Thesis (MEng (Electrical Engineering))--Cape Peninsula University of Technology, 2019 / Electric utilities are confronted with challenges like rising fuel costs, aging equipment, increasing energy demand, frequency regulation and the difficulty to integrate renewable energy resources into the grid. The presence of photovoltaic (PV) penetration on the utility grid is also increasing significantly in recent years. With the recent rise in PV penetration and the advancement of the global PV industry, there is an urgent and a necessary need to introduce features in PV systems that will make them respond smartly. However, much of these can be addressed without negatively affecting the total performance and power quality of the grid. Hence, engaging smart Grid technologies, and leveraging the benefits of the distributed nature of PV, new prospects to unearth value can be created. Through the implementation of progressive energy storage techniques, efficient two-way communications, a grid-tied PV system can create significant value, mostly through improved PV contribution in grid support functions like frequency regulation. An enhanced frequency regulation functioning scheme for a grid-connected photovoltaic (PV) system is modelled in MATLAB/Simulink software environment. The system is designed to operate in grid ancillary services precisely, frequency regulation function. The model consists of a Photovoltaic (PV) plant with a battery connected to the grid through a three-phase inverter. A bi-directional DC-DC converter between the grid and the battery system is included. The model has a battery storage system that provide steady and regular active/reactive powers available while the grid transmit specific amounts of power needed for a specific duration. According to the design, either the grid or the PV system depending on the dominant energy situation charges the battery. The battery is designed to discharge only when the grid demands energy from the PV and if the PV system fails to meet the demanded active power or reactive power. The PV system and the battery storage is integrated with the grid with the aid of dc-ac inverter in such a manner that bi-directional flow of active and reactive power is achieved. A 1 MW PV system is connected to the utility grid through a three-phase voltage source inverter system. The grid nominal frequency is set at 50 Hz under normal operation. However, the frequency decreased when the PV was not producing required power hence, the battery responded almost instantaneously and returned the frequency to the nominal frequency. The effectiveness of battery storage system for utility grid frequency regulation was substantiated from the simulation results attained.

Integrating renewable energy and energy storage systems provides a way of operating the electrical grid system more energy efficiently and stably. Thermal storage and batteries are the most common devices for integration. One approach to integrating thermal storage on site is to use ice in combination with the cooling system. The use of ice storage can enable a change in the time variation of electrical usage for cooling in response to variations in PV availability, utility prices, and cooling requirements.A number of studies can be found in the literature that address optimal operation of onsite PV systems with batteries or ice storage. However, although it is a natural and practical question, it is not clear which integrated storage system performs better in terms of overall economics. Ice storage has low initial and maintenance costs, but there is an efficiency penalty for charging of storage and it can only shift electrical loads associated with building cooling requirements. A battery’s round-trip efficiency,on the other hand, is quite consistent and batteries can be used to shift both HVAC and non-HVAC loads. However, batteries have greater initial costs and a significantly shorter life. This research presents a tool and provides a case study for comparing life-cycle economics of battery and ice storage systems for a commercial building that has chillers for cooling and an on-site photovoltaic system. A model predictive control algorithm was developed and implemented in simulation for the two systems in order to compare optimal costs. The effect of ice storage and battery sizing were studied in order to determine the best storage sizes from an economic perspective and to provide a fair comparison

The diploma thesis was focused on evaluation of non-thermal (cold) plasma seed treatment of cabbage (Brassica oleracea var. capitata), on its health and production properties and on the effects against Xanthomonas campestris pv. campestris (Xcc). A soil fungus Trichoderma virens (TVI) was used as additional seed treatment. The field experiment showed that microwave, low pressure, 500 W non-thermal plasma and 4 minute exposure time did not have a significant effect on Xcc, but had a positive influence - in combination with Xcc and TVI - on plants´ vitality and yield. Further, this plasma treatment, in combination with Xcc, had a negative impact on seeds´ germination. Non-thermal plasma treatment with the above-mentioned parameters proved to be unsuitable for cabbage seed treatment.

The work is focused on the observation of the effect of selenium nanoparticles [Se] on seedlings of head cabbage, whose seeds were inoculated with Xanthomonas campestris pv campestris (Pammel) Dowson. The paper summarizes protocols of nanoparticle synthesis using various methods. A special part was devoted to methods of synthesis of selenium [Se] nanoparticles. Methods of conventional synthesis and methods of biological synthesis have been described. When using a preparation containing nanoparticles, the effect on bacteria inoculated on seed was clearly seen. Increasing concentration of the product visibly appeared to be stronger. The use of SelenBact appears to be very promising when applied to seed contaminated with bacteria Xanthomonas campestris pv campestris (Pammel) Dowson.

One of the most pressing problems nowadays is climate change and global warming. As it name indicates, it is a problem that concerns the whole earth. There is no doubt that the main cause for this to happen is human, and very related to non-renewable carbon-based energy resources. However, technology has evolved, and some alternatives have appeared in the energy conversion sector. Nevertheless, they are relatively young yet. Since the growth in renewable energies technologies wind power and PV are the ones that have taken the lead. Wind power is a relatively mature technology and even if it still has challenges to overcome the horizon is clear. However, in the PV case the technology is more recent. Even if it is true that PV modules have been used in space applications for more than 60 years, large scale production has not begun until last 10 years. This leaves the uncertainty of how will PV plants and modules age. The author will try to analyse the aging of a specific 63 kWp PV plant located in the roof of a building in Gävle, monitoring production and ambient condition data, to estimate the degradation and the new nominal power of the plant. It has been found out that the degradation of the system is not considerable. PV modules and solar inverters were studied, and even if there are more elements in the system, those are the principal ones. PV modules suffered a degradation of less than 5%, while solar inverters’ efficiency dropped from 95,4% to around 93%.

Abstract This thesis study is on designing and analysing the “Electric Power System of an Emergency Energy Module”. KTH is running a project to create a mobile system for power supply in refugee camps and during the recovery of natural disasters. This is an independent power system comprising solar, wind and biomass based power generations and control. The design and analysis of electric power system is mainly focused on increasing the renewable energy efficiency of the system while saving excess power on the battery bank and controlling the battery discharging.   The analysis of the designed electric power system is done with using actual site data of solar irradiation and wind for one week period. Further, it has been developed a program based on MS Excel for analysing the module performances at any site in the world.   Keywords: Emergency Energy Module; Integration of wind and solar PV / Emergency Energy Module Project

The German initiative Energiewende aims to decrease their dependence on nuclear andfossil-based energy, and to increase the share of variable renewable energy sources (V-RES).This transformation calls for new technical solutions that can meet future stakeholderneeds. Distributed battery storage (DBS), which can be used as a complement to theunreliable V-RES, is such a solution.In this thesis, the possibilities for incorporating DBS into the German energy market werefirst analyzed. This was followed by calculations of the economic potential for DBS, and lastlya possible business model for Vattenfall associated with the identified businessopportunities was developed. The assessment shows big opportunities of incorporating DBSinto the future energy system since it can increase the reliability and stability of thedecentralized generation of V-RES. DBS will also be the cheapest solution for an averagehousehold 2030, making the technology a profitable solution. A suitable business model hasalso been identified for Vattenfall, which focuses on the activities of leasing the DBS-units toprosumers and utilizing excess capacity for ancillary services to TSO’s and DSO’s. Theancillary services that can be utilized include frequency regulation and peak shaving.Theoretically the thesis contributes with knowledge about the increasing possibilities of DBSbecoming a large part of the future German power system. The thesis will also be a practicaltool for utilities on how to adapt their business offering with regards to the new market.

The cooperation between large scale Concentrated Solar Power plants (CSP) and Solar Photovoltaic (PV) parks can offer stability in power supply and enhance the capacity factor of the CSP plant intended to cover a common demand on the power system. Moreover, it can offer an investment option with lower risk. This Master thesis project presents optimum plant configurations for both technologies under the same meteorological and market conditions. The study is based in the South African electricity market and the Renewable Energy Independent Power Producer Program currently in place in the country. Using MATLAB and TRNSYS softwares, a series of detailed codes were designed in order to model both technologies energy transformation process. The main approach was to design the nominal operation point of both technologies for a given typical meteorological year data and respective technical conditions for each case. Then, a transient simulation was done in order to obtain the electricity yield. The intention was to measure the internal rate of return, levelized cost of electricity and capacity factor for each technology and the combined configuration (CSP-PV plant) under different scenarios and operation modes while a firm capacity was maintained. It was found that the plants can be economically feasible by sizing a storage unit capable of just covering the peak hours. The solar multiple sizes can vary depending on the scenario and plant configuration. Moreover, the internal rate of return increases with the capacity of the CSP in all cases. After the results were obtained, a comparison with a single CSP plant and the optimum CSP-PV plant was done in order to evaluate the performance of the proposed cooperation. Even though the internal rate of return of the CSP-PV plant was found to be within a good range for investment, the CSP-alone alternative offered always higher internal rate of return and lower levelized cost of electricity values. Nonetheless, it was found that the capacity factor of the combined configuration was favored by the integration of PV. The PV alone configuration hold the lowest levelized cost of electricity, thus considered the best option for and investment in South Africa due to its independence towards incentives. Combined PV-CSP systems were also found to be an attractive investment under the South African scheme if the CSP capacity is similar to the PV power plant.

Energy is a basic need for the overall growth and improvements of people’s living standard.But around 2 to 3 billion people in the world have no access to electric lighting. Like otherdeveloping countries the rural electrification in Ethiopia is very low and government takessome actions to promote the investment in these areas but due to economic constraints andlow level of technological advancement the growth is very low.This study focuses on solar PV based rural electrification, its impact on environment andsocio-economic development in Rema village. Three cases studies: typical households,small scale business center and public services are considered for systematic study.Interviews from villagers, existing energy system, literature data and HOMER software areused to calculate energy demand and cost of electrification. A comparison between theresults is carried out.According to the village survey the existing PV home system has a positive impact on a socioeconomic development of the village of Rema. Solar PV electricity can be used in generatingincomes. It is also used for climate mitigation by curbing CO2 emission and can be used forclimate adaptation by reducing the deforestation and facilitate carbon sequestration. PVbased electrification of health center and schools have played a vital role in improving thequality of services. The presence of refrigerator helped to have vaccines and medicines4preserved for different types of killer diseases. The teaching-learning process of schoolsimproved due the presence of electricity. The solar powered water supply in near areasreduced the time required for fetching water and made girls to focus on their education.Most villagers has positive attitude towards the technology but unsatisfied with the currentsystem size. The high level of technical skills required for maintenance and the small numberof solar technicians’ available in the village is also a problem reported in the village. HOMERsoftware is used to model the existing energy system and the required energy demandbefore PV based rural electrification and after PV based rural electrification. A new model isdeveloped depending on the villagers demand. . Modeling result shows that 3 kWP and 12kWP were found to be enough to fulfill the demand in clinics and schools with an initialinvestment of 18576 and 80704US$, respectively and a PV size of 165 Wp, 250 Wp and 350Wp is required for households with agriculture only, mixed and small scale business income,respectively. This led a requirement of initial capital of US$ 654, 1848 and 2339,respectively. However, these initial investments are unaffordable for most of the villagers.PV systems required for households with agriculture only, has lower investment per Wattthan others, while investment per Watt for small scale business has lower than householdswith mixed type. Therefore, the battery size plays an important role in the investment,operation and maintenance costs.The two main problems associated with solar PV in rural electrification are financial capabilityand technical problems. These problems can be curbed by loan arrangement and trainingthe villagers. But to make sustainable it must be used for income generating activities.

The development of high capacity factor solar power plants is an interesting topic, especially when considering the climate and economic conditions of a location such as the Chilean Atacama Desert. The hybridisation of solar photovoltaic (PV) and concentrating solar power (CSP) technologies for such an application is a promising collaboration. The low cost of PV and dispatchability of CSP, integrated with thermal energy storage (TES), has the promise of delivering baseload electricity at a lower cost than what could be achieved with CSP alone. Therefore, the objective of this work was to evaluate whether or not a hybrid PV-CSP plant is more economically viable, than CSP alone or hybrid PV-diesel, for baseload generation. To analyse this hypothesis, a techno-economic optimisation study of a PV-CSP hybrid plant with battery storage and fossil fuel backup was performed. In doing so, a methodology for the identification of optimum solar hybrid plant configurations, given current technology and costs, to best satisfy specific location weather and economic conditions was developed. Building on existing models, for the PV and CSP components, and developing models for further hybridisation, a complete PV-CSP model was created that could satisfy a baseload demand. Multi-objective optimisations were performed to identify optimal trade-offs between conflicting technical, economic and environmental performance indicators. For the given economic and technical assumptions, CSP hybridised with fossil fuel backup was shown to provide electricity at the lowest cost and have the lowest project capital expenditure. This configuration showed a 42% and 52% reduction in the levelised cost of electricity in comparison to CSP alone and hybrid PV-diesel, respectively. It also provides a 45% reduction in CAPEX in comparison to CSP alone. PV-CSP integration increases capital costs and the cost of electricity, but reduced the use of fossil fuel backup and thereby reduced emissions, when compared to CSP with fossil fuel backup. However PV-CSP showed a 97% reduction in CO2 emissions when compared to hybrid PV-diesel. Furthermore, it showed a 35% and 46% reduction in LCOE in comparison to CSP alone and hybrid PV-diesel.