Blockchain has been touted as the next big technological advance. But what does it mean for renewable energy? Essentially an online register that securely stores information, blockchain serves as a repertoire of knowledge accessible to everyone. Rather than being controlled by one entity, blockchain is spread across multiple computers and uses a form of data logging to ensure that the information cannot be changed or corrupted. By decentralizing data and protecting the way it is manipulated, blockchain promotes transparency and the sharing of information. As such, the record has immense potential in helping shape a wave of new technology and our ability to interact with it. Blockchain is far more than just a platform for cryptocurrency. Many startups are already using blockchain as a tool to make energy grids more accessible and sustainable. The idea behind creating energy grids linked to blockchain is fairly simple: by giving consumers total control over where they source their energy as well as the information behind the production itself it drives competition and promotes sustainable energy. Consumers using a smart-grid that relies on blockchain will be able to compare their energy providers and buy directly from them. In Estonia, a blockchain-powered smart grid called WePower has been testing just how well a choice-driven energy market could work by teaming up with an independent energy provider who shares their energy data in real time.