We focus on exploring the opportunities related to blockchain in regard to three different types of energy communities i.e., industrial microgrid, apartment building and virtual community, as seen by a group of Finnish energy sector experts. To address the research problem, we first summarize results from literature for blockchain as an enabler for energy communities, discuss the technical aspects of blockchain and summarize the status of ongoing pilots and demonstrations around blockchain. Our results from empirical study among energy industry experts show that there clearly is potential for blockchain as an enabler especially of energy efficient use of resources, trading without intermediaries, load balancing, new business, automated functions and long-range in system valuable resources. Despite this potential, multiple gaps exist and future research on blockchain is still called for.