Decrease Energy Costs Research Articles

Long-term price guidance mechanism for integrated energy systems based on gated recurrent unit - vision transformer prediction and fractional-order stochastic dynamic calculus control

Against the backdrop of global climate change, renewable energy (RE) performs significant effects in reducing carbon emissions. Nevertheless, volatile RE sources disrupt the energy supply-demand balance (ESDB) in the energy market. Flexible energy (FE) can effectively mitigate the problem with high flexibility and controllability. FE sources are widely distributed in integrated energy systems (IESs). However, existing methods guide scattered FE in IESs with insufficient accuracy. To accurately guide FE, this study proposes an improved long-term price guidance mechanism (ILPGM) based on gated recurrent unit (GRU)- vision Transformer (ViT) prediction and fractional-order stochastic dynamic calculus (FSDC) control. The ILPGM combines GRU and ViT for baseline load forecasting and applies the FSDC method. The ILPGM can optimize the energy consumption of IESs and promote the ESDB while decreasing energy costs. The ILPGM is applied to the IES at Arizona State University-Tempe. The experimental results indicate that: the average coefficient of determination of electrical and heat energy under ILPGM is 97.69 %, realizing flexible regulation of energy consumption; the ILPGM can save 26.36 % actual cost and 94.62 % potential cost savings for the IES; compared to the previous long-term price guidance mechanism, the ILPGM provides an additional 5.87 % total cost savings and 28.65 % potential savings.

Energy-efficient heat pump-assisted pre-concentration integrated with sequential [EMIM][BF4] and ethylene glycol-based extractive distillation for enhanced recovery of ethanol and isopropyl alcohol from wastewater

Recovering ethanol and isopropyl alcohol (IPA) from wastewater offers significant economic and environmental advantages. In this work, 1-ethyl-3-methylimidazolium tetrafluoroborate ([EMIM][BF4]) and ethylene glycol (EG) are proposed as double entrainers for separating IPA/ethanol/water mixtures. The novel process sequentially uses [EMIM][BF4] to separate ethanol/water and IPA/water azeotropes, followed by EG for near-boiling mixture of ethanol/IPA. Energy-economic comparisons of extractive distillation process using single and double entrainers are performed. To address the issue of high water content in mixtures, the heat pump-assisted pre-concentration (HPP) integrated with extractive distillation processes are proposed. Subsequently, the effect of water content in the mixtures on process performances are analyzed. The results indicate that compared to using a single entrainer [EMIM][BF4] or EG process, the double entrainers process reduces energy cost and total annual cost (TAC) by 19.9% to 45.3% and 18.6% to 52.7%, respectively. The HPP scheme effectively reduces the mole fraction of water from 60% to 26.05%, further decreasing energy costs by 4.2% to 22.2%. The energy cost and TAC of the double entrainers process decreases by 4.8% to 50%, and 2.8% to 52.1% compared with the single entrainer process under HPP schemes. The double entrainers [EMIM][BF4]-EG process shows promising prospects from energy and economic perspectives.

Socio-techno-economic-environmental investigation of scenarios-based combination sources of green energy system - A case study in Spain

The importance of development, generation, enhancement, and integration of renewable energy sources into the current energy network is excellent; however, the successful implementation of these technologies highly relies on the appropriate regulations, type of application, and the careful consideration of social-economic-technical-environmental analysis. In this research, the PRISMI Plus toolkit, which has been proven as a powerful toolkit in PRISMI projects for islands, the dataset provided by the municipality, and the update of the Sustainable Energy Action Plan were utilized for effective techno-economic analysis, comparing the flexibility of renewable energy systems including photovoltaic and wind turbines and planning of renewable energy scenarios of “Onda” town, in eastern Spain. The examined scenarios consist of a baseline scenario, a 50 % share scenario, and a 100 % share scenario. The baseline scenario entails no change in emissions or new installations of renewable energy resources. In contrast, the 50 % share and 100 % reduction in emissions are achieved through the installation of suitable-sized renewable energy sources, respectively. In scenarios 2 and 3, Electric Vehicles (EVs) are considered to be restricted to smart charging functionality only, and no Vehicle-To-Grid (V2G) is allowed. Based on the techno-socio-economic assessment, the second scenario has a more extensive technical capability to investment ratio compared to the other scenarios. Therefore, the 50 % share scenario is considered more worthwhile. This hypothetical situation has the potential to decrease energy costs by as much as 10 %, diminish relying on fossil fuels for electricity production, confine Greenhouse Gas (GHG) emissions, generate employment opportunities at the local level, and guide the municipality towards the ideals of a sustainable and energy self-sufficient city. Although similar research has been done for other cities, the novelty of this research is in the health consideration.

The Impact of Building Morphology on Energy Use Intensity of High-Rise Residential Clusters: A Case Study of Hangzhou, China

Building operations account for a large amount of energy use and CO2 emissions, and the morphology of buildings in residential clusters strongly impacts energy efficiency performance. However, little research has focused on the morphology and energy electricity usage of high-rise residential clusters in hot summer and cold winter (HSCW) regions. We investigated 96 residential clusters in Hangzhou, China, and established a corresponding morphology database. Additionally, we obtained annual electricity consumption for 16 of these residential clusters. With this database, we performed optimization of morphological parameters upon energy use intensity (EUI) using a genetic algorithm (GA). Specifically, the cooling, heating, and lighting EUIs of high-rise residential clusters were studied. After implementing the optimized morphological parameters, there was a reduction of up to 7.73% in EUI. According to regression analysis, the average aspect ratio was the most significant factor influencing EUI (r = −0.907), followed by floor area ratio (r = −0.755), average orientation (r = 0.502), and average number of floors (r = −0.453). These results indicate that a higher intensity of land development with a greater floor area ratio, average aspect ratio, and average number of floors can reduce total energy consumption. Additionally, we found that an average building orientation of southwest 15° (with respect to south) is optimal. The findings of this study can assist urban planners and designers in developing more sustainable residential clusters, leading to decreased energy costs and CO2 emissions.

Achievements and problems in studying the mechanism of thermal potential transfer regulation between liquids

The relevance of the study is determined by its focus on one of the key problems of the Ukrainian economy, namely the problem of energy resources, which is a necessary step in the development of resource management and planning strategies in the context of modern challenges and instability in the energy market. The purpose of the study is to determine the hydrodynamic and mass-heat transfer characteristics of the process of mixing liquids with different thermal potentials, and to investigate the influence of design factors on the intensity and efficiency of the flow jet. Experimental methods were used to specify the hydrodynamic and mass-heat transfer parameters of the liquid mixing process, and modelling was used to analyse the influence of design factors and develop a scientifically based methodology for calculating new device designs. An approach is obtained that allows solving two problems simultaneously: to decrease energy costs through their rational operation and to reduce environmental pollution, avoiding harmful emissions that occur during fuel combustion. The functional scheme of the test stand is described, the research methodology is presented, and statistical modelling of the influence of parameters on the length of the liquid jet is carried out. Studies of the energy efficiency of the initial stage of the interaction of thermal potentials during the generation of a liquid jet in a recuperative heat exchanger of mixed action to ensure storage conditions and potential movement in front of the nozzle are presented. A mathematical model for describing the length of a continuous water jet when flowing out of the nozzle is proposed and an analysis of the laminar flow of liquid from the nozzle is performed. The length of the continuous water jet when flowing out of the nozzle is determined and the technical capabilities of the process are identified. The efficiency of installing the tip in front of the nozzle for creating turbulent mixing and the method of controlling the water supply during the mixing of thermal potentials are determined. To control the water supply process, a step-by-step method has been developed that allows gradually increasing or decreasing the length of a continuous water jet through the nozzle. The results of the study provide an opportunity to optimise heat exchangers and mixing machines to increase their efficiency and productivity

Renovation of an Academic Building’s Envelope, Lighting, and Air Conditioning System According to Thailand Building Energy Code for Energy Consumption Reduction

This study evaluated the feasibility of building renovation with regard to the aspects of economy and energy. An academic building located in Bangkok, Thailand was selected for a case study. Four sub-systems, namely, the building envelope, lighting system, air conditioning unit, and electrical system, were renovated. From the energy perspective, Thailand’s Building Energy Code was used as an evaluating standard, and the BEC software (Version 2.6.0) was employed for the calculations. The economic feasibility of the renovation was determined on the basis of the internal rate of return and discounted payback period. It was demonstrated that the renovation can result in a reduction in the annual energy consumption of the entire building by up to 55.44%. In regards to economic feasibility, the renovation project can achieve a payback period of 4.98 years with 20.89% IRR. In addition, the renovation of a building can lead to spare capacity of the transformer for electric vehicle charger loads. Thus, the renovation of an old building into an energy-efficient building in compliance with building code can afford benefits both in terms of electricity consumption reduction and decreased energy cost for the project owner and provide opportunity for the building to support future load.

An Examination of Households’ Attitudes towards Renewable Energy Source Investments in Lower Silesian Voivodeship

This study presents findings from an empirical investigation into households’ decisions to further invest in renewable energy sources (RES). In the Lower Silesian Voivodeship, the survey gathered responses from 300 single-family homeowners who had already invested in RES. Notably, household income emerged as a significant influencer, with higher income levels correlating to a greater inclination for RES investment. Surprisingly, owning photovoltaic batteries was associated with reduced intent for further RES investment, potentially indicating contentment with prior outcomes. Moreover, many respondents reported decreased energy costs post-RES investment, underscoring its economic viability. Nonetheless, results also revealed a perceived shortfall in government financial support, suggesting a need for more effective support mechanisms. Economic factors, including financial accessibility and perceived profitability, were pivotal drivers for RES investment. Policy interventions should account for these factors to bolster green energy adoption, particularly for low-income households. Future research should probe the reasons behind perceived government support insufficiency and discern the roles of different forms of financial assistance. These endeavors could refine policy frameworks and invigorate energy transition efforts. In conclusion, the study highlights households’ keen interest in RES investment in the Lower Silesian Voivodeship. Household income stood out as a critical determinant, underlining economic factors’ sway over investment decisions. An intriguing observation was that prior photovoltaic battery ownership might temper enthusiasm for future RES investments. Most respondents experienced energy cost reduction, reinforcing RES benefits, though calls for improved government support remain. Economic considerations drive RES investment and warrant policy attention. Future research could probe the causes of perceived support shortfalls and untangle financial aid impacts for more targeted approaches to energy transition.

Predicting Silica Deposition from Superheated, Pressurized Steam Using Numerical Modeling of Nucleation, Agglomeration and Deposition

A model that can be used to quantify silica deposition from superheated depressurized steam is developed. Classical nucleation theory, agglomeration and deposition onto a wall are combined in a numerical model that calculates the concentration profile, the particle size distribution and the deposition in a flow through a pipeline after a sudden increase in supersaturation. The work presented here is an important step in understanding the mechanisms governing precipitation from supercritical and superheated steam as produced by deep geothermal wells drilled in magmatic areas. The power potential in such systems can be significantly higher than for conventional systems if utilized efficiently. The presented results can be applied to improve industrial designs and decrease energy costs. The model predicts the amount of precipitation along a pipe at various supersaturations, and the resulting deposition velocity in a straight pipe correlates fairly well with recent experimental results. There is a high number of nanocolloids formed close to the pressure reduction position, where deposition is at its maximum. Downstream, larger agglomerates develop, and deposition decreases as the number of particles and the overall concentration decreases. The local maximum deposition rate increases with increasing supersaturation. The calculations show that deposition mechanisms are as important as the chemical process of solidification when estimating where and how most material will be deposited. The rapid formation and deposition of solids predicted indicate that depressurization along with solid capture could be used to rid fluid of silica.

Real-time rolling-horizon energy management of public laundries: A case study in HSB living lab

Energy Management Systems (EMSs) play a vital role in managing energy consumption for both utilities and consumers. By using EMSs, utilities can influence on energy usage and ensure a more reliable and efficient grid operation, while consumers can make informed decisions about their energy consumption, leading to significant cost savings and reduced environmental impact. In this paper, a real-time rolling-horizon model is developed for managing energy consumption in public laundries aiming at minimizing energy costs, peak demand, and CO2 emission under the traditional Energy-Based Tariff (EBT) and the Power-Based Tariff (PBT). The developed model can not only reduce energy costs, peak demand, and CO2 emission by optimal task scheduling for washing machines and tumble dryers but also ensure users' preferences for a comfortable lifestyle. To demonstrate the effectiveness of the proposed EMS, several simulations were performed under different scenarios using real data and by a realistic case study in HSB living lab demonstration site. The simulation results reveal that implementing the proposed EMS can significantly decrease energy costs and peak demand in public laundries by 13.59% and 39.40%, respectively, when using the PBT tariff. However, the reduction in energy costs and peak demand is negligible when using the EBT tariff. Likewise, the results indicate that using the EMS and changing tariffs have a minimal impact on CO2 emissions reduction.

Optimal scheduling and management of pumped hydro storage integrated with grid-connected renewable power plants

Pumped hydro-energy storage will become a fundamental element of power systems in the coming years by adding value to each link in electricity production and the supply chain. The growth of these systems is essential for improving the integration of renewables and avoiding dependence on fossil fuel sources, such as gas or oil. This paper presents the modeling and application of an optimal hourly management model of grid-connected photovoltaic and wind power plants integrated with reversible pump-turbine units to maximize the monthly operating profits of the energy system and meet electricity demand. The techno-economic dispatch model is formulated as a mixed-integer optimization problem. To assess the proposed model, it is applied to a Spanish case study system, and the results are obtained for an entire year. The combination of renewable energy and pumped hydro energy storage reduces energy dependence by decreasing energy costs by 27 % compared with a system without storage to satisfy the required electricity demand. The findings confirm that storage plays a key role in energy transition to ensure the security and stability of power systems with a higher share of renewable generation.

Electrochemical Oxidation of Furfural on NiMoP/NF: Boosting Current Density with Enhanced Adsorption of Oxygenates.

Substituting the low-value oxygen evolution reaction (OER) with thermodynamically more favored organic oxidation such as furfural oxidation reaction (FOR) is regarded as a perspective approach to decrease energy cost of hydrogen evolution from water splitting. However, the kinetic of FOR can be even more sluggish than OER under large current density. In this work, a strategy is proposed to accelerate FOR by enhancing the adsorption of oxygenates on active sites. Over the prepared NiMoP/NF anode, only 1.46V versus RHE is required in furfural solution to achieve 500mA cm-2 , significantly better than the OER activity over commercial RuO2 /NF under the same current density (1.57V vs RHE).

Simulation and multi-objective optimization of Claus process of sulfur recovery unit

Although natural gas can provide energy with minimum greenhouse gas emissions compared to other fossil-derived fuels, the sulfur removal is the major challenge associated with its use in various applications. In this work, sulfur recovery unit was simulated using the Aspen HYSYS. The environmental, energy, and economic analyses of the process based on special criteria (profit (PBT), weighted global warming potentials (WGWP), and energy consumption (NQ)) were analyzed. After consideration of the sensitivity analysis of the process, the single and multi-objective optimizations were carried out by integrating the HYSYS simulations with MATLAB codes with the Genetic Algorithm method. Feed temperature, feed molar flow rate, combustion air temperature, and reboiler temperature are decision variables in this work. The results show that with increasing the feed temperature, the energy consumption decreases, so, the cost of energy decreases. Also, with increasing the feed temperature, and reduction of consumed energy, the equivalent CO2 emission (which is calculated based on total energy consumption) reduces, so, WGWP decreases. Maximization of PBT, Minimization of WGWP, and Minimization of NQ were considered as the single objective optimizations, separately. Optimum values of decision variables were found. For multi-objective optimization, three different cases were considered: Case 1 (Max. PBT and Min. WGWP), Case 2 (Max. PBT and Min. NQ), Case 3 (Min. WGWP and Min. NQ). In all these cases, it can be found Pareto optimal frontier. The results show that the feed molar flow rate and air combustion temperature variables have more effect than other variables.

Waste Water Heat Recovery Systems types and applications: Comprehensive review, critical analysis, and potential recommendations

One of the most effective ways to deal with the effects of the current global energy crisis is to reduce energy consumption and rely energy management strategies. As a result, waste heat/energy recovery might be a helpful option for decreasing energy costs and environmental effect. It entails finding a practical way to apply any engineering system’s wasted heat where the percentage of wasted heat is too high in global. In this context, waste hot water is a rich source of wasted energy that, if recovered, can significantly cut down on the amount of electricity used worldwide. Within this framework, the present research paper provides a thorough analysis of Waste Water Heat Recovery Systems (WWHRS) in terms of performance, design, tools and applications. In addition, it is highlighting the key elements associated with WWHRS, including the wastewater sources and approaches used in the literature for waste water heat recovery. Moreover, the present paper demonstrates the effect of the heat recovery from the drain waste water on economically and discuss the technical barriers to using WWHRS. It will be demonstrated that the feasibility of recovering heat from waste water could decrease significantly the cost of energy consumption for residential or industrial application. In addition, the main tools that are used for heat recovery systems is the heat exchanger where various types are used and the thermal performance are strongly affected by the choice of heat exchangers. Moreover, based on the literature review, it is shown that the methods of studying the thermal performance of the heat recovery system are experimental and/or numerical and in some cases the study is performed analytically. Finally, all discussed and presented studies demonstrate that the WWHRS has a significant benefits and could be considered for new residential construction.

Comparative study of regular and smart grids with PV for Electrification of an academic campus with EV charging.

The current global greenhouse gas (GHG) emission rates will increase the average global temperature by 1.5°C by 2050. This will be detrimental for organisms and ecosystems, as well as human well-being. Many countries have pledged to halve their emissions by 2030 and reach net zero targets by 2050. Optimum generation of electricity from sustainable green sources and its use to charge electric vehicle (EV) batteries will solve this problem to greater extent. The best places to capture solar energy, use it to meet load demand and charge EV batteries are the large open car parking areas near retail stores, academic institutes, industrial areas, and offices. This study targets the open parking areas of an academic campus (King Saud University, Riyadh) to meet the load demand of 25,000 kWh/day with a peak load of 4180kW and charging the batteries of parked EVs. Four system designs, simple grid, standalone photovoltaic (PV), simple grid and PV, and smart grid and PV, are compared. Currently, the cost of energy (COE) of the grid is US $ 0.085 in KSA. In comparison, the COE of standalone PV is almost 4.5 folds higher and in simple grid with PV, it is around 58% higher. However, a renewable penetration of 53.8% is achieved. In the third option, smart grid with PV, the COE is 24% lower compared to the base case. A 54.3% of the total energy produced is sold back to the grid, and the total renewable penetration of 77.7% is achieved. To observe the effect of energy sale limit on project parameters, the sensitivity analysis is performed. It can be observed that with a 1MW increase in the limit, the COE decreases by around 20% and net present cost (NPC) by around 6%. The proposed models for the solar car parks can be used elsewhere with similar climatic conditions.

Изменения биомеханики у пациентов с гонартрозом при внутрисуставном введении протеза синовиальной жидкости «Гиапро»

Introduction Deforming osteoarthritis is the most common articular disease, with gonarthrosis accounting for a quarter of the patients aged 50 years and over. The disease is associated with impaired function, pain, disability, reduced quality of life and requires total joint replacement in severe cases. There is no clear understanding of the causes of the disease, however, the pathogenesis is well studied. Intra-articular injection of synovial fluid prostheses including hyaluronic acid is one of the approaches to restore the properties of synovial fluid. Stabilometry that is a rare use in orthopaedics, and no use in this aspect was added to the traditional treatment effectiveness assessment. The objective was to explore biomechanical changes in patients with Kellgren-Lawrence grade II-III gonarthrosis who underwent a series of three knee injections of synovial fluid prosthesis over a period of 6 months. Material and methods An open prospective non-comparative study was performed for 30 patients with unilateral gonarthrosis at a mean age of 60 (56; 63) years. The effect of intra-articular injections of a sterile mannitol heat-stabilized biopolymer synovial fluid prosthesis on the biomechanics was evaluated in two samples using WOMAC score (overall and ≥ 30). Biomechanics was assessed in the form of stabilometry. Standardized stabilography and questionnaires were used at 3 follow-up visits: at 0 month (before administration), at 3 and 6 months. Results General sample showed no cases of true drift of the stabilogram parameters, decreased area of the statokinesiogram, and the WOMAC ≥ 30 sample demonstrated an additional improvement in the speed parameters of vertical oscillation at 6 months, a decreased area of the statokinesiogram at 3 months and at 6 months, decreased energy costs at 6 months (p < 0.05). Discussion Positive changes in stabilometry indicated a decreased pain and fatigue reactions in a vertical static position in gonarthrosis during the treatment. Most effects were statistically significant in moderate and severe dysfunction and pain. Intra-articular injection of synovial fluid prosthesis objectively improved the physiometric parameters of the support reaction. Conclusion Three intra-articular injections of a synovial fluid prosthesis based on mannitol-stabilized hyaluronic acid used in gonarthrosis Kellgren-Lawrence grade II-III showed improved body posture parameters of maintaining upright posture and reduced energy consumption in moderate and severe knee pain according to dynamic stabilometry for at least 6 months.

AHHO: Arithmetic Harris Hawks Optimization algorithm for demand side management in smart grids

Energy management strategies are crucial to efficiently scheduling appliances and preventing peak generation due to increased energy demand. It is essential to manage the demand and supply of energy based on the consumer’s consumption patterns using various heuristic optimization techniques. Additionally, the end-user is more concerned with minimizing electricity costs and reducing peak-to-average ratios (PARs). This work proposes an arithmetic Harris hawks optimization (AHHO) as a new approach for improving the Harris hawks algorithm to optimize residential demand response (DR) load management in a smart grid. Our method employs arithmetic and lightweight flight operators based on the Lévy flight distribution to generate diverse design solutions and improve the HHO’s exploration capabilities. We consider 15 smart appliances and categorize them based on how much energy they use, computing the electricity price using real-time pricing (RTP) and critical peak pricing (CPP). While maintaining user satisfaction within operational and power limits, the objective is to decrease energy costs and PAR. We evaluate the effectiveness of our proposed AHHO approach against nine cutting-edge algorithms using both RTP and CPP schemes. The findings demonstrate that our suggested approach performs better than the other algorithms because it achieved cost savings of 42.10% and 30% under RTP and CPP schemes, respectively. Meanwhile, it also reduced PAR by 55.17% and 50% under RTP and CPP schemes, respectively.

Multi-objective optimization of integrated energy systems based on demand response

ABSTRACT The implementation of demand response (DR) in the operation optimization of the integrated energy system has become one of the research hotspots worldwide with the rapid development of the energy network. Integrated gas-electricity system (IGES) operators can allocate different energy carriers more rationally and decrease energy cost and exergy input considering the DR scheme. However, DR was mainly applied to electric power systems in the past, while natural gas systems were less considered. In this paper, based on the theory of price-elasticity, and simultaneously with the consideration of the DR for end-user (EDU) of electricity and natural gas, the optimization model of the IGES is established, which includes two objective functions, the minimum operating cost of the integrated system and the maximum EDU satisfaction. The constraints include compressors and gas storages in the natural gas system, coal and gas generator units in the electric power system, Pow to gas units, and EDU gas/electric load changes. Subsequently, the proposed model is employed for an integrated 7-node natural gas system and 6-node power system with the sensitivity analysis for operating cost. The results demonstrate that the implementation of DR brings specific economic benefits to the operation of the entire system, the total operating cost is reduced by 16.6%, and the natural gas load is reduced by 89.9%. The implementation of DR balances the 24-hour load, reduces the fluctuation of the EDU load, increases the efficiency of the load shifting, and alleviates the instability of upstream production and transportation.

MELANIN: THE PHILOSOPHICAL STONE OF MOLECULAR BIOLOGY AND ITS IMPLICATIONS ON DISSOLVED OXYGEN LEVELS IN WATER AND FERTILITY OF AGRICULTURAL SOIL

Two fundamental problems now are: the growing contamination of water throughout the world, and the progressive loss of fertility of agricultural soil. The lack of revenue is a significant impediment to financing water. Water pollution is a key part of the climate change. Unless the water sector addresses efficiently the challenges inhibiting creditworthiness, new sources of revenue aren´t likely to flow to the water sector. There are two ways to pay for water infrastructure: tariffs and taxes. Worldwide, there is the cycle of “building” water infrastructure, and then “neglecting” it by not maintaining or repairing these assets because the resources aren’t available. Specifically, when local governments, water utilities, and other providers can significantly expands their collection systems efficiently, improves significantly water quality, reducing the non-revenue water, and decrease energy costs, then they can become viable, efficient, safe, and bankable service providers. Current methods to improve water quality date back to the French Revolution, and to date they are carried out on a larger scale, with more sophistication, greater energy expenditure, more CO2 emissions, greater production of toxic sludge, and yet, the quality of the water is not better, on the contrary it is declining as the contamination of the water continues to be incessantly, increasingly, cumulative and more and more complex. Despite the centuries that have passed, one factor has gone relatively disregarded: the levels of dissolved oxygen in the water and in soil. The better the quality of the water, the higher the levels of dissolved oxygen, and vice versa. Which also applies to agricultural soil, because the more oxygen is present, the more fertile the soil and vice versa. Addressing the low levels of dissolved oxygen in the water, until now it seems that it is considered as something secondary, as if it were something accessory, something like a parameter that would even improve spontaneously as soon as the levels of contamination of the precious liquid improve. But this has not happened so far with any method and in any part of the world. In addition to a lack of interest in developing processes to raise dissolved oxygen levels in the water and soil, there is the problem that the few available to date are too expensive. But the discovery of the unsuspected capacity of the human body to extract oxygen from water, dissociating it like plants; it means a light at the end of the tunnel.

Cascaded heat merit order for industrial energy systems to evaluate district heating potential

Industrial companies are undergoing a transformation to decrease energy costs and reduce emissions. The integration of renewables, sector coupling technologies, and industrial waste heat lead to complex interconnected industrial energy systems. As district heating systems play a decisive role for the integration of industrial waste heat in the building sector, barriers must be analyzed to overcome the gap between waste heat potential and waste heat use. Although data from production systems and their on-site energy supply are becoming available in the ongoing process of digitization, information deficits can be identified as one of the main barriers to couple industrial energy systems with district heating. We present a data-based methodology to evaluate the potential of industrial energy systems for connecting to district heating systems. Data from production systems, energy converters, thermal networks and necessary parameters of district heating systems are merged into a data model to determine a cascaded heat merit order and indicators for the energetic, economic and ecological potential. To set up the cascaded heat merit order, an algorithm for balancing complex industrial energy systems is integrated within the data model. In a case study, we apply the methodology to data of an industrial site. Besides increasing transparency through visualization of the cascaded heat merit order and corresponding indicators, the results show a base load potential of up to 0.8 MW over a year.

A Transactive Energy Framework for Inverter-Based HVAC Loads in a Real-Time Local Electricity Market Considering Distributed Energy Resources

Rapidly increasing distributed energy resources (DERs) bring more fluctuating output power to the distribution network and put forward a higher requirement on local regulation resources for maintaining the network's balance. Heating, ventilation, and air conditioning (HVAC) loads account for more than 40% of power consumption in modern cities and have huge regulation potential as flexible loads. However, HVACs equipped with inverter devices have rarely been studied for providing regulation services in the local electricity market (LEM), even though they have exceeded regular fixed-speed HVACs. To address this issue, this article proposes a real-time LEM and a distribution network's optimization framework to exploit the regulation potential of inverter-based HVACs considering multiple DERs. This LEM can avoid iterations in real time and significantly decrease the difficulty related to the participation of small end-users in urban distribution networks. Moreover, in this article, we propose a transactive capacity evaluation method to assist end-users in deciding their inverter-based HVACs regulation capacities in the real-time LEM, which considers buildings’ thermal features, users’ multiple comfort requirements, and dynamic ambient temperature. On this basis, a multilevel bidding strategy is developed for inverter-based HVACs to decrease energy cost, increase fluctuating DERs local utilization rate, and alleviate the distribution network's congestion. Finally, a realistic distribution network is utilized to verify the effectiveness of the proposed methods.