A rich ecosystem of blockchain-based projects has emerged since the introduction of Bitcoin in 2008. New protocols seek to improve the performances of blockchain systems. In particular, the energy consumption of blockchains has been particularly decried. Unfortunately, those new proposals are often evaluated with ad hoc tools and experimental environments. Therefore, reproducibility and comparison of these new contributions with the state of the art of blockchain technologies are complicated. To the best of our knowledge, only a few tools partially address the design of a generic benchmarking of blockchain technologies (e.g., load generation). This paper introduces BCTMark, a generic framework for benchmarking blockchain technologies on an emulated network in a reproducible way. Based on this novel framework, we studied a key aspect of modern blockchains' energy consumption: smartcontract execution. Based on experiments and the analysis of one year of real-world Ethereum transactions, we measured and modeled smart-contracts' energy consumption on Ethereum. Furthermore, this study details how the replication of contract calls execution can impact their energy cost. In particular, we give insights on the energy consumed by smart-contracts on Ethereum over one year.