Maritime decarbonization requires propulsion systems that are low-emission and dynamically suitable for repeated short-route operation. This paper presents a route-inspired, time-domain power-balance assessment of proton exchange membrane fuel cell (PEMFC)-based hybrid architectures for a 1.80 m prototype catamaran. A real ferry operating context in the Suez Canal region was translated into a representative 15 min prototype operating cycle repeated over an 8 h operating window. Three cases were evaluated under the same DC-bus load basis: Case 1, PEMFC + Battery; Case 2, PEMFC + PV; and Case 3, PEMFC + PV + Battery. The PEMFC-battery calculations were based on DC-bus power balance, converter, battery-current, and SOC equations, while the PV contribution was calculated using a shipboard PV power model with PVGIS seasonal irradiance and temperature inputs. The results show that Case 1 eliminates repeated startup deficits through battery support, whereas Case 2 reduces PEMFC loading but cannot remove startup deficits without an energy buffer. Under the best seasonal PV input, July, the PV peak reached 84.88 W, and the PV-used energy in Case 2 was 399.64 Wh. Case 3 increased the utilized PV-bus energy to 450.87 Wh, maintained the final SOC at 0.90, and removed the repeated transient deficits under the adopted ideal power-balance assumptions. Therefore, the PEMFC + PV + Battery architecture is selected as the preferred configuration for the next experimental prototype phase.
Journal:Acta Historica Universitatis Klaipedensis
Volume 21 (2010): Klaipėdos krašto aneksija 1939 m.: politiniai, ideologiniai, socialiniai ir kariniai aspektai = The 1939 Annexation of Klaipėda Region: Political, Ideological, Social and Military Issues, pp. 175–187
Abstract
The key topics discussed in the article are related to the dating of the commencement of construction of Kriegsmarine coastal defence and antiaircraft (Flak) artillery batteries in Memel (Klaipeda). The author argues that the most important goal of Kriegsmarine was to protect the port entrance channel from attacks or blocking from the sea. Therefore, the period of March 1939 to the early 1940 discussed in the article could have been used to build fortifications for coastal defence batteries. Stationary fortifications for Flak batteries around the city could have been built in a later period. Until then, temporary emplacements for Flak guns could have been constructed in the surrounding areas. Field research data on Tauralaukis Flak battery gave more credibility to the presumptions presented in the article. Some shell remains revealed ammunition marks stating that this ammo was made in 1941.