Green Software: an overlooked factor in the sustainability discourse

  • Discussions about ICT resource efficiency often focus on hardware, overlooking  software as a decisive factor in environmental calculations

  • The “blue angel label for resource- and energy efficient software” provides a framework for certfication of software that adheres to strict climate protection measures

  • The German Competence Center IT Economy is compiling a list of “recyclable APIs” to increase the “re-use of code, software, and resources”

Sustainability and digital transformation are two megatrends that go hand in hand. Discussions about the ICT sector’s potential to become greener often focus on the climate impact of hardware: rare minerals and how they are sourced, electronics waste, or energy consumption of devices. Several labels attempt to certify sustainable hardware products to give consumers the possibility to “think green” when buying smartphones or computers. Although awareness about the importance of software as a factor in green tech is increasing, until recently, there was no such label for software.

The “Blue angel label” for software that is sustainable by design

In 2019, a team of researchers led by Professor Stefan Naumann from the Environmental Campus Birkenfeld introduced criteria for a potential certification scheme for sustainable software: the “blue angel label for resource- and energy efficient software”. Among the criteria to be certified are:

  • Controllability: users should be able to configure software according to their individual needs (e.g. night mode, dark mode)
  • Sufficiency: new software versions should not require more computing power, hard-disk space, or bandwidth unless new functions explicitly necessitate it. Core functions should also remain available on older hardware
  • Power awareness: software should manage the energy consumption of hardware as efficiently as possible, including energy-saving modes and “shut down-friendliness” (software should not incentivise users to keep hardware on continuously)

These and other criteria can help to reduce the energy consumption of devices and significantly extend their life cycle by avoiding premature obsolescence, which is an issue of significant concern to SMEs with limited resources. Software producers can now apply for the label and certify their software in three areas energy efficiency, resource efficiency, and transparent interfaces.

Openness and interoperability as decisive criteria for sustainable software

In our position paper on Sustainable Digitalisation, DIGITAL SME has mentioned openness and interoperability as crucial factors in green technologies.

The catalogue of criteria for the “blue angel” label states that using standards for open data formats is “decisive for avoiding dependence on a software product (customer lock-in), which can enforce unnecessary resource consumption both in the case of keeping an inefficient product and in the case of a (costly) switch to another product”[1]. The German Competence Centre IT economy is compiling a list of “recyclable interfaces (APIs)” to increase the “re-use of code, software, and resources”.

DIGITAL SME will continue to raise awareness about different aspects in the discourse around sustainability and digital transformation. We want to show that the ICT sector, driven by innovative SMEs and startups, is indispensable in the fight for more environmental and social sustainability.

Read more about our approach to sustainable digitalisation on our campaign page.

[1]  Catalogue of criteria for sustainable software, p. 19. Source:
This article was written for our #SustainableDigitalisation campaign on the basis of an article by our partner Kompetenzzentrum IT-Wirtschaft. It is not a commercial initiative. As part of a new series about different aspects of sustainable digitalisation like Green(er) Technologies, we will post jointly developed articles like this one to raise awareness about the importance of ICT in Europe’s transition to a green and digital economy.

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