Ensuring the security of power generation systems is a pillar of the proper functioning of each state. Energy security is fundamental to ensure both economic growth and social welfare. As energy storage has not developed in an efficient extent, covering the current and prospective power demand is a major challenge for transmission system operators. Moreover, the activities that are to be taken should be technically and economically justified and need to meet the requirements of environmental protection. Cooperation between neighboring countries in the field of electricity exchange is among the activities undertaken to ensure the safety of the power generation systems. The integration of electricity markets is one of the key challenges of the European Union’s energy policy. The European Commission issued a directive on interconnection, according to which the capacity of interconnections should total 10% of installed capacity until 2020 (and 15% until 2030) in each Member State. The main objective of this study is to assess the changes in electricity imports and exports in 2003–2018 and to investigate the current level of cross-border exchanges between Poland and the neighboring countries. This paper also answers the question of whether Poland will fulfil the obligations set by the European Commission. In addition, the paper presents the risks and the challenges related to fulfilling the mentioned commitments. The results of the study indicate that the development and modernization of network infrastructure in the field of cross-border exchange are necessary because, in the context of the forecasted increase in electricity demand, Polish generation units will not be able to meet the demand.
Power loss mechanisms in small area monolithic-interconnected photovoltaic modules (MIM) are described and evaluated. Optical and electrical losses are quantified and individual loss components are derived for loss mechanisms of small area radial (radius = 1 mm) pie-shaped six-segment GaAs MIM laser power converter. At low monochromatic homogeneous illumination (Glow = 1.8 W/cm2, λ0 = 809 nm) conversion efficiency of the cell, designed for a low irradiance, is reduced by 3.7%abs. due to isolation trench optical losses and by 7.0%abs. due to electrical losses (mainly perimeter recombination). Electrical losses in a device designed for a high irradiance, result in 18%abs. decrease of output power under homogeneous monochromatic illumination (Ghigh = 83.1 W/cm2, λ0 = 809 nm), while 11.6%abs. losses are attributed to optical reasons. Regardless the irradiance level, optical losses further increase if the device is illuminated with a Gaussian instead of an ideal flattop beam profile. In this case, beam spillage losses occur and losses due to isolation trenches and reflections from metallization are elevated. On top of that, additional current mismatch losses occur, if individual MIM’s segments are not equally illuminated. For the studied device, a 29 μm off center misalignment of a Gaussian shaped beam (with 1% spillage) reduces the short circuit current Isc by 10%abs. due to the current mismatch between segments.