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 produce electricity for multiple subscribing customers who receive on-bill credits. The act also stipulates that the public utility must grant these credits according to rules set by the commission, which will oversee the implementation and enforcement of the act.

Additionally, the bill includes provisions for the transferability of on-bill credits among subscribing customers and allows them to assign their credits to nonprofit organizations or low-income energy programs. The public service commission is granted authority to adopt rules regarding bill credit rates, participation opportunities, and consumer protections, ensuring nondiscriminatory access to shared solar energy facilities. The act is set to take effect immediately upon passage and approval, with the commission required to establish rules within one year of the effective date.