CO HB1059

Defines "energy storage system" as commercially available technology that retains, stores, and delivers electricity through chemical, thermal, mechanical, or other means, excluding solar and wind energy facilities.

Adds "clean energy resource" and "energy storage system" to the definition of public utility for property tax purposes, treating them similarly to renewable energy facilities.

Requires the state property tax administrator to value energy storage systems and clean energy resources using methods similar to those applied to hydroelectric, wind, geothermal, biomass, and solar energy facilities.

Updates renewable energy facility definitions to include connected energy storage devices where the primary purpose is to store energy in valuations for wind and solar facilities.

Takes effect January 1, 2021, subject to referendum petition; requires consideration of energy storage nameplate capacity in addition to generation capacity when calculating renewable energy facility costs.