Search

This PhD thesis explores what can be considered a sustainable energy system on a global scale and what methods and tools can help sustainable energy policy design and assessment. Energy system modelling and sustainable energy system narratives are the two main areas of interest of this thesis. First current energy systems modelling practice was analyzed in the context of sustainable energy development, as well as how social science contributes to research focusing on sustainable energy. This revealed several main research gaps related to the topic of this thesis, including: (1) Most of existing energy system models have unrealistic or oversimplified assumptions that can negatively impact the quality of the models’ outputs and consequently the quality of decision-making informed by such models; (2) There is a limited instrumental value of the available theories related to sustainable energy system development; (3) Current practice lacks global energy system narratives that would contribute a holistic understanding of the purpose and long-term goals of the energy system. Global energy system narratives would also contribute to the principles of sustainable design of the energy system. The remainder of the thesis became an attempt to close these identified research gaps in order to answer the main research questions. System dynamics, steady-state economics and energy justice theory are the main methodological and conceptual components of the thesis’ research design. The contribution of the thesis includes: 1. A list of questions defining the current energy paradigm which can be used as a guidance for a sustainable energy system modelling; 2. A developed steady state of energy concept implying that energy sufficiency should be a universal energy system goal in the context of a long-term energy system sustainability; 3. A list of requirements for a socially sustainable energy provision based on energy justice principles. This list can be used as guideline for sustainable energy policy assessment and design; 4. A system dynamics model of electricity access provision in Sub-Saharan Africa. The model demonstrates an example of how energy system modelling: i) can be combined with sustainable energy system narratives for addressing methodological and disciplinary gaps in energy system research and ii) can contribute to better sustainable energy system policy design and assessment., This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 675153

Tækifæri á sviði ferðaþjónustu og nýtingar orkuauðlinda eru oft nefnd sem leiðir til þess að takast á við breytta atvinnuhætti, sporna við fólksfækkun í dreifbýli og skapa verðmæti. Báðar greinarnar nýta náttúruna sem auðlind en geta þær farið saman eða eru fyrirsjáanlegir hagsmunaárekstrar milli þeirra? Til þess að komast að því hvort ferðaþjónustuaðilar telji fyrirhugaðar virkjunarhugmyndir rýra möguleika ferðaþjónustunnar til að efla byggð í landinu voru tekin hálfstöðluð viðtöl við 65 ferðaþjónustuaðila á sex svæðum á landinu. Að mati viðmælenda er ferðaþjónustan sú atvinnugrein sem býður upp á mesta möguleika til framtíðar til að efla atvinnulíf í dreifbýli og höfðu þeir flestir séð þess glögg merki undanfarin ár. Margir viðmælenda töldu orkuvinnslu og ferðaþjónustu fara illa saman vegna neikvæðra áhrifa orkuvinnslu á náttúruna, grundvallarauðlind ferðaþjónustunnar. Óvissa um hvar verður virkjað í framtíðinni þótti jafnframt hafa tafið fyrir fjárfestingu og markaðssetningu í ferðaþjónustu á ákveðnum svæðum. Nokkrir viðmælenda nefndu dæmi um farsæla sambúð orkuframleiðslu og ferðaþjónustu og kom fram að góð samvinna milli greinanna gæti dregið úr hagsmunaárekstrum á milli þeirra. Þeir töldu að tekjur af báðum atvinnugreinunum mættu skila sér betur til svæðanna þar sem þær verða til., Opportunities in the tourism industry along with the harnessing of energy resources are commonly referred to as means of dealing with changes in employment structure, to counteract depopulation in rural areas, and as a way to create capital. Both fields utilize nature as a resource, but can they coexist or are conflicts foreseeable? In order to find out whether the tourist industry consider that proposed power plant developments will diminish the possibilities of the tourism sector to strengthen local settlements semi-structured interviews were conducted with 65 tourist service providers in six different parts of Iceland. In the opinion of the interviewees the tourism sector is the industry that offers the best long-term possibilities to strengthen the economy in rural areas and most of them had seen clear indications of this in recent years. Many interviewees felt that energy production and tourism do not concur because the negative effects energy production can have on nature, the core resource for the tourist industry. Uncertainty over where power developments will be located was thought to have delayed investment and marketing efforts in certain areas. A few of the interviewees mentioned examples of successful cohabitation of energy production and tourism and it was pointed out that favourable collaboration between the two industries could diminish their conflict of interest. Moreover, it was stated that the income from both industries could reach the areas where it was generated more effectively.

Low temperature geothermal resources provide hot water that is commonly used for space heating and various applications. A geothermal resource is considered to be a renewable energy source that can be utilized by current and future generations if sustainability considerations are respected. The goal of this work is to determine if utilization of a geothermal reservoir can be optimized under sustainable operation. One way to carry out this kind of optimization is to connect reservoir and operational optimization models directly. The underlying reservoir model used here is a lumped parameter model (LPM). A LPM model can be used to simulate pressure (drawdown) changes in a low temperature reservoir with respect to harvesting levels. One scenario is to maximize the present value of profit where important parameters include production rate, water level (drawdown) and production capacity from which the profit can be calculated. Optimization over a time period subject to underlying developing constraints is often referred to as dynamic optimization. This problem is essentially a mixed integer non-linear dynamic optimization problem, often referred to as mixed integer dynamic optimization (MIDO). Three solution methods for the optimization problem are discussed, tested and compared. The parameters of the LPM are obtained by non-linear least square estimation where the LPM is essentially a simplified approach to characterize a spatially distributed reservoir. Data from four different geothermal fields are calibrated to the LPM, validated with split validation and the best calibrations chosen for the optimization application. Profit is first maximized assuming long-term production based on demand from historical data. Different performance indices for the geothermal utilization are then optimized and various scenarios are considered and compared under annually increased demand., Lághitajarðvarmasvæði eru auðlindir sem gera það kleift að heitt vatn sé nýtt til húshitunar fyrir heimili eða margskonar atvinnustarfsemi. Jarðvarmi er talin vera endurnýjanleg auðlind sem komandi kynslóðir munu geta nýtt sér að því tilskildu að sjálfbær nýting sé höfð að leiðarljósi. Markmiðið með þessu verkefni er að komast að því hvort hægt sé að besta sjálfbæra nýtingu á slíkri auðlind. Ein leið til að útfæra slíka bestun er að tengja forðafræðilíkan beint við rekstrar-bestunar líkan (e. operational optimization). Slíkt líkan er hægt að nota til að herma þrýstingsbreytingar (breytingar í niðurdrætti) í lágvarma jarðhitageymi (e. low temperature reservoir) með tilliti til framleiðslugetu. Taka má fyrir tilfelli þar sem hagnaður er bestaður þar sem mikilvægar breytur sem nota má til að reikna hagnað eru meðal annars, framleiðslustig, vatnshæð (niðurdráttur) og framleiðslugeta. Þegar bestað er yfir tímabil með undirliggjandi breytilegri skorðu er oft talað um hreyfina bestun (e. dynamic optimization). Þetta vandamál er í eðli sínu blendin ólínuleg hreyfin bestun (e. mixed integer non-linear dynamic optmization) oft kallað blendin hreyfin bestun (e. mixed integer dynamic optimization). Þrjár lausnaraðferðir eru ræddar, prófaðar og bornar saman. Kennistærðir forðafræðilíkansins eru fengnar með ólínulegri aðferð minnstu kvaðrata, en forðafræðilíkanið sýnir í eðli sínu fram á mikla einföldun á flóknu jarðvarmakerfi þar sem rúmfræðilegir eiginleikar kerfisins eru ekki teknir með inn í myndina. Gögn frá fjórum mismunandi jarðvarmasvæðum eru aðlöguð að forðafræðilíkaninu. Þessi aðlögun er staðfest og bestu niðurstöðurnar notaðar í bestuninni. Hagnaður er fyrst hámarkaður fyrir langvarandi vinnslu og m.v. að söguleg eftirspurn haldist óbreytt. Að lokum er mismunandi markföllum beitt til að besta nýtingu jarðvarmakerfa og margs konar tilvik eru skoðuð miðað við að eftirspurn sem byggð er á sögulegum gögnum aukist á árs grundvelli., I would like to thank Orkuveita Reykjavikur (Reykjavik Energy) for their funding anddata and Landvirkjun and Orkusjodur (The National Energy Authority) for funding. Myuniversity, Reykjavik University, School of Science and Engineering I thank for generalsupport and funding.