Consumers are adopting clean, flexible technologies such as smart thermostats, electric vehicles, and batteries at a rapid rate. Virtual power plants (VPPs) combine these technologies across participating customers to create a resource that can reduce, shift, or generate electricity when needed. By providing these services to the power system, VPPs can make significant contributions to grid reliability while directly compensating those consumers who participate. This presentation will introduce the concept of VPPs, describe their potential for facilitating affordable decarbonization of the power sector, and address barriers to deploying VPPs at scale.