Finding Significant Differences in the Energy Consumption when Comparing Programming Languages and Programs

The EU Green Deal mirrors the societal concern regarding climate change. In the software industry this means reducing the energy consumption of a program. This can be done by looking both at the hardware and the software used. We take a software approach and focus on the programming language choices and how a computer program is written. The programming languages we investigate are Java, JavaScript, Python, PHP, Ruby, C, C++ and C#. We compare programs from The Computer Language Benchmarks Game and these programs are divided in groups that solve the same problem.We find that the choice of programming language and the way of writing your program influences the energy consumption. The programming languages that consume the least amount of energy over all the problems are C and C++, albeit these programming languages consume more energy when compilation flags are minimized. However, in some cases we could not prove that there was a difference in the energy consumption. We also find that the hardware used to run the programs has an influence on the energy consumption. We find that the runtime of a program correlates with the energy consumption, but a shorter runtime does not necessarily result in a lower energy consumption.