ABSTRACT
There has been a sharp rise of cost of energy with the decrease in water head. That is why during the past years, the high out put projects were preferably constructed on high and medium head sites. The availability of such sites being now reduced, the increased power demand requires to investigate possibilities of utilsing low head sites.
Bulb generating sets represent a successful step in the search for economical low head development. Axial machines are considered the best choice for increasing outputs and reducing excavation costs considerably due to their simplified forms and their smaller dimensions when compared to vertical kaplan machines of the same capacity.
The bulb turbine with an upstream generator is a direct result of the development for low head applications. It is now being substituted for the vertical Kaplan generating units under the lowest heads. The paper will briefly discuss the comparison in their designs and operating characteristics.
