Energy Balance Of System Research Articles

Database of hourly and daily sums of total radiation at Russian antarctic stations: analysis of changes in total radiation for the entire period of observations in Antarctica

Given the significant changes in the climate on the planet as a whole, databases and archives of data on the main climate-forming characteristics of the atmosphere, collected over long periods of time in various regions of the globe and, in particular, in the polar regions, acquire a special role. Total solar radiation is one of the most important parameters affecting the energy balance of the Earth-atmosphere system. We have created a database (DB) of hourly and daily sums of total radiation (Q) at the Russian Antarctic stations, designed to study the radiation regime of the Antarctic, from the beginning of actinometric observations to 2019. The information presented in the database was collected at five Antarctic stations — Bellingshausen, Vostok Mirny, Novolazarevskaya and Progress. The database has undergone a state registration procedure and is registered under No. 2020621401. The article gives a description of the structure of the DB and presents detailed information for each station. To provide an example of how database information can be used, characteristics of the total radiation in different parts of the Antarctic continent are obtained. Thus, it is found that the average monthly amounts of Q in the continental part of Antarctica on the high plateau (Vostok station) in conditions of minimal cloudiness and high transparency during the Antarctic summer are maximum and average 1240 MJ/m2. At the same time, at the tip of the Antarctic Peninsula (Bellingshausen station) during the same period, the average monthly amounts of Q due to the almost constantly present cloud cover do not exceed 570 MJ/m2. In the coastal areas at the three remaining stations, the average monthly amounts of total radiation range from 908 MJ/m2 (Progress) to 950 MJ/m2 (Mirny). Estimates of variability characteristics of daily, monthly, and annual sums of total radiation at all the five stations for the entire observation period up to 2019 were also obtained. The absence of statistically significant long-term trends in the annual and monthly sums of total radiation at all the stations under consideration was noted. The results of their analysis indicate that there are no significant changes in the inflow of total solar radiation to the Antarctic surface over more than sixty years of actinometric observations.

The Effect of Azimuth and Tilt Angle Changes on the Energy Balance of Photovoltaic System Installed in the Southern Slovakia Region

Energy balance of the photovoltaic system is influenced by many factors. In this article the effect of tilt and azimuth angle changes of the photovoltaic system energy production is analyzed. These parameters have significant impact on the amount of solar radiation which hits on the photovoltaic panel surface and therefore also on the energy absorbed by the module surface. The main aim of research was identification of the optimal position of photovoltaic system installation in the southern Slovakia regions. The experimental apparatus had two setups consisting of polycrystalline photovoltaic modules. The first setup was used for identification of the tilt angle changes in the range (0–90°). The second one was focused on the detection of the azimuth angle effect to the energy production. The measurement results were statistically processed and mathematically analyzed. Obtained dependencies are presented as two-dimensional and three-dimensional graphical relations. Regression equations characterize time relations between the tilt or azimuth angle and the energy produced by the photovoltaic system in Southern Slovakia. Obtained simplified mathematical model was verified by analytical model. Presented models can be used for the dimensioning and optimization of the photovoltaic system energy production.

Automatic shape detection of ice crystals

Clouds have a crucial impact on the energy balance of the Earth-Atmosphere system. They can cool the system by partly reflecting or scattering of the incoming solar radiation (albedo effect); moreover, thermal radiation as emitted from the Earth's surface can be absorbed and partly re-emitted by clouds leading to a warming of the atmosphere (greenhouse effect). The effectiveness of both effects crucially depends on the size and the shape of a cloud's particulate constituents, i.e. liquid water droplets or solid ice crystals. For studying cloud microphysics, in situ measurements on board of aircraft are commonly used. An important class of measurement techniques comprises optical array probes (OAPs) as developed since the 1970s [13]. While water droplets can be assumed as spherical, the shape and size of ice particles are highly variable. The currently used analysis methods to determine the particles’ size from OAP detection do rarely consider shape details or fine structures of ice particles, which may lead to artificial biases in the results.In this paper, we present two new computational analysis methods, combined in an hybrid approach, for an automatic classification of ice particles and water droplets. The first method computes the principal components of a cloud particle and uses them to determine an ellipse, which can then be used to filter for spherical particles. The second method uses convolutional neural networks (CNNs) for the classification of columns and rosettes, respectively. Although we currently only classify these two particle types with CNNs, the presented method can be easily adapted for the classification of other particle types. The particularity of our method is that we use a virtual data set to pre-train the networks, which are then further trained with a smaller amount of manually classified real cloud particles in a fine tuning step. We evaluated our models on a small data set of real cloud particles and in a final field test on OAP image data that was not previously classified. The precision of this field test was better than 81% and ranged up to 98%, demonstrating that the new methods are suitable for providing profound shape classifications of cloud particle images obtained by OAP measurements. All methods we describe in this paper have been implemented in Python and C and are fully open source. Code and documentation are available on Github (https://github.com/lcsgrlch/oap).

INVERSING GLACIER ALBEDO IN HIGH MOUNTAIN ASIA BASED ON SENTINEL-3 SATELLITE DATA

Abstract. Surface albedo, defined as the ratio of the upward to downward solar irradiance, is an important climate parameter in the surface energy budget. Among them, glacier albedo is the link between glaciers and the hydration process of climate and cold zones, and it is also an important factor restricting the development of distributed glacier energy-material balance model. Changes in the albedo of ice and snow can alter the energy balance of the entire geo-gas system and can also cause local and even global climate change. Glaciers in High Mountain Asia have experienced heterogeneous rates of loss since the 1970s. The positive feedback effect of ice and snow makes its albedo an important indicator of ice and snow surface mass balance. This study used partly Sentinel-3 level-1b data of High Mountain Asia in 2017, RGI (Randolph Glacier Inventory) 6.0 and SPP (Snow Properties Processor) developed by the ESA’s team to extract the region's mountain glacier albedo in SNAP (Sentinel Application Platform) environment. At present, the products of the whole year of 2017 have been produced, with a time resolution of one month and a spatial resolution of 300 m.

Life cycle assessment and energy comparison of aseptic ohmic heating and appertization of chopped tomatoes with juice

The energy balance and life cycle assessment (LCA) of ohmic heating and appertization systems for processing of chopped tomatoes with juice (CTwJ) were evaluated. The data included in the study, such as processing conditions, energy consumption, and water use, were experimentally collected. The functional unit was considered to be 1 kg of packaged CTwJ. Six LCA impact assessment methodologies were evaluated for uncertainty analysis of selection of the impact assessment methodology. The energy requirement evaluation showed the highest energy consumption for appertization (156 kWh/t of product). The energy saving of the ohmic heating line compared to the appertization line is 102 kWh/t of the product (or 65% energy saving). The energy efficiencies of the appertization and ohmic heating lines are 25% and 77%, respectively. Regarding the environmental impact, CTwJ processing and packaging by appertization were higher than those of ohmic heating systems. In other words, CTwJ production by the ohmic heating system was more environmentally efficient. The tin production phase was the environmental hotspot in packaged CTwJ production by the appertization system; however, the agricultural phase of production was the hotspot in ohmic heating processing. The uncertainty analysis results indicated that the global warming potential for appertization of 1 kg of packaged CTwJ ranges from 4.13 to 4.44 kg CO2eq. In addition, the global warming potential of the ohmic heating system ranges from 2.50 to 2.54 kg CO2eq. This study highlights that ohmic heating presents a great alternative to conventional sterilization methods due to its low environmental impact and high energy efficiency.

Main processes affecting global average surface temperature

<p indent=0mm>Since the industrial revolution, the greenhouse effect caused by greenhouse gas emissions has led to an increase in the net radiative forcing on the Earth’s surface, and the global mean surface temperature (GMST) has continued to rise, accompanied by multi-time scale oscillations including inter-annual decadal and multi-decadal oscillations. Changes in GMST, which reflect the integrated response of the climate system to the combination of external radiation forcing and internal natural variables, are one of the key indicators for understanding the impact of human activities on global climate change. Previous studies have basically determined the contribution of major physical modes of the global surface temperature, such as the El Niño-Southern Oscillation (ENSO), the Pacific Decadal Oscillation (PDO) and the Atlantic Multidecadal Oscillation (AMO) based on Empirical Orthogonal Function (EOF) method. In addition to the above climate modes, the physical processes affecting GMST changes also include volcanic eruptions, observation data system errors and so on. Based on the above research progress and these two basic assumptions (there is no long-term changing trend due to factors such as natural variabilities, volcanic eruption events, or system error of observation equipment; a single event does not affect the remotely related structure of the main physical mode), EOF decomposition is applied to the surface temperature of ERSST v3b and HadISST v1.1 ocean observation data in this paper, so as to obtain the TR warming trend item with ENSO, PDO and AMO removed, and thus, by using Ensemble Empirical Mode Decomposition (EEMD) method, to break down each TR time series into components on multiple different time scales and summarize them into low frequencies, high frequency and trend items. The land and ocean data (HadCRUT.4.6) are used to compare ocean data (ERSST v3b and HadISST v1.1) results and conduct a statistical analysis on the errors introduced by EMD methods. This study found that the main physical processes affecting changes in the GMST include global warming caused by the anthropogenic greenhouse gas emissions, the cooling effects caused by aerosols, the internal variables in the global climate system, the system errors caused by changes in the observing system, data noise, and other factors that have not yet been identified. Based on ERSST V3b and HadISST v1.1 observational data, this study also analyzed and determined the impact and contribution of each factor to GMST changes. This could be a key step to identify the effects of human activities and natural variability on global climate change. There are two main conclusive contributions in this paper. One contribution was to quantify the time scale and intensity of the impact of volcanic eruptions on GMST. We estimated the impact of five major volcanic eruptions since 1950 (Agung, 1963; Merapi, 1974; St. Helens, 1980; Pinatubo, 1991; Nabro, 2011). The cumulative effects of these five major volcano events in ERSST and HadISST approximately caused global warming to slow down by 0.32−0.47 and 0.45−0.67°C, respectively. Another major contribution is to find that the TR item of GMST still has a recent global warming mitigation phenomenon after the removal of the three major climate models, that is, there are some processes in the Earth’s climate system that are different from the above three physical models, which could significantly affect the TR changes. Therefore, global warming tends to slow down (warming hiatus). In modern climate conditions, anthropogenic radiative forcing continues to increase, and the heat absorbed by the global climate system continues to increase during global warming hiatus period. That is, even if the amount of heat energy used to heat up the surface of the global surface reduced, this “reduced” amount of heat still remains in the climate system, such as the mid-deep ocean. The results further underscore the necessity for understanding the critical physical processes that lead to global warming from the perspective of the energy balance of the climate system.

Regional flow motion and heat energy balance analysis of a 10,000 class pharmaceutical cleanroom with secondary return air conditioning system

• Cleanroom with the secondary return system was modeled with airflow and energy network. • The air change rate has a notable influence on the mean age of air globally and locally. • The air change rate has a small effect on contaminant removal effectiveness and air change efficiency. • Promotion of return air volume in the occupied area could reduce local pollutant concentration levels; • Computational fluid dynamics procedure was validated by the on-site measurements. Improving air quality in occupied area has always been the core focus of ventilation design in cleanrooms. A 10,000 class pharmaceutical cleanroom, with secondary return system, was firstly introduced. Full computational fluid dynamics procedure validated by on-site measurements was then applied to model such cleanroom airflow and particle transport. Energy balance of this ventilation system was also analyzed. Details of room airflow and contaminant fields for the specific zone (above the device and around the human body) were subsequently analyzed concerning the effect of delivering ventilation flow rate and return air volume. Representative parameters, mean age of air, contaminant removal effectiveness, and air change efficiency at the occupied zone and the whole space were evaluated. Results demonstrate that promotion of the return air volume in the occupied area could appropriately reduce pollutant concentration level. Moreover, an increase in ACH (air change rate per hour) did not always shorten the local age of air near the equipment. For a large ACH, it not only will raise the dust around the machine again, it will also cause uncomfortable flow draft. Additionally, when ACH = 20 h − 1 and 25 h − 1 were achieved respectively, the age of air was reduced by 32% and 21.4% in the whole room and further done by 31.1% and 23.5% in the occupied zone; with identical changes, room air change efficiency (RACE) was achieved at 49.3 % and 50.4 %, respectively. It shows that the increase of ACH seems to have little effect on the air change efficiency. When ACH increases from 15 h −1 to 20 h −1 , the efficiency of pollutant removal at the occupied zone will not be significantly improved ( ε = 1.78).

Geomechanical analysis of formation deformation and permeability enhancement due to low-temperature CO2 injection in subsurface oil reservoirs

Several benefits of CO2 injection are reported in the literature such as its ability to mitigate greenhouse gas emissions and the increase in oil recovery at a low cost. However, the correlated reservoir-engineering problems with low-temperature CO2 injection including formation damage and leakage risk are still uncertain and has not been comprehensively investigated. This research examines the effect of low-temperature CO2 on lowering of formation breakdown pressure, and the associated formation damage from a geomechanical prospective. This study presents the coupling of the equilibrium stress equation, the system energy balance equation, continuity equation, and saturation equation to develop thermoporoelastic model for the reservoir rock. We determined the cooling-induced formation damage due to decrease in temperature and thermal stresses, formation contraction and tensile stresses, and examine its effects on formation properties, stresses, joint and fracture stability. We observed that low-temperature CO2 would create a low thermal stress region and thus the formation could fail in tension. This process might increase formation permeability but it would decrease the stability of reservoir, basement and caprock. We analyzed several factors affecting formation deformation such as injection rate for both miscible and immiscible CO2 flooding, formation porosity, depth, temperature, and formation breakdown pressure. We also compared our results and findings with experimental data, finding excellent match and similar consequences. Furthermore, as a sequence of low-temperature CO2 injection, the initial formation breakdown pressure was initially at 2560 psi and it reduced to 1928 for immiscible case and 1270 psi for miscible case in the selected case study. We also propose that shallow reservoirs should be avoided for CO2 capture and storage because of stability issues.

Identification of Suitable Biomass Torrefaction Operation Envelops for Auto-Thermal Operation

Auto-thermal operation of biomass torrefaction can help avoid additional heat investment and the associated costs to the system. This work provides a general method for relating the feedstock-specific parameters to the energy balance and pre-diagnosing the potential of auto-thermal for different biomass torrefaction and pyrolysis systems. Both solid and gas thermal properties under various torrefaction conditions and their influences to the torrefaction system energy balances are considered. Key parameters that influence the process auto-thermal operation are analyzed, which include torrefaction reaction heat, torrefaction conditions, drying method, biomass species, and inert N2 flowrate. Equations of torgas and biomass higher heating values (HHVs), as well as the torrefaction reaction heat at different operating conditions are developed. It is found that torgas and biomass HHVs increase with torrefaction temperature and biomass weight loss. Torrefaction reaction heat has a linear relationship with the biomass weight loss, with a positive slope at 250–260°C, and a negative slope at 270–300°C, which indicates that torrefaction shifts from endothermic to exothermic at ∼270°C. Applying advanced drying technology and avoiding the use of N2 can help the system achieve auto-thermal operation at lower torrefaction temperature and residence time, thus leading to a higher process energy efficiency and product yield. This is the first work to relate the micro level element changes of biomass to the macro level process energy balances of the torrefaction system. This work is important in design and operation of the torrefaction system in both pilot and industrial scales to improve process efficiency and predict product quality in a reliable and economic manner.

Impact of wind and solar power plants on the reliability of the IPS

One of the most promising areas in the development of the electric power industry is generally regarded to lie in expanding the share of renewable energy sources (RES) in the electric energy balance of power systems in the form of wind and solar power plants (WPP and SPP), the saving of organic fuel (coal, gas, fuel oil) and the reduction of environmentally harmful emissions into the atmosphere considered to be their most important advantages. However, the impact of RES on the controllability of the modes of operation of electric power systems and on the reliability of the IPS operation remains quite unexplored.Currently, the global energy industry uses 318 million kW of WPP and about 142.4 million kW of SPP, of which the major West European countries account for about 227 million kW, or 49.3%. On average, wind and solar power plants account for almost 30% of the total generating capacity in Western Europe, with Denmark having the largest share of WPP (47%) and Germany having the highest share of SPP (18.6%). However, an uncontrolled growth in the share of WPP and SPP in the structure of generating capacities of power systems begins to manifest itself in a sharp decline in the reliability of the power industry due to the fact that a number of negative properties of WPP and SPP have not been taken into account (at least, to a sufficient extent), which manifested themselves in practice in a system accident in the UK power system that occurred on August 09, 2019, when, as a result of an "ordinary" short circuit, a system accident occurred, with up to 1.1 million consumers with a total load of 1690 MW disconnected from the power supply system for a period of 15 to 45 minutes. This is estimated to have resulted in economic losses for consumers amounting to 12.3–15.0 million USD.The reason for this is that the high sensitivity of WPP, SPP, CCGT and gas piston units to voltage and frequency drops is not properly considered in conditions of insufficient capacity of the rotating (mobile) generation reserve. Damage can be prevented by increasing the rotating reserve within the available reserve of the power system, which will require an increase in funds for maintaining the same due to additional fuel consumption. The ratio of reduction of probable damage to consumers and the cost of additional fuel consumption for maintenance of a required rotating reserve in the power system allows to economically substantiate the strategy and scale of introduction of renewable energy sources to the power industry.

Nocturnal passive cooling by transpired solar collectors

A novel use of the commercially available transpired solar collector is presented in the current paper. The reliable solar air heating system loses heat to the night sky if mounted on a building roof so it can be used as a passive cooling system based on thermal radiation. The collector plate cools down below ambient temperature and has the potential to cool the air as it is drawn through the perforations by a fan. A model has been elaborated for the cooling process based on heat transfer between the system components and energy balance equations. A method has been developed in order to choose the most suitable equivalent sky temperature model, as the radiative heat flow to the sky is the driving force of the cooling process and thus its accuracy is of utmost importance. The model has been validated by a series of field measurements carried out using a 5 m2 setup in Edirne, Turkey. It has been found that the collector plate cools down up to 4.3 K below ambient temperature and it has the potential to cool air by up to 4.0 K. The system reached a maximum cooling performance of 66.5 W/m2, while the average cooling performance was 34.6 W/m2. It has been found that the collector plate cools down below ambient temperature an hour before sunset and does not reach ambient until one hour after sunrise under clear sky. A new Nusselt number correlation has been developed for the convection heat transfer between a perforated plate and the transpiring air flow.

Improving two-stage thermophilic-mesophilic anaerobic co-digestion of swine manure and rice straw by digestate recirculation

The anaerobic co-digestion (coAD) of swine manure (SM) and rice straw (RS) is appealing for renewable energy recovery and waste treatment worldwidely. Improving its performance is very important for its application. In this study, long-term semi-continuous experiments were conducted to evaluate the improving effects of digestate recirculation on the performance, energy recovery, and microbial community of two-stage thermophilic-mesophilic coAD of swine manure (SM) and rice straw (RS). The experimental results indicated that the coAD systems of SM and RS (mixing ratio of 3:1) with or without digestate recirculation could not realize phase separation. The reactors of both coAD systems were characterized by pH values ranging from 7.74 to 7.85, methane production as 0.41 ± 0.02 and 0.44 ± 0.03 L/L/d, and stable operation. Notably, digestate recirculation increased total methane production, organic matter removal, and reaction rate of the coAD system by 9.92 ± 5.08, 5.22 ± 1.94, and 9.73–12.60%, respectively. Digestate recirculation improved the performance of the coAD by significantly increasing the abundance of Methanosarcina (from 4.1% to 7.5%–10.7% and 35.7%) and decreasing that of Methanothermobacter (from 94.2% to 87.3%–83.6% and 56.8%). Thus, the main methanogenesis pathway of the coAD system was changed by digestate recirculation and the methane production was effectively improved. Although the energy input of the coAD system increased by 30.26%, digestate recirculation improved the energy balance of the total system by 6.83%.

Дослідження теплового балансу світлопрозорих конструкцій

Проаналізовано розвиток нормативних документів України щодо енергоефективності стосовно євроінтеграційних процесів. Із врахуванням теплового балансу будівлі виділено ряд конструкцій та систем, які мають безпосередній вплив на цей параметр. Досліджено вплив базових параметрів світлопрозорих конструкцій у варіантах, які найчастіше зустрічаються у практиці, на їх тепловий баланс.

Algorithm for maintaining the energy balance of the power supply system of the earth remote sensing spacecraft under critical operating conditions

In this paper, we consider the problem of maintaining the energy balance of the power supply system of the Earth remote sensing spacecraft in critical operating conditions with the most intense cyclogram of the spacecraft operation, the maximum state of degradation of energy sources and storage devices, as well as with the minimum time to replenish useful energy.The problem of maintaining balance is formulated as a problem of nonlinear mathematical programming with functional constraints. Goal of the work is improving the efficiency and survivability of the remote sensing spacecraft and maintaining the energy balance of the power system in critical operating conditions by transferring the storage devices of the accumulating subsystem of the spacecraft to a given level of charge in the minimum charge time. An algorithm for controlling the accelerated charge of the rechargeable battery with the analysis of the Nickel-hydrogen battery temperature and its time derivative is developed.in some cases, the rechargeable battery replenishment time was reduced by 12−20%. The proposed algorithm for maintaining the energy balance can be used to select the stages of the accumulating subsystem charge current and transition from the current stage to the next one in a minimum time, providing flexibility in managing the modes of electricity storage with the adaptation of the charging current profiles to changing critical operating conditions.

Phase Shift of Planetary Waves and Wave–Jet Resonance on Tidally Locked Planets

Abstract Recent studies found that atmospheric superrotation (i.e., west-to-east winds over the equator) on tidally locked planets can modify the phase of planetary waves. But a clear relationship between the superrotation and the magnitude of the phase shift was not examined. In this study, we re-investigate this problem using a 2D linear shallow-water model with a specified uniform zonal flow. We find that the degree of the phase shift is a monotonic but nonlinear function of the strength of the mean flow and the phase shift has two limits of -π and +π. The existence of these limits can be explained using the energy balance of the whole system. We further show that a resonance between the Rossby wave and the mean flow occurs when the speed of an eastward jet approaches to the westward phase speed of the Rossby wave, or a resonance between the Kelvin wave and the mean flow happens when the speed of a westward jet approaches to the eastward phase speed of the Kelvin wave. The resonance mechanism is the same as that found in the previous studies on Earth and hot Jupiters. Moreover, in the spin-up period of a 3D global atmospheric general circulation simulation for tidally locked rocky planet, we also find these two phenomena: phase shift and wave–jet resonance. This study improves the understanding of wave–mean-flow interactions on tidally locked planets.

Modeling Evapotranspiration of Winter Wheat Using Contextual and Pixel-Based Surface Energy Balance Models

HighlightsThree contextual-based (CB) and two pixel-based (PB) models were evaluated to estimate ET of rainfed winter wheat.Instantaneous available energy estimation and ET upscaling impacted model performance.The CB models performed better at instantaneous and daily scales compared to the PB models.ET estimation biases increased during low vegetation and drier conditions, especially for the PB models.Abstract. Surface energy balance (SEB) models based on thermal remote sensing data are widely used in research applications to map evapotranspiration (ET) across various landscapes. However, their ability to capture ET from winter wheat remains underexplored, especially in practical applications such as integrated resource management and drought preparedness. Investigating winter wheat ET dynamics is important in agricultural regions such as the Southern Great Plains of the U.S., where winter wheat is extensively cultivated. The goal of this study was to evaluate the performance of five fully automated SEB models, three contextual-based (CB) and two pixel-based (PB), in estimating instantaneous and daily ET of winter wheat by comparing the model results with flux tower observations. The CB models included Surface Energy Balance Algorithm for Land (SEBAL), Mapping Evapotranspiration at high Resolution with Internalized Calibration (METRIC), and Triangular Vegetation Temperature (TVT). The PB models included Surface Energy Balance System (SEBS) and Two-Source Energy Balance (TSEB). Model evaluation during two winter wheat growing seasons (2016-2018) using 28 Landsat images showed that the instantaneous ET estimates from METRIC and TSEB had the smallest (RMSE = 0.14 mm h-1) and largest (RMSE = 0.27 mm h-1) errors, respectively. At the daily scale, SEBAL was the best performing model (RMSE = 1.0 mm d-1), followed by TVT (RMSE = 1.1 mm d-1), METRIC (RMSE = 1.2 mm d-1), SEBS (RMSE = 1.3 mm d-1), and TSEB (RMSE = 1.5 mm d-1). Overall, the CB models provided smaller errors than the PB models. Larger errors in daily ET estimation were observed during low vegetation and drier conditions, especially for the PB models. Keywords: Flux tower, Landsat, Southern Great Plains, Water use.

ANALYSIS OF THE POWER BALANCE OF THE TECHNOLOGICAL SYSTEM FOR GRINDING AGRICULTURAL PLANT WASTE

Despite some decisions approved by the Government of Ukraine to address the problems of efficient and environmentally sound solid waste management, in particular those that accumulate as a result of economic activity of the agro-industrial complex of the state, their practical implementation of measures declared by the Government is currently low. levels. Among a number of deterrents, the main ones include: lack of centralized recycling facilities and economically accessible for small facilities technical and technological base of waste processing, ineffective environmental control and the necessary management practices. However, vegetable waste is not always used, although it is a valuable raw material that can be used as a raw material for the production of fuel pellets, which will significantly reduce the energy dependence of the enterprise. An integral part of the technological cycle of processing plant residues into fuel briquettes is the preparation of biomass for briquetting in order to ensure the required particle size. Given the strategic importance of the formation of material and technical base to ensure highly efficient processing of agricultural waste of plant origin, as well as high energy consumption, which marks the traditional preparation of biomass for briquetting, there is a need for research to solve the problem of energy efficient grinding of structurally heterogeneous materials. high moisture content, which determines the relevance of the article. Thus, in order to achieve high efficiency of the process of grinding waste of plant origin, promising ways to reduce the energy consumption of this process based on the energy balance of the vibratory crusher rotor type and analysis of relationships between elements of the structural block diagram of the energy balance of the technological system "Vibration-rotor crusher - the processed environment ".

Energy balance and performance assessment of PV systems installed at a positive-energy building (PEB) solar energy research centre

The energy balance and performance of all Photovoltaic (PV) systems installed at Fotovoltaica/UFSC solar energy laboratory (www.fotovoltaica.ufsc.br) in Florianópolis, Brazil (27° S; 48° W) were demonstrated over time, from Aug/2017 to Feb/2020. The laboratory was designed as a zero-energy building (ZEB) with PV systems installed on rooftops and façades, not maximising annual generation, but to achieve a compromise between aesthetic appeal and the energy output. Further PV systems were installed on the same site in the shapes of a carport, an electric bus (eBus) shelter and charging station, and different ground-mounted PV systems fixed at latitude tilt and single-axis tracking. Monthly analyses were carried out during the period, such as the solar irradiation availability on site, changes in the number of building occupants, the increase of installed capacity of PV systems, and energy generation and consumption. With 111 kWp, the total PV generation in the period could supply 148% of building energy needs and 97% of the Fotovoltaica/UFSC Laboratory (building plus eBus). However, there were some downtime events in certain PV systems due to R&D activities, which affected total energy production. If systems had operated at their optimal performance all the time, the laboratory could have generated 38% more energy, which means 134% of building plus eBus consumption. Therefore, the Fotovoltaica/UFSC Laboratory can be considered not only a ZEB, but a positive-energy building (PEB). The issues discussed in this paper apply not only to the particular case-study presented; they demonstrate the potential of BIPV in enabling energy positive buildings.

Energy Balance of a Continuous Structural Health Monitoring System based on Energy Harvesting

The Structural Health Monitoring (SHM) may be a relevant technique to monitor historical buildings, masonry, bridges, etc. It becomes even more important if it can be applied in a continuous way, once incorporated in a Wireless Sensor Network (WSN), being able to provide data in an automatic and endless mode without any human intervention. Of course, WSN needs a power source, a role prevalently held by batteries. However, this solution has several issues: it is not eco-friendly and needs a periodic replacement hence increasing costs and reducing the SHM spread. The Energy Harvesting (EH) is a very promising technique to supply WSN. It converts the environmental energy into electrical energy allowing its local accumulation, within the sensor node, in supercapacitor or rechargeable batteries. Anthropic environments are plenty of energy (photovoltaic, kinetic, etc) but this is a non-continuous source and then an energy balance could highlight the suitability of an EH solution. This work is aimed to present a clear picture of EH for SHM by considering all the previous elements in the context of cultural heritage. The result is the definition of specific applications in which those WSNs, based on EH, could be competitive with respect to more traditional technologies.

Technical, Financial, and Environmental Feasibility Analysis of Photovoltaic EV Charging Stations With Energy Storage in China and the United States

This study assesses the feasibility of photovoltaic (PV) charging stations with local battery storage for electric vehicles (EVs) located in the United States and China using a simulation model that estimates the system's energy balance, yearly energy costs, and cumulative CO2 emissions in different scenarios based on the system's PV energy share, assuming silicon PV modules, and 5 kWh of storage capacity. Results show that systems located in commercial or office parking lots and used for charging EVs during working hours can be a feasible solution in all locations from a technical, financial, and environmental perspective in comparison with not only gasoline-fueled vehicles but also with grid-only charging. PV shares of 50% and 75% are achievable in all locations with PV array sizes in the order of 1–1.5 kWp, whereas a 100% PV share is possible but might result in high system costs. Scenarios with PV charging and local storage show emissions reductions of 60%–93% in the USA and 28%–93% in China compared with a gasoline-fueled vehicle.