Engineering and economic features of grid solar energy in Russia

The results of works on designing, mounting, and testing a grid-connected photovoltaic station based on thin-film tandem photovoltaic modules with a peak power of 2 kW are presented. Approaches and methods to analyze such stations, as well as techniques for constructing similar objects and payback mechanisms, are described. The role and site of electric energy storage units entering into a grid solar power plant are considered.     

Study of doped higher manganese silicides crystals by transmission electron diffraction and electron backscatter diffraction

The microstructure of Al-, Ge-, and Mo-doped higher manganese silicide crystals (HMS), grown by the Bridgman method have been investigated by transmission electron diffraction, electron backscatter diffraction, scanning electron microscopy, and X-ray energy-dispersive spectrometry. It is shown that the matrix crystal has the Mn₄Si₇ structure. The introduction of Ge and Mo impurities into an HMS crystal results in the precipitation of Si-Ge solid solution and molybdenum disilicide. The size of precipitates varies in a wide range: from several nanometers to several hundreds of micrometers. The following orientation relationships between Ge-Si precipitates and the Mn₄Si₇ crystal were determined: (112) $[\bar 110]$ Ge-Si ‖ (010)[100] Mn₄Si₇. Polycrystalline MoSi₂ precipitates form a multicomponent texture along the [001] Mn₄Si₇ direction. Small amounts of cubic MnSi and Al-Mn-Si alloy precipitates were revealed. In addition, Al oxide was observed mainly in crystal pores. It is shown that 0.5–0.8 at % Al, 0.4–0.6 at % Mo, and 1.5–2.0 at % Ge impurities are incorporated into the Mn₄Si₇ lattice.