A constant renewable contribution can come from geothermal resources, some hydro schemes and sustainably supplied biomass; variable resources can also contribute to firm supply through geographic diversity, storage, interconnection and demand management. These examples refute the absolute “never.” They do not show that every renewable mix can economically supply an unchanged constant demand without additional resources. Baseload is a load/system service rather than an intrinsic virtue of one generator. Long low-wind periods and seasonal storage require energy-capacity accounting, while dispatchable clean systems may make an inflexible minimum-output plant less desirable.
