This report aims to make a comparison between the Swedish and Spanish electricity market, the design of new improvements that could achieve a better operation for both markets as well as the price forecasting for both spot markets. These enhancements are oriented to decrease electricity prices, energy use and the system CO2 emissions. Also, the main organizations of the market and their roles has been characterized, clarifying the functions of the Market Operator and the System Operator. In addition, the different markets, the trading products and the price formation have been explained and the picture of the market structure has been achieved with enough depth. Moreover, some of the most used methods in Time Series Analysis has been enumerated to understand which techniques are needed for forecast the electricity prices and the methodology used (Box-Jenkins Method) has been explained in detail. Later, all these methods have been implemented in an own code developed in Python 3.6 (TSAFTools .py) with the help of different statistics libraries mentioned during the method chapter. On the other hand, the description of the market situation has been carried out for both countries. Power installed capacity, electricity generation, average prices, main renewable technologies and policies to increase the renewable energy share has been analysed and corresponding described. Then, to estimate the market’s future spot electricity prices, ARIMA models have been selected to analyse the evolution of the day-ahead price using the TSAFTools.py. The final models show a proper performance in the two markets, especially in the Nordpool, achieving an RMSE: 37.68 and MAPE: 7.75 for the year in 2017 in Nordpool and a RMSE: 270.08 and MAPE: 20.24 in OMIE for 2017. Nordpool spot prices from 2015 to 2016 has been analysed too but obtaining a result not as good as the year 2017 with an RMSE: 49.01 and MAPE: 21.42. After this analysis, the strengths and weaknesses of both markets are presented and the main problems of the Spanish electricity system (power overcapacity, fuel dependency, non-cost-efficient renewable energies policies, lack of interconnexion capacity etc.) and the Swedish electricity system (dependency for nuclear power, uncertainty for solar electricity Generation) are presented. Finally, due to the quick development of the energy sector in the last years and the concern of the European Committee to reach a new design for the electricity market, different kinds of recommendations for the future have been considered.

The objective of this report was to implement battery cycling and an intermittent current interruption (ICI) method for determining battery resistance into a simple lithium-ion battery model in the finite element methods (FEM) program COMSOL Multiphysics, andevaluate how accurately the model reflects the behaviour of voltage and internal resistance with respect to experimental results. The ICI technique consists of repeating the steps of first having a longer charging period and then having a short current interruption, where the internal resistance is calculated from the voltage drop that occurs when the current is turned off. The model was evaluated against measurements, made with the same technique (ICI), on assembled NMC-graphite batteries. Codes written in the statistical programming language “R” were used to process the data from both COMSOL and the experiments. Both the batteries and the model were constructed with a reference electrode, to enable measurement of each electrode by itself. The results as documented in this report show that it is possible to simulate the measurement technique in COMSOL, but that both the resistance and voltage profiles differed quite a lot from the behaviour of the tested batteries. The resistance of the positive electrode did however give good results and it was possible to improve the model by changing some parameters. The magnitude of the resistance, which was already quite close, could be improved by changing the porosity and particle size, and the voltage profiles were improved when using voltage-data achieved from the real measurements.

Abstract There are rural areas in Ghana which are off-grid but where there is a need for street lighting. Street lighting facilities in such areas typically store electrical power in lead-acid batteries. The goal of this thesis is to construct a facility where fuel cells and hydrogen accumulation replace lead-acid batteries. The construction consists of a solar cell which transmits DC power to an electrolyzer which in turn produces hydrogen and oxygen. The gases accumulate in the container until nightfall when it starts providing DC power to street lighting via a fuel cell. The street lights can operate between 5 - 10 hours per day, depending on the power of the lamp. Besides providing street lighting the device may also be used for other purposes such as indoor lighting, charging of mobile phones etc. This means that, in addition to the basic purpose of providing electrical power to the street lights, other co-benefits of social significance can be achieved. The device is designed not to create any harmful emissions during operation, thus being environmentally sustainable. Further research on the device may in a second step entail: Construction of a prototype on a smaller scale, where calculations and function are tested. If it turns out well, a third step can begin: To build a full scale plant to be tested on site in Ghana.

When speaking about energy it means speaking about life, activity, economy, growth and environmental issues. The issue of energy has been the main article all over the world in recent years, this is due to the importance of energy to life and its impact on the environment. For example, Paris climate change meeting in 2015 is one of the recent global meeting which directly related to the energy use by nations. The meeting was mainly focused up on the restriction of greenhouse gas emission which implies that industries should think about other alternative energy resources rather than fossil fuel for positive impact on climatic change. This is one of the cases that led industries into greater competition in the global market. Industries must consider energy alternatives which is safe for the environment and by using such energy a competitive product with better quality and quantity should be produced. This challenge has motivated industries to look and study the energy that they are using currently. Studies and researches show that one of the main and most abundant energy resources that most of these industries can get is by improving the energy efficiency or managing the energy that they currently use. The main aim of this thesis is to provide Arizona chemical plant (Kraton) at Sandarne on the potential energy saving by managing their energy use. The first wisdom in energy utilization is managing and using the energy they possess efficiently. In Arizona plant at Sandarne, the product named “Pitch” (a natural viscoelastic polymer or rosin) is a fuel used as the primary energy supply for the production of steam by boilers. The steam may be utilized well but the energy in the condensate (after steam loses its latent heat) is not addressed well enough. Hence this paper has studied on how significant is the energy lost by the steam condensate is and how its recovery can be used to save energy and cost. The plant produces about an average of 11.42 ton of steam each hour in a year. This steam can be returned or fully recovered (100%) as condensate from the law of conservation of mass since only energy is lost from the steam. But the plant returns a maximum of about 3ton of condensate each hour. This amount is relatively low compared to the amount of condensate recovery possibility. Recovery possibility of condensate return showed that the plant at Sandarne can return at least 8.5 ton of condensate  each hour. In comparison with the current return estimated 5.5 ton of condensate is being lost simply as waste each hour leading to about 400 SEK minimum cost loss. The calculation of cost is in minimum because the charge from water supply and condensate effluent disposal charge are not considered. In this paper only recovery from the easily recoverable steam condensate is being considered (25% of the system) which resulted in payback time of the proposed investment 1.88 years without considering the above explained charges. It is much motivating study considering the generalized approach and over simplified method. If a deeper investigation is made on the potential, it can be clearly shown that how significant the potential is in securing and sustaining energy and environmental issues. Ensuring the security and sustainability of energy which addresses the environmental issue precisely will help the plant to stay on the race of global market competition.   Keywords: Energy efficiency, Boiler efficiency, Energy management, Condensate recovery,

An existing furnace oil fired boiler is used to supply process steam to an instant tea manufacturing factory. The instant tea is manufactured the Broken Mixed Fannings (BMF) through extraction and other required processes. The average steam consumption of the plant is 6000 kg/h at 10 barg pressure. During the process, tea waste is generated at a nominal rate of 50,000 kg/day, about 2000 kg/h at around 70% MC content on wet basis. At the moment this waste tea is either dumped in the surrounding area by spending money or sent to landfilling purposes, which create environmental issues.   The tea waste coming out at 70% MC wet basis, is looked at to press through continuous belt press to reduce the moisture content to about 55% on wet basis. The water removed from this pressing process is sent to effluent treatment plant at the factory. The output from the belt press is sent to a steam operated  The average generation of tea waste from the instant tea manufacturing process process is about 2000 kg/h, after pressing in the belt press an output rate of about 1,400 kg/h at 55% MC. This amount of tea waste at 55% MC is sent to a rotary steam tube dryer and the MC is reduced from 55% to 30% and the output rate from the steam tube dryer is about 857 kg/h. The amount of steam consumed by the rotary steam tube dryer at 6 barg pressure is 760 kg/h. Then the tea waste from the rotary tube dryer is mixed with firewood of 30% MC and fed to the boiler to generate process steam, out of which 857 kg/h steam at 6 barg pressure is sent back to the rotary steam dryer. From tea waste alone, a steam amount of 2,472 kg/h can be supplied after giving steam to the rotary steam dryer. The balance steam amount of 3,528 kg/h for the process requirement is supplied by burning additional firewood at 30% MC content. The tea waste fuel and firewood in combination have an overall moisture content of 30% on wet basis. The boiler is rated at 10,000 kg/h F & A 100 deg C with an actual generating capacity of about 9000 kg/h at 10 barg operating pressure at 70 deg C feed water temperature. By implementing the combination of belt press, rotary steam tube dryer and firewood boiler in place of the existing furnace oil fired boiler, an annual monetary saving of 168 Mn SLR/year can be achieved with a simple payback period of 21 months which is a highly feasibly project.

The building sector consumes 32% of global energy used, and it is responsible for 20% of total greenhouse gases emissions. In Europe, more than one third of the buildings are 50 years or older, thus, it is critical that new dwellings are designed in the most efficient way from an energy perspective, since the consequences of the decisions taken today will remain during decades. The use of Building Information Modeling (BIM) software is promising for the design of a wide range of constructions; from small dwellings to big apartment buildings. These programs allow the architect, designer or civil consultant to perform several simulations of the energy behavior of a building in a timely manner, even before a single brick is put in place. Among them, IDA ICE software utilized in this thesis is a top rated program, situated by some authors within the four main building energy simulation tools. This is an outstanding fact considering that it is estimated in more than 400 the number of available BIM programs. With the help of IDA ICE it will be demonstrated that for a dwelling object of study, located in Madrid (Spain), it is possible to save up to 4 250€ through the entire life of the building if the proper orientation is chosen. The discussed literature and results will also show that orientation is, by far, the most critical passive design parameter related to a building, from which the efficacy of other related measures depends on.   It will be also proven that the optimal orientation depends on the weather where the dwelling is located, even though a general trend consisting in orienting the houses located in the northern hemisphere to the south, and vice versa, is observed. Building orientation, BIM programs, building energy consumption, passive design parameters, IDA-ICE simulation tool.

The ambition of the Swedish government is rapidly concentrating on the development of the renewable energy systems especially on wind energy, bio energy and solar energy. It has been observed on the growth of the production of electricity and heat from these three mentioned renewable energy systems. But, relatively in Sweden the share of production of electricity obtained from PV is quite smaller than the other two. The PV electricity production in Sweden comprises in a large scale of mainly the grid connected distributed PV systems and with a small number of installed solar parks. The aim of this paper is to analyze the viability of installing mid -size PV solar parks in Sweden and to simulate the effect of the proposed project in the village’s (Åled is the village where the proposed site is located) and the country’s electricity production. This study includes designing, simulation and financial analysis of different grid connected centralized mid -size capacities of PV solar parks of 250 kWp,500 kWp,1MWp and 2MWp. They are all fixed ground mounted systems. Moreover, it also discusses the main reasons that hinders decision makers, the PV complications that are connected to the grid, Sweden’s energy regulations particularly the emission regulation and the financial policies of PV. Also, study visit, telephone and email contacts have supplemented it. This study was done with the collaboration of Nyedal Solenergi, in which the proposed site was owned by the company and this paper will be a future guide for the investment of the mid-size PV solar park. According to the study a discussion has been made with the grid supplier (EON) in that area on the investment on one of the designed projects which are presented in this paper. The results of the study show that the effect of the proposed systems on the production of electricity in the village of Åled was between 2.68 – 21.4 % and the impact on the country’s PV electricity production was 0.2 – 1.58 %. And, the possibility of installing mid-size PV solar parks generally in Sweden particularly in the proposed site is possible and economically it is viable but not profitable for system capacities less than 1 MW. As the IRR found for all capacities is greater than the estimated WACC, hence each proposed capacity has the possibility of paying back all its investment costs in about 23 years. So, the profitability is very low in case of the 250 kWp and 500 kWp but for the others they have about 7-8 years of profitability. A sensitivity analysis also has shown the impact of initial investment costs, O & M costs and electricity export rate on the IRR, NPV and equity payback. The initial investment cost and electricity export rate were seen with high effect on the IRR, NPV and equity payback. The LCOE calculated was higher than the average electricity spot price (300 SEK/MWh) for 250 kWp and 500 kWp but lower for the other two capacities. The overall impact for the financial analysis was due to the decreasing of module prices, the rules that changes every year on electricity subsidies for renewables, tax reductions and rapid decreasing of electricity spot prices. In the future if the price of modules continues decreasing, spot price increases, more modification of the subsidy and introduction of new PV technologies integrated with other sources of energy is done then such projects could be more profitable.

During the 21st century there has been a rapid increase in grid-connected photovoltaic (PV) capacity globally, due to falling system component prices and introduction of various economic incentives. To a large extent, PV systems are installed on buildings, which means they are widely distributed and located close to the power consumer, in contrast to conventional power plants. The intermittency of solar irradiance poses challenges to the integration of PV, which may be mitigated if properly assessing the solar resource. In this thesis, methods have been developed for solar variability and resource assessment in the built environment on both national and local level, and have been applied to grid integration studies. On national level, a method based on building statistics was developed that reproduces the hourly PV power generation in Sweden with high accuracy; correlation between simulated and real power generation for 2012 and 2013 were 0.97 and 0.99, respectively. The model was applied in scenarios of high penetration of intermittent renewable energy (IRE) in the Nordic synchronous power system, in combination with similar models for wind, wave and tidal power. A mix of the IRE resources was sought to minimise the variability in net load (i.e., load minus IRE, nuclear and thermal power). The study showed that a fully renewable Nordic power system is possible if hydropower operation is properly planned for. However, the contribution from PV power would only be 2-3% of the total power demand, due to strong diurnal and seasonal variability. On local level, a model-driven solar resource assessment method was developed based on low-resolution LiDAR (Light Detection and Ranging) data. It was shown to improve the representation of buildings, i.e., roof shape, tilt and azimuth, over raster-based methods, i.e., digital surface models (DSM), which use the same LiDAR data. Furthermore, the new method can provide time-resolved data in contrast to traditional solar maps, and can thus be used as a powerful tool when studying the integration of high penetrations of PV in the distribution grid. In conclusion, the developed methods fill important gaps in our ability to plan for a fully renewable power system.

To maximize the effectiveness of the rapidly increasing capacity of installed wind energy resources, new models must be developed that are capable of more nuanced control of each wind turbine so that each device is more responsive to inflow events. Models used to plan wind turbine arrays and control behavior of devices within the farm currently make questionable estimates of the incoming atmospheric flow and update turbine configurations infrequently. As a result, wind turbines often operate at diminished capacities, especially in arrays where wind turbine wakes interact and inflow conditions are far from ideal. New turbine control and wake prediction models must be developed to tune individual devices and make accurate power predictions. To that end, wind tunnel experiments are conducted detailing the turbulent flow in the wake of a wind turbine in a model-scale array. The proper orthogonal decomposition (POD) is applied to characterize the spatial evolution of structures in the wake. Mode bases from distinct downstream locations are reconciled through a secondary decomposition, called double proper orthogonal decomposition (DPOD), indicating that modes of common rank in the wake share an ordered set of sub-modal projections whose organization delineates underlying wake structures and spatial evolution. The doubly truncated basis of sub-modal structures represents a reduction to 0.015% of the total degrees of freedom of the wind turbine wake. Low-order representations of the Reynolds stress tensor are made using only the most dominant DPOD modes, corrected to account for energy excluded from the truncated basis with a tensor of constant coefficients defined to rescale the low-order representation of the stresses to match the original statistics. Data from the wind turbine wake are contrasted against simulation data from a fully-developed channel flow, illuminating a range of anisotropic states of turbulence. Complexity of flow descriptions resulting from truncated POD bases is suppressed in severe basis truncations, exaggerating anisotropy of the modeled flow and, in extreme cases, can lead to the loss of three dimensionality. Constant corrections to the low-order descriptions of the Reynolds stress tensor reduce the root-mean-square error between low-order descriptions of the flow and the full statistics as much as 40% and, in some cases, reintroduce three-dimensionality to severe truncations of POD bases. Low-dimensional models are constructed by coupling the evolution of the dynamic mode coefficients through their respective time derivatives and successfully account for non-linear mode interaction. Deviation between time derivatives of mode coefficients and their least-squares fit is amplified in numerical integration of the system, leading to unstable long-time solutions. Periodic recalibration of the dynamical system is undertaken by limiting the integration time and using a virtual sensor upstream of the wind turbine actuator disk in to read the effective inflow velocity. A series of open-loop transfer functions are designed to inform the low-order dynamical system of the flow incident to the wind turbine rotor. Validation data shows that the model tuned to the inflow reproduces dynamic mode coefficients with little to no error given a sufficiently small interval between instances of recalibration. The reduced-order model makes accurate predictions of the wake when informed of turbulent inflow events. The modeling scheme represents a viable path for continuous time feedback and control that may be used to selectively tune a wind turbine in the effort to maximize power output of large wind farms.

The basic problem that this work wishes to address concerns the  unsustainable use of water resources in many places of the world. In some places, the problem leads to human suffering and death while also obstructing social and economic development. In other places, where the consequences are less severe, natural environments are seriously damaged. A significant part of the solution to this problem lies in the planning and decision-making domain. The overall aim of this thesis is therefore to contribute to the available knowledge on planning and management for the sustainable use of water resources. Planning as a process is in focus, both in itself and in the organisational and legal contexts that affect how planning processes are performed.   The main methodological approach used, and the theoretical contribution made here, is the deriving and discussion of a set of deductive criteria for the development and assessment of planning processes for the sustainable use of water resources (Papers III and IV). The criteria were derived using a multi-disciplinary approach, where the relevant literature on how to transform the concepts of ‘integration’ and ‘participation’ – both key principles for sustainable development in relation to planning – into an analytical framework of twelve criteria, was reviewed and synthesised. The derived criteria concern issues such as, how to integrate knowledge and values into the planning process and how to generate commitment, legitimacy or acceptance for the resulting plan, by democratic means. The criteria are then used to assess the EU Water Framework Directive (WFD) – an extensive legal framework which will steer water planning in the EU Member States for several decades to come – and to assess the planning processes that follows on from WFD implementation in Sweden.   The analysis contained in (Paper V) showed that the WFD erects few formal barriers to good planning practices. The analysis also showed however, that the planning processes that follow on from its implementation will need to be adapted to compensate for the weak legal support in a number of important areas, namely, the use of knowledge from beyond the natural sciences, the use of methodologies for the explicit handling of values and the use of procedures for democratic participation. Several recommendations are also made in respect of how the WFD could be supplemented in order for it to become a stronger support in planning processes for the sustainable use of water.   The analysis of the ongoing water planning processes in Sweden (Paper VI) showed that knowledge of how to work with values and how to create forms and methods of participation and collaboration remain clearly underdeveloped. In consequence, the main objectives behind participation – the provision of knowledge and perspectives for the process and the creation of legitimacy, acceptance or engagement – are actually at risk. Recommendations include complementing the existing knowledge base with insights from the social sciences and the humanities, to create well informed learning systems within the new water administration and to make use of alternative methods for the handling of values.   In addition to this, two papers from the thesis (Papers I and II) concern the situation pertaining before WFD implementation in Sweden. By comparing the system for municipal land and water planning (the former main system for long-term water planning in Sweden) with WFD prescriptions, and with the organisation of the new water administration bodies, some potential implications of WFD implementation were identified. From here it followed, that the development of forms of co-operation between the concerned administrative organisations, and in respect of the democratic involvement of the public and other concerned actors, were crucial in creating an integrative, effective and democratic system for water planning in Sweden.   The thesis also illustrates the use of a tentative model for the operationalisation of ‘sustainable development’. The tentative model is described in the thesis, and it constitutes the methodological baseline for the thesis, since five of the papers contained herein use various approaches related to this model.