Abstract: Generally, hydropower investments involve impressive investment, large quantities of materials and work power. For each of them, there are several steps of development, from the first decision of considering the idea, to the practical put in function. One of the most important phases is the decision of the general solution of the construction.
Presently, there are considered the technical acceptance of the solution and the economic evaluation, based on the actualized investments principle. The paper proposes some other criteria to evaluate the investments opportunity and extension, in the context of the technical and operational necessities.
The criterion are presented in a general form and particularized for hydropower plants investments. There are special mentions for small or micro- hydropower.
All the scientific conclusions should be supported by laboratories experiences, practical confirmations or integrated and trusty measurements. The criterion efficacy is confirmed by a practical study of a rehabilitation work evaluation.

Brief Biography of the Speaker:
Mr. Alexandru Viorel POPESCU is the Director of Hydro Division of S.C. ENERGOMONTAJ S.A. Bucharest, the most important company in Romania developing production, design and research activities in energy field.
From 1983 until present, Ms. Popescu dedicates all his efforts to hydropower installations development, by his work in production and also by developing specific researches in cooperation with the most prestigious institutions form Romania and other countries (France, Austria, and Japan).
Besides the production and design work, Mr.Popescu is involved in scientific researches, publishing more the 10 articles, high level indexed, in different scientific reviews and conferences proceedings.
Presently, Mr. Popescu just finalized the doctoral thesis with the title: Criteria for the performance improvement of the hydro energetic investments. By this work, he is valuating his large technical and scientific experience.
One of the most important scientific contributions he has in the energy field is referred to the micro hydro plants construction and autoimmunization.