Just like the improved water and wind turbine, there should be an improved solar-based energy source, for example a solar tower.
The tower would be a multiblock consisting of tower pieces in the middle and mirrors placed around it. It would heat up gradually during the day. The speed of this process would be determined by the nuber of mirrors placed around the tower. Water could be circulated inside which would turn into steam much like in a steam boiler. This steam can then be extracted and used in the steam turbines to generate electricity.
The mirrors could be used around the solar distiller as well to speed up the distillation.