Harnessing the Potential of Power-to-Gas Technologies. Insights from a preliminary analysis focused on Belgium

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Model Reduction in Capacity Expansion Planning Problems via Renewable Generation Site Selection

peer reviewedThe accurate representation of variable renewable generation (RES, e.g., wind, solar PV) assets in capacity expansion planning (CEP) studies is paramount to capture spatial and temporal correlations that may exist between sites and impact both power system design and operation. However, it typically has a high computational cost. This paper proposes a method to reduce the spatial dimension of CEP problems while preserving an accurate representation of renewable energy sources. A two-stage approach is proposed to this end. In the first stage, relevant sites are identified via a screening routine that discards the locations with little impact on system design. In the second stage, the subset of relevant RES sites previously identified is used in a CEP problem to determine the optimal configuration of the power system. The proposed method is tested on a realistic EU case study and its performance is benchmarked against a CEP set-up in which the entire set of candidate RES sites is available. The method shows great promise, with the screening stage consistently identifying 90% of the optimal RES sites while discarding up to 54% of the total number of candidate locations. This leads to a peak memory reduction of up to 41% and solver runtime gains between 31% and 46%, depending on the weather year considered

The Role of Power-to-Gas and Carbon Capture Technologies in Cross-Sector Decarbonisation Strategies

This paper proposes an optimisation-based framework to tackle long-term centralised planning problems of multi-sector, integrated energy systems including electricity, hydrogen, natural gas, synthetic methane and carbon dioxide. The model selects and sizes the set of power generation, energy conversion and storage as well as carbon capture technologies minimising the cost of supplying energy demand in the form of electricity, hydrogen, natural gas or synthetic methane across the power, heating, transportation and industry sectors whilst accounting for policy drivers, such as energy independence, carbon dioxide emissions reduction targets, or support schemes. The usefulness of the model is illustrated by a case study evaluating the potential of sector coupling via power-to-gas and carbon capture technologies to achieve deep decarbonisation targets in the Belgian context. Results, on the one hand, indicate that power-to-gas can only play a minor supporting role in cross-sector decarbonisation strategies in Belgium, as electrolysis plants are deployed in moderate quantities whilst methanation plants do not appear in any studied scenario. On the other hand, given the limited renewable potential, post-combustion and direct air carbon capture technologies clearly play an enabling role in any decarbonisation strategy, but may also exacerbate the dependence on fossil fuels

Global electricity network - Feasibility study

With the strong development of renewable energy sources worldwide, the concept of a global electricity network has been imagined in order to take advantage of the diversity from different time zones, seasons, load patterns and the intermittency of the generation, thus supporting a balanced coordination of power supply of all interconnected countries. The TB presents the results of the feasibility study performed by WG C1.35. It addresses the challenges, benefits and issues of uneven distribution of energy resources across the world. The time horizon selected is 2050. The study finds significant potential benefits of a global interconnection, identifies the most promising links, and includes sensitivity analyses to different factors, such as wind energy capacity factors or technology costs

Collaborative Virtual Screening Identifies a 2-Aryl-4-aminoquinazoline Series with Efficacy in an In Vivo Model of Trypanosoma cruzi Infection

Probing multiple proprietary pharmaceutical libraries in parallel via virtual screening allowed rapid expansion of the structure-activity relationship (SAR) around hit compounds with moderate efficacy against Trypanosoma cruzi, the causative agent of Chagas Disease. A potency-improving scaffold hop, followed by elaboration of the SAR via design guided by the output of the phenotypic virtual screening efforts, identified two promising hit compounds 54 and 85, which were profiled further in pharmacokinetic studies and in an in vivo model of T. cruzi infection. Compound 85 demonstrated clear reduction of parasitemia in the in vivo setting, confirming the interest in this series of 2-(pyridin-2-yl)quinazolines as potential anti-trypanosome treatments

Fifth European Dirofilaria and Angiostrongylus Days (FiEDAD) 2016

Peer reviewe

Siting Strategies for Variable Renewable Generation Assets in Capacity Expansion Planning Frameworks

In the eve of a climate crisis generated by the sustained combustion of fossil fuels across various economic sectors, decarbonising worldwide power systems has been a cornerstone in reaching net-zero targets in the upcoming decades. To this end, widely-available renewable energy sources (RES) such as solar irradiance or wind have been recently harnessed at scale in order to replace fossil-based generators in the electricity mix of power systems around the world. However, such resources are inherently variable on time scales ranging from minutes to years and integrating them in power systems typically complicates planning and operational procedures. Several solutions have been advocated to alleviate these issues, including the large-scale deployment of electricity storage systems or the implementation of demand response programs. Alternatively, since RES are heterogeneously-distributed in space and time, it has been suggested that siting RES electricity production assets so as to exploit this diversity may reduce the aggregate output variability of power plants as well as the residual electricity load (i.e., total load minus renewable production). The concept of renewable sources spatiotemporal complementarity formalises this idea and makes for the chief concept investigated in this thesis. The manuscript starts by revealing how connecting remote RES sites could lead to reduced probabilities of low-generation events. Then, a framework explicitly designed to assess the spatiotemporal complementarity between geographically dispersed RES assets is introduced and leveraged to devise optimisation models seeking to identify deployment patters with maximum complementarity among sites. Once an optimisation problem for siting RES assets based on complementarity criteria is made available, the value of spatiotemporal complementarity for power systems is assessed. Essentially, this is made possible via a multi-stage approach that works as follows. In the first stage, a highly-granular siting problem identifies a suitable set of sites where RES assets could be deployed according to a pre-specified criterion (e.g., spatiotemporal complementarity, output maximisation). In the second stage, the subset of previously identified sites is passed to a capacity expansion planning framework that sizes the power generation, transmission and storage assets that should be deployed and operated in order to satisfy pre-specified electricity demand levels at minimum cost. Furthermore, a third stage may also be leveraged should a more accurate estimation of the impact of different siting criteria on the operation of power systems is sought. This stage is formulated as a classical unit commitment and economic dispatch problem and, given the capacities of power generation, transmission and storage assets resulted from the second stage, provides a more detailed view on the daily operation of the power system assets. Finally, inspired by the workings of the aforementioned routine, a method to reduce the spatial dimension and decrease the computational burden of capacity expansion planning problems while preserving a detailed representation of RES assets is proposed

Strategies for Provision of Secondary Reserve Capacity to Balance Short-Term Fluctuations of Variable Renewable Energy

Recent trends and projections show a massive shift in power generation towards variable renewable energy (VRE), especially wind and solar PV. Renewable energy technologies are expected, in the upcoming decades, to become the primary source of electricity production and this will attract inherent design and operational challenges of power systems. One such challenge is posed by the ability of power systems to cope with short-term fluctuations, or intermittency, of variable renewable energy technologies. Strategies linked to this issue are related to the use of one specific subset of power system ancillary services, namely the active power control mechanism, responsible for the activation of primary, secondary and tertiary or reserves. The scope of this thesis is to develop and present a methodology that comes as solution to sizing and allocation of secondary reserves. The first part of the thesis (i.e. dimensioning of system-wide secondary reserve requirement) is based on high-resolution load and VRE generation time series. Input data is processed to represent more accurately the challenges secondary control has to cope with; and statistically analyzed according to predefined security-of-supply levels. Supplementary requirements of secondary reserve (SR) due to VRE extensions are also estimated. The second part of the project (i.e. reserve allocation throughout a proposed generic grid model) treats the joint optimization of the active power economic dispatch during normal operation (previously available as part of a grid optimization software) and the secondary reserve capacity allocation problem. It is mathematically formulated as a linear programming model and bound by generating units’ technical constraints, as well by the physical limitations of the transmission network. The output of the SR sizing methodology, validated for a case study on the Czech Republic’s power system, serves as an input to the optimization tool subsequently developed.Att upprätthålla en hög nivå av elförsörjningskvalitet till lägsta kostnad har alltid varit av största vikten för energisystemoperatörer. Medan förnybar energi blir mer tillgänglig, och med framtida utvecklingstrender och förväntade prognoser i åtanken, har den här situationen blivit ännu mer uppmärksammad och fått större betydelse. Förnybar energiteknik förväntas bli primärkällan för elproduktion under de kommande decennierna och kommer att utmana den nuvarande design och operationstrategier av dagens energisystem. Orsaken är att en ständig växande elproduktion baserat på solceller och vindkraft skapar en svårhanterad variabilitet i elsystemet som i sin tur översättas till produktionsprofiler med både stor frekvensvariation och begränsad styrbarhet. I detta sammanhang blir vikten av åtgärder för aktivt produktionskontroll och därmed utjämning av medfödda systemfluktuationer uppenbar. Strategier som löser denna frågan är beroende på aktiva systemkontrollmekanismer som kan delas upp i: primärt, sekundärt och tersiärt kontroll (eller således reserver). Syftet med detta examensarbete är att utveckla och testa en metod för optimal dimensionering och fördelning av sekundära reserver i ett nationellt kraftnät. Den första delen (dimensionering av sekundära reserver) tacklar komponenten av systemvarationer på kort sikt, oavsett den variabla kraftkällan (dvs. sol eller vind). De nämnda variationerna händer på en tidskala som är tillräcklig liten så att nödvändiga balanskorrigeringar kan ske via operativa reserver. Modellen är utvecklad runt högupplösningsbelastning och bildningstidsserier. Först, tidserienera applicerar en low-pass filter som tar bort stokastiska, högfrekventa spets för att kunna visa kraven för sekundära reserver under dess aktiveringstider. Användning av skillnaden mellan positiva och negativa fluktuationer leder till en optimering uppåt och neråt av sekundära reserver. Tidserierna klassificeras på grund av relevanta kriterier för varje fluktuationskälla. Analysen av den subsekventa fördelningen koncentrerar sig på de uppsättningar som delar samma statistiska egenskaper. En godtycklig önskad säkerhetsnivå (e.g. 95 %) beaktas och används för alla definerade kategorier, vilka summeras efteråt för att tydliggöra den totala kraven på kraftreserven. Slutligen utvecklas ett heuristisk tillvägagångsätt för att kunna uppskatta det ytterligare behovet av sekundära reserver in samband med den befintliga ökningen av variabel produktion i det studerade systemet. Metoden för dimensionering av sekundära reserver, som har validerats för Tjeckiens kraftsystem, fungerar som inmatning för optimeringsverktyget som har utvecklats därefter. Andra delen av projektet (alltså fördelning av reserver genom en föreslagen generisk nätmodell) behandlar punktoptimeringen för ekonomsik tilldelning av genererad elektricitet och problemet med fördelningen av sekundära reserver. Detta är matematiskt formulerad i form av en linear programmodell och är bunden av tekniska begränsnigar inom elgenereringsenheterna, samt fysiska begränsningar inom transmissionsnätverket. Modellen som avänds för utvecklingen av optimeringsverktyget är ett generisk eltnätverk med allmänna funktioner, likt ett typiskt centralamerikansk eller väst-afrikansk elnätverk (vattenkraftdominerad, hög men outvecklad solkraft och/eller vindkraft potential), med tanke på att elnätets generiska karaktär saknar den föreslagna reservfördelningsmetodens validering