This thematic report presents the various approaches and methodologies that address the challenge of estimating the energy consumption of the Bitcoin blockchain. Although the report is focusing upon the whole spectrum of consensus mechanisms, due to the high energy consumption of Bitcoin blockchain, only methodologies that analyse the energy consumption of the Bitcoin are available and thus, covered by the report.

Apart from the various diverse applications of blockchain technologies across several sectors ranging from finance and supply chain to the pharmaceutical and energy sectors, cryptocurrencies on the various blockchains are constantly under the spotlight. To also address the topic of cryptocurrencies, this report also deals with the topic of energy efficiency of the ICT infrastructure that is used for cryptocurrency mining.