Flex-Efficiency

FLEX-EFFICIENCY Flex-Efficiency / Nabe, Christian A. (Rights reserved) ( -

Der Spotmarktpreis als Index für eine dynamische EEG-Umlage

DER SPOTMARKTPREIS ALS INDEX FÜR EINE DYNAMISCHE EEG-UMLAGE Der Spotmarktpreis als Index für eine dynamische EEG-Umlage / Nabe, Christian A. (Rights reserved) ( -

Renewable Electric Energy Integration: Quantifying the Value of Design of Markets for International Transmission Capacity

Integrating large quantities of supply-driven renewable electricity generation remains a political and operational challenge. One of the main obstacles in Europe to installing at least 200 GWs of power from variable renewable sources is how to deal with the insufficient network capacity and the congestion that will result from new flow patterns. We model the current methodology for controlling congestion at international borders and compare its results, under varying penetrations of wind power, with a model that simulates an integrated European network that utilises nodal/localised marginal pricing. The nodal pricing simulations illustrate that congestion - and price - patterns vary considerably between wind scenarios and within countries, and that a nodal price regime could make fuller use of existing EU network capacity, introducing substantial operational cost savings and reducing marginal power prices in the majority of European countries.Power market design, renewable power integration, congestion management, transmission economics

The regional species richness and genetic diversity of Arctic vegetation reflect both past glaciations and current climate

AIM : The Arctic has experienced marked climatic differences between glacial and interglacial periods and is now subject to a rapidly warming climate. Knowledge of the effects of historical processes on current patterns of diversity may aid predictions of the responses of vegetation to future climate change. We aim to test whether plant species and genetic diversity patterns are correlated with time since deglaciation at regional and local scales. We also investigate whether species richness is correlated with genetic diversity in vascular plants. LOCATION : Circumarctic. METHODS : We investigated species richness of the vascular plant flora of 21 floristic provinces and examined local species richness in 6215 vegetation plots distributed across the Arctic. We assessed levels of genetic diversity inferred from amplified fragment length polymorphism variation across populations of 23 common Arctic species. Correlations between diversity measures and landscape age (time since deglaciation) as well as variables characterizing current climate were analysed using spatially explicit simultaneous autoregressive models. RESULTS : lts Regional species richness of vascular plants and genetic diversity were correlated with each other, and both showed a positive relationship with landscape age. Plot species richness showed differing responses for vascular plants, bryophytes and lichens. At this finer scale, the richness of vascular plants was not significantly related to landscape age, which had a small effect size compared to the models of bryophyte and lichen richness. MAIN CONCLUSION : Our study suggests that imprints of past glaciations in Arctic vegetation diversity patterns at the regional scale are still detectable today. Since Arctic vegetation is still limited by post-glacial migration lag, it will most probably also exhibit lags in response to current and future climate change. Our results also suggest that local species richness at the plot scale is more determined by local habitat factors.Compilation of the species richness data was made possible through the TFI Networks grant to CD, “Effect Studies and Adaptation to Climate Change,” under the Norforsk initiative (2011 – 2014) which supported two CBIONET-AVA workshops held in Denmark during 2013. The genetic studies were funded by the Research Council of Norway (grant nos. 150322/720 and 170952/V40 to CB).http://http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1466-82382017-04-30hb2016Plant Production and Soil Scienc

Averting biodiversity collapse in tropical forest protected areas

The rapid disruption of tropical forests probably imperils global biodiversity more than any other contemporary phenomenon¹⁻³. With deforestation advancing quickly, protected areas are increasingly becoming final refuges for threatened species and natural ecosystem processes. However, many protected areas in the tropics are themselves vulnerable to human encroachment and other environmental stresses⁴⁻⁹. As pressures mount, it is vital to know whether existing reserves can sustain their biodiversity. A critical constraint in addressing this question has been that data describing a broad array of biodiversity groups have been unavailable for a sufficiently large and representative sample of reserves. Here we present a uniquely comprehensive data set on changes over the past 20 to 30 years in 31 functional groups of species and 21 potential drivers of environmental change, for 60 protected areas stratified across the world’s major tropical regions. Our analysis reveals great variation in reserve ‘health’: about half of all reserves have been effective or performed passably, but the rest are experiencing an erosion of biodiversity that is often alarmingly widespread taxonomically and functionally. Habitat disruption, hunting and forest-product exploitation were the strongest predictors of declining reserve health. Crucially, environmental changes immediately outside reserves seemed nearly as important as those inside in determining their ecological fate, with changes inside reserves strongly mirroring those occurring around them. These findings suggest that tropical protected areas are often intimately linked ecologically to their surrounding habitats, and that a failure to stem broad-scale loss and degradation of such habitats could sharply increase the likelihood of serious biodiversity declines.Keywords: Ecology, Environmental scienc

Efficient Integration of Renewable Energies in the German Electricity Market

Im Rahmen der Liberalisierung der Elektrizitätswirtschaft wird eine zunehmende Durchführung von Koordinationsaufgaben des Elektrizitätsversorgungssystems durch Märkte und Marktpreise angestrebt. In dieser Arbeit wird untersucht, wie Strommärkte gestaltet sein müssen, um eine effizienten Durchführung von Koordinationsaufgaben, die durch die Integration von Anlagen zur Nutzung erneuerbarer Energien in das System entstehen, zu gewährleisten. Die ermittelten Gestaltungsrichtlinien werden an der gegenwärtigen deutschen Marktgestaltung gespiegelt, um Handlungsempfehlungen abzuleiten. Zur Untersuchung wird der industrieökonomische Strukur-Verhalten-Ergebnis Ansatz angewendet, nach dem die Marktergebnisse unterschiedlicher Regulierungen von Marktstrukturen und Marktverhalten verglichen werden, um daraus Rückschlüsse auf die Effizienz der Regulierungsform abzuleiten. Die Integration von erneuerbaren Energien führt zu keinen grundsätzlich neuen Koordinationsaufgaben, sondern erschwert die in jedem Elektrizitätsversorgungssystem bestehenden. Im kurzfristigen Zeitbereich handelt es sich vor allem um die Bereitstellung und den Einsatz von Reserveleistung. Im langfristigen Zeitbereich betrifft dies die Abstimmung des Kraftwerksparks hinsichtlich der Verhältnisse von Investitions- zu Betriebskosten der einzelnen Kraftwerke und seiner Flexibilitätsstruktur auf die Charakteristika der erneuerbaren Energien. Die kurzfristigen Koordinationsaufgaben mit dem Netz bestehen aus erhöhten Anforderungen an das Netzengpassmanagement zur Erzielung eines kostenoptimalen Redispatchs. Langfristig muss zwischen den Kosten des Netzausbaus und des dauerhaften Engpassmanagements abgewogen werden. Bei der Durchführung der von erneuerbaren Energien beeinflussten Koordinationsaufgaben sind im kurzfristigen Zeitbereich zentrale und integrierte Marktarchitekturen den dezentraleren Architekturen überlegen: Die Erhöhung von kurzfristigen Koordinationsanforderungen erneuerbaren Energien durch die Inflexibilitäten von Erzeugern und Verbrauchern bedeutet eine erhöhte Informationsdichte, die bei der Koordination berücksichtigt werden muss. Werden diese Informationen in einem Markt zentralisiert, kann eine erhöhte produktive Effizienz des Kraftwerkseinsatzes erzielt werden. In Deutschland werden die gestiegenen Koordinationsaufgaben durch die Integration von Windgeneratoren geprägt. Die bestehende Marktarchitektur weist bei der Koordination im kurzfristigen Zeitbereich Ineffizienzen auf. Diese zeigen sich bei einer Analyse der Durchführungsregeln des Regelenergiemarktes sowie der dort erzielten Marktergebnisse in Form von deutlichen Abweichungen von wettbewerblichen Preisen. Die indirekte Integration von erneuerbaren Energien in den Strommarkt führt zu zusätzlichen Transaktionskosten durch Profiltransformationen. Die im Jahr 2004 erfolgte Novelle des Erneuerbare Energien Gesetzes, das die Marktintegration definiert, enthält Maßnahmen zur Verminderung dieser Ineffizienzen, jedoch wird am Prinzip der indirekten Integration festgehalten. Auf Basis der Analyseergebnisse werden Veränderungen der Regulierung der Marktstruktur vorgeschlagen. Eckpunkte sind die die Einführung einer Direktvermarktung sowie die Zentralisierung und Integration von kurzfristigen Koordinierungsaufgaben in einer Institution. Der Aufgabenbereich dieser Institution umfasst die Abwicklung des day-ahead-, intraday- und Regelenergiemarktes sowie des Netzengpassmanagements. Weiterer Forschungsbedarf besteht in der Quantifizierung von Effizienzgewinnen durch die vorgeschlagenen Maßnahmen sowie zur Analyse der Auswirkungen auf die Strompreisstruktur.Liberalisation of the electricity sector aims to carry out coordination tasks within the system by markets and market prices. This study examines how markets need to be designed to carry out coordination tasks caused by integration of renewable energies in an efficient way. This question is applied to the German electricity system and recommendations are derived from identified deficits. The examination uses the structure-conduct-performance approach of industrial organisation economics. Integration of renewable energies does not result in entirely new coordination tasks but complicates those that exist in any electricity supply system. Within the short-term coordination tasks provision and operation of reserve capacity is affected by renewable energies. Long-term coordination means that the relation between fixed and variable costs of generators as well as generator flexibility has to be adjusted to the characteristics of renewable energies. The relevant short-term coordination task with the network is congestion management. In the long run costs of grid expansion and permanent congestion management have to be balanced. For the execution of short-run coordination tasks integrated and centralised market architectures are superior to decentralised architectures. The increase of short-term coordination tasks due to renewable energies caused by inflexibilities of consumers and conventional generators results in more information that has to be considered. By centralising that information in one market, an increase in productive efficiency can be obtained. In Germany the increased coordination tasks are determined by the integration of wind generators into the electricity system. The present German market architecture results in inefficiencies in short-term coordination. This is demonstrated by an analysis of procedural rules and prices of the ancillary service markets. They demonstrate that market performance is low and significant deviations from competitive prices can be found. The indirect integration of renewable energies in the market results in additional transaction costs due to additional load profile transformations. The revision of the German electricity feed-in law of 2004 includes measures to reduce these inefficiencies, but the principle of indirect integration is maintained. Based on the results of the analysis, adaptations of the market structure are proposed: A direct commercialisation of electricity on the market by owners of renewable energy systems as well as a centralisation and integration of short-term coordination tasks in one institution. The main tasks of this organisation include the execution of the day-ahead, intra-day and ancillary service market as well as the network congestion management. Further research is necessary to quantify achievable efficiency gains by the proposed measures as well as the effects on the structure of electricity prices

Ultra high wind energy penetration in an isolated market

Paper presented at the IEEE Power and Energy Society 2008 PES General Meeting - Conversion and Delivery of Electrical Energy in the 21st Century, 20-24 July 2008, Pittsburgh, PA, USAThis paper addresses the market design implications of implementing ultra high (up to 42%) wind energy penetration in an isolated market. High wind penetration is becoming an increasing feature of many markets and the impact to such markets will need to be analyzed. In this paper, the Single Electricity Market (SEM) market design is analyzed in the context of increasing wind penetration and given the results of the recently published All Island Grid Study which indicated that ultra high wind capacity could be accommodated subject to certain key assumptions.Science Foundation IrelandConference websitehttp://ewh.ieee.org/cmte/PESGM08/Charles Parsons Energy Research AwardsCharles Parso