Blockchain constitutes a technological breakthrough, spanning across diverse sectors, eliminating the need for intermediaries in peer-to-peer transactions and revolutionising the way information is stored, verified, and shared in a decentralised, transparent and secure manner. To validate and ensure the security, transparency and integrity of transactions, cryptocurrencies, one of Blockchain’s main applications, rely on consensus mechanisms, such as Proof-of-Work. This verification method consumes vast amounts of energy, sourced in most of the cases from fossil fuels, thus contributing to the increase of greenhouse gas emissions. The global shift toward a more sustainable and zero-carbon future has not left the cryptocurrency community unaffected, as the mining industry has been under scrutiny for its excessive power consumption with miners examining diverse ways to green their operations. This thesis studies cryptocurrencies, and more specifically Bitcoin, with a clear objective to investigate its energy consumption, environmental and energy impact, as well as the challenges and opportunities arising from this technology amid global efforts to sustainability and greenhouse gases reduction. Furthermore, this research goes beyond the widely studied carbon footprint, offering a comprehensive assessment of Bitcoin’s ecological impact by also examining electronic waste, water and land usage, as well as air and noise pollution. At the same time, it studies the positive aspect and capabilities of cryptocurrency mining and its emerging solutions, including renewable energy integration, energy-efficient consensus mechanisms, and innovative concepts for balancing demand and supply.