Technical versus socio-economic and environmental criteria in power transmission projects

In recent years, the efforts of countries to reach agreements on the development of cross-border electricity interconnection have intensified because they optimize energy resources and constitute the most significant instantaneous support for the security and continuity of electricity supply. In addition, interconnections play a key role in the integration of electricity markets. However, the planning of European electricity infrastructures constitutes complex analyses due to the large number of factors involved. This article applies a multicriteria methodology for the evaluation and prioritization of cross-border interconnection projects with the simulation of different scenarios, in total 12 scenarios, to study the effect of changes in the selected criteria on the results obtained. To test the defined methodology, the variation in the weight of different criteria in the assessment of a new cross-border electrical interconnection project between Spain and France is studied. It was verified that the tool is coherent and that the analysis developed improves the understanding of such large and complex projects and can facilitate the prioritization of project portfolios with a clear and explicit method

Measuring the internationalization of the wind energy industry

Wind energy has grown from less than 20 gigawatts (GW) in 2000 to 590 GW by the end of 2018 and already provides 6% of the electricity consumed in the world. During this period, the wind energy technology industry has evolved from a local to a global business. To illustrate the globalization of this sector, this research assesses the effectiveness of the firms’ international strategies based on empirical indicators. The intensity, the speed of internationalization, the geographic extensity and diversification are calculated and analyzed. The results indicate that the most successful firms are the market leaders Vestas and Siemens Gamesa Renewable Energy, and they are characterized by leading in both the depth (sales abroad/total sales) and width (number of countries) of internationalization as well as in geographic diversification. These companies are closely followed by four European and American firms: Enercon, Nordex, General Electric and Senvion. To date, Chinese firms, leaders in the largest market (China), are in general unable to internationalize as effectively as firms from other constituencies. Our results reveal that strong rivalry pressure in the domestic market is not a guarantee for the international competitiveness of its best-performing firms in the case of the wind energy industry – unless there are special characteristics in that domestic market

Mitigating energy system vulnerability by implementing a microgrid with a distributed management algorithm

This work presents a management strategy for microgrid (MG) operation. Photovoltaic (PV) and wind generators, as well as storage systems and conventional units, are distributed over a wide geographical area, forming a distributed energy system, which is coordinated to face any contingency of the utility company by means of its isolated operation. The management strategy divides the system into three main layers: renewable generation, storage devices, and conventional units. Interactions between devices of the same layer are determined by solving an economic dispatch problem (EDP) in a distributed manner using a consensus algorithm (CA), and interactions between layers are determined by means of a load following strategy. In this way, the complex behaviour of PV and wind generation, the battery storage system, and conventional units has been effectively combined with CA to solve EDP in a distributed manner. MG performance and its vulnerability are deeply analysed by means of an illustrative case study. From the observed results, vulnerability under extreme conditions could be reduced up to approximately 30% by coupling distributed renewable generation and storage capacity with an energy system based on conventional generation

Techno-economic modelling of water electrolysers in the range of several mw to provide grid services while generating hydrogen for different applications: a case study in spain applied to mobility with fcevs

The use of hydrogen as energy carrier is a promising option to decarbonize both energy and transport sectors. This paper presents an advanced techno-economic model for calculation of optimal dispatch of large-scale multi MW electrolysis plants in order to obtain a more accurate evaluation of the feasibility of business cases related to the supply of this fuel for different end uses combined with grid services' provision. The model is applied to the Spanish case using different scenarios to determine the minimum demand required from the FCEV market so that electrolysis facilities featuring several MW result in profitable business cases. The results show that grid services contribute to the profitability of hydrogen production for mobility, given a minimum but considerable demand from FCEV fleets

Optimal electricity price calculation model for retailers in a deregulated market

The electricity retailing, a new business in deregulated electric power systems, needs the development of efficient tools to optimize its operation. This paper defines a technical-economic model of an electric energy service provider in the environment of the deregulated electricity market in Spain. This model results in an optimization problem, for calculating the optimal electric power and energy selling prices that maximize the economic profits obtained by the provider. This problem is applied to different cases, where the impact on the profits of several factors, such as the price strategy, the discount on tariffs and the elasticity of customer demand functions, is studied. © 2005 Published by Elsevier Ltd

Offshore wind installation: Analysing the evidence behind improvements in installation time

The most important single event of the last years in wind energy technology is the reduction in the cost of producing wind electricity offshore, a reduction that can reach 75%, depending on the system boundary considered, for installations commissioned by 2024. Surprisingly, there is very little scientific literature showing how this reduction is being achieved. The objective of this paper is to analyse the evidence behind cost reduction in one of the most significant cost elements of offshore wind farms, the installation of foundations and turbines. This cost is directly dependent on the daily rates of the installation vessels and on the days it takes to install those wind farm elements. Therefore, we collected installation data from 87 wind farms installed from 2000 to 2017, to establish the exact time for installation in each. The results show that advances have reached 70% reduction in installation times throughout the period for the whole set, turbine plus foundation. Most of these improvements (and the corresponding impact in reducing costs) relate to the larger size of turbines installed nowadays. There is, therefore, not any leap forward in the installation process, but only incremental improvements applied to turbines that are now four times as large as in 2000

Multi-state techno-economic model for optimal dispatch of grid connected hydrogen electrolysis systems operating under dynamic conditions

The production of hydrogen through water electrolysis is a promising pathway to decarbonize the energy sector. This paper presents a techno-economic model of electrolysis plants based on multiple states of operation: production, hot standby and idle. The model enables the calculation of the optimal hourly dispatch of electrolyzers to produce hydrogen for different end uses. This model has been tested with real data from an existing installation and compared with a simpler electrolyzer model that is based on two states. The results indicate that an operational strategy that considers the multi-state model leads to a decrease in final hydrogen production costs. These reduced costs will benefit businesses, especially while electrolysis plants grow in size to accommodate further increases in demand

Improved graph model for interdependent gas and electricity critical infrastructures

Interdependence between gas and electricity transmission networks is a subject of concern due to the expanding use of gas for electricity generation in combined-cycle power plants around the world. This paper proposes a novel and much more accurate representation of natural gas and electrical networks based on graph theory, which includes all the assets of both systems and their couplings and offers a more realistic topological model of the two coupled networks. The representation is proposed as a scale-free graph and is mathematically validated in test networks, finding that the representations maintain the same characteristics of traditional graphs, but with more topological detail of the infrastructures

Multi-state optimal power dispatch model for power-to-power systems in off-grid hybrid energy systems: A case study in Spain

The electricity production from Renewable Energy (RE) in isolated locations requires long-term energy storage systems. To that end, Hybrid Energy Storage Systems (HESS), through a combination of hydrogen and batteries, can benefit from the different advantages of both technologies. This paper presents a hybrid Power-to-Power (PtP) Optimal Power Dispatch (OPD) model for isolated systems with no electric grid access. Currently, the electricity supply in such cases is usually based on a mix of RE as the primary energy source sustained by a diesel genset acting as a backup generator. In this context, the model delivers the hourly energy flows between renewable production sources, energy storage devices and the electrical load, which minimises costs and Green House Gases (GHG) emissions. For validation purposes, the model was tested through its application to a case study in an isolated area in the Canary Islands, Spain. The results show that the algorithm calculates the hourly OPD successfully for a given plant sizing, considering the defined operational states of the different assets. These operational constraints showed a decrease in the PtP round-trip efficiency of 5.4% and a reduction of the hydrogen production of 9.7%. Finally, the techno-economic analysis of the results proves that the combination of hydrogen and batteries with RE production is a feasible alternative to phasing out fossil fuels for the selected case study – reducing the diesel generator usage down to 1.2% of the yearly energy supply

Phasing out steam methane reformers with water electrolysis in producing renewable hydrogen and ammonia: A case study based on the Spanish energy markets

Deploying renewable hydrogen presents a significant challenge in accessing off-takers who are willing to make long-term investments. To address this challenge, current projects focus on large-scale deployment to replace the demand for non-renewable hydrogen, particularly in ammonia synthesis for fertiliser production plants. The traditional process, involving Steam Methane Reformers (SMR) connected to Haber-Bosch synthesis, could potentially transition towards decarbonisation by gradually integrating water electrolysis. However, the coexistence of these processes poses limitations in accommodating the integration of renewable hydrogen, thereby creating operational challenges for industrial hubs. To tackle this issue, this paper proposes an optimal dispatch model for producing green hydrogen and ammonia while considering the coexistence of different processes. Furthermore, the objective is to analyse external factors that could determine the appropriate regulatory and pricing framework to facilitate the phase-out of SMR in favour of renewable hydrogen production. The paper presents a case study based in Spain, utilising data from 2018, 2022 and 2030 perspectives on the country's renewable resources, gas and electricity wholesale markets, pricing ranges, and regulatory constraints to validate the model. The findings indicate that carbon emissions taxation and the availability and pricing of Power Purchase Agreements (PPAs) will play crucial roles in this transition - the carbon emission price required for total phasing out SMR with water electrolysis would be around 550 EUR/ton CO2