The industry sector accounts for a vast amount of the world’s total energy use, as much as 37% during 2018. Using energy in a sustainable way is necessary from both an environmental and an economical perspective, and it is therefore relevant to take measurements that result in a more efficient use of energy. One way for industries to become more energy efficient is to recover the waste heat, which is energy that otherwise would go to waste. This report aims to find a method to recover and reuse the low temperature waste heat available at the life science company Cytiva’s production site in Uppsala, Sweden. The proposed solution will be to use the waste heat for heating a vertical greenhouse. The study will examine whether this is feasible, and also how installing photovoltaics affects the energy use. Furthermore, the environmental impact of operating the greenhouse with waste heat is also investigated by calculating the CO2 equivalent. The low temperature waste heat that Cytiva provides relevant for this study is 6683 kW, which will be used to heat up the greenhouse. Simulations in the software IDA ICE will be used to construct and simulate a model of the vertical greenhouse. Results from the simulations show that the chosen size, 25 x 50 x 35.5 meters, gives a good approximation according to the wanted temperature range, 18.3-32.2°C. Furthermore, the results imply that the total energy use, 790 652 kWh, and average power, 90.26 kW is less than the available waste heat and there is a large amount that still is unused. The CO2 equivalent is calculated to be 29 317 kg. A sensitivity analysis is made to evaluate the window-to-wall ratio as well as the size of the entire greenhouse. It showed that both parameters are critical and makes a big difference in the simulations.

L'intensité et la fréquence des feux de forêt ont augmenté dans les paysages nordiques, perturbant le cycle et le transport du carbone dans les continua terrestres-aquatiques. Cependant, l’effet des feux de forêt sur la dynamique du carbone lacustre reste méconnu en raison du manque d'études comprenant des comparaisons interrégionales et des bilans de carbone incluant différentes formes avec des destins (évasion, export, stockage) contrastés. Nous avons analysé la concentration et la proportion des formes dominantes du carbone (Carbone Organique Dissout (COD), Carbone Inorganique Dissout (CID), Carbone Organique Particulaire (COP), CO2, CH4) dans 54 lacs situés dans des bassins versants brûlés par rapport à des bassins versants témoins dans 3 régions nordiques tempérées et boréales du Québec et du Minnesota, sur un gradient de 3 ans après le feu. Dans l'ensemble, les lacs étaient plus semblables à l'intérieur des régions qu'entre les régions, indépendamment du feu, mais il y avait des effets intrarégionaux du feu. Le COD a augmenté dans les lacs des bassins versants brûlés malgré l'absence d'effet significatif sur les concentrations de CO2 et de CH4. En outre, les feux de forêt augmentent la contribution du COD aux bilans total de carbone du lac, ce qui favorise la réduction de la transparence de l'eau et augmente le potentiel de transformation in-situ du carbone par minéralisation. Ce changement de la dynamique de C dans les lacs, qui se traduit par une augmentation de la quantité et de la proportion de COD, suggère que les feux de forêt causent une exportation de carbone dans les bassins versant boréaux, dont le destin reste inconnu. Grâce à l'intégration de diverses formes de carbone ayant des taux de renouvellement et des destins différents, cette étude met en évidence un effet supplémentaire du feu sur le cycle du carbone, détectable à plus long terme que la perte directe de carbone terrestre due à la combustion de la végétation, dont l'importance au niveau du bassin versant reste à déterminer et qui pourrait avoir un impact sur le cycle du carbone à l'échelle mondiale. / Wildfires' intensity and frequency have increased across northern landscapes, disrupting carbon cycling and transport across terrestrial-aquatic continua. However, it remains unclear how lake carbon dynamics respond to fires due to the lack of studies including cross-regional comparisons and carbon budgets with more than two C forms. We analyzed the concentration and distribution of the dominant C forms (Dissolved Organic Carbon (DOC), Dissolved Inorganic Carbon (DIC), Particulate Organic Carbon (POC), CO2, CH4,) in 54 lakes in burned vs control catchments in three north temperate and boreal regions of Quebec and Minnesota within a 3-year post-fire gradient. Overall, lakes were more similar within than among regions regardless of fire, but there were intraregional fire effects. DOC increased in lakes in burned watersheds despite no significant effect on concentrations of CO2 and CH4. We showed that the fire effect was most apparent when accounting for climate and local geomorphologic lake properties. In addition, wildfires increase the contribution of DOC to whole-lake C budgets favouring reduction of water transparency and greater opportunity for in-situ carbon processing through mineralization. This lake C dynamic change through an increased quantity and proportion of DOC suggests a potential long-term firemediated carbon export with a yet undetermined fate in boreal watersheds. Through the integration of various C forms with different turnover rates and fates, this study highlights an additional fire effect on C cycling that is detectable at a longer time scale than the direct terrestrial C loss from burned vegetation which importance at the watershed level remains to be determined and may impact global C cycling.