC indicators?

Transparent cost estimation is essential for planning energy networks. Standardised reference values for specific infrastructure costs can improve the quality and credibility of assessments and enable consistent comparisons across the EU.

Under the TEN-E Regulation, ACER is required to develop and publish a set of UIC indicators and corresponding reference values every three years. These indicators provide a common framework for assessing the investment costs of comparable energy infrastructure projects.

What did ACER observe?

The 2026 ACER report provides updated cost information for energy infrastructure, expressed per unit (kilometre, installed power, capacity). It analyses the factors influencing infrastructure costs over time, using cost data and technical information collected from project promoters between October 2025 and January 2026. The report also includes additional indicators and a sensitivity analysis based on an alternative methodology that accounts for cross-country differences in labour costs.

ACER’s analysis shows that: 

• Infrastructure costs have increased above inflation across most categories (e.g. electricity lines, cables and substations). As the indicators are based on historical data from commissioned projects, they do not fully reflect current price levels and may underestimate actual costs.
• Cost drivers point to increased exposure to price volatility and dependence on supply chains, particularly for materials from third countries, as well as other manufacturing-related costs.
• Data representativeness remains limited for several infrastructure categories, with inputs unevenly distributed across countries, which can affect the robustness of the indicators. Future updates would benefit from data covering a wider range of commissioned projects across countries and infrastructure categories.

Despite some limitations, the indicators provide valuable insights into infrastructure costs and support more transparent and informed planning decisions.

Looking ahead

As the assessment is based on historical data from commissioned projects, the indicators may not yet fully reflect recent cost developments. Further work is needed to better capture these cost developments in future updates, for example by exploring alternative methodologies or taking into account recent tender outcomes. ACER notes that regulatory oversight, stronger cooperation on supply chains and better use of existing infrastructure can alleviate bottlenecks.