StatusThe thesis was presented on the 14 June, 2007
Approved by NCAA on the 20 September, 2007
Abstract– 0.18 Mb / in romanian
The basic scientific results regarding the research topic mentioned above are as they follow:
1. An analytical model of revenues and costs linked to the usage of low and medium size cogeneration units was developed. On the base of this model a specialized software for calculation of the cogeneration investments economic efficiency was elaborated.
2. A methodology of economic efficiency evaluation for the new sources of energy was designed.
3. To evaluate the feasibility of distributed energy sources the concept of reference power sources was proposed and the types and characteristics of these sources were defined.
4. For a cogeneration unit a method of total costs allocation between generated heat and power was elaborated. The method allows a non-discriminating treatment of the relevant two forms of energy and is based on the application of the cost ratios for the separate production of specific energies.
5. The carried out investigation showed that for the heat and power market conditions of the Republic of Moldova feasible are only the installations of cogeneration of 500kW and more, with the annual heat loading degree not less than 50%. In respect to wind installations, feasible are only those with capacity of 250kW and more. Solar PV installations of the coming decade are not feasible at all, while solar thermal units are competitive on the market and today.
6. For local networks encompassing distributed energy sources two indicators of quality of the network structure were identified and investigated, these are so called “branch-network“ multiplier (Км) and the structure index (m). The criteria has proven to be the most general criteria of technical and economic performance of the local power networks.
7. A property of the idealized, economically sized, engineering networks has been identified, regarding the existence of a multitude of line layouts, varying in many aspects – the structure, extension possibilities etc. but with similar low cost.