A simulation framework for electricity markets

Electricity Markets are paramount to the economy of any country and therefore lie at the foundation of society. These markets are usually very complex when compared to traditional financial markets due to the physical nature of the asset traded, difficulty of storage and distribution. Supply and demand balancing, network constraints, renewable energy influx, desire of participants to maximise their own profits, their risk aversion, fuel costs required for production, and the market clearing mechanism, do not exhaust the list of factors that influence the market outcome, but are perhaps the most important ones. The market outcome includes the prices and quantities allocated whose understanding is of great importance for market regulators and market participants alike. This work is focused on improving the fundamental understanding of the Spot Electricity Markets which lie at the core of Electricity Trading and represent the majority of trading volume. In particular we focus on Day Ahead Auctions which represent the vast majority of Spot Electricity trading, due to the difficulty of storing electricity, coupled with uncertainty in demand and production patterns. Every market has its own peculiarities and, we consider as a case study the Central Western European (CWE) Day Ahead Auction (DAA) for the period of 01/01/2019−31/12/2019. The Central Western European market includes Austria, Belgium, Germany, France and the Netherlands. Following an introductory chapter, due to the lack of full and complete network constraints historical data, Chapter 2 is focused on the reconstruction of historical network constraints, that are a key input in any fundamental model considering the electricity grid’s structure. Further, network constraints may impose price decoupling between countries, which is of great interest to practitioners, academics and regulators. The task is very challenging due to the input data being very large and sparse. We reconstruct the network constraints data, known as the Power Transmission Distribution Factors (PTDFs) and Remaining Available Margins (RAMs), by first recovering the underlying time dependent signals known as the Generation Shift Keys (GSKs) and Phase Angles (PAs), and the electricity grid characteristics, via a mathematical optimisation problem that is solved by exploiting problem structure. The second step maps GSKs and PAs to the network constraints via the electricity grid characteristics. Our reconstruction achieves good in- and out-of- sample relative errors when compared to a naive approach. With the network constraints available, and by obtaining the cost and capacity characteristics of suppliers, in Chapter 3 we formulate a fundamental model to resolve for the zonal prices and quantities assigned to each participant, based on a simplification of the CWE market clearing mechanism, known as the Social Welfare Maximisation Problem (SWM). We also propose a novel market clearing mechanism which we call the Total Cost Minimisation Problem, because as we show, the prices are generally much lower and the total cost of supplying electricity is guaranteed to be lower by definition. Solving the Cost Minimisation problem is more challenging than solving the SWM, due to zonal prices appearing as explicit variables, but we obtain strong (but partial) analytical results to aid numerical solutions and provide efficient numerical algorithms. For both clearing mechanisms, demand is considered as inflexible, and producers bid marginal prices linear in the quantities produced. Since as expected, the SWM better represents the target data, this is further used as the market clearing mechanism. We consider the case when producers truthfully bid (TB) their cost curves, which is usually assumed by the regulators and many academic papers. However, we also consider the case of players trying to maximise their own profit, tand thus forming a Game Theoretic (GT) framework. For our CWE case study, both GT and TB models generally give an accurate representation of the actual price outcomes. Further, we define a method based on simple hypothesis testing to identify if and when the players are bidding strategically (gaming). We show that in fact, while for a large majority of times we cannot say with high confidence whether the players are bidding strategically or bidding truthfully, the number of times we are confident that players are gaming is much higher than the number of times we are confident that the players are bidding truthfully. Our results show that, in general, strategic bidding appears to be especially pronounced at peak demand hours: between 8am − 1pm and 5pm − 9pm. A different regime, where renewable energy influx appears to dominate the price action is also identified and this effect is generally more pronounced at off-peak morning hours (0am − 6am). Our model can thus be used as a fundamental approach for market outcome and price prediction, understanding the impact various fundamental factors on the price, understanding of producers’ behaviour, and identifying if and when players are not bidding truthfully. These are all of interest to academics, market participants, and regulators

Biochar a promising strategy for pesticide-contaminated soils

Soil pesticide contamination induced by modern agriculture has become a serious global issue. Its uncontrolled and inefficient application is among the main reasons for their enrichment in plants and animals subsequently transferred to humans and providing a public health risk. Biochar as a renewable and economical carbonaceous material provides a natural solution for immobilizing pesticides and improving soil health. The biochar impact in agricultural contaminated soil is governed by various factors such as the physico-chemical properties of biochar, pyrolysis, soil conditions, and the application method, which can lead to significant gaps in the removal or mitigation of toxic substances. The current study summarizes the negative effects of pesticide use and the advantages of biochar according to other remediation techniques, succeeded by the mechanism and controlling factors on minimizing pesticide leaching and bioavailability in soil. In addition, the role of biochar on fundamental processes of adsorption, desorption, biodegradation, and leaching is discussed. Ultimately, the major future research regulation and key strategies that are fundamental for pesticidecontaminated soil remediation are proposed

The influence of postemergence herbicide on the main yield components in white lupin (Lupinus albus L.) – cv. "Ruxandra"

White lupin (Lupinus albus L.) is an underutilized crop that started to become extremely interesting for bio and conventional farmers due the high protein content of the seeds and, mainly, due the nitrogen fixation capacity. Nowadays, challenging economic environment and changing climate conditions had led to a bust in fertilizers prices worldwide. Identification and utilization in crop rotation systems of crop with nitrogen fixation capacity is an optimal alternative. One of the biggest problem in the white lupin cultivation technology is caused by the special sensitivity of this species at postemergence herbicide. This sensibility makes weed control a very difficult task for farmers. In this paper we present results obtained in 2022 season at the Ezăreni Farm, Iasi, Romania. Principal yield components were studied and compared among postemergence herbicide variants. Comparative studies were done using the cultivar RUXANDRA, obtained and registered by us

Plant density and foliar fertilization effects on essential oil content of fennel (Foeniculum vulgare mill.)

Aromatic and medicinal plant species can be defined as boundless sources of raw materials which can be used as well in food and pharmaceutical industry. Essential oils extracted from different parts of the aromatic plant species are of increasing interest in cosmetic industry. Some chemical compounds from volatile oils are preferred over the synthetic ones, as natural extracts involve less risk factors as far as consumer`s health goes. The aim of this research was to determine the main effects of plant density and foliar fertilization on essential oil yield of two varieties of fennel Foeniculum vulgare var. vulgare and Foeniculum vulgare var. dulce. The experiment was carried out using randomized block design with three replications. The distances between rows were 50 cm, 75 cm and 100 cm. The plant spaces on the row was 30 cm in all treatments. In case of each plant density, three foliar fertilizers were applied, with different composition, in terms of macronutrients, micronutrients and amino acids. The results showed that both factors, plant density and foliar application of fertilizers had significant impact on the essential oil content of both sweet fennel and bitter fennel

The effect of abiotic stress on white lupin (Lupinus albus l.) cv. "Mihai" plants in different density conditions

Lupinus albus (white lupin) is a crop well adapted to marginal lands and has a large potential for enhanced bio economy use. In general, lupins have the ability to fix atmospheric nitrogen, mobilise soil phosphate and are suitable for low nutritional cultivation. Modern varieties should be selected for high yield of green silage or high yield of seeds which contain more than 20% oil, more than 40% protein and the remaining materials are carbohydrates, mainly oligosaccharides characterized as “prebiotics”. In this experiment, three new white lupin sorts were tested in experimental fields. Breeding activities we compensated by optimized cultivation technology for these cultivars. One of the biggest problem in the white lupin cultivation this year was caused by the extreme draught and high temperatures registered during the vegetation period. Results present the observations obtained in 2022 season at the Ezăreni Farm. Comparison of the selected cultivars was performed using two different density condition. Results indicated that white lupins could be an interesting alternative for farmers and can contribute to new optimised crop rotation system

Work satisfaction in the food industry - a premise for economic performance

The greatest challenge for Romania’s food industry is to achieve technical and economic parity with the rest of Europe. Therefore, businesses require productive employees, and labor productivity depends on employee satisfaction. This study’s primary objective was to investigate employee satisfaction in the bakery industry in order to enhance economic performance. This topic is rarely researched, but it is necessary to enhance the economic performance and work processes of this industry. A combination of quantitative and qualitative research methods were used, including an online questionnaire survey of 254 employees and a focus group meeting with 17 managers from 60 companies in the Northeast and Southeast regions of Romania. Total pay (5.3 points on a 1–7-point scale), amount of work (4.9 points), and number of working hours (4.8 points) were the top motivators. The average weighted value for job satisfaction on a scale of 100 points was 27.4 points. The relationship between labor costs and employee satisfaction was strong. Low levels of satisfaction are costlier for employers than high levels of satisfaction. The originality of this study lies in its determination of how strongly employees perceive each aspect of job satisfaction and its correlation to the economic performance of companies

Research on the improvement of some technological parameters for Bromus inermis Leyss. seed crops

The fodder base represents the most significant means of increasing economic efficiency in the livestock sector. For this, permanent and sown meadows are an important source of fodder. The establishment of temporary meadows on the lands of steppe and forest-steppe areas, poorly productive, with erosion problems, the improvement of permanent meadows by overseeding, the reforestation of slopes, slopes, irrigation canals, requires the production of large quantities of perennial grass seeds, the most important species being Bromus inermis Leyss. The production of seeds for these species is done in separate cultures, according to a specific technology. Through the research carried out within the Research - Development Station for Meadows, Vaslui, was studied the influence of two factors, respectively, the distance between the rows and fertilization with mineral fertilizers on the behavior of the species Bromus inermis Leyss., in the first year of vegetation, being analyzed the ability of installation of the species and some morphoproductive elements

Research on the optimization of the industrial hemp cultivation technology for the full use of biomass

The main purpose of the research was to identify the optimal technology for cultivating industrial hemp, so that the obtained biomass can be fully processed at the farm level, without special equipment in this regard. The variety used in the experiment was Zenit, created by the Agricultural Research and Development Station Secuieni, Neamt county. Within the cultivation technology, three technological variants were tested: uncut plants, plants cut once and plants cut twice ("Secuieni" method of hemp cultivation). The optimal technological variant for the full use of hemp biomass was the cultivation technology with a single cut, where the production of grains and biomass ensured the best economic efficiency of the hemp culture

The impact of salinity stress on antioxidant response and bioactive compounds of Nepeta cataria L.

In this study, the ability of Nepeta cataria L. to grow and synthesize bioactive compounds on soil treated with different salt concentrations was tested to evaluate the opportunity of cultivating it in soils affected by salinization. N. cataria L. was grown in soil containing specific amounts of NaCl, Na2SO4, and their mixture. After harvesting, the plants were analyzed from the morphological and physiological point of view. Salinity stress inhibited the growth, with the highest decrease of the plant yield up to about 70% in the case of salt mixture, and smaller values for the separate salt treatments. In the same time, as a defense mechanism, there was an increase of granular trichomes’ density, as observed with the scanning electron microscope. For mild concentrations of salt, the amount of chlorophyll pigments was enhanced, while for stronger salinity stress, it decreased. The opposite behavior was evidenced for the polyphenol content, as antioxidant activity was used as a protective mechanism against reactive oxygen species produced under salinity stress. The antioxidant activity was considerably higher for separate NaCl and Na2SO4 treatments than for the salt mixture variants. The results showed that the species Nepeta cataria L. reacts well to high salinity levels, with an increased content of bioactive compounds and antioxidant activity even for the highest studied salinity conditions

Salinity Stress Influences the Main Biochemical Parameters of Nepeta racemosa Lam.

In this work, the effects of salt stress on Nepeta racemosa Lam. were studied to analyze the possibility of using it as a potential culture for salinity-affected soils. A total of nine concentrations of salts—NaCl (18, 39, and 60 mg/100 g soil), Na2SO4 (50, 85, and 120 mg/100 g soil), and a mixture (9 g NaCl + 25 g Na2SO4, 19 g NaCl + 43 g Na2SO4, and 30 g NaCl + 60 g Na2SO4/100 g soil)—simulated real salinity conditions. Environmental electron microscopy offered information about the size and distribution of glandular trichomes, which are very important structures that contain bioactive compounds. The chlorophyll pigments, polyphenols, flavonoids, and antioxidant activity were determined based on spectrophotometric protocols. The results have shown a different impact of salinity depending on the salt type, with an increase in bioactive compound concentrations in some cases. The highest polyphenol concentrations were obtained for Na2SO4 variants (47.05 and 46.48 mg GA/g dw for the highest salt concentration in the first and second year, respectively), while the highest flavonoid content was found for the salt mixtures (42.77 and 39.89 mg QE/g dw for the highest concentrations of salt in the first and, respectively, the second year), approximately 100% higher than control. From the Pearson analysis, strong correlations were found between chlorophyll pigments (up to 0.93), antioxidant activity and yield for the first harvest (up to 0.38), and antioxidant activity and flavonoid content for the second harvest (up to 0.95). The results indicate the possibility of growing the studied plants in salt-stress soils, obtaining higher concentrations of bioactive compounds