• Energy Research
• FR close

Abstract The concept of a cTES (for cold Thermal Energy Storage) is experimentally investigated in this paper. It aims at demonstrating its technical relevancy, for arid regions, in improving the efficiency of a dry cooled turbine's condenser. Gain is realized by postponing total or part of the daily heat exhausted from the condenser and shifting the release of the remaining heat during the night-time when the ambient temperatures are lower. The global system consists in a 13 m3 dual-media water/rock thermocline TES connected to a 110 kW heat source and a 100 kW dry cooler. Experiments have been first conducted to validate the thermal storage behavior in well-controlled operations. Then, the thermal storage has been connected in parallel with the dry cooler to highlight the global behavior of the “dry cooler / cTES” cooling system under different operation's conditions. Results confirm that the cTES is able to compensate the performances loss of the dry cooler during daytime in case of high ambient temperature and to evacuate heat and to store cold during nigh-time. The control of the cTES is simple, characterized by continuous and smooth transitions from one mode to another and without discontinuities in performances and operations.

This dissertation presents a stock-flow consistent (SFC) model which provides a theory-consistent representation of Viet Nam's general structure - a small open economy - and offers policy simulation capabilities to meet the needs of policymakers. We are the first to develop an empirical SFC model for Viet Nam. The model comprises six institutional sectors: firms, central bank, commercial banks, government, households and rest of the world. Due to the availability of financial data, the balance sheet and flow matrix are built based on the principles of the system of national accounting SNA 2008 and by gathering data from different sources. It justifies several simplification hypotheses made in the model. Building upon economic theory but also a data-driven approach, besides accounting equations, behavioural equations are estimated econometrically by using annual data from 1997 to 2019. The model can be used for policy simulation or scenario analysis to assess the impacts/effects of policies or shocks on the Vietnamese economy. We implement three types of shock to test the usefulness of the model: fiscal policy, monetary policy and foreign shock. Then, we analyse the different transmission mechanisms of the effects on economic growth and different components of Gross Domestic Product (GDP), prices and the financial side of the economy, including interest rates and changes in financial assets of each sector. Especially we perform two specific exercises using the model. The first one aims to analyse the different consequences of the policy responses of the Vietnamese government to cope with the COVID-19 pandemic on both the real and financial sides of the economy. We examine the potential effects on public debt sustainability, which is always a concern of the government. The second application is related to the macroeconomic impacts of climate change and the potential effects of adaptation measures by integrating damage functions and adaptation investment into the macroeconomic model. Albeit time-consuming, the ...

Synthesis of cork-derived ceria ecoceramic, an emerging porous catalyst, for enhancing solar thermochemical water splitting.

The recent implementation of the EU Emissions Trading Scheme (EU ETS) in January 2005 created new financial risks for emitting firms. To deal with these risks, options are traded since October 2006. Because the EU ETS is a new market, the relevant underlying model for option pricing is still a controversial issue. This article improves our understanding of this issue by characterizing the conditional and unconditional distributions of the realized volatility for the 2008 futures contract in the European Climate Exchange (ECX), which is valid during Phase II (2008-2012) of the EU ETS. The realized volatility measures from naive, kernel-based and subsampling estimators are used to obtain inferences about the distributional and dynamic properties of the ECX emissions futures volatility. The distribution of the daily realized volatility in logarithmic form is shown to be close to normal. The mixture-of-distributions hypothesis is strongly rejected, as the returns standardized using daily measures of volatility clearly departs from normality. A simplified HAR-RV model (Corsi, 2009) with only a weekly component, which reproduces long memory properties of the series, is then used to model the volatility dynamics. Finally, the predictive accuracy of the HAR-RV model is tested against GARCH specifications using one-step-ahead forecasts, which confirms the HAR-RV superior ability. Our conclusions indicate that (i) the standard Brownian motion is not an adequate tool for option pricing in the EU ETS, and (ii) a jump component should be included in the stochastic process to price options, thus providing more efficient tools for risk-management activities.

Optimisation-based Energy Management Strategies for hybrid and electric vehicles have to face some issues for real-time applications. In this study,an online adaptive optimisation-based strategy is used for an electric vehicle with a Hybrid Energy Storage System including supercapacitors and batteries. The SCs voltage limitations are taken into account by using a feedback control. Indeed the voltage limitation is a key point for safe operations in the vehicle. A comparison with a more classical optimisation-based method is performed by simulations on a normalised driving cycle. The results point out a more effective behaviour of the adaptive strategy.

The Nuclear Energy Agency organised its third workshop on ‘Science and values in radiological protection’ in November 2012 in Tokyo. One of the issues addressed, non-cancer effects, had also been addressed in the first two science and values workshops (Helsinki, Finland, 2008; Vaux-de-Cernay, France, 2009), but presented several new elements of relevance to International Commission on Radiological Protection discussions of the evolution of the system of radiological protection. Radiological protection science, both epidemiological and biological, now suggests that stroke and heart disease may well be caused by radiation exposure at doses of the order of 0.5 Gy or less. Further, it is possible that such detriments may be caused by either chronic or acute exposures. While significant uncertainties remain, the need to consider non-cancer detriment in risk assessment and in the development of protection strategies is now a significant scientific and ethical question. This paper will present the results of the Nuclear Energy Agency science and values workshop discussion of non-cancer risks, and of the questions and possible future directions raised during the workshop.

This paper extends recent work on interruption insurance for electric power by introducing onsite backup generation capacity as a supplementary form of interruption insurance. The basic model of interruption insurance as a mechanism for differential pricing is reviewed, the incentive for providing onsite backup generation capacity is demonstrated and the interaction between onsite backup generation and interruption insurance is analyzed. Two types of onsite backup, customer and utility owned, are discussed. It is shown that individuals’ economic incentives to install onsite backup generation dominate the utility’s incentive. Hence customer owned onsite backup decisions will pre-empt the utility’s plan to mitigate compensation payments by providing onsite backup generation.