Linear Multiuser Receivers for Asynchronous MC-CDMA Systems

Publication in the conference proceedings of EUSIPCO, Antalya, Turkey, 200

Control experiences and energetic optimization studies for a series hybrid electric vehicle

Among the research and development subjects of ENEA, an important theme is the study of innovative vehicles, of electric and hybrid-electric type, with high energy efficiency and low emissions. This paper deals with features and working methods throughout the roll bench testing of the ENEA hybrid Daily, a 6m series hybrid developed by ALTRA, IVECO and ANSALDO, equipped with a controller developed in collaboration between ENEA and University of Pisa, to evaluate the real effectiveness of different control algorithms in achieving significant fuel economy improvements. Two testing campaigns were performed, the first one at fixed generator and storage conditions, according to a number of European, American and Japanese urban driving cycles, the second one according to a fixed urban driving cycle, at different working conditions for generator set-point and storage state-of-charge. Results obtained during the first campaign, reported in previous papers and here partially resumed, demonstrated that it is possible to reduce fuel consumption with respect to the conventional version of the same vehicle. The second testing campaign demonstrated the need to correctly manage the battery state-of-charge, because of the great reduction in battery charging-discharging efficiency due to high current condition typical of HEV and the negative influence that high SOC levels demonstrated on motorgenerator operations. Starting by the experimental data, it was also possible to obtain an input-output energetic model of the system that enables us to find the generator operating points that match minimal specific fuel consumption for each value of the power average demand

Cost effective power-to-X plant using carbon dioxide from a geothermal plant to increase renewable energy penetration

In the framework of a scenario with an always increasing share of generation from variable renewable sources, the need for systems able to store energy or to convert the excess generation into useful goods is becoming of paramount importance. While several projects and pilot plants deal with direct energy storage or with the conversion of the excess generation into other energetic goods (hydrogen or methane) often overlooking economic considerations, this paper proposes a cost-effective approach in which liquified methane and oxygen are produced and sold on their specific markets, which represents one of the first profitable Power-to-X applications at current market values. The paper presents the completely new and never investigated before idea of coupling the plant with a freely available source of pure carbon dioxide from a geothermal unit, thus making it possible to produce synthetic methane to be liquefied, stored and then used in other sectors of the society. The carbon dioxide coming with the geothermal fluid is no longer released in the environment as it currently naturally happens even when not going through the geothermal facility. Detailed models of the main system components were created, and an optimization procedure was carried out. Interestingly, the revenues from the sale of liquefied oxygen are well above those coming from synthetic methane and turn the system profitable. With a proper operation planning, bidding on the electricity day-ahead-market, a large hydrogen storage system proved to be unnecessary. The results of the system optimization clearly show that this kind of systems, although conceived in a very favourable condition, can become profitable only if the energy storage function is coupled with the production of other goods services. Assuming an average electricity price of 52 €/MWh, the plant profitability is achieved for an LNG selling price of 0.45 €/kg and an LOx price around 0.30 €/kg. These figures will rapidly decrease in the near future as lower electricity prices are forecasted