<p>Vertical farming (VF) as a newer sector of controlled-environment agriculture (CEA) is proliferating as demand for year-round, local, fresh produce is rising. However, there are concerns regarding the high capital expenses and significant operational expenses that contribute to fragile profitability of the VF industry. Enhancing resource-use efficiency is a strategy to improve profitability of the VF industry, and different approaches are proposed in the three chapters of this dissertation. LEDs are used for sole-source lighting in VF, and although they recently have significantly improved electrical efficiency and photon efficacy, the Lambertian design of the illumination pattern leads to significant loss of obliquely emitted photons beyond cropping areas. In chapter 1, close-canopy lighting (CCL) is proposed as one effective energy-saving strategy, through which unique physical properties of LEDs were leveraged, and two CCL strategies (energy efficiency and yield enhancement) were characterized at four different separation distances between light-emitting and light-absorbing surfaces. Dimming to the same light intensity at all separation distances resulted in the same biomass production while significant energy savings occurred at closer distances. Significantly higher light intensity and yield were achieved under closer separation distances in the yield-enhancement strategy for the same energy input. The energy-utilization efficiency (g fresh/dry biomass per kWh of energy) was doubled in both scenarios when the separation distance between LED emitting surface and crop surface was reduced maximally. At reduced separation distances, the chance of photon escape from growth areas is less, and canopy photon capture efficiency is improved.</p><p>Optimizing environmental conditions for indoor plant production also helps improve resource-use efficiency for the nascent vertical-farming industry. Although significant technical advancements of LEDs have been made, use of efficient far-red (FR) LEDs has yet to be exploited. As a recent proposed extension to traditional photosynthetically active radiation (PAR, 400-700 nm), FR radiation (700-750 nm) contributes to photosynthesis as well as photomorphogenesis when added to shorter wavelengths of traditional PAR. However, the interaction of FR with other environmental parameters such as CO2 is less studied. In chapter 2, the interaction effect of four FR fluxes (as substitution for red) in combination with three different CO2 concentrations were investigated at three distinctive stages of young-lettuce production. The highest biomass achieved at all stages occurred at 800 mmol mol-1 CO2 compared to 400 and 1600 mmol mol-1. A photomorphogenic effect of FR to promote leaf length was pronounced at the earliest stages of development, at which FR did not contribute to higher biomass accumulation. At more developed stages, 20 mmol m-2 s-1 of FR substituting for red contributed to biomass accumulation similar to shorter wavelengths of traditional PAR, whereas higher fluxes of FR in the light recipe resulted in undesirable quality attributes such as longer leaves.</p><p>Optimizing environmental conditions for indoor production with emphasis on light intensity and CO2 concentration at four distinctive stages of lettuce production was investigated in chapter 3. Utilizing the Minitron III gas-exchange system, light and CO2 dose-response profiles were characterized at four distinctive crop-development stages through instantaneous gas-exchange measurements at crop level. At all developmental stages, as CO2 concentration increased, photosynthesis increased up to 500 mmol mol-1, above which the incremental rate of photosynthesis was reduced. Light-dose response profiles were characterized at 400 or 800 mmol mol-1 CO2, and as light intensity increased, photosynthesis increased up to 650 mmol m-2 s-1. However, when instantaneous power (Watts) consumed for lighting was taken into consideration, power-use efficiency as the ratio of output photosynthesis increment to input power increment (to increase light intensity), decreased at higher light intensities. Vertical farming as a nascent and growing industry is facing limitations including marginal and even elusive profitability. Optimizing environmental conditions for indoor plant production such as these will help improve resource-use efficiency and profitability of the vertical farming industry.</p>

This paper focuses on exterior lighting strategies for suburban green areas in Stockholm, using the Nytorps gärde case study as an example. The research methodology employed includes a literature review, a survey, quantitative measurements, and expert interviews. The study highlights the importance of sustainable urban spaces, the inherent conflict in meeting the needs of both people and the ecosystem and proposes strategic measures for green spaces, including a proposed solution for a footpath involving low energy consumption and reduced feelings of threat, whilst at the same having a minimal light pollution footprint. The importance of involving and considering the nocturnal environment in urban planning is emphasised, with a proposal for light/night planning at a strategic level. Local and general strategies are proposed as are implementing good light pollution discipline and lighting controls. The thesis aims to provide lighting design guidance for the proposed development while advocating for the preservation of darkness, the importance of listening to women and girls in shaping the nocturnal environment, and a proposal for time-based light interventions that respect the dark environment.

Two phenomena form the basis for this thesis; bad lighting for children and our connection to nature. The former has somehow largely stayed unchanged through the years, the second one is rapidly changing for the worse. Lighting in spaces designed for children in Sweden often seem like an afterthought focusing on the quantitative aspects, ignoring the qualitative; following standards but often forgetting who the space is meant for. At the same time, cities are becoming denser, making nature something many people actively have to seek out to experience - children’s definition of nature is slowly changing.How can outdoor lighting for children become better? Using the Ringmuren preschool in Uppsala, Sweden, as a case study, this thesis proposes an alternative way of thinking when designing light for children and how it can encourage a connection to nature. The design proposal was made using interviews, site analysis, research and experiments inside a digital twin custom made for RIngmuren preschool. The direct result of this project is a digital twin and a lighting concept, but it also argues that the practicalities of analysing and designing lighting is one thing; getting the people in power to understand why good lighting is important is the first, and largest, hurdle. Producing good, affordable examples of good lighting design that can be applied to varying situations is a good place to start to at the least initiate a discussion.

Uniform lighting in public spaces like study rooms in libraries, is still a common practice. However, uniformly lit spaces are unable to simultaneously meet the needs of multiple users and can create dull environments. The objective of this thesis is to analyze users’ behavior under different lighting conditions in study rooms and investigate whether alternative lighting designs, which step away from uniformity, could be more beneficial than uniform lighting, from a human performance and well-being perspective.A uniformly lit study room in the library of KTH was chosen as the main case study of this investigation and was thoroughly analyzed and evaluated through qualitative and quantitative research. Under the initial hypothesis that the lighting in this study room does not meet its users’ needs and fails to create an inspiring and comfortable environment, three additional study rooms in different Swedish libraries were comparatively analyzed through observations, interviews, and questionnaires, so as to better understand individual users’ needs and lighting preferences in study rooms. The research revealed the existence of various types of users with different personal preferences regarding lighting in order to feel comfortable and alert. A new conceptual lighting proposal is presented for the study room in KTH library, following an uneven lighting approach that utilizes different lighting zones to accommodate individual needs and affect the sense of comfort, alertness, and ultimately, the well-being of multiple types of users.

The master’s thesis investigates daylight qualities and visitors’ perception in the central atriumof Medelhavsmuseet in Stockholm, Sweden. The investigation started from personal observationof the space where a feeling of darkness was experienced despite the existing skylight.The visitors’ perception of daylight and space were examined through a survey, and it wascompared to daylight simulations where it was proven that the museum’s daylight quality couldbe classified as a minimum. It is suspected that visitor perception of the space was consideredto be bright due to the use of artificial light, and the brightness of the prevailing weather conditionsduring the time of the survey (mid-April). The daylight conditions as per the survey andsimulations are considered to be sufficient if not a little muted during the lighter half of the year,but during the darker seasons, they are likely to be insufficient. Furthermore, it is proposed thatre-designing the skylight, changing the way the artwork is displayed or changing the materialof the skylight could drastically improve daylight quality, in turn benefiting visitor experience.

This thesis report deals with the meaning of dynamics in lighting in context of the current state oflighting technology and how certain aspects of those can be applied to a specific space.Former studies discovered that biophilic aspects in design can create great benefits for the usersof a space. Natural elements is what we humans most affiliate to. Based on those findings I implementedaspects of dynamics in lighting into my design proposal assuming to be able to give theusers of the MIDDLA space benefit by recreating some degree of ‘virtual biophilia’.MIDDLA is the laboratory of the Media Technology and Interaction Design department of KTH.Characteristics of these facilities are unique as it is located in the attic floor of the oldest buildingon campus which is rather restricted in terms of daylighting and room clearance. Focus is put onthe corridor to evolve into an extension of the laboratory itself as a study area.Future post-occupancy research could be worthwhile of being conducted in combination with furtherdevelopment of the lighting design.

Detta examensarbete riktar sig in på att undersöka olika typer av solceller, batterier och lampor för att ta fram och jämföra två system av solcellsdriven gatubelysning i Stockholm och Kiruna. Sverige befinner sig väldigt norr ut på jordklotet vilket innebär en stor kontrast i soltimmar under sommar- och vinterhalvåret. Arbetets huvudsyfte är att ta fram ett solcellsdrivet system där energi genererad under sommaren kan lagras i ett batteri och sedan kompensera för energiunderskottet under vintern. Resultaten visar att skillnaden av genererad energi är stor beroende på vilken solcell som används. Beroende på val av solceller skiljer sig även kravet på batterikapaciteten för respektive ort. Energiupptaget från solceller i Stockholm och Kiruna skiljer sig markant, detta beror på olikheten av globalstrålningen.  Resultaten från kostnadsberäkningen visar att belysningssystemen som studeras i arbetet är dyrare i Kiruna än i Stockholm, detta beror på skillnaden i krav på batterikapacitet utifrån genererad energi från solcellerna. Val av batteri- och solcellstyp har även en påverkan på kostnaden. / This thesis focuses on examining different types of solar cells, batteries, and lamps to develop and compare two systems of solar-powered street lighting in Stockholm and Kiruna. Sweden is located very north of the globe, which means a great contrast in sunny hours during the summer and winter months. The main purpose of the study is to develop a solar-powered system where energy generated during the summer can be stored in a battery and then compensate for the energy deficit during the winter. The results show that the difference in generated energy is large depending on which solar cell is used. Depending on the choice of solar cells, the requirement for battery capacity for each location also differs. The energy uptake from solar cells in Stockholm and Kiruna differs significantly, this is due to the difference in global radiation. The results from the cost calculations show that the lighting systems studied in the thesis are more expensive in Kiruna than in Stockholm, this is due to the difference in requirements for battery capacity based on the energy generated from the solar cells. The choice of battery and solar cell type also has an impact on the cost.

Reflector design stemmed from the need to shape the light emitted by candles or lamps. Over 2,000 years ago people realized that a mirror shaped as a parabola can concentrate light, and thus significantly boosts its intensity, to the point where objects can be set afire. Nowadays many applications require an accurate control of light, such as automotive headlights, streetlights, projection displays, and medical illuminators. In all cases light emitted from a light source can be shaped into a desired target distribution with a reflective surface. Design methods for systems with rotational and translational symmetry were devised in the 1930s. However, the freeform reflector shapes required to illuminate targets with no such symmetries proved to be much more challenging to design. Even when the source is assumed to be a point, the reflector shape is governed by a set of second-order partial non-linear differential equations that cannot be solved with standard numerical integration techniques. An iterative approach to solve the problem for a discrete target, known as the method of supporting ellipsoids, was recently proposed by Oliker. In this research we report several efficient implementations of the method of supporting ellipsoids, based on the point source approximation, and we propose new reflector design techniques that take into account the extent of the source. More specifically, this work has led to three major achievements. First, a thorough analysis of the method of supporting ellipsoids was performed that resulted in two alternative implementations of the algorithm, which enable a fast generation of freeform reflector shapes within the point source approximation. We tailored the algorithm in order to provide control over the parameters of interest to the designers, such as the reflector scale and geometry. Second, the shape generation algorithm was used to analyze how source flux can be mapped onto the target. We derived the condition under which a given source-target mapping can be achieved with a smooth continuous surface, referred as the integrability condition. We proposed a method to derive mappings that satisfy the integrability condition. We then use these mappings to quickly generate reflector shapes that create continuous target distributions as opposed to reflectors generated with the method of supporting ellipsoids that create discrete sets of points on the target. We also show how mappings that do not satisfy the integrability condition can be achieved by introducing step discontinuities in the reflector surface. Third, we investigated two methods to design reflectors with extended sources. The first method uses a compensation approach where the prescribed target distribution is adjusted iteratively. This method is effective for compact sources and systems with rotational or translational symmetry. The second method tiles the source images created by a reflector designed with the method of supporting ellipsoids and then blends the source images together using scattering in order to obtain a continuous target distribution. This latter method is effective for freeform reflectors and target distributions with no sharp variations. Finally, several case studies illustrate how these methods can be successfully applied to design reflectors for general illumination applications such as street lighting or luminaires. We show that the proposed design methods can ease the design of freeform reflectors and provide efficient, cost-effective solutions that avoid unnecessary energy consumption and light pollution.

Designing the elements of a theatrical production is a unique and often experimental process. This process changes from show to show, and it can be difficult for a viewer to differentiate mistakes from design choices without a background in lighting. That is why it is important to take a look at the design process step by step. Two goals I strove for when designing Savage In Limbo were, how the director's concept blended with a design and if the integrity of the designer's vision was evident on stage. To explore these goals, script analysis and consideration of the director's vision are two very important processes. Additionally, an exploration of the design process will better describe the growth and personal achievements of the design. This thesis will show the process of the lighting design for The University of Central Florida's 2011 production of John Patrick Shanley's Savage In Limbo. The project will highlight the design achievements and the goals explained previously, and create a formal dialogue on this specific design in order to provide insight into the process. When analyzing the design it was important that I assessed the process as well as the product by looking at whether the design met the expectations of the script and audience. This thesis will also explore how my past experiences, education and current skill level have prepared me for this design process in order to create a guideline for others interested in the development of knowledge needed for design.

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