No abstract

The present paper aims to highlight how the transition from tradition energy consumers to prosumers is being promoted in the European Union and what the actual status in Romania is. Starting from the main European policy pillars, the paper presents the rationale behind the transformation of consumers into prosumers.

This paper covers the hydrogen technologies regarding the role of hydrogen as an energy carrier and the possibilities of its production and use. It is initially presented the modalities and the efficiency of the current technologies of obtaining hydrogen, detailing its obtaining by the electrolysis of the water, the electrochemical efficiency and the specific consumption of electricity as well as the thermodynamics of the electrochemical processes. The following paragraph addresses hydrogen conversion possibilities. This paragraph details the thermodynamic analysis of the fuel cell, the external characteristic of the fuel cell and the types of fuel cell. The last paragraph addresses the possibilities of using the fuel cells for electrical vehicles and cogeneration systems for buildings.In this context, the traditional transport and distribution grid will have to adapt to the new realities as they will need to actively participate in the internal energy market by the transformation of the traditional electricity grid in energy flow, from unidirectional to bidirectional through the production of hydrogen offering the same facilities as the gas grid.

No abstract

In this paper, an analysis of different micro-CHP systems is made from the point of view of benefits and limitations of several prime movers used in micro-CHP systems: reciprocating engines, Stirling engines, micro steam and gas turbines and fuel cell systems. A comparison using the metrics and weighting factors is suggesting that the reciprocating engines and the Stirling engines are more appropriate for the micro-CHP. In another analysis, micro-CHP factors related to efficiency and thermal/electric power for different prime movers are compared. Micro-CHP systems with Stirling engine has the best score. The electric efficiency is better for micro-CHP systems with reciprocating engines, and Stirling engines are in the second place. The thermal efficiency is better for micro-CHP systems with Stirling engines followed by reciprocating engines. Stirling engines use an external heat source, which simplifies design, minimizes noise and vibration, and allow multi-fuel use. These features make the Stirling engine a promising alternative to the internal combustion engine.