Огляд ринку сонячної енергетики України: стан та комерційні перспективи

Today, solar energy is called the energy of the future, and many companies make significant investments in the construction of such power plants. The article provides an overview of the commercial perspectives of this market, determines the size of investments and the return on the project. Modern solar panels are able to operate without additional investments for decades and, from the point of view of the authors, in the long term the electricity generated in this way will not only cost-effective, and extremely profitable. The global situation in the energy market and in the field of renewable energy, in particular, is considered. The reasons that triggered the development of renewable energy sources, the key of which are the dangers of nuclear energy and environmental pollution, are explained. Along with this, we consider the structure of the market of renewable energy sources in Ukraine, where the geographic location is favorable for the implementation of solar energy projects. The climate of Ukraine is characterized by a large number of sunny days: in terms of insolation, Ukraine is significantly superior to European leaders in solar energy. This basic factor allows us to talk about the commercial perspectives of solar power generation projects implemented in Ukraine. Against the background of these perspectives is considered the structure of the energy market in Ukraine and the investment attraction of renewable energy projects. Market trends in the development of the solar energy market were discussed, which are expected to contribute to the development of new market niches, such as after-sales services, as well as the transformation of existing business models against the backdrop of the introduction of new facilities.Сьогодні багато хто називає сонячну енергію енергією майбутнього, і багато компаній вкладають значні інвестиції в будівництво таких електростанцій. У статті наведено огляд комерційних перспектив цього ринку, визначені розміри інвестицій і окупність проекту. Сучасні сонячні батареї в змозі працювати без додаткових капіталовкладень десятки років і, з точки зору авторів, в довгостроковій перспективі електроенергія, згенерована таким чином, стане не просто рентабельною, а надприбутковою. У статті розглянута глобальна ситуація в сфері ринку енергетики і в сфері відновлюваних джерел енергії, зокрема. Пояснені причини, які послужили поштовхом у розвитку відновлюваних джерел енергії, ключовими з яких є небезпека атомної енергетики і забруднення навколишнього середовища. На ряду з зазначеним, розглянута структура ринку відновлюваних джерел енергії на Україні, географічне розташування якої сприятливо для реалізації проектів сонячної енергетики. Для клімату України характерна велика кількість сонячних днів: за ступенем інсоляції Україна значно перевершує європейських лідерів в сонячній енергетиці. Зазначене є базовим фактором, що дозволяє говорити про комерційні перспективи проектів сонячної електрогенерації, що реалізуються в Україні. На тлі зазначених перспектив розглянута структура енергетичного ринку на Україні і інвестиційна привабливість проектів відновлюваної енергетики. Обговорено ринкові тенденції розвитку ринку сонячної енергетики, які, як очікується, на тлі введення нових об'єктів сприятимуть розвитку нових ринкових ніш, таких як сервісне обслуговування, а також трансформації існуючих бізнес-моделей

Experimental evidence of ageing and slow restoration of the weak-contact configuration in tilted 3D granular packings

Granular packings slowly driven towards their instability threshold are studied using a digital imaging technique as well as a nonlinear acoustic method. The former method allows us to study grain rearrangements on the surface during the tilting and the latter enables to selectively probe the modifications of the weak-contact fraction in the material bulk. Gradual ageing of both the surface activity and the weak-contact reconfigurations is observed as a result of repeated tilt cycles up to a given angle smaller than the angle of avalanche. For an aged configuration reached after several consecutive tilt cycles, abrupt resumption of the on-surface activity and of the weak-contact rearrangements occurs when the packing is subsequently inclined beyond the previous maximal tilting angle. This behavior is compared with literature results from numerical simulations of inclined 2D packings. It is also found that the aged weak-contact configurations exhibit spontaneous restoration towards the initial state if the packing remains at rest for tens of minutes. When the packing is titled forth and back between zero and near-critical angles, instead of ageing, the weak-contact configuration exhibits "internal weak-contact avalanches" in the vicinity of both the near-critical and zero angles. By contrast, the stronger-contact skeleton remains stable

Spatially resolved microwave pulsations of a flare loop

A microwave burst with quasi-periodic pulsations was studied with high spatial resolution using observations with the Nobeyama Radioheliograph (NoRH). We found that the time profiles of the microwave emission at 17 and 34 GHz exhibit quasi-periodic (with two well defined periods P 1 = 14–17 s and P 2 = 8–11 s) variations of the intensity at different parts of an observed flaring loop. Detailed Fourier analysis shows the P 1 spectral component to be dominant at the top, while the P 2 one near the feet of the loop. The 14–17 s pulsations are synchronous at the top and in both legs of the loop. The 8–11 s pulsations at the legs are well correlated with each other but the correlation is not so obvious with the pulsations at the loop top. For this P 2 spectral component, a definite phase shift, P 2 /4 ≈ 2.2 s, between pulsations in the northern leg and loop top parts of the loop have been found. The length of the flaring loop is estimated as L = 25 Mm (≈34 ) and its average width at half intensity at 34 GHz as about 6 Mm (≈8 ). Microwave diagnostics shows the loop to be filled with a dense plasma with the number density n 0 ≈ 10 11 cm −3, penetrated by the magnetic field changing from B 0 ≈ 100 G near the loop top up to B 0 ≈ 200 G near the north footpoint. A comparative analysis of different MHD modes of the loop demonstrates the possibility of the simultaneous existence of two modes of oscillations in the loop: the global sausage mode, with the period P 1 = 14–17 s and the nodes at the footpoints, and a higher harmonics mode (possibly with the radial wave number l > 1), with P 2 = 8–11 s

Anatomy of point-contact Andreev reflection spectroscopy from the experimental point of view (review)

We review application of point-contact Andreev-reflection spectroscopy to study elemental superconductors, where theoretical conditions for the smallness of the point-contact size with respect to the characteristic lengths in the superconductor can be satisfied. We discuss existing theoretical models and identify new issues that have to be solved, especially when applying this method to investigate more complex superconductors. We will also demonstrate that some aspects of point-contact Andreev-reflection spectroscopy still need to be addressed even when investigating ordinary metals.Comment: 20 pages, 18 figs. V2: Ref.60 and footnote 3 are added, a number of minor fixe

Multiple Andreev Reflections in Weak Links of Superfluid 3He-B

We calculate the current-pressure characteristics of a ballistic pinhole aperture between two volumes of B-phase superfluid 3He. The most important mechanism contributing to dissipative currents in weak links of this type is the process of multiple Andreev reflections. At low biases this process is significantly affected by relaxation due to inelastic quasiparticle-quasiparticle collisions. In the numerical calculations, suppression of the superfluid order parameter at surfaces is taken into account self-consistently. When this effect is neglected, the theory may be developed analytically like in the case of s-wave superconductors. A comparison with experimental results is presented.Comment: 12 pages, 9 figures, RevTeX

A Discrete Version of the Inverse Scattering Problem and the J-matrix Method

The problem of the Hamiltonian matrix in the oscillator and Laguerre basis construction from the S-matrix is treated in the context of the algebraic analogue of the Marchenko method.Comment: 11 pages. The Laguerre basis case is adde