• Energy Research

[EN] During the last several decades, demand response programs have played a crucial role in the management of the electrical energy system worldwide. Thus, demand response programs, offered by either system operators or utilities, have contributed to solve different matters that appear in the habitual operation of the power grid. Currently, there are no successful experiences of demand response applications in the natural gas system. However, it seems natural that, in line with the current trends in the energy sector, demand response concepts will be eventually essential for the better and more efficient operation of natural gas systems. The research here presented leads with the analysis of demand response as a strategic tool for the gas system operator to manage better the natural gas network. Thus, this research demonstrates as demand response could represent a great opportunity for consumers to play an active role in the operation of the natural gas grid. In this paper, the ability of consumers to participate in the balancing of natural gas in the transmission network is assessed and the utilization of demand response resources to help reducing the imbalances in the natural gas system is demonstrated.

This research study explores the technology of biomass syngas production by using an experimental downdraft fixed-bed gasifier coupled to a two-cylinder engine, designed and implemented at the Polytechnic University of Valencia, Spain. Furthermore, it deals with the study of the experimental and analytical relations between the driving thermodynamic parameters that control the gasification process, in order to contribute to the development of a theoretical model for the design of a small-scale gasification facility. Different experiments have been performed to investigate the variations in parameters such as low heating values, the air–syngas ratio, the reduction and combustion temperature, efficiency, and electrical power generation during the continuous functioning of the gasification power production facility. The results obtained show that the low heating value is directly related to the inlet air flow rate, so that it increases when the air flow increases, while the increase in the inlet air flow of the gasifier makes both the reduction and the combustion temperature increase. Moreover, the efficiency of the motor–generator reaches a maximum value of 0.204 at the maximum power (around 5 kW), being characterized by an excellent operating range for the air–fuel ratio of a gasification facility.

The aim of this research is to contribute into the diffusion of biomass power systems by analyzing and testing the throat sizing influence on the operation of a gasification plant coupled with an internal combustion engine. In order to do this, the assessment of the proper operation range for some of the driving process parameters has been carried out. The analysis has been focused on such parameters as pressure drop of the fixed bed reactor, the inlet air flow, the syngas production, electrical power production and efficiency, looking for improving the performance and guaranteeing the proper system operation. Two different campaigns of tests have been carried out for figuring out the best design on the reactor. Based on this analysis, the most convenient throat diameter has been determined (in this case, around 10 cm), producing an increment in the production of syngas of about 31%. This modification has demonstrated also an increment of the electrical power produced by the gasification plant of about 40%, which means an increment in the motor generator efficiency of 35%.

This paper deals with how demand response can contribute to the better integration of renewable energy resources such as wind power, solar, small hydro, biomass and CHP. In particular, an economic evaluation performed by means of the micro-power optimization model HOMER Energy has been done, considering a micro-grid supplied by a biomass gasification power plant, operating isolated to the grid and in comparison with other generation technologies. Different scenarios have been simulated considering variations in the power production of the gasified biomass generator and different solutions to guarantee the balance generation/consumption are analyzed, demonstrating as using demand response resources is much more profitable than producing this energy by other conventional technologies by using fossil fuels.

[EN] The gradual increase in energy consumption that has been produced during the last years, together with the massive implementation of renewable generation technologies, has motivated a significant increment in the variability and unpredictability of power generation, along with the subsequent increment in the cost of grid management and higher probability of contingencies. As a result, the customers' participation in the solution of these problems by means of DR actions is more and more applied worldwide. In this framework, the existing similarities between the electricity and natural gas systems permit to expect a successful application of DR concepts for a more efficient operation of natural gas systems by using the flexibility of consumers. In order to develop DR products in the gas system, services that consumers may offer have been investigated. Therefore, the proposed methodology includes the analysis of the management actions that system operators must address in the daily management of the systems (such as balancing, pipeline congestion or reserve shortages in underground storages), the identification of DR products that have been successfully developed for power system operators or the metering and communication needs for the full exploitation of the flexibility in this sector. (c) 2021 Elsevier Ltd. All rights reserved.

Landfills are one of the most common ways to dispose the solid urban waste in many countries due to their relatively simple technical requirements, operational costs and low investment. Moreover, biogas produced in landfills can be used as a renewable energy source for power generation. The Valencian Region is one of the largest solid urban waste producers in Spain, and therefore, it has an unexplored potential of landfill biogas production. This paper aims to estimate the potential of biogas landfill production for power generation in the Valencian Region. Statistical data from solid urban waste in landfills in the provinces of Alicante, Castellón, and Valencia was gathered. Then the potential of landfill biogas production was estimated by means of waste classification for each province. To provide information related to the use of landfill gas as an alternative source of energy, results presented in this work show that the Valencian Region has an important potential to use landfill biogas from solid urban waste as a renewable source for power generation, and also provide information to the regional government, academic researches, policy makers and investors.

Spanish electrical generation has traditionally included high pollutant energy resources, like fuel or carbon. However, disturbing ever-increase in the average temperature of Planet Earth has led to a search for sustainability in the energy scenario. Therefore, Spanish electrical generation mix is prone to replace contaminant energy resources by non-contaminant, such renewables. Concretely, Spain is one of the countries with more solar peak annual hours. Nevertheless, having enough space to increase solar fields has been widely question. In this paper, an unrealistic scenario where all the annual Spanish consumption would be covered by photovoltaics is deeply analysed. Considering real electrical Spanish consumption data from 2017, required total quantity of solar panels has been quantified. Additionally, the study takes the hypothesis that all the panels should be placed on Spanish desert zones for two main reasons. First, total solar peak annual hours there are higher than in other Spanish regions. Last, making there the installation would give use to previous wasted zones. Obtained results indicate that around 691 million of 330Wp solar panels would be required for this issue, taking up 492175 km2. This space means only a 0.77% of all Iberian Peninsula. These outcomes clearly show that there is suitable and enough space to increase solar fields in Iberian Peninsula.