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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Quantifying sustainability for industry: a New Zealand electricity power sector case study

Cheng, Bernard Cho Ming January 2008 (has links)
Sustainable development is now being recognised as a vital component of our society in the environmental, ethical, social, technological, economic, and institutional aspects, or dimensions, so, this thesis develops a framework to quantitatively measure sustainability. This thesis is distinctive in that it focuses on quantitative methods encapsulated in a formal assessment procedure and includes sustainability concepts that have rarely been put into practical use in sustainability reports. The framework is designed along the strategy that the methodology needs to be scale invariant and recursive, meaning the procedure is the same irrespective of the scale the user is interested in, and that different people can focus at different levels of sustainability by following a similar procedure. While the quantification process is aimed to be as unbiased as possible, a configuration of the tools from Total Quality Management (TQM) is adapted to identify sustainability indicators which are then mapped onto a scalar with mathematical functions. The sustainability indices are presented according to the amount of details needed by different users ─ some may need just one overall figure while others may need sustainability indices broken down by the six sustainability dimensions and presented on a spider diagram, while others may need all the details for analysis. This methodology also caters for sustainability analysis by different stakeholders. To fully demonstrate the potential of the methodology, the author has chosen to test it on a large-size industry sector so that it can have the capacity to be scaled up to a country or down to a small business, and on an industry sector that is important on its own right. Furthermore, this sector needs to be illustrative and has nontrivial complex problems. Under these criteria, the electricity sector of New Zealand was selected. The robustness of the methodology was investigated with inputs from three evaluators with different views: a standard view from the author that was made after much research in the sector and in the concepts of sustainability, a view with an environmental bias and one that focuses on commercial interests.
2

Quantifying sustainability for industry: a New Zealand electricity power sector case study

Cheng, Bernard Cho Ming January 2008 (has links)
Sustainable development is now being recognised as a vital component of our society in the environmental, ethical, social, technological, economic, and institutional aspects, or dimensions, so, this thesis develops a framework to quantitatively measure sustainability. This thesis is distinctive in that it focuses on quantitative methods encapsulated in a formal assessment procedure and includes sustainability concepts that have rarely been put into practical use in sustainability reports. The framework is designed along the strategy that the methodology needs to be scale invariant and recursive, meaning the procedure is the same irrespective of the scale the user is interested in, and that different people can focus at different levels of sustainability by following a similar procedure. While the quantification process is aimed to be as unbiased as possible, a configuration of the tools from Total Quality Management (TQM) is adapted to identify sustainability indicators which are then mapped onto a scalar with mathematical functions. The sustainability indices are presented according to the amount of details needed by different users ─ some may need just one overall figure while others may need sustainability indices broken down by the six sustainability dimensions and presented on a spider diagram, while others may need all the details for analysis. This methodology also caters for sustainability analysis by different stakeholders. To fully demonstrate the potential of the methodology, the author has chosen to test it on a large-size industry sector so that it can have the capacity to be scaled up to a country or down to a small business, and on an industry sector that is important on its own right. Furthermore, this sector needs to be illustrative and has nontrivial complex problems. Under these criteria, the electricity sector of New Zealand was selected. The robustness of the methodology was investigated with inputs from three evaluators with different views: a standard view from the author that was made after much research in the sector and in the concepts of sustainability, a view with an environmental bias and one that focuses on commercial interests.
3

The Viability of Installing Mid-Size PV Solar Parks in Sweden : "A paper that evaluates the economic viability of installing mid-size PV solar parks ranging from 250 kW to 2 MW in the village of Åled."

Ghebre, Temesghen Tesfazghi January 2017 (has links)
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.
4

Prediction of the Impact of Increased Photovoltaics Power on the Swedish Daily Electricity Spot Price Pattern / Prediktion av påverkan från ökad solelproduktion på det dagliga elspotprismönstret i Sverige

Fahlén, Saga January 2022 (has links)
As the demand for electricity increases throughout the globe while we want to reduce the use of fossil fuels, the need for renewable energy sources is bigger than ever. In countries where solar power makes up a large part of the total energy production, the overall electricity spot price level has become lower. This thesis investigates the underlying mechanism that drives the energy market, and in specific, how the solar power impacts the electricity spot price. We present results from studies made in other markets, and introduce a Regime Switching model for explaining the impact in Sweden. We show that an increase of photovoltaics power has a price lowering effect on the daily price pattern in price area SE3 and SE4.
5

Stochastic Modeling Of Electricity Markets

Talasli, Irem 01 January 2012 (has links) (PDF)
Day-ahead spot electricity markets are the most transparent spot markets where one can find integrated supply and demand curves of the market players for each settlement period. Since it is an indicator for the market players and regulators, in this thesis we model the spot electricity prices. Logarithmic daily average spot electricity prices are modeled as a summation of a deterministic function and multi-factor stochastic process. Randomness in the spot prices is assumed to be governed by three jump processes and a Brownian motion where two of the jump processes are mean reverting. While the Brownian motion captures daily regular price movements, the pure jump process models price shocks which have long term effects and two Ornstein Uhlenbeck type jump processes with different mean reversion speeds capturing the price shocks that affect the price level for relatively shorter time periods. After removing the seasonality which is modeled as a deterministic function from price observations, an iterative threshold function is used to filter the jumps. The threshold function is constructed on volatility estimation generated by a GARCH(1,1) model. Not only the jumps but also the mean reverting returns following the jumps are filtered. Both of the filtered jump processes and residual Brownian components are estimated separately. The model is applied to Austrian, Italian, Spanish and Turkish electricity markets data and it is found that the weekly forecasts, which are generated by the estimated parameters, turn out to be able to capture the characteristics of the observations. After examining the future contracts written on electricity, we also suggest a decision technique which is built on risk premium theory. With the help of this methodology derivative market players can decide on taking whether a long or a short position for a given contract. After testing our technique, we conclude that the decision rule is promising but needs more empirical research.
6

Analýza a rizikovost spotových kontraktů s elektřinou / An analysis and a risk of spot energy contracts

Martinec, Adam January 2014 (has links)
This diploma thesis deals with spot energy trading in the Czech Republic. The first section focuses on legal market environments, market members, and types of individual markets. This serves as an introduction to the second and the final section, which answers the question of the advantageousness of spot energy trading. The final section illustrates a practical demonstration of an optimization analysis of energy costs in a particular company. The contribution of this thesis, in my opinion, is the practical description of the calculation of energy costs in one company or an association of companies, which are considering the spot energy purchase, and a transfer of the responsibility for the deviation.
7

Model Predictive Control for Ground Source Heat Pumps : Reducing cost while maintaining comfort

Bokne, Isak, Elf, Charlie January 2023 (has links)
Today, the control of heat pumps aims to first and foremost maintain a comfortable indoor temperature. This is primarily done by deciding input power based on outside temperature. The cost of electricity, which can be rather volatile, is not taken into account. Electricity price can be provided on an hourly rate, and since a house can store thermal energy for a duration of time, it is possible to move electricity consumption to hours when electricity is cheap. In this thesis, the strategy used in the developed controller is Model Predictive Control (MPC). It is a suitable strategy because of the ability to incorporate an objective function that can be designed to take the trade-off between indoor temperature and electricity cost into account. The MPC prediction horizon is dynamic as the horizon of known electricity spot prices varies between 12 and 36 hours throughout the day. We model a residential house heated with a ground source heat pump for use in a case analysis. Sampled weather and spot price data for three different weeks are used in computer simulations. The developed MPC controller is compared with a classic \textit{heat curve} controller, as well as with variations of the MPC controller to estimate the effects of prediction and model errors.  The MPC controller is found to be able to reduce the electricity cost and/or provide better comfort and the prioritization of these factors can be changed depending on user preferences. When shifting energy consumption in time it is necessary to store thermal energy somewhere. If the house itself is used for this purpose, variations in indoor temperature must be accepted. Further, accurate modeling of the Coefficient of Performance (COP) is essential for ground source heat pumps. The COP varies significantly depending on operating conditions and the MPC controller must therefore have a correct perception of the COP. Publicly available weather forecasts are of sufficient quality to be usable for future prediction of outside temperature. For future studies, it would be advantageous if better models can be developed for prediction of global radiation. Including radiation in the MPC controller model would enable better comfort with very similar operating costs compared to when the MPC controller does not take radiation into account.

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