The Role of Plug-In Electric Vehicles with Renewable Resources in Electricity Systems

Deux voies technologiques, la génération d’électricité renouvelable et l’électrification des véhicules, sont souvent avancées comme solution à deux des plus grands défis de notre époque : satisfaire à une demande énergétique croissante tout en réduisant les émissions de gaz à effet de serre. La réalisation de ces deux objectifs implique le besoin de transférer une partie de la demande de combustibles fossiles vers d’autres sources d’énergie primaire. La diffusion des énergies renouvelables et des véhicules électriques rechargeables (VER) a été entravée par des obstacles importants, malgré leur potentiel reconnu d’améliorer la durabilité énergétique dans les secteurs de l’électricité et du transport. Les deux technologies ont des synergies naturelles entre elles : les VER sont une source inhérente de flexibilité du côté de la demande aussi bien que de l’offre, qui pourraient aider à mitiger les effets négatifs de la variabilité de la génération d’électricité renouvelable. Dans cet article nous examinons les obstacles au déploiement des renouvelables et des VER, ainsi que les synergies entre les deux voies technologiques. Nous soulevons des questions autour de l’implémentation ainsi que des mesures d’incitation et des modèles d’affaires qui pourraient empêcher ou aider à réaliser la valeur de ces synergies. Nous proposons enfin de nouvelles problématiques de recherche qui pourraient amener à résoudre ces questions d’implémentation.Two technology options, renewable electricity generation and vehicle electrification, are being promoted to achieve two of the greatest objectives of this century: meeting growing global energy demand while reducing greenhouse gas emissions. Addressing both objectives implies shifting part of this energy demand away from fossil fuels to other primary energy sources. Renewables and plug-in electric vehicle (PEV) adoption has been hindered by significant challenges despite their known potential to improve energy sustainability in electric power systems and transportation. The two technologies have natural synergies between them, however: PEVs are a natural source of demand -and supply-side flexibility, which can help mitigate the negative ancillary effects of renewable variability and uncertainty. In this paper we discuss the issues hindering renewable and PEV adoption and the synergies between these two technology pathways. Finally, we raise some issues with implementation and challenges with incentive and business plan design that may hinder fully realizing these synergies. We also propose some important research questions that would help address these implementation issues

The Value of Concentrating Solar Power and Thermal Energy Storage

This paper examines the value of concentrating solar power (CSP) and thermal energy storage (TES) in four regions in the southwestern United States. Our analysis shows that TES can increase the value of CSP by allowing more thermal energy from a CSP plant’s solar field to be used, by allowing a CSP plant to accommodate a larger solar field, and by allowing CSP generation to be shifted to hours with higher energy prices. We analyze the sensitivity of CSP value to a number of factors, including the optimization period, price and solar forecasting, ancillary service sales, capacity value and dry cooling of the CSP plant. We also discuss the value of CSP plants and TES net of capital costs

Transmission Benefits of Co-Locating Concentrating Solar Power and Wind

In some areas of the U.S. transmission constraints are a limiting factor in deploying new wind and concentrating solar power (CSP) plants. Texas is an example of one such location, where the best wind and solar resources are in the western part of the state, while major demand centers are in the east. The low capacity factor of wind is a compounding factor, increasing the relative cost of new transmission per unit of energy actually delivered. A possible method of increasing the utilization of new transmission is to co-locate both wind and concentrating solar power with thermal energy storage. In this work we examine the benefits and limits of using the dispatachability of thermal storage to increase the capacity factor of new transmission developed to access high quality solar and wind resources in remote locations

Capacity Value of Concentrating Solar Power Plants

This study estimates the capacity value of a concentrating solar power (CSP) plant at a variety of locations within the western United States. This is done by optimizing the operation of the CSP plant and by using the effective load carrying capability (ELCC) metric, which is a standard reliability-based capacity value estimation technique. Although the ELCC metric is the most accurate estimation technique, we show that a simpler capacity-factor-based approximation method can closely estimate the ELCC value. Without storage, the capacity value of CSP plants varies widely depending on the year and solar multiple. The average capacity value of plants evaluated ranged from 45%?90% with a solar multiple range of 1.0-1.5. When introducing thermal energy storage (TES), the capacity value of the CSP plant is more difficult to estimate since one must account for energy in storage. We apply a capacity-factor-based technique under two different market settings: an energy-only market and an energy and capacity market. Our results show that adding TES to a CSP plant can increase its capacity value significantly at all of the locations. Adding a single hour of TES significantly increases the capacity value above the no-TES case, and with four hours of storage or more, the average capacity value at all locations exceeds 90%

Comparison of Capacity Value Methods for Photovoltaics in the Western United States

This report compares different capacity value estimation techniques applied to solar photovoltaics (PV). It compares more robust data and computationally intense reliability-based capacity valuation techniques to simpler approximation techniques at 14 different locations in the western United States. The capacity values at these locations are computed while holding the underlying power system characteristics fixed. This allows the effect of differences in solar availability patterns on the capacity value of PV to be directly ascertained, without differences in the power system confounding the results. Finally, it examines the effects of different PV configurations, including varying the orientation of a fixed-axis system and installing single- and double-axis tracking systems, on the capacity value. The capacity value estimations are done over an eight-year running from 1998 to 2005, and both long-term average capacity values and interannual capacity value differences (due to interannual differences in solar resource availability) are estimated. Overall, under the assumptions used in the analysis, we find that some approximation techniques can yield similar results to reliability-based methods such as effective load carrying capability

Capacity Value of Solar Power: Report of the IEEE PES Task Force on Capacity Value of Solar Power

This paper reviews methods used for adequacy risk assessment considering solar power, and for assessment of the capacity value of solar power. The properties of solar power are described as seen from the perspective of the balancing authority, comparing differences in energy availability and capacity factors with those of wind. Methodology for risk calculations considering variable generation (VG) are then surveyed, including the probability background, statistical estimation approaches, and capacity value metrics. Issues in incorporating VG in capacity markets are described, followed by a review of applied studies considering solar power. Finally, recommendations for further research will be presented

Outcomes After Stereotactic Body Radiation Therapy as a Bridging Modality to Liver Transplantation for Hepatocellular Carcinoma

Purpose: For patients with hepatocellular carcinoma awaiting liver transplantation (LT), stereotactic body radiation therapy (SBRT) has emerged as a bridging treatment to ensure patients maintain priority status and eligibility per Milan criteria. In this study, we aimed to determine the efficacy and safety of SBRT in such situations. Methods and Materials: A retrospective analysis was conducted of the outcomes of 27 patients treated with SBRT who were listed for LT at 1 institution. Among these, 20 patients with 26 tumors went on to LT and were the focus of this study. Operative reports and postoperative charts were evaluated for potential radiation-related complications. The explant pathology findings were correlated with equivalent dose in 2 Gy fractions and tumor size. Results: Median pretreatment tumor size was 3.05 cm. Median total dose of radiation was 50 Gy delivered in 5 fractions. Pathologic complete response (pCR) was achieved in 16 tumors (62%). Median interval from end of SBRT to transplant was 287 days. Of the 21 tumors imaged before transplant, 16 or 76% demonstrated a clinical complete response based on modified Response Evaluation Criteria in Solid Tumors criteria. There was no significant correlation between pCR rate and increasing tumor size (odds ratio [OR], 0.95; 95% confidence interval, 0.595-1.53) or pCR rate and equivalent dose in 2 Gy fractions (OR, 1.03; 95% confidence interval, 0.984-1.07.) No patients experienced radiation-related operative or postoperative complications. Of the 27 patients who were listed for transplant, the dropout rate was 22%. Two of the 5 patients with Child-Pugh score 10 died of liver failure. Conclusions: These data demonstrate that SBRT as a bridging modality is a feasible option, with a pCR rate comparable to that of other bridging modalities and no additional radiation-related operative or postoperative complications. There was no dose dependence nor size dependence for pCR rate, which may indicate that for the tumor sizes in this study, the radiation doses delivered were sufficiently high

Analysing the Impact of Rationality on the Italian Electricity Market

International audienceWe analyze the behavior of the Italian electricity market with an agent-based model. In particular, we are interested in testing the assumption that the market participants are fully rational in the economical sense. To this aim, we extend a previous model by considering a wider class of cases. After checking that the new model is a correct generalization of the existing model, we compare three optimization methods to implement the agents rationality and we verify that the model exhibits a very good fit to the real data. This leads us to conclude that our model can be used to predict the behavior of this market

Multi-agent Electricity Markets and Smart Grids Simulation with Connection to Real Physical Resources

The increasing penetration of distributed energy sources, mainly based on renewable generation, calls for an urgent emergence of novel advanced methods to deal with the associated problems. The consensus behind smart grids (SGs) as one of the most promising solutions for the massive integration of renewable energy sources in power systems has led to the development of several prototypes that aim at testing and validating SG methodologies. The urgent need to accommodate such resources require alternative solutions. This chapter presents a multi-agent based SG simulation platform connected to physical resources, so that realistic scenarios can be simulated. The SG simulator is also connected to the Multi-Agent Simulator of Competitive Electricity Markets, which provides a solid framework for the simulation of electricity markets. The cooperation between the two simulation platforms provides huge studying opportunities under different perspectives, resulting in an important contribution to the fields of transactive energy, electricity markets, and SGs. A case study is presented, showing the potentialities for interaction between players of the two ecosystems: a SG operator, which manages the internal resources of a SG, is able to participate in electricity market negotiations to trade the necessary amounts of power to fulfill the needs of SG consumers.This work has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement N. 641794 (project DREAM-GO). It has also received FEDER Funds through the COMPETE program and National Funds through FCT under the project UID/EEA/00760/2013. The authors gratefully acknowledge the valuable contribution of Bruno Canizes, Daniel Paiva, Gabriel Santos and Marco Silva to the work presented in the chapter.info:eu-repo/semantics/publishedVersio