In the Electric Reliability Council of Texas (ERCOT) compressed air energy storage (CAES) is currently viewed as the most promising energy storage technology due to Texas having suitable geology for CAES and few locations suitable for pumped-hydro storage. CAES is a proven technology but the economics for new facilities are uncertain. This work quantified the economic prospects for CAES in ERCOT as a function of installed wind capacity, natural gas price, and CAES capital cost. Two types of models were developed and used in this work. The first type of model was a CAES dispatch optimization model, which determined the maximum operating profits a CAES facility could earn given a set of electricity and ancillary services market prices. These models were used to examine several separate research questions relating to the maximum potential for CAES and the impact of uncertainty and other real-world complications. The models determined that the maximum operating profit from 2002-2010 varied widely from year to year and averaged $120-140/kW-year, which is likely below the operating profits required to justify investing in CAES. The models also determined that current price forecasting methods are sufficient to earn approximately 95% of the operating profits achievable with perfect knowledge of all prices in the year. The second type of model was a unit commitment model of ERCOT, which determined the least-cost operation of all the generators in the generation fleet to meet given load. The unit commitment model was used to determine electricity and ancillary service market prices under different assumptions about natural gas price, installed wind capacity, and installed CAES capacity. The CAES dispatch optimization model was then used to determine the operating profits of a CAES facility under these scenarios. CAES operating profits were found to increase with increasing natural gas price and installed wind capacity and to decrease with increasing installed CAES capacity. CAES operating profits were estimated to support installed CAES capacities from zero to more than 6 GW, depending on the natural gas price, installed wind capacity, installed CAES capacity, and the CAES capital costs. The strongest determinant of the maximum CAES capacity that would be profitable is the natural gas price, followed by the CAES capital costs. / text

This paper explores how the concept of Vehicle to Grid (V2G) could bring benefits to California's electric grid, transportation sector, and environmental goals.

Cette thèse s'inscrit dans le cadre du projet Innov'hydro, qui regroupe cinq laboratoires de Grenoble INP conjoints avec le CNRS et l'Université Grenoble Alpes et vise à mener une étude sur l'ensemble constitué par la turbine et le générateur électrique. Dans ce cadre, cette thèse menée dans G2Elab est dédiée aux techniques de contrôle avancées pour convertir de manière efficace l’énergie hydraulique en énergie électrique.Lorsque la centrale hydroélectrique est connectée aux réseaux comme fournisseur, à savoir le «mode PQ», elle délivre la quantité exacte de puissance active et réactive en fonction de la demande réelle ou permet d'exploiter au maximum la ressource primaire disponible. Cette thèse se focalise sur le dernier cas: le convertisseur côté machine confirme la vitesse de rotation optimale pour atteindre la puissance maximale; le convertisseur côté réseau assure la tension constante du circuit intermédiaire et envoie une alimentation de bonne qualité au réseau. Une topologie conventionnelle basée sur un générateur synchrone à aimant permanent (PMSG) est implémentée. Elle est composée d'une turbine hydraulique, de PMSG, de convertisseurs de source de tension dos à dos avec PWM en interaction avec le réseau.Une centrale hydroélectrique à vitesse variable (VS-HEP) est un système non linéaire variant dans le temps, perturbé par diverses incertitudes. Ainsi, cette thèse est dédiée à l’amélioration de la robustesse du contrôle et de la capacité de rejet des perturbations. Les contributions de cette thèse sont les suivantes:1. Modèle hydraulique et application de PHIL• Un modèle hydraulique tridimensionnel à échelle réduite est établi de manière flexible pour diverses conditions de fonctionnement en laboratoire.• Le modèle dynamique de l'actionneur à aubes directrices est introduit afin de prendre en compte les effets de la dynamique induite sur l'ensemble des performances électriques.• Sur la base du benchmark PHIL en temps réel flexible du G2Elab, un banc d'essai hydraulique à vitesse variable est construit, en cours d'adaptation pour le modèle à échelle réduite proposé.2. Contrôle avancé de la robustesse élevée et de la capacité de rejet de perturbations• Un contrôleur de vitesse basé sur ADRC est proposé pour améliorer les performances de suivi de vitesse, permettant ainsi un fonctionnement MPPT efficace. Un observateur de couple est intégré pour atténuer les effets des variations de couple hydraulique.• Un contrôleur ESO est implémenté dans la boucle de contrôle DC-Link. Il atteint une plus grande robustesse et améliore la dynamique de contrôle. Et il est simple à concevoir et à employer pour des ingénieurs.3. Technique de synchronisation basée sur ESO• Un ESO-PLL amélioré est proposé. Les incertitudes internes et les perturbations externes dans le système PLL sont estimées via ESO et activement compensées par une dynamique en boucle fermée en temps réel, ce qui permet une grande robustesse dans la gestion des perturbations.• Un intégrateur généralisé (GI)-ESO est proposé pour les systèmes présentant des perturbations sinusoïdales à haute fréquence. Un intégrateur généralisé est introduit pour estimer la perturbation haute fréquence dans la conception.• Une PLL basée sur GI-ESO est proposée pour les utilitaires distordus. Les erreurs haute fréquence apparaissant dans la phase estimée peuvent être éliminées en utilisant le GI-ESO.4. Gestion optimale des centrales hydroélectriques à stockage pompé• Une approche de programme dynamique est utilisée pour gérer de manière optimale le temps de pompage et de génération d'un système hydroélectrique hybride à stockage par pompage.• Les bénéfices de tous les régimes de fonctionnement à vitesse variable et à vitesse fixe sont comparés.• Les bénéfices quotidiens augmentent par rapport au mode de fonctionnement normal. Parallèlement, les restrictions hydrauliques et la consommation d’eau peuvent être respectées. / This PhD thesis is in the frame of project Innov'hydro, which involves five joint Grenoble INP laboratories with the CNRS and Grenoble Alpes and aims to review the assembly composed by the turbine and the electric generator. Within this frame, this thesis carried out in G2Elab, is dedicated to advanced control techniques for efficiently converting the hydraulic energy into electric power.When the hydro-electric plant is connected with the grids as a supplier, namely `PQ mode', it either delivers the exact amount of active and reactive power according to the actual demand or allows to exploit the maximum of the available primary resource. This thesis is targeting on the latter case: The machine-side converter confirms the optimal rotational speed to achieve the maximum power; the grid-side converter ensures the constant DC-link voltage, and to send the good quality power to the grid. A conventional variable-speed direct drive Permanent Magnet Synchronous Generator (PMSG)-based topology is implemented, it is composed of a hydraulic turbine, a PMSG, back-to-back voltage source converters with PWM interacting with the three-phase grid.A Variable-Speed Hydro-Electric Plant (VS-HEP) is a nonlinear time-varying system disturbed by various uncertainties. Thus, this thesis devotes more efforts to improving the control robustness and disturbance rejection ability. The contributions of this thesis are as follows:1. Hydraulic model and PHIL implementation• A reduced-scale hydraulic model is flexibly established for various laboratory operation conditions.• The dynamic model of guide vane actuator is introduced in order to take into account the effects of the induced dynamics on the whole electric performance.• Based on the flexible real-time PHIL benchmark in G2Elab, a variable speed hydraulic test rig is built, being adapted to the proposed reduced-scale model.2. Advanced control of high robustness and disturbance rejection ability• An ADRC-based speed controller is proposed to improve the speed tracking performance, thus enabling efficient MPPT operation. Besides, a torque observer is incorporated to mitigate the effects caused by hydraulic torque variations. Experimental results prove its advantages for VS-HEP application.• An enhanced ESO-based controller is implemented into DC-link control loop. It achieves higher robustness and improve control dynamics. And it is simple to design and employ for practical engineers.3. ESO-based synchronization technique• An enhanced ESO-PLL is proposed. The internal uncertainties and external disturbances in PLL system are estimated via ESO and actively compensated into closed-loop dynamics in real-time, which can achieve high robustness in dealing with disturbances.• A Generalized Integrator (GI)-ESO is proposed for system with high-frequency sinusoidal disturbances. A generalized integrator is introduced to estimate the high-frequency disturbance in the design.• A GI-ESO-based PLL is proposed for under power quality degradation issues (unbalanced voltage, harmonics, and voltage offset). The high-frequency errors appearing in the estimated phase can be eliminated by employing the GI-ESO.4. Optimal management of pumped-storage hydro-electric plant• A forward dynamic program approach is used to optimally manage the pumping and generating operation time for a hybrid pumped-storage hydro-electric system.• The profits for all operation regimes of variable speed operation and fixed speed are compared.• The daily profits increase compared with the normal operation mode, meanwhile, it can maintain the hydraulic restrictions and water consumption to local residents.

The U.S. government is responsible for protecting the country's energy and technology infrastructure. Critics argue the United States has failed to prepare, protect and respond to incidents involving the national electric grid leaving communities vulnerable to prolonged power outages. Protection of investor owned utilities' critical infrastructure is vulnerable to cyber and physical harm from the absence of criminalizing the intrusion of private sector computer networks, the lack of cybersecurity threats in emergency management, and the absence of cyber-intelligent leadership supports this argument. The purpose of this study was to introduce an electric grid protection theoretical concept, while identifying whether cybersecurity law and emergency management, amongst the investor-owned utility community, has an optimized relationship for protecting the national electric grid from harm. Easton's political system input/output model, Sommestad's cybersecurity theory, and Mitroff's crisis management theory provided the theoretical foundations for this study. The study utilized a mixed method research design that incorporated a Likert collection survey and combined quantitative chi-square and qualitative analysis. The key findings identified that cybersecurity law and the use of emergency management in the electric grid protection theory were not optimized to protect the national electric grid from harm. The recommendations of this study included the optimization of the theory elements through educational outreach and amending administrative cybersecurity law to improve the protection of the national electric grid and positively impacting social change by safeguarding the delivery of reliable electric energy to the millions of Americans who depend upon it.

Deregulation of the electricity industry has altered the investment landscape for new resources. Multiple resource adequacy constructs are in use today around the world and represent diverging opinions of how much interaction regulators should have on the procurement of new resources. The report compares the resource adequacy constructs in Australia, Texas, California and the Northeast of the United States and discusses the future of resource adequacy. The report concludes that a hybridized construct that blends the high offer caps of energy-only markets, the prescriptive nature of resources in capacity markets and a strong price-responsive demand will likely be the future of resource adequacy. / text

No description available.

Master of Science / Department of Electrical and Computer Engineering / Anil Pahwa / The unusual weather events during the polar vortex of 2014 illuminated the needs for fuel diversity for power generation in order to allow reliable operation of the electricity grid. A system wide reliability assessment for winter months should be undertaken in addition to the summer months to ensure reliable operation of the electricity grid throughout the year. Severe weather conditions that lead to equipment malfunction during the polar vortex should be thoroughly investigated and remediations to ensure satisfactory future performance of the grid must be undertaken. Environmentally unfriendly emissions from power plants must be minimized but diversity of generation fuel must be maintained. Future energy policies must be formulated with consideration that approximately 14 GW of coal generation in Pennsylvania Jersey Maryland Regional Transmission Organization’s control area available during the polar vortex will be retired by 2015 and replaced with plants that utilize fuel types other than coal.

Energy storage technologies have the potential to revolutionize the electric grid by allowing for the integration of renewable generation while increasing the utilization and efficiency of current grid assets. These technologies include pumped hydroelectric storage, compressed air energy storage (CAES), flywheels, batteries, thermal energy storage (TES), super capacitors, and superconducting magnetic energy storage (SMES). While energy storage has been implemented in some areas, its benefits are greatly undervalued by current regulatory frameworks leading to suboptimal outcomes for grid operators, utilities, and ratepayers. Large-scale adoption of storage technologies will require regulatory frameworks that recognize the benefits of grid-scale storage across generation, and transmission and distribution. This thesis discusses the need for storage, currently available and developing storage technologies, and the present regulatory environment.

For the grid to be stable, the supply of power must equal the demands of the consumer at every moment during the day. The unpredictable intermittent nature of wind results in inconsistent power generation. Energy storage technologies coupled with a wind farm can not only provide power during fluctuations but also maintain a stable and reliable grid. The objective of the thesis is to perform a comprehensive analysis of different types of energy storage technologies that can be coupled with a wind farm. The analysis is performed on the basis of multiple characteristics which affect their viability. We identified key characteristics for a range of storage technologies, including lead-acid, sodium-sulphur, nickel cadmium, lithium-ion, superconducting magnetic energy storage, electrochemical capacitors, flywheels, flow batteries, pumped hydro and compressed air energy storage systems. We performed a comparison study to analyze trade-offs and assessed potential improvement areas that will make them more competitive in the electric power industry. We suggested viable energy storage systems that could be better and suitable for different applications for an electric grid integrated with a wind farm.

Le développement des énergies renouvelables éolienne et solaire implique de repenser les modèles à long terme du système énergétique. En effet, les impacts à court et long terme des productions intermittentes éolienne et solaire sur le système électrique entraînent un besoin de flexibilité : centrales de production très réactives, gestion de la demande,amélioration du réseau électrique ou stockage d’électricité. Le premier apport majeur à l’état de l’art est l’ajout du stockage d’électricité et du réseau électrique européen dans le modèle POLES (Prospective Outlook on Long-term Energy Systems). Un nouveau mécanisme d’investissement a été développé, mieux adapté aux enjeux des renouvelables ; il inclut plusieurs valeurs économiques du stockage. D’autre part, une nouvelle typologie applicable à la fois aux modèles de prospective énergétique et aux outils détaillés du secteur électrique,a montré l’intérêt de rassembler ces deux approches. Ainsi, la deuxième contribution principale est le couplage annuel de POLES à un modèle d’opération du système électrique,EUCAD (European Unit Commitment And Dispatch), qui optimise l’allocation technico économique des centrales européennes de production et de stockage. Les échanges bidirectionnels d’informations permettent de bénéficier à la fois de la cohérence à long terme des scénarios économiques de POLES et du détail technique d’EUCAD. Un scénario conservateur prévoit un développement rapide des options de flexibilité les moins chères :interconnexions, stockage hydraulique et gestion de la demande – que ce soit par des effacements de consommation ou par l’optimisation de la charge et décharge des batteries de véhicules électriques. Les batteries stationnaires, plus chères, sont développées en seconde partie de siècle. Leur développement pourrait être accéléré par une réduction des coûts fixes du stockage plus efficace qu’une amélioration du rendement. Les liens explicites entre renouvelables intermittents et stockage d’électricité ressortent aussi des résultats. / The current development of wind and solar power sources calls for an improvement of longtermenergy models. Indeed, high shares of variable wind and solar productions have shortandlong-term impacts on the power system, requiring the development of flexibility options:fast-reacting power plants, demand response, grid enhancement or electricity storage. Ourfirst main contribution is the modelling of electricity storage and grid expansion in the POLESmodel (Prospective Outlook on Long-term Energy Systems). We set up new investmentmechanisms, where storage development is based on several combined economic values.After categorising the long-term energy models and the power sector modelling tools in acommon typology, we showed the need for a better integration of both approaches.Therefore, the second major contribution of our work is the yearly coupling of POLES to ashort-term optimisation of the power sector operation, with the European Unit CommitmentAnd Dispatch model (EUCAD). The two-way data exchange allows the long-term coherentscenarios of POLES to be directly backed by the short-term technical detail of EUCAD. Ourresults forecast a strong and rather quick development of the cheapest flexibility options: gridinterconnections, pumped hydro storage and demand response programs, including electricvehicle charging optimisation and vehicle-to-grid storage. The more expensive batterystorage presumably finds enough system value in the second half of the century. A sensitivityanalysis shows that improving the fixed costs of batteries impacts more the investments thanimproving their efficiency. We also show the explicit dependency between storage andvariable renewable energy sources.