The "Montana Solar Shares Act" establishes a framework for shared solar energy facilities in Montana, distinguishing shared solar customers from net metering customers. The bill defines key terms such as "on-bill credit," "shared solar energy facility," and "subscribing customer," and outlines the requirements for public utilities to interconnect these facilities to their distribution systems. It mandates that shared solar energy facilities must have a generating capacity between 50 kilowatts and 5 megawatts and must provide on-bill credits to at least two subscribing customers within the same service territory. The act also stipulates that the public utility must grant on-bill credits based on the proportion of electricity generated for each subscribing customer.

Additionally, the bill grants the Public Service Commission the authority to implement and enforce the provisions of the act, including establishing rules for bill credit rates, participation opportunities, and consumer protection. The commission is required to adopt these rules within one year of the act's effective date. The act is designed to promote the use of shared solar energy while ensuring safety, reliability, and equitable access for all customer classes. It will take effect immediately upon passage and approval.