Comprehensive Overview of Power System Flexibility during the Scenario of High Penetration of Renewable Energy in Utility Grid

Increased deployment of variable renewable energy (VRE) has posed significant challenges to ensure reliable power system operations. As VRE penetration increases beyond 80%, the power system will require long duration energy storage and flexibility. Detailed uncertainty analysis, identifying challenges, and opportunities to provide sufficient flexibility will help to achieve smooth operations of power system networks during the scenario of high share of VRE sources. Hence, this paper presents a comprehensive overview of the power system flexibility (PSF). The intention of this review is to provide a wide spectrum of power system flexibility, PSF drivers, PSF resources, PSF provisions, methods used for assessment of flexibility and flexibility planning to the researchers, academicians, power system planners, and engineers working on the integration of VRE into the utility grid to achieve high share of these sources. More than 100 research papers on the basic concepts of PSF, drivers of the PSF, resources of PSF, requirement of the PSF, metrics used for assessment of the flexibility, methods and approaches used for measurement of flexibility level in network of the power system, and methods used for the PSF planning and flexibility provisions have been thoroughly reviewed and classified for quick reference considering different dimensions.

Assessment of the Working Performance of an Innovative Prototype to Harvest Hemp Seed in Two Different Conditions of Terrain Slope

After many decades when its cultivation was prohibited, hemp is regaining its position as one of the most versatile cultivated crops. Multiplication of monoecious hemp varieties requires manual male plants rouging to keep a high share of monoecious plants in the population. It forces relatively small multiplication fields usually oscillating around 5 ha, where the use of big harvesting machines is not economically feasible. The B-800 mower prototype for hemp panicles proved to be a good alternative to harvest seeds of tall fibrous hemp. The test results of the mower analyzed in this study show that although seed loss on a moderate slope (0.37%) was significantly higher than on a flat slope (0.13%), it was still much lower than in the case of harvesting hemp seed with a combined harvester. Moreover, the field efficiency of 93% is very satisfactory as it is reported for much bigger machines. Finally, the harvesting costs proved to be much lower than most of the machines used for harvesting hemp seed.

Impact of the first wave of COVID-19 on the employment of older people in Latvia, the Baltic States and Europe

The study bases on the SHARE Wave 8 COVID-19 Survey conducted in June-August 2020 in 26 European countries and Israel via CATI. The association between health status of older workers and their involvement into labour market in Latvia is the strongest in Europe. In the short term, the first wave of the infection outbreak affected the employment of older population in the Baltic States to much lesser extent than in most of participating countries. The proportion of those workers who experienced unemployment, lay-off or closure of business, as well as changes in the number of working hours was considerably lower than average values. The branches with traditionally high share of older workers (education, healthcare, agriculture, administrative services) were least affected by lockdown measures. Remote work from home in the Baltic States as well as combining work from home with usual work place was lower than the European average. The existing labour legislation in Latvia does not ensure sufficient protection of workers’ rights and health in the situation of remote work.

Renewables, Reliability and Efficiency in Electricity Markets

The choice to use electricity markets to transition to an ultra-high renewable electricity sector depends on whether a high level of reliability and efficiency can be achieved. This study presents a reliability, resiliency and adaptability policy framework for a liberalized power system with a high share of renewables. This framework provides policy insights regarding electricity market reliability and the implications of remuneration mechanisms for renewables. Our analysis shows that it is necessary to reconsider adequacy assessments of liberalized power systems, to enhance the definition of the loss of load probability, and to explicitly consider the probability that the market clears. Under these conditions, electricity markets can theoretically achieve reliability and efficiency with large percentages of variable and intermittent renewable resources with zero or near-zero marginal costs, and market and technical challenges can be addressed.

AGROENERGY EFFICIENCY OF IMPROVED TECHNOLOGIES FOR CREATION AND USE OF ALFALFA-CEREAL HAYMAKING IN THE NON-CHERNOZEM ZONE

On the basis of field experience in the creation of alfalfa-grass stands on sod-podzolic soil of the Non-Chernozem zone, a high agroenergetic efficiency of improved technologies has been established, including two zoned varieties of alfalfa changeable (Lugovaya 67 and Pastbishchnaya 88) in combination with agrotechnical methods (change in the composition of leguminous species in the previous period and pre-sowing inoculation of alfalfa seeds with complementary strains of Sinorhizobium meliloti). As a result of the application of the agro-energy method for assessing the production of exchangeable energy and total anthropogenic costs in uniform indicators according to the international SI system (GJ/ha), their payback was established — 8–11 times. This was achieved due to a high share of natural factors (88–91% of total costs), additional nitrogen input into the production process due to increased symbiotic fixation (141–171 kg/ha per year) and long-term use — for 7 years. The productivity of 1 hectare was 62–64 GJ/ha metabolic energy, the collection of protein was 956–1120 kg/ha, the saving of anthropogenic costs due to the exclusion of the use of nitrogen fertilizers was 17–21 GJ/ha.

CUSTOMS CLEARANCE OF ENERGY SOURCES IMPORTS

Background. The high share of imported energy resources in the structure of the fuel and energy complex reduces the level of energy security. Ukraine is 85% dependent on imports of petroleum products. In such conditions, it is important to ensure the effective functioning of the Energy Customs of the State Customs Service, which carries out customs control and clearance throughout the customs territory of Ukraine. The analysis of recent research and publications has shown that systematic studies of features of customs control and registration of energy sources are absent. However, scientists have studied the peculiarities of energy moving across the customs border in Ukraine and the EU, the problematic issues of customs formalities for goods moving across the customs border of Ukraine by pipeline. The aim of the article is to study and systematize information on customs clearance of energy sources in Ukraine, identify problematic issues and develop proposals to improve the efficiency of the Energy Customs of the State Customs Service. Materials and methods. The information base contains scientific publications of domestic scientists, normative-legal and legislative base of Ukraine. Methods of analysis and synthesis, scientific generalization and comparison of data from scientific sources are used. Results. The main tasks of the Energy Customs of the State Customs Service in ensuring the implementation of policy in the field of customs are analyzed. The analysis of dynamics of export-import operations with oil products on the market of Ukraine for 2011–2020 is carried out. Proposals have been developed to speed up and simplify customs control of oil products and increase the efficiency of the Energy Customs of the State Customs Service. Conclusion. To increase the efficiency of the Energy Customs, it is necessary to intensify work in the areas of: use of technical means of customs control, installation of weighing systems, introduction of express laboratories to strengthen control and reduce customs clearance time, purchase and use resources of leading price agencies to control customs value of oil products, use of oil products labeling for identification purposes.

SPECIALIZATION IN AGRICULTURE

The article summarizes the approaches to the definition of specialization in agriculture. The factors and conditions for the optimal location of agricultural production in the region are shown. Unlike the pre-reform period, when the main link in the specialization of agricultural production were collective and state farms, to a lesser extent - subsidiary farms of industrial enterprises, today territorial specialization at the level of municipal production volumes and create the necessary infrastructure for this. Specialization should be viewed as a process of structural changes in production, when resources are redistributed between the production of various types of products, new proportions are formed, in agriculture - primarily in land use. In this case, it is proposed to determine the specialization of municipal districts based on their contribution to the production of specific types of products in the region and average annual growth rates. Based on the ratio of these indicators, the following types of municipalities were identified in the areas of specialization - growth points (with a high share in the volume of production and high growth rates) and stagnating territories (when a high share in the volume is combined with low growth rates). Compiled maps of the specialization of agricultural production in the municipal districts of the Republic of Bashkortostan for today and for the future, for the period up to 2030. Determination of the specialization of agricultural production in municipal districts for the future, allows you to create the necessary infrastructure in them, taking into account the changed conditions, to make fuller use of the existing potential.

Legal Regulation of Hydrogen in Germany and Ukraine as a Precondition for Energy Partnership and Energy Transition

In August 2020, Germany and Ukraine launched an energy partnership that includes the development of a hydrogen economy. Ukraine has vast renewable energy resources for “green” hydrogen production and a gas transmission system for transportation instead of Russian natural gas. Based on estimates by Hydrogen Europe, Ukraine can install 8000 MW of total electrolyser capacity by 2030. For these reasons, Ukraine is among the EU’s priority partners concerning clean hydrogen, according to the EU Hydrogen strategy. Germany plans to reach climate neutrality by 2045, and “green” hydrogen plays an important role in achieving this target. However, according to the National Hydrogen Strategy of Germany, local production of “green” hydrogen will not cover all internal demand in Germany. For this reason, Germany considers importing hydrogen from Ukraine. To govern the production and import of “green” hydrogen, Germany and Ukraine shall introduce legal regulations, the initial analysis of which is covered in this study. Based on observation and comparison, this paper presents and compares approaches while exploring the current stage and further perspectives for legal regulation of hydrogen in Germany and Ukraine. This research identifies opportunities in hydrogen production to improve the flexibility of the Ukrainian power system. This is an important issue for Ukrainian energy security. In the meantime, hydrogen can be a driver for decarbonisation according to the initial plans of Germany, and it may also have positive impact on the operation of Germany’s energy system with a high share of renewables.