This thesis aimed to uncover the magnitude and effect of residential E-cooling demand on the Dutch energy market. Currently, little is known about the subject even though, due to rising temperatures and the increase in the amount of heat pumps, the amount and with that the effects of residential E-cooling demand is expected to rise sharply in the upcoming decades. First, the magnitude and patterns of residential E-cooling were uncovered by developing a thermodynamical model of the average Dutch residential houses. The effects of E-cooling were then tested by implementing the cooling demand in Pandapower and Plexos, testing the effects on local physical grids and on the overall power market respectively. The results showed a doubling of the cooling demand between 2025 and 2030 and a maximum annual cooling demand of approximately 0.4 TWh. The maximum cooling demand amounted to 2 TWh when alternative weather data was used reducing weather data limitations. In addition, it was shown how the demand for residential cooling has the potential to decrease local power quality when more than 40% of households actively cool their houses simultaneously, increasing network costs. Finally, it was also proven how power prices could increase due to higher demand and how revenue for certain generation components could double, or decrease by 20% in our grid during heat waves when accounting for residential E-cooling demand. This thesis provided among the first in-depth analysis of the magnitude and consequences of residential E-cooling demand on the Dutch energy market. It showed how cooling demand is expected to increase and what the consequences are of this increase.

Silicon carbide (SiC) and silicon oxide (SiOx) have garnered increased attention to reduce the parasitic absorption at the p layer when compared to p-aSi.An outstanding question is how the integration of p-SiC and p-SiOx impacts the metastability of the solr cells. Previous work in the PVMD group at TU Delft has studied the stability of the p-nc-SiOx in detail revealing from experimental results that stable efficiency remains elusive.
This thesis investigates the impact of p-a-SiC on the light-induced degradation (LID) of p-i-n solar cells, aiming to compare its degradation performance with that of p-nc-SiOx. Prior to comparison, p-a-SiC fabrication via plasma-enhanced chemical vapor deposition (PECVD) is extensively explored, as it serves as a widely used light absorber in thin-film silicon solar cells. Various parameters such as power pressure and gas flow rate of the source gas for silicon carbide formation are meticulously studied to achieve optimal P-a-SiC performance. Once the optimal fabrication conditions are identified, light absorption experiments are conducted and characterized using JV and EQE measurements to assess LID performance.

The transition to renewable energy sources requires advanced energy storage solutions to manage their intermittent nature. This thesis explores the feasibility of implementing Battery as a Service (BaaS) for a renewable energy community (RECs) setting, aiming to incorporate this model as part of an existing stacked revenue framework utilized by battery owners across various energy markets. By directly linking battery owners with energy communities, the study shows that renting out battery storage can eliminate intermediary overheads, thus providing financial benefits to both parties. The research addresses two main questions: developing a stacked revenue model for grid-connected batteries including energy communities, and comparing different battery sizing and control methods across various tariff schemes. The findings suggest that the proposed revenue model optimizes energy use and reduces costs for the community. This thesis contributes to the research field by presenting a viable economic model for integrating battery storage into decentralized energy communities.

High-voltage circuit breakers protect and control the electrical power grid, making their reliability of the essence. Robustly assessing the technical `health' of every circuit breaker in operation is key for an optimal maintenance strategy and safety measures, but is traditionally not performed in a data-driven, statistical fashion. The goal is to design an indexation method for the health of the high-voltage SF6 circuit breakers of TenneT TSO NL using its available (monitoring) data. This indexation is performed through modelling the hazard rate of major and minor component failures with the Cox proportional hazards model. Failure modes and their causes are investigated using large-scale surveys on historical failure data and covariates for the model are chosen accordingly. The hazard rate for minor failures is found to be increasing with the asset's operating voltage level, its average switching frequency, certain manufacturers, and its relative SF6 leakage rate, of which the last relation has not been modelled before to our knowledge. Using the model output, the circuit breakers' probabilities of future failure are estimated, shown to have some predictive power, and incorporated into a color-coded scoring system. Using this quantitative measure of their condition, the TSO should be able to better manage its asset portfolio and risks. However, data quality, especially for major failures, is found to be low and poses a limitation, as well as a possibility for future research.

Thin-film silicon technology creates electricity out of micrometer thick silicon absorber layers, which makes this technology less material heavy compared to classic crystalline technology. This advantage can be further exploited with the transition towards flexible thin-film technology, where the non-modular cost can be further reduced compared to traditional crystalline solar parks ect. However, thin films have limited absorption coefficients at higher wavelengths which means the optical pathlength must be maximised to overcome this limitation. In literature, the highest efficiencies are obtained with the creation of periodic textures resulting in 10.2%, 12.7% or 14% for nanocrystalline, micromorph and triple junction silicon technology. All these cells are made on silicon substrates which means the back of the cell is textured but if the front side of the solar cell is textured, efficiencies can outperform the current holding records. A methodology is designed to create periodic micro-textures on Corning glass to improve the total absorption of lower energetic wavelengths. However, the creation of random micro-textures (Aluminum Zinc oxideand Indium Tin Oxide sacrificial texturing)(AZO-/ ITO textures) is also researched because different methodologies exist and limited knowledge exists on which methodology results in the highest amount of scattering. Second, a comparison between random and periodic textures must be made. Both types of textures undergo optical- and physical parametrisation after which both aspects are correlated to each other to gain a deeper understanding of light management. For random textures, Haze-values between 93-86% are obtained. These high values are obtained because the created craters are characterised by an increased depth for identical crater widths. Second, each methodology has its characteristic depth-width ratio which explains the optical superiority of one (ITO textures). For periodic textures, Haze-values lie between 50-3% with a maximum obtained aspect ratio of 0.18 but the optical response is not comparable to random textures because diffraction is the dominant light management technique. Therefore Angular Intensity Distribution measurements must be performed, which resulted in the conclusion that the created ITO textures stay superior (also compared to literature) while the AZO textures have a similar performance compared to the periodic texture. This translates itself in a superior external quantum efficiency (EQE) of ITO from 800nm on. Between 600-800nm, the periodic textures are superior.

Peer-to-peer trading and energy communities have garnered much attention over the last few years due to the wider spread of distributed energy resources. Much research has been performed on the mechanisms and methodologies behind their implementation and realisation. However, the efficiency and micro-structure of trading in such markets raise many important challenges. To analyse the efficiency of peer-to-peer energy markets, we consider two different popular approaches to peer-to-peer trading, i.e. centralised and decentralised and explore the economic benefits these models bring given optimal trading schedules computed by a joint schedule optimizer. In both these modes, benefits can be realised mainly due to the diversity in consumption behaviour and renewable energy generation between prosumers in an energy community.
This diversity decreases quickly as more peer-to-peer energy contracts are established and more prosumers join the market, leading to significantly diminishing returns. In this work, we aim to quantify such effects using large-scale real-world data from two trials in the UK, i.e. the Low Carbon London project and the Thames Valley Vision project.
We show that only a small number of peer-to-peer contracts and a fraction of the prosumers are needed to realise the majority of the Gains from Trade.

To keep the generation adequacy of the power system up to standards, more and more countries in Europe are setting up capacity mechanisms. In a capacity mechanism power generation units receive payments for having their capacity available when this is needed (during moments of electrical supply shortage). These payments are received on top of payments that could be received from the energy markets or ancillary service markets [4]. This gives incentives to generation units to be available when needed and create a better investment climate in generation capacity. In this way, these capacity mechanisms can increase the security of supply. In the past, countries in Europe could implement such a capacity mechanisms locally, only local capacity providers (e.g. generation units) were allowed to participate. But the European Commission has developed new regulations which state that it is allowed for capacity providers to participate in cross­border capacity mechanisms. In this way capacity providers can receive additional payments from participating in foreign capacity mechanisms. But this raises questions, because the contribution (capacity value) of a capacity providers is thought to be dependent on its location. This thesis analyzes what the effect of the new EU regulations regarding cross-­border participation is on the payments resulting from capacity mechanisms. To answer this, the relevant EU wide regulations are analyzed and combined with the regulations of the capacity mechanism as implemented in Great Britain (at the time of writing), to find a likely implementation of a capacity mechanism in which cross­-border participation is allowed. A generation adequacy model was built and combined with the likely implementation of a capacity mechanism to analyze what the expected payments from the capacity mechanism will be to local and cross-­border capacity providers. This was done to analyze how attractive it is for capacity providers to participate in two capacity mechanisms. The generation adequacy model that is used consists of two areas, these areas represent Great Britain and France. For the model the same input data was used as in [38]. A Monte Carlo sampling method was used to analyze when payments are due. It was found that with the implementation of the new regulations regarding cross-­border participation in capacity mechanisms it is very attractive for capacity providers to be participating in two capacity mechanisms. But EU regulations set a limit on the amount of capacity that is allowed to participate in a cross­border capacity mechanism. Capacity providers have to compete with other capacity providers in a market based manner to be allocated to participate in a cross­-border capacity mechanism. This will likely lead to a break even point where participating in two capacity mechanisms generates an equal income as participating in just a local capacity mechanism. To analyze how much generation units contribute to the security of supply of a cross-­border capacity mechanism, the two area adequacy model was used. An analytical method was used to calculate the capacity value of the generation units. It was found that generation units can contribute to the security of supply of a cross­-border area, although it does support the area it is located in more than the cross-­border area. When the interconnection between the areas has a larger capacity, the effect of a generation unit to the cross-­border area becomes larger. It was concluded by implementing the new regulations in the model in this thesis, that the capacity-mechanisms do not give financial incentives to invest in generation capacity for the security of supply of a cross­-border area. This might lead to sub­optimal investments, because generation units can contribute to the security of supply of a cross­-border area.

This research evaluates and optimises the competitiveness of a combined wind, solar, and electrolyser plant in the Dutch electricity and hydrogen market. For the electricity market, this study used the EPEX spot market, where most electricity is traded. The hydrogen market is far less transparent than the electricity market; hence, a market had to be simulated for this study. It was assumed that the price of hydrogen is set by the production cost of hydrogen through steam methane reforming, because this is by far the largest producer of hydrogen in the current market. For both markets, it was assumed that an unlimited amount of electricity and/or hydrogen could be sold at the market price at any time. The competitiveness of the hybrid plant was determined by the Net present value of the hybrid plant. This NPV was calculated for nine research scenarios placed on two axes, a climate action axis, and a time axis. The climate axis represents the amount of climate action taken by governments and industries. The time axis represents the commercial operating date, varying from 2021 until 2030; this will illustrate how the plant competitiveness evolves.

In earlier times the climate crisis was ignored. However, these days it is acknowledged as one of the most important challenges the world is facing. With increased awareness of anthropogenic emissions, most sectors are changing rapidly. One of those sectors is the offshore wind energy sector. As a consequence of the Paris Climate Agreement, the European Commission adoptedan offshore renewable strategy that aims to install at least 60 GW of offshore wind by 2030 and up to 300 GW by 2050. With the increasing capacity of offshore wind being constructed, new wind farms will move gradually further offshore. This, therefore, requires a need for significant investments in large-scale wind farms and in the required grid infrastructure to be able to transmit the large amounts of electricity produced offshore to the consumers onshore.Thus the need for cost-efficient integration of the North Sea transmission arises. Currently, existing offshore wind farms are being investigated as potential gateways in order to achieve this offshore transmission network integration in a cost-efficient manner.In this master thesis project, the effects of various future connection schemes and market setups on the business cases of offshore wind farms were investigated. The study focuses on a location in the North Sea close with similar geographical characteristics as a large sandbank called the Doggerbank. First, a literature study was performed to obtain background knowledge about the offshore situation. Relevant assets were identified, multiple offshore gridtypologies were found and different offshore governance models and market setups have been identified. In addition, the theoretical background of constructing a business case for offshore wind farms from a Dutch and British perspective was explored. The main cost drivers were identified and can be distinguished in capital expenditures and operational expenditures. In addition, these cost categories were quantified in order to set up a business case for an offshore wind farmat a specified location. The cost category taking up most of the investment was found to be the grid connection, taking approximately 30% of the total investments. In addition, British built wind farms require more initial investment with respect to the Dutch wind farms, due to a difference in governance models between the countries. Next, the methods by which a wind farm can collect income was explored. Various categories were identified being; revenueby selling the commodity, power purchase agreement, financial support schemes and green certificates. Historical wind data was used to determine a wind profile. In addition, the historical market data was added to quantify the cash flow of an offshore wind farm. Last, an expression of the Levelized Cost of Energy (LCOE) was found for a Dutch and British constructed offshore wind farm respectively.To obtain insights into the effects of the North Sea transmission integration on the business case of offshore wind farms, a scenario-based modelling & simulation approach was adopted. First, a conceptual model has been developed. This was done by, first, identifying the situationin which the problem occurs and second, determining the modelling scope. Next, the in- and outputs were explained and the simplifications used for the model were presented accordingly. Various scenarios were developed in order to be able to simulate distinct future situations in which a wind farm may be required to operate. These system changes are predominantly caused by different connection scenarios or by a change in market setups. First, a base model was developed, to understand the basic operations of a wind farm. Next, the reference case using a Dutch and British wind farm connected to their own national electricity market was simulated that represents the current situation of existing offshore wind farms. Then, a cross-border connection was added to the reference case under the current home market setup. Subsequently, a change in market setup, the offshore bidding zone, was introduced.The first insights were obtained through simulation of the reference case, which represents the current situation. Large wind farm projects far from shore were found to be most likely still dependent on support through subsidy schemes. This holds for both a Dutch and British perspective regarding the construction. The first scenario on which the effects were simulated, describes a situation in which a connection to a foreign market is introduced to the reference case. The results of these simulations show no substantial changes in the cash flow of theoffshore wind farms. However, large amounts of costs imposed on society were identified under this scenario. When the offshore bidding zone was introduced as a new market setups in a cross-border connection various results were found. First, for a Dutch wind farm in this connection and under this market setup, the revenues tent to increase with respect to the reference case. However, for a British wind farm a clear decline in the collected revenues by the wind farm developers was observed. Nevertheless, due to the regulatory conflicts thatwere identified in the cross-border connection scenario under the current home market setup, a change to the offshore bidding zone market setup seems desirable. This implies that under current regulation, the offshore bidding zone market setup shows no issues being compliant with EU legislation and National regulation.An additional step was performed in this master thesis project, that adopts the objective to identify instruments that could mitigate these declines in revenues under an offshore bidding zone market setup. These instruments are regarded as mitigation options or mitigation schemes. The academic method of a policy scorecard was adopted, and additional desk research was performed to identify current proposals for mitigation schemes in the literature. Eight mitigation schemes were found from which seven were applicable to an offshore biddingzone market setup. These could be distinguished into support through operations and through regulatory changes. It was found that, within the scope of this research, which is looking into the economic effects and the feasibility of the identified mitigation schemes, the Contract for Difference scheme seems to be the best choice as it provides stability for the wind farm developers, and is the most cost-efficient option with respect to society. Good alternatives were identified to be the redistribution of congestion income and granting windfarm developers a so-called "Transmission System Operator -light" certificate that allows for a share in the congestion income. However, there is a broader political impact, in terms of financial budget requirements on a member state level, general public support for support schemes and overall effectiveness of support schemes in broader policy objectives. As a consequence, it is recommended for future research to further investigate different domains than the economically and feasibility domains that have been presented in this research. In order to solve the current issue, thesedomains require additional investigated to obtain this broader perspective and to eventually be able to make political decisions.

There has been a rapid development in the growth of Wind power generation in the last decade. This has led to wind power becoming a major contributor to the modern electrical grids. For the grids that are still based on conventional sources of energy, integrating wind power causes a serious impact on their performance. While the Windfarm must ensure the quality of power it supplies to the grid, the wind farm should itself remain resistant from the small disturbances coming from the grid. The power electronic converters used in the integration process are often responsible for the disturbance. These disturbances include, among other issues, the generation of certain harmonics based on the high-frequency converter switching. This affects the power quality and performance of the entire system. Certain harmonics are often amplified by resonating impedance. This phenomenon of harmonic resonance has been identified as a major cause of several grid failures.

In this master thesis, a study is carried out to investigate the generation and propagation of harmonics in a wind farm network. A modified IEEE-13 node feeder has been considered as a network accommodating a wind farm. The suggestive wind farm consists of 10 wind turbines, with each turbine connected at a different node of the modified IEEE-13 node feeder. These wind turbines are connected with the grid using an IGBT converter and an LCL filter. The switching topology and filter tuning has been discussed in detail. All the components comprising a wind turbine including cables, Voltage Source Converters (VSCs), transformers, filters and control system have been included.

The modelling is carried out in MATLAB/Simulink with the necessary data taken from the literature survey. A control system governing the switching of the IGBT converter has been developed. It consists of power control and a current control scheme. A DQ transformation scheme has been selected for the current control of the wind farm. A Phase-Locked Loop (PLL) is used to synchronize the converter with the grid and a Pulse Width Modulator (PWM) is used to generate gate pulses, controlling the switching of the IGBT switches.

The simulations have been carried out for 5 cases: the base case, de-tuned control system, disconnection of a part of the grid, wind speed dynamics and finally, a combination of all the above contingency cases termed as "the worst-case scenario". Each case is designed to represent the impacts inside a real offshore wind farm. A quantitative and qualitative analysis has been carried out for the harmonic distortions at different buses of the wind farm network under each case.
Results from the simulations show the harmonic orders that are common across the frequency spectrum in different cases. The base case provided relatively low voltage harmonics, but with more disturbances in the network, higher harmonic content was observed. The harmonic order corresponding (or nearest) to the switching frequency of the IGBT converter and the resonant frequency of the network, contributed the most for the Total Harmonic Distortion (THD).

In the field of photovoltaics, tandem cells have emerged as a promising technology with high power conversion efficiencies. The academic society grew interest toward this technology due to its high generation capabilities at low production costs. For the time being, most of the research efforts are limited to the lab performance of these cells. However, real life performance studies allow for better understanding of the design effects and yield potentials of this technology. The commercially available yield prediction tools do not involve energy yield prediction models for tandem modules. In addition, they fall short at modelling all the aspects influencing the PV energy yield. The PVMD Toolbox, developed by the Photovoltaic Materials and Devices group at Delft University of Technology, is proposed to serve this need. This thesis presents the work done to develop version 4 of the toolbox. A calibrated lumped element model (CLEM) was developed to simulate the electric performance at the cell level. The CLEM combines the accuracy of physical models with the speed of lumped-element models to generate hundreds of thousands of simulations within a single minute. Additional models were implemented in the toolbox to account for the effects of cell interconnections and metallization on the energy output. Besides, a cell mapping algorithm was developed to reduce the AEY simulation time. This algorithm proved beneficial by reducing the number of required electric simulations by 86% at the small cost of 0.226% bias. Afterwards, the accuracy of the thermal and electric models was validated against two datasets. The simulated results showed a great agreement to the measurements with total energy yield deviations from the measurement of 2.65% and 4.15%, compared to 7.43% in version 3. Therefore, version 4 of the toolbox offers more accurate simulations with a reduced computation speed by a factor of 45.
The CLEM and cell interconnection models were utilized to perform energy yield simulations on tandem modules. Case studies were performed on c-Si/tandem modules to investigate the implications of design choices. After optimizing the STC output of four design options, the toolbox was used to simulate the energy yield for each of them. Then, the optical and electric performance of the modules were studied. The tandem modules proved advantageous, with energy yield increase ranging between 12.91% and 27.13% compared to SHJ modules. In addition, specific yield computations confirmed the sensitivity of tandem modules to meteorological conditions. The final result of this thesis is a first-time combination of modelling spectral irradiance, thermal, and cell and module electric aspects for energy yield simulations of tandem modules.

One of the main challenges of today is the energy transition from fossil fuels to green renewable energy. One new concept that can aid this transition is the smart charging of electric vehicles. Smart charging is utilizing the flexible availability of an electric vehicle to charge on a time when this is most valuable, while complying to the constraint that it needs to be fully charged when the vehicle unplugs. This research focuses on the use of smart charging for cost optimization on the ETPA intraday market, in combination with the day ahead market. During this research it has first been investigated what the properties of the intraday market and the available electricity fleet were and which difficulties they pose. One of the most challenging properties were the limited volume constraints placed on the orders in the limit order and the constraint that the sessions had a binary charge speed, meaning they can either fully charge or not charge at all. This combination creates and NP-hard optimization problem. The second main difficulty is online nature of the market, meaning a solution for the hard optimization problem has to be done within seconds. Current research in the field of smart charging on the intraday markets and smart charging in general has not been able to provide this research with a feasible scheduling optimization method. This leads us to the main contribution of this research: the proposal of a new optimization method which computes an (online) approximate scheduling of a fleet, with binary charge settings, that optimizes on the costs of multiple electricity markets including the ETPA intraday and day ahead market. Through empirical testing it has been shown that re optimization in an online environment can be done within maximally a quarter of a second, with a fleet of 10000 EVs per day. Testing has also shown that it can schedule these EVs with a maximum error or 33 kW per PTU, which is an error of 0.16% on a 10000 session per day fleet. The newly proposed optimization methods has immediately been utilized to test the maximum trading possibilities of the ETPA intraday market. Only purchasing on the day ahead and intraday market has shown some possible opportunities, but the real opportunity lies within full trading on the day ahead and intraday market. Cost reductions of up to 6ct/kW could be achieved compared to not smart charging at all. Online tests, using no forecasting model, has shown almost no cost reduction compared to only smart charging on the day ahead market. This is due to the algorithm trading when the least of profit can be made, wasting the profit possibility. This research has provided the first building blocks to achieve a optimization model for smart charging on the ETPA intraday market. For the optimization model to be completely ready it must be able to optimize over PTUs, that have different lengths, and be able to make use of forecasted prices and volumes computed by an external forecasting model.

Destructive consequences of trapped space charges within HVDC coaxial cable insulation, such as accelerated aging, degradation, and breakdown, are some of the most significant challenges that manufacturers and users usually come up with. Pulsed Electro-Acoustic (PEA) method is a widely-used method for space charge detection and measurement, in which the space charge profile is mapped through acoustic waves that are excited by applied pulsed-voltage. There are a few practices for pulse application into PEA circuit. Pros and cons of the different injection practices have been remained unknown due to limited accessibility to the critical points like the core conductor. Modeling of the pulse injection setups can help us with simulating the essential parameters, like voltage and current, at the unreachable spots. The way how the circuit can be modeled, selecting adequate software and transmission line model, strengths and weaknesses of the injection practices and the changes required for possible optimization in the practices are challenging questions that need to be answered. This thesis develops frequency-dependent models for all the PEA injection setups that are usually deployed for Medium Voltage (MV) mini-cables geometry. It shows, through a validation
process, that PSCAD/EMTDC phase model can yield sufficiently accurate results with reference to the lab measurements. In the next stage, the questioned strengths and weaknesses of each original design setup are determined through a series of lab tests and computer-aided simulations by utilizing of which the best setup is recognized. Seeking some approaches for further optimization of the setups is also another aim of this research. This thesis proves that the PSCAD/EMTDC phase model is capable to present an acceptably exact model for the circuits, despite having some limitations that will be explained. Operational
versions of all setups, in which the fundamental problems are cleared up, will also be proposed in this thesis. Among all the setups, Core Pulse Injection (CPI) and Table Pulse Injection (TPI) practices offer the best non-optimized (original design) and optimized results, in terms of quality of the delivered voltage across the target dielectric respectively, while the original design of Double Side Pulse Injection (DSPI) and Single Side Pulse Injection (SSPI) seem to be unreliable due to severe oscillatory behaviors. Nevertheless, two modified versions for DSPI and SSPI show quality results.

The rising number of electricity consumers poses a challenge to power generators and grid operators in maintaining a balanced grid. Peak shaving is a technique that consists of shifting electricity consumption from hours of high demand to times of low demand, and has been gaining popularity in recent years. It allows to reduce peak loads which must be met at all times, which in turn reduces the need to resort to less efficient and more expensive power plants to see that all peaks are met. This paper proposes two methods to operate a battery energy storage system (BESS) for peak shaving of daily load profiles, based on the dynamic programming (DP) algorithm. The first approach treats historical profiles as deterministic paths and solves the DP algorithm for each profile. Then, an operating plan is obtained in real-time by combining the policies calculated for each path. The second approach treats data as stochastic paths, from which it derives a probabilistic model for the target path. Given this model, the DP algorithm obtains an operating plan for the entire day ahead. We also propose three modifications that can be applied to the two methods which aim at the improving the reliability of the methods. The performance of the proposed methods is examined through numerical experiments on both artificial and real data.

In a bid to battle global warming the Dutch government has set ambitious targets to cut CO2 emissions in the Dutch Climate Agreement [1]. Aside from this state-driven initiative in line with the Paris agreement, several Dutch cities have presented their own climate initiatives. The city of Amsterdam has pledged to reduce its CO2 emissions by 55% in 2030 compared to 1990 levels which surpasses the national goal by 5% [2]. The capital has laid out a detailed plan to achieve these goals and it is clear that the electrification of mobility and heating, along with the roll-out of solar energy across the city, will play an important role in the future. Amsterdam is planning to install 1 million solar panels by 2022, aims to ban non-electric cars from the city by 2030 [3] and wants all buildings to be heated gas-free by 2040. While all of these steps are very helpful regarding the reduction of greenhouse gasses, they pose a big challenge to local grid operator Liander to ensure sufficient grid capacity [4]. The spokesperson of Alliander (parent of Liander) estimates that in 2050, peak power demand in Amsterdam could be 2.5 to 6 times higher than now. From the 25 substations in the city, which transform high-voltage electricity to middle-voltage, a minimum of 11 will not have sufficient capacity by 2030. The problem lies with an increase in both electricity supply and demand. On the supply side, as more and more Renewable Energy Sources (RES) have entered the Dutch energy mix in the past decade the strain on the electricity grid has increased. While wind turbines have largely been built offshore and feed into the high voltage grid, on-land turbines and especially large scale solar generation are mainly connected to the middle-voltage (MV) grid which is primarily designed to distribute electricity, not to accept it. On a sub-level, solar panels installed on private roofs deliver their electricity to the low-voltage (LV) grid. The capacities of cables and transformers in residential areas are sized to deliver electricity from generator to consumer, and not the other way around. Liander has indicated that capacity is sufficient to deal with privately owned solar for now, but that the significant increase envisioned by the city of Amsterdam will pose a problem in the future.

Offshore wind power plants are subject to adverse electrical conditions that are more severe than onshore cases, due to the long cable connection to the shore. Among these conditions are amplified voltage distortion at (inter)harmonic frequencies, as well as stability issues. An important aspect of wind turbine generator control is the phase-locked loop (PLL), a method to synchronize the output current with the grid voltage. In the case of voltage distortion, an error occurs in the estimated phase-angle of the PLL, which results in an additional distortion in the output current. This research focuses on 5 different variants of PLLs and compares their behaviour when implemented in a grid-side inverter of a wind turbine. The comparison is based on deriving the equivalent small-signal output impedance of the inverter for each PLL, which can be used for stability analysis of the wind farm connected to the onshore grid by a typical cable connection. A conclusion is drawn on the effect of each PLL variant on the output distortion as well as the stability.

In this thesis, an algorithm that calculates the hosting capacity of independent PV, or EV charger systems was created. The hosting capacity is based on slow voltage variations and voltage unbalances caused by worst case PV generation and EV charging scenarios. The algorithm was run for four different commercial and industrial networks, and a range of network impedances. The outcome of the algorithm resulted into two figures for each of the networks, representing the possible installed capacity of PV and EV charger systems, respectively.