Upper Limit and Power Generation Loss of Water Supplement from Cascade Hydropower Stations to Downstream Under Lancang-Mekong Cooperation

In cross-border water supplement cooperation, the supplement water discharged from upstream hydropower stations is the key to improving downstream benefits, but will lead to upstream power generation loss, so the upstream hydropower stations have to be aware of how much water they can offer and how much power they will lose to make the water supplement cooperation more reasonable. Therefore, this study puts forward a model to calculate the upper limit flow of water supplement of cascade hydropower stations under firm power constraints and water level constraints and proposes a new optimization method called the “collaborative-independent” joint optimization method to calculate the power generation loss under water supplement constraints. The results show that the upper limit flow will increase with the increase of annual inflow, and the uncertainty of the distribution of inflow in the year will also affect the upper limit flow: the larger the proportion of non-flood season inflow, the higher the upper limit flow. In normal and wet years, delaying water supplement time can significantly increase the upper limit flow by about 5% per month. Additionally, the “collaborative-independent” joint optimization method newly proposed in this paper can significantly improve the local optimization problem compared to the traditional optimization method. The power generation loss increases with the increase of water supplement flow, and delaying water supplement time can significantly reduce the power generation loss. The results of this paper can provide essential data support for future water resources cooperation negotiations in the Lancang-Mekong river basin to promote efficient and orderly water resources cooperation in the basin.

Inter-firm power relations and working conditions under new production models

In investigating recent changes to the automotive industry production process, such as modularisation, our work emphasises the process of fragmentation of production as a configuring element of inter-firm power relationships, and as an explanatory element in working conditions. From a theoretical framework focused on power relations, we analyse by way of a selected case study how the capabilities of companies and their network positions, together with the agency of labour, shape the power relations that influence the evolution of working conditions. The study does indeed find relevant changes to inter-firm relationships, for example, within networks of assemblers and suppliers, but without a consequent re-balancing of power. This finding serves to explain differences in the evolution of working conditions between distinct companies, these conditions being fully functional to a strategy for profitability and thus difficult to reverse. JEL Codes: J31, L14, L62

The Role of Natural Gas in Energy Transition

As of 2004 and continuously to this day, the annual growth rate of renewable sources has been greater than that of all fossil fuels combined. In the midst of this transition to cleaner energy, natural gas is the only fossil fuel that has increased its share in the global energy matrix. Technological changes in the LNG supply chain, as well as transformations in the global natural gas market, largely explain this growth. This publication provides evidence on the fundamental role that natural gas plays in the energy transition, given that: (i) its greenhouse gas emissions are substantially lower than those of oil and coal; (ii) it provides the firm power necessary to complement intermittent renewable energies; (iii) it is particularly safe compared to other fossil fuels. In line with these attributes, the International Energy Agency projects that the share of natural gas in the global energy matrix by 2040 will remain stable (around 24%), even in its Sustainable Development Scenario, which would allow to meet the goals established in the Paris Agreement.

From Firm Solar Power Forecasts to Firm Solar Power Generation an Effective Path to Ultra-High Renewable Penetration a New York Case Study

We introduce firm solar forecasts as a strategy to operate optimally overbuilt solar power plants in conjunction with optimally sized storage systems so as to make up for any power prediction errors, and hence entirely remove load balancing uncertainty emanating from grid-connected solar fleets. A central part of this strategy is the plant overbuilding that we term implicit storage. We show that strategy, while economically justifiable on its own account, is an effective entry step to achieving least-cost ultra-high solar penetration where firm power generation will be a prerequisite. We demonstrate that in the absence of an implicit storage strategy, ultra-high solar penetration would be vastly more expensive. Using the New York Independent System Operator (NYISO) as a case study, we determine current and future costs of firm forecasts for a comprehensive set of scenarios in each ISO electrical region, comparing centralized vs. decentralized production and assessing load flexibility’s impact. We simulate the growth of the strategy from firm forecast to firm power generation. We conclude that ultra-high solar penetration enabled by the present strategy, whereby solar would firmly supply the entire NYISO load, could be achieved locally at electricity production costs comparable to current NYISO wholesale market prices.

From Firm Solar Power Forecasts to Firm Solar Power Generation: An Effective Path to Ultra-High Renewable Penetration - A New York Case Study

We introduce firm solar forecasts as a strategy to operate optimally overbuilt solar power plants in conjunction with optimally sized storage systems so as to make up for any power prediction errors, hence entirely remove load balancing uncertainty emanating from grid-connected solar fleets. A central part of this strategy is plant overbuilding that we term implicit storage. We show that strategy, while economically justifiable on its own account, is an effective entry step to least-cost ultra-high solar penetration where firm power generation will be a prerequisite. We demonstrate that in absence of an implicit storage strategy, ultra-high solar penetration would be vastly more expensive. Using the New York Independent System Operator (NYISO) as a case study, we determine current and future cost of firm forecasts for a comprehensive set of scenarios in each ISO electrical region, comparing centralized vs. decentralized production and assessing load flexibility’s impact. We simulate the growth of the strategy from firm forecast to firm power generation. We conclude that ultra-high solar penetration enabled by the present strategy, whereby solar would firmly supply the entire NYISO load, could be achieved locally at electricity production costs comparable to current NYISO wholesale market prices.

Use of pumped hydro energy storage to complement wind energy: A case study

The dependency of RES on the weather and climate increased the interest on bulk energy storage methods to supply firm power. Pumped-hydro energy storage systems are a step ahead among other bulk energy storage methods because these are more efficient and they have higher storage capacities. The present study focuses on the use of grid connected wind-pumped hydro power station supply energy. A hybrid wind-pumped hydro storage system was designed and simulated using real data, and economic analysis was performed by calculating the basic pay-back period, the net present value and the internal rate of return. According to the results, it is found that the hybrid system is actively used and a part of the electricity is supplied from the wind-pumped hydro system. In addition, it was obtained that the pumped hydro storage systems are very suitable to be used together with wind power plants.

PROSOPOGRAPHIA BELLI BATONIANI / Prosopographia Belli Batoniani

Victorious in the battle against Mark Antony for mastery over Rome, Octavian gradually revised the previously existing Republican system with a new regime, in which the “first among the equals” was in fact the sovereign ruler. Aiming to secure his power and its undisturbed succession in the next generation of Julio-Claudians, Octavian placed his own men in key positions in the state. These were not only individuals who were in a client relationship with Octavian Augustus, but also individuals whom the Princeps tied to his own family with marriage bonds; in that way he made a wide network of kin and marital interdependency on himself. This paper deals with a small section of that network – with Augustus’ legates who fought in Illyricum between 6 and 9 AD. These were the governors of three provinces – Illyricum, Moesia and Galatia – whose armies participated in the suppression of the great Pannonian-Dalmatian uprising. All three provinces were imperial, which means that the Princeps, and not the Senate, was in charge for election of their administrators. Illyricum, Moesia and Galatia are clear examples of the political and personal network Augustus cast over the Empire, and represent a model that was to be applied in other provinces – even those under senatorial authority. Narratives of historical sources about the Pannonian-Dalmatian uprising mention seven pivotal individuals in leading positions in the Roman army, in legions that during the three wartime years operated in Illyricum. These are: Tiberius (commander-in-chief of the joint military force – No. 4), Germanicus (his subordinate, a member of Augustus’ immediate family – No. 5), Marcus Valerius Messalla Corvinus Messallinus (governor of Illyricum in the year of the outbreak of the uprising – No. 9), Aulus Caecina Severus (governor of Moesia – No. 7), Marcus Plautius Silvanus (governor of Galatia – No. 8), Marcus Aemilius Lepidus (governor of Pannonia, northern part of recently divided Illyricum, in the last year of the war – No. 6), and Caius Vibius Postumus (governor of Dalmatia, southern part of recently divided Illyricum, in the last year of the war – No. 10). A number has been assigned to each of these men to fascilitate the tracking of their complex relations by blood and marriage which tied most of them mutually, and with Augustus himself. Numbers are also assigned to Augustus (No. 1), Mark Antony (No. 2) and Marcus Vipsanius Agrippa (No. 3), whom the Princeps firmly tied with his family. A short survey of activities of these seven legates in Illyricum during the war (6-9 AD) is followed by the second part of the paper that minutely explains their blood and marital relations. To each of the other persons relevant to our narrative a number is also assigned in order to track them through Augustus’ network. Extensive analysis of their mutual relations show that some of them were firmly related through family to the Julio-Claudians (Valerius Messallinus and Aemilius Lepidus), some were tied with client more than marital bonds (Plautius Silvanus), and some apparently were not highly dependent on Princeps (Caecina Severus and Vibius Postumus). However, all of them constituted important parts of the network which Augustus threw over the Empire, providing for himself and his successors secure and firm power, and for the State the long desired pax Romana.