Author explains a necessity of supply optimization to construction sites with small storage areas. This paper takes account of conditions existing in Poland. From among all factors discussed by the author, first of all, we should point at construction works on plots located in densely built-up areas, obtained by demolition of existing buildings, as well as a necessity of plots utilization after demolished buildings that technical conditions do not allow for further exploitation.

Current power grid and market development, characterized by large growth of distributed energy sources in recent years, especially in Europa, are according energy storage systems an increasingly larger field of implementation. Existing storage technologies, e.g. pumped-storage power plants, have to be upgraded and extended by new but not yet commercially viable technologies (e.g. batteries or adiabatic compressed air energy storage) that meet expected demands. Optimal sizing of storage systems and technically and economically optimal operating strategies are the major challenges to the integration of such systems in the future smart grid. This paper surveys firstly the literature on the latest niche applications. Then, potential new use case and operating scenarios for energy storage systems in smart grids, which have been field tested, are presented and discussed and subsequently assessed technically and economically.

The application of renewable energy sources poses the problems connected with output volatility. In order to decrease this effect the energy storage technologies can be applied, particularly fuel cells connected with hydrogen storage. In this paper the application of SOFC system for a household in Poland is proposed. Economic and technical analysis is performed. It was found that the proposed installation is profitable after 25 years of operation when compared with conventional solution - heat pumps and gas-fired boilers.

Considering concrete nonlinearity, the wave height limit between small and large amplitude sloshing is defined based on the Bernoulli equation. Based on Navier-Stokes equations, the mathematical model of large amplitude sloshing is established for a Concrete Rectangle Liquid-Storage Structure (CRLSS). The results show that the seismic response of a CRLSS increases with the increase of seismic intensity. Under different seismic fortification intensities, the change in trend of wave height, wallboard displacement, and stress are the same, but the amplitudes are not. The areas of stress concentration appear mainly at the connections between the wallboards, and the connections between the wallboard and the bottom.

Finite fossil fuel resources, as well as the instability of renewable energy production, make the sustainable management of energy production and consumption some of the key challenges of the 21st century. It also involves threats to the state of the natural environment, among others due to the negative impact of energy on the climate. In such a situation, one of the methods of improving the efficiency of energy management – both on the micro (dispersed energy) and macro (power system) scale, may be innovative technological solutions that enable energy storage. Their effective implementation will allow it to be collected during periods of overproduction and to be used in situations of scarcity. These challenges cannot be overestimated - modern science has a challenge to solve various types of problems related to storage, including the technology used or the control/ /management of energy storage. Heat storage technologies, on which research works are carried out regarding both storage based on a medium such as water, as well as storage using thermochemical transformations or phase-change materials. They give a wide range of applications and improve the efficiency of energy systems on both the macro and micro scale. Of course, the technological properties and economic parameters have an impact on the application of the chosen technology. The article presents a comparison of storage parameters or heat storage methods based on different materials with specification of their work parameters or operating costs.

Dr. Krzysztof Fic of the Poznań University of Technology discusses energy storage, aesthetic medicine’s quest for immortality, and how much time goes into being a scientist.

This study was executed to investigate the potential of agar-agar, a nontoxic and non-degradable

gelling agent, as a promising coating agent to improve and protect banana fruit

against fungal postharvest diseases i.e., crown, finger, neck and flower end rots which are

caused by fungal isolates of Colletotrichum musae and Fusarium moniliforme. Coated-ba-nana

fruit samples with different concentrations of agar-agar suspension particularly at

2.0 g · l−1 exhibited a significant reduction in incidence and severity of postharvest diseases

compared to untreated fruit. Banana fruits dipped in agar suspension at 2.0 g · l−1 for 5, 10

and 15 min showed significant reduction in disease incidence and severity. Moreover,

application of agar suspension as a coating agent at 2.0 g · l−1 significantly decreased

weight loss (%), firmness loss (%), and soluble solid concentration of banana fruit for

15 days at 25 ± 2°C. Scanning electron microscopy observation confirmed that the fruit

coated with agar colloid at 2.0 g · l−1 had significantly fewer cracks and showed smoother

surfaces than untreated fruit. This explains the quality improvement in agar-coated fruit

compared to uncoated fruit. Overall, agar colloid, a safe coating agent, could be used to

protect banana fruit against postharvest rot diseases and extend fruit storage life during

ripening and storage.

In the paper, the Reynolds transport theorem (RTT) for three phase systems is developed, in terms associated with a moving control volume. The basic tools applied to the derivation are the generalized transport theorem by Truesdell and Toupin, and generalized surface transport theorem by Aris as well as Slattery. The final results referenced to a generic extensive quantity demonstrate the theorem in the integral instantaneous form. As a further illustration of applicability of the theorem relation developed some specific forms are deduced from such as for multiphase systems in terms of fixed control volume, surface systems and homogeneous spatial systems.

The mathematical model that described the relationship between cell-count decay and storage time in fixed bacterioplankton samples from three Antarctic lakes of differing trophic status was determined after a one-year experiment. Bacterial density was estimated by epifluorescence microscopy. Cell count data fitted a negative exponential model in all three cases (p < 0.00001). However, the slopes of their curves were significantly different (p < 0.01), as well as the percentage of bacterial loss after a period of two months. This fact might be related to the limnological characteristics of the water bodies, though the individual genetic variability of their bacterioplankton should not be left aside. Original bacterial numbers in the samples could also be a reason of the differences observed in the pattern of decay in cell counts. Thus, applying a general decay function to any sample and assuming the idea that freshwater bacterioplankton samples can be stored for a two month-period before the bacterial counts decay, can lead to an erroneous estimation of bacterial numbers with direct consequences in ecological investigations.

The aim of the article is a preliminary assessment of the possibility of using ATES (Aquifer Thermal Energy Storage) technology for the seasonal storage of heat and cold in shallow aquifers in Poland. The ATES technology is designed to provide low-temperature heat and cold to big-area consumers. A study by researchers from the Delft University of Technology in the Netherlands indicates very favorable hydrogeological and climate conditions in most of Poland for its successful development. To confirm this, the authors used public hydrogeological data, including information obtained from 1324 boreholes of the groundwater observation and research network and 172 information sheets of groundwater bodies (GWBs). Using requirements for ATES systems, well-described in the world literature, the selection of boreholes was carried out in the GIS environment, which allowed aquifers that meet the required criteria to be captured. The preliminary assessment indicates the possibility of the successful implementation of ATES technology in Poland, in particular in the northern and western parts of the country, including the cities of: Gdańsk, Warsaw, Wrocław, Bydgoszcz, Słupsk, and Stargard.

The paper describes factors influencing the development of electricity storage technologies.

The results of the energy analysis of the electric energy storage system in the form of hydrogen are

presented. The analyzed system consists of an electrolyzer, a hydrogen container, a compressor, and

a PEMFC fuel cell with an ion-exchange polymer membrane. The power curves of an electrolyzer

and a fuel cell were determined. The analysis took the own needs of the system into account, i.e. the

power needed to compress the produced hydrogen and the power of the air compressor supplying

air to the cathode channels of the fuel cell stack. The characteristics describing the dependence

of the efficiency of the energy storage system in the form of hydrogen as a function of load were

determined. The costs of electricity storage as a function of storage capacity were determined. The

energy aspects of energy accumulation in lithium-ion cells were briefly characterized and described.

The efficiency of the charge/discharge cycle of lithium-ion batteries has been determined. The

graph of discharge of the lithium-ion battery depending on the current value was presented. The key

parameters of battery operation, i.e. the Depth of Discharge (DoD) and the State of Charge (SoC),

were determined. Based on the average market prices of the available lithium-ion batteries for the

storage of energy from photovoltaic cells, unit costs of electrochemical energy storage as a function

of the DoD parameter were determined.

The aim of this document is to present the topic of modeling district heating systems in order to enable optimization of their operation, with special focus on thermal energy storage in the pipelines. Two mathematical models for simulation of transient behavior of district heating networks have been described, and their results have been compared in a case study. The operational optimization in a DH system, especially if this system is supplied from a combined heat and power plant, is a difficult and complicated task. Finding a global financial optimum requires considering long periods of time and including thermal energy storage possibilities into consideration. One of the most interesting options for thermal energy storage is utilization of thermal inertia of the network itself. This approach requires no additional investment, while providing significant possibilities for heat load shifting. It is not feasible to use full topological models of the networks, comprising thousands of substations and network sections, for the purpose of operational optimization with thermal energy storage, because such models require long calculation times. In order to optimize planned thermal energy storage actions, it is necessary to model the transient behavior of the network in a very simple way – allowing for fast and reliable calculations. Two approaches to building such models have been presented. Both have been tested by comparing the results of simulation of the behavior of the same network. The characteristic features, advantages and disadvantages of both kinds of models have been identified. The results can prove useful for district heating system operators in the near future.

The paper presents results of research focused on modelling heat storage tank operation used for forecasting purposes. It presents selected issues related to mathematical modelling of heat storage tanks and related equipment and discusses solution process of the optimisation task. Presented detailed results were obtained during real-life industrial implementation of the optimisation process at the Siekierki combined heat and power (CHP) plant in Warsaw owned by Vattenfall Heat Poland S.A. (currently by Polish Oil & Gas Company - PGNiG SA) carried out by the Academic Research Centre of Power Industry and Environment Protection, Warsaw University of Technology in collaboration with Transition Technologies S.A. company.