Sweden has since a few years back suffered from a bottleneck in the power transmission lines stemming from a lack of “space” on the grid that transports the power that is generated in the northern parts to the middle and southern parts of the country. A long-term solution would be to increase the grid's capacity by building more transmission lines, however in the meantime, a short-term solution would be to increase our power flexibility. Meaning that the energy consumption gets moved from hours of high demand to hours with low demand and by shutting off equipment. This is called power flexibility and has been researched more in recent times in projects like this. This project will mainly focus on demand-side flexibility which is about how the consumers use their electrical power. In collaboration with Uppsala Arenor och Fastigheter, power usage in one of the company’s properties will be made more flexible. This is achieved by mapping how much power each part of the property utilizes and estimating how much power the electrical equipment in that area consumes. Then determining if that piece of equipment can be either rescheduled to avoid hours of high-powerdemand in Uppsala or turned off without causing major consequences to the property. From this it will be decided if it can be added as a flexibility resource and after that the total power flexibility of the facility will be tallied. Lastly, suggestions on how to implement the power flexibility resources and recommendations for further improvements in future projects will be made. The results of the project were that the selected property Studenternas had an average power usage of 185kW during the day and of that 38% could be utilized as a power flexibility resource. The total power flexibility was therefore 71.2 kW which comes from the laundry rooms and the arena lighting while the other places in the facility contributed with a neglectable amount.

The power balance of an electrical power system is crucial to the quality of the delivered electricity as well as the security of supply. In a scenario where Swedish nuclear power plants are being phased out and replaced by renewable energy sources new constraints are added to the power balance equation since the production of many renewable energy sources, such as wind and solar power, are intermittent by nature. This leads to a situation where the currently available regulating power might have difficulties to manage the increasing frequency fluctuations in the power grid. One possible solution to the problem is to build gas turbines for the purpose of peak power generation capacity. An alternative option would be to increase customer flexibility; that is Demand Response. This master thesis investigates how the market for Demand Respond can be designed and which potential Demand Response volumes different policy programs might release. This is done through a mixed approach. Firstly, a scientific review of previously documented Demand Response experiences compares and categorizes different Demand Response programs in a typology based on the parameters cost, volume and feasibility. Subsequently an interview series with different market agents, predominantly through interviews with the Swedish energy intensive industry, identifies the existing Demand Response potential in Sweden and offers the paradigm needed to transfer the results to a future hypothetical situation. The typology of Demand Response programs and estimation of the future industrial Demand Response potential in Sweden are the main new knowledge contributions of this master thesis. The scope however is limited to the Swedish market geographically and focuses on the time horizon 2020-2050. It is also assumed that only existing technologies are likely to be implemented on a large scale over the given time horizon. The results of this master thesis suggest that a Real Time Pricing model would realize the largest potential of Demand Response and to a relatively low cost. This solution however requires actions and further development of both the pricing model and in technology. Firstly, all market agents must have free access to real time price information, something that is lacking today. Secondly, a smart grid with hourly meters is required. If policymakers consider security of supply to be more important than a low system cost, Direct Control or a continuation of the Strategic Reserve is to be preferred according to the conclusions of this report. Previous studies have placed the existing potential for industrial Demand Response in Sweden between 600 and 900 MW. This report suggests that the available volume is in the upper region of the mentioned interval already today and has potential to rise significantly in the future as industries become more aware of the concept and the transmission grid is becoming more flexible. Another driving force for increased Demand Response volumes are the increased price fluctuations which are expected as a consequence of a greater share of renewable energy sources. For the future Demand Response potential, a cost perspective is introduced and a distinction between different response durations is made. More specifically the results indicate that the potential industrial Demand Response volume will be about 1,500 MW in 2030, given a response duration time of 4 h and a spot price on 2,000 SEK/MWh. If 1,500 MW of peak generation capacity could be avoided through active Demand Side Management, it would reduce the system cost with about 350 Million SEK annually. Consequently, there is a business case for Demand Response and the issue is likely to be subject to further investigation and discussion in the future. On the long term however industrial Demand Response must be compared with other flexibility options, e.g. as import/export or energy storages but also residential Demand Response, and is in such case likely to be outcompeted due to its relatively high variable cost of providing capacity.

The Postclassic (pre-conquest) Nahua often performed displays of religious devotion. Usually involving stripping victims of their skin, flesh and internal organs, these public, state-sanctioned rites have been understood as astonishing, even exceptional, for their brutality. As a consequence, scholars have focused on human sacrifice at the steps of the Templo Mayor; ritual away from the imperial capital Tenochtitlan has remained very poorly understood. Where attempts have been made to understand regional practices, scholars have generally assumed binary distinctions between central versus periphery or state versus local. Existing studies fail to appreciate Nahua ritual as fluid and dynamic, instead casting ceremonial behaviour across space as unrelated and fundamentally oppositional. Integrating the ethnohistorical and archaeological records, this thesis takes understandings of Nahua ritual in new directions by examining the relationship between the public arena, the sacred landscape and domestic spheres. Crucially, this thesis argues that rituals were sensitive to circumstantial pressures and personal imperatives, across hierarchies,space and time. In so doing, this study suggests a more fluid model for understanding Nahua ritual than binary distinctions can allow. A lack of appreciation for variation or agency in ritual performance has perpetuated the understanding that the Nahua were trapped in a cycle of ferocious ritualism which left little room for critical thought. Using alphabetic, pictorial and archaeological evidence for a rounded perspective, this thesis examines the intersection between official structures and personal agency to question the notion that all Nahuas unthinkingly repeated human sacrifice and other ritual bloodshed. This study argues that the household was a crucial arena for the normalisation of the blood debt which permitted the acceptance of mass public human sacrifice. This thesis finds that, within the Nahua's symbiotic worldview, activities of the temple, mountain and household rituals were mutually supporting. Moreover, it is shown that the Nahuas chose to adapt their rituals throughout the years, to suit individual preferences and environmental circumstances. Taken as a whole, my findings suggest that the Nahuas sought to control their daily existence by adapting rituals to assuage violent and impulsive supernatural forces.

In the region of Uppland, a shortage of electric power during cold days has emerged during the past years by virtue of the electrification of the society and industry in general. As a result, a power flexibility market managed by the CoordiNet project has commenced to hopefully create a more reliant, eco-friendly and accessible electricity supply. Uppsala kommun wishes to participate in the market but needs a solution for communication between market and technology and smart control methods. In this project, the solution to the problem, consisting of a mobile app, API, database, server and deep learning model, almost meets the requirements to participate on the market this autumn. With more time and resources, the product can hopefully be completed, enabling both economic and city growth in the region.

This thesis describes the flexible voltage control of a multi-level-voltage-reinjection voltage source converter. The main purposes are to achieve reactive power generation flexibility when applied for HVdc transmission systems, reduce dynamic voltage balancing for direct series connected switches and an improvement of high power converter efficiency and reliability. Waveform shapes and the impact on ac harmonics caused by the modulation process are studied in detail. A configuration is proposed embracing concepts of multi level, soft-switching and harmonic cancellation. For the configuration, the firing sequence, waveform analysis, steady-state and dynamic performances and close-loop control strategies are presented. In order not to severely compromise the original advantages of the converter, the modulated waveforms are proposed based on the restrictions imposed mathematically by the harmonic cancellation concept and practically by the synthesis circuit complexity and high switching losses. The harmonic impact on the ac power system prompted by the modulation process is studied from idealistic and practical aspects. The circuit topology being proposed in this thesis is developed from a 12-pulse bridge and a converter used classically for inverting power from separated dc sources. Switching functions are deduced and current paths through the converter are analysed. Safe and steady-state operating regions of the converter are studied in phasor diagrams to facilitate the design of simple controllers for active power transfer and reactive power generations. An investigation into the application of this topology to the back-to-back VSC HVdc interconnection is preformed via EMTDC simulations.

France is planning a strong development of solar photovoltaics (PV) and wind power in the medium term disrupting the power system. This Master Thesis analyzes the impacts of variable renewable energy production on the supply-demand balance from 2021 to 2025 in France. The model used relies on a dynamic programming method. The analysis is based on the assessment of indicators such as price signals, margins, loss of load duration (LOLD), expected energy not served (EENS) and nuclear drop stop that characterize the supply-demand balance and the security of supply of the electricity system. Wind power and PV are two very different technologies. Their load factor is very sizeable as it characterize their seasonality, variability and predictability and has an impact on all medium-term indicators. Wind power and PV have low marginal costs and their production is seasonal and in anti-phase. With new installed capacity, their added production in the supply-demand balance will substitute first the imports from the interconnections until saturation and then nuclear and thermal power plant production. Prices decrease with the same seasonality as the production and need to be considered when establishing the nuclear planning for the years to come. In addition a re-optimization of hydro power is observed. In terms of security of supply, wind power is more efficient than PV when assessing the reduction of LOLD but both are far from the performance of combined cycle gas turbines (CCGT). Lastly, the lack of nuclear production opportunities increases considerably more with PV due to a very localised production during the day which coincides in summer with periods of low consumption. Wind power and PV are two distinct technologies and should not be put in the same category when assessing their impact on the power system. / Frankrike planerar en stark utveckling av solceller (PV) och vindkraft på medellång sikt för att störa kraftsystemet. Detta examensarbete analyserar effekterna av varierande produktion av förnybar energi på balans mellan utbud och efterfrågan från 2021 till 2025 i Frankrike. Modellen som används bygger på en dynamisk programmeringsmetod. Analysen baseras på bedömningen av indikatorer som prissignaler, marginaler, förlust av lasttid (LOLD), förväntad energi som inte serveras (EENS) och kärnkraftsfallstopp som kännetecknar efterfrågan och utbudssäkerheten för el systemet. Vindkraft och solceller är två mycket olika tekniker. Deras belastningsfaktor är mycket stor eftersom den kännetecknar deras säsongsvariation, variation och förutsägbarhet och påverkar alla medellångsiktiga indikatorer. Vindkraft och solceller har låga marginalkostnader och deras produktion är säsongsbetonad och i fas. Med ny installerad kapacitet kommer deras extra produktion i utbuds- och efterfrågan att ersätta importen från sammankopplingarna till mättnad och sedan produktion av kärnkraft och värmekraftverk. Priserna sjunker med samma säsong som produktionen och måste beaktas när kärnkraftsplaneringen fastställs för de kommande åren. Dessutom observeras en återoptimering av vattenkraften. När det gäller försörjningstrygghet är vindkraft effektivare än solceller vid bedömning av minskningen av LOLD men båda är långt ifrån prestanda för kombinerade cykelturbiner (CCGT). Slutligen ökar avsaknaden av kärnkraftsproduktionsmöjligheter betydligt mer med solceller på grund av en mycket lokal produktion under dagen som sammanfaller på sommaren med perioder med låg konsumtion. Vindkraft och solceller är två olika tekniker och bör inte placeras i samma kategori när man bedömer deras inverkan på kraftsystemet.