Heat Market Research Articles

100% renewable heat supply in Berlin by 2050 – A model-based approach

The energy crisis posed major challenges, especially for the heating sector. The European gas price increased from 16€/MWh in March 2021 to 227€/MWh in March 2022, which led to a debate in Germany around reshaping the heat supply to decrease energy import dependence. However, many actors on the heating market are reluctant to make the necessary investments to reduce dependence on natural gas. Although, independence of fossil energy imports by 2050 would be possible with a switch to a 100% renewable heat supply for Berlin.Based on the linear open-source energy system model GENeSYS-MOD, a 100% renewable-based energy system is modeled. GENeSYS-MOD is extended to model district heating, which is crucial for Berlin's heat supply. Furthermore, the modeling of heat pumps and a data set for Berlin is revised.The modeling considers the tightened climate protection targets, which means a 95% CO2 reduction by 2045 compared to 1990. By 2050, 100% of the transport, industry, electricity, and building sectors` emissions are mitigated.The results suggest the immediate exploitation of the existing renewable energy potential and seasonal heat storages, as well as a necessity for a major increase in renovation rates. The upcoming coal phase-out in Berlin in 2030 should be met by a mix of heat pumps and biomass. If heat pump resources are exhausted, direct electric heating is deployed as last resort option.

Evaluating the Potential for Solar District Heating with Pit Thermal Energy Storage in Sweden

Sweden was among the first countries to install solar thermal plants for district heating (DH) as early as in 1970s. However, in recent years, the focus on solar DH installations has shifted primarily to Denmark and Germany, with only one recent installation reported in Sweden. Nonetheless, due to changes in the overall heating market, the use of large-scale storage (both with and without solar heat) is becoming increasingly important. Despite significant advancements in adopting DH systems, the combination of solar DH with PTES is not well studied from Swedish context. The economic and geological prerequisites for the deployment of PTES remain largely unexplored. This paper explores the integration of large-scale solar thermal systems into DH networks in Sweden, particularly highlighting the feasibility and potential of pit thermal energy storage (PTES) systems. Through findings from a national project, this paper assesses the techno-economic-geological viability of PTES alongside solar thermal collectors, providing insights into the project’s methodological approach and initial findings.

Sustaining power distribution network submerged in plug-in hybrid CNG-electric vehicles for future green transportation: A risk-constrained analysis

The urgent need to address environmental issues, particularly the reduction of greenhouse gas emissions, has become a global priority. In this pursuit, various technologies are being explored to facilitate the promotion of sustainability. This study focuses on a virtual energy hub (VEH) integrated with Plug-in hybrid gas-electric vehicles (PHGEVs), various energy sources, and storage devices. However, the presence of fossil-based energy sources like combined heat and power (CHP), diesel generation (DG), boilers, and gas-based operation modes of PHGEVs, resulted in the release of carbon emissions. In this concern, the power-to-gas (P2G) technology, with its immense potential, is being considered to absorb and recycle captured CO2 emissions into methane gas, thereby enhancing economic and sustainability perspectives. Furthermore, uncertain parameters including the charge and discharge of PHGEVs, the price of the day-ahead market for heat and power, energy demands, and wind speed are considered in the VEH, the management of which is achieved through the downside risk constraint (DRC) method. The proposed model is implemented and tested on an IEEE 33-bus test system. Results show that P2G reduces the CO2 level by a mean of 3.7 %. Also, for the minimum of 3.2 % profit reduction, the risk level has fallen by nearly 100 %.

Критерии теплосетевых организаций: проблемы правоспособности

Amendments to the heat supply laws came into force over a year ago, providing criteria for acquiring the status of a heat network company. The purpose of these innovations was to bring order to the heat market and maintain competent professional players. It aimed at consolidating network assets in the last resort heat supplier, the unified heat distribution company, and depriving enterprises that lack the necessary material, labor, and technical resources for proper maintenance and repair of heat networks of the status of a heat network company. The intermediate results of the reform suggest now that the legislator’s expectations were not fully met. While disclosing the historical peculiarities of heat industry development in the pre-reform period, this article examines the factors that first led to the emergence of multiple heat network companies in the heat supply market and then prompted the legislator to take measures to optimize the number of regulated organizations. To simulate the potential effects of legal regulation, the author examines the electric power industry, which is related to heat supply. The legislator had already established criteria for local grid organizations in this industry several years before the reform of heat network companies. However, the legal position of the Constitutional Court of the Russian Federation prevented the legislator’s efforts from being fully implemented. To address the problem at hand, the author suggests transitioning from quantitative to qualitative criteria for evaluating an entity’s compliance with the status of a heat network company. This approach will prioritize the reliability of heat supply over using compliance as a formal basis for depriving bona fide enterprises of the status of a professional player in the heat market.

Пространственная организация рынков продукции топливно-энергетического комплекса России

The article analyzes the markets of fuel and energy complex products in Russia, i.e. of oil, natural gas, coal, electricity, and heating energy. Among the emphasized features of the markets of fuel and energy complex products are the manifold of regulatory influences, the dependence of geographical boundaries of the markets on the development of the corresponding infrastructure, the presence of vertical and horizontal integration, the high dependence of the national markets of the complex products on the corresponding world markets. The combination of the described features on each of the markets of fuel and energy complex products forms a variety of conditions for their functioning within the boundaries of the national economy, which sets the direction of commodity flows and determines the development of the relevant transport infrastructure, which, in turn, are manifested in the spatial organization of product markets (their geographical segmentation). The research algorithm consisted of the analysis of sectoral markets based on the following parameters: properties of energy as a commodity, resource base, characteristics of producers, consumption structure, infrastructure development, and institutional conditions. Based on the combination of parameters, segments were identified for each of the fuel and energy complex product markets. The oil, natural gas, coal and heating market have two segments each: western and eastern. In the coal market, the eastern segment itself has two segments: eastern coastal and eastern mainland. The electricity market has three segments: western, eastern and northeastern. The analysis allows us to identify the western and eastern segments in each of the fuel and energy complex product markets, which are diametrically different in their characteristics. The stability of the distribution of the country’s territories by segments suggests the presence of invariants determined by the parameters of physical space, the effect of which is weakly susceptible to regulatory influences

Методичні аспекти ціноутворення на ринках теплової енергії за аукціонного підходу

The development of competition in the heat energy markets with main heating networks is possible on the basis of the organization of unilateral heat auctions between heat producers. A prerequisite for opening competition in the heat energy markets is the separation of heat generation and heat networks, as well as the provision of regulated access to heat networks for independent producers. In terms of time segmentation, it is advisable to introduce: annual auctions, where basic heat needs are being contracted; monthly auctions – for peak needs, and daily auctions – for hourly imbalances. The article proposes organizational and technological regulations for conducting annual heat auctions, which should cover 80–90% of heat needs. Heat auctions should function according to the declared pricing method, where the producers who are the auction winners receive income for the contracted volumes of heat generation at a given price, while consumers pay a single weighted average price. Heat auctions operate under centralized dispatching, which provides for the coordination of physical and commercial heat energy flows, taking into account the technical specifics of heat networks. The article substantiates variants of economic and mathematical models of auction pricing in the heat energy market with different configurations of heat networks. As such a configuration, are considered heating networks with: 1) unlimited flow connections; 2) insulated heat producers; 3) system restrictions on throughput capacities within the heating area; 4) one-way and 5) two-way flows between adjacent heating areas. Establishment of a fair price for heat energy is reduced to solving the function of minimizing the weighted average price of heat energy for consumers under the following conditions: a) full satisfaction of consumer demand for thermal energy; b) technical capabilities of heat generation; c) connections and throughput capacities of heating networks within the heating area; d) directions of flows and capacity between adjacent heating areas. Each heat network represents a unique configuration of these conditions, therefore, the solution of the economic and mathematical problem of setting the auction price for heat energy will be different in each local heat market. Approbation of the proposed approach proves that with a large number of regulatory and systemic restrictions within the heating area, the price of thermal energy will increase, while bilateral flows of thermal energy between adjacent heating areas lead to a decrease in the price of thermal energy. The proposed methodological aspects of auction pricing for thermal energy should be introduced in large and medium-sized settlements with trunk networks, which will allow independent heat producers who work on renewable energy sources or have excess and waste heat to integrate into the market, contributing to the decarbonization of the city and the country as a whole.

Multi-objective optimization application for a coupled light water small modular reactor-combined heat and power cycle (cogeneration) systems

The goal of this research is to propose a way to maximize small modular reactor (SMR) utilization to gain better market feasibility in support of carbon neutrality. For that purpose, a comprehensive tool was developed, combining off-design thermohydraulic models, economic objective models (levelized cost of electricity, annual profit), non-economic models (saved CO2), a parameter input sampling method (Latin hypercube sampling, LHS), and a multi-objective evolutionary algorithm (Non-dominated Sorting Algorithm-2, NSGA2 method) for optimizing a SMR-combined heat and power cycle (CHP) system design. Considering multiple objectives, it was shown that NSGA2+LHS method can find better optimal solution sets with similar computational costs compared to a conventional weighted sum (WS) method. Out of multiple multi-objective optimal design configurations for a 105 MWe design generation rating, a chosen reference SMR-CHP system resulted in its levelized cost of electricity (LCOE) below $60/MWh for various heat prices, showing economic competitiveness for energy market conditions similar to South Korea. Examined economic feasibility may vary significantly based on CHP heat prices, and extensive consideration of the regional heat market may be required for SMR-CHP regional optimization. Nonetheless, with reasonable heat market prices (e.g. district heating prices comparable to those in Europe and Korea), SMR can still become highly competitive in the energy market if coupled with a CHP system.

Mutual-benefit of district heating market and network operation for prosumers integration

ABSTRACT Integration of prosumers in district heating networks brings new challenges to the market and the network operation since they can change the thermal flow and increase competition. Thus, it is mandatory to develop new market structures and network management mechanisms. In this scope, this work proposes the implementation of a coordination methodology based on a peer-to-peer market without a supervising entity. The goal is to achieve higher revenue by coping with the requirements of each agent. Furthermore, the model is validated through network nodal analysis inspired by the power sector. The results in a Nordic network point out that the coordination methodology can provide compromise solutions between market negotiation and network operation. This methodology succeeded in providing reliable network solutions, fixing 99.88% of network burdens just after one iteration, and encouraging prosumers’ integration. This increases market competition which lowers the energy costs for consumers while avoiding the network’s operating burdens.

Transformation of the Polish Heating Sector Based on an Example of Select Heat Energy Companies Supplying Energy to Local Government Units

The aim of this study was to identify changes in the Polish heating sector and assess modernization investments in the field of energy transformation. This research covered 30 municipalities in Poland that applied for the II National Competition for Local Government Units for the Most Energy Innovative Local Government. In terms of changes, the analysis covered the years 2002–2021 and in the investment assessment, data from 2021 were used, as well as plans and strategies of enterprises and local governments. To assess planned investments in district heating companies, an original method of assessing social needs and the ability and readiness of enterprises to modernize the infrastructure in the field of heating was developed. It considers the emissivity factor of a heating plant and the assessment of investments by experts according to nine criteria. The method was used to assess changes in the district heating system in 30 municipalities in Poland. The shaping of the energy strategy in Poland is influenced by the climate and energy policy of the European Union (EU), which assumes that by 2040, households and industries will be heated with system heat or low-emission energy sources. Poland is the second-largest district heating market in the European Union, but heat production in the country is dependent on coal, which is why this sector requires transformation in the coming years. Research shows that thermal energy companies modernizing their installations more often use low-emission technologies than zero-emission ones. The main objectives of investments in energy production are the decarbonization of the heating system and a reduction in greenhouse gas emissions, as well as social needs in the field of connecting houses and flats to the system networks.

Renewable gases in the heating market: Identifying consumer preferences through a Discrete Choice Experiment

Renewable gases like biomethane or Synthetic Natural Gas (SNG) can play an important role in short-to mid-term decarbonization of the residential heating sector. By (partially) replacing the dominant natural gas, they accomplish two major goals: lowering CO2 emissions and lessening import dependencies. While existing research points to great production potential and technical options for producing renewable gases, the demand side has largely been neglected. Yet consumer decision making is highly relevant for climate change mitigation. Against this backdrop, we conducted a Discrete Choice Experiment with 512 heating consumers in Germany, a country with a high dependency on natural gas. We decomposed the gas tariff into six attributes (share of renewable gas, labels, regionality, biomethane feedstock, supplier type, and price) with varying attribute levels.We identified knowledge gaps regarding both biomethane and SNG technologies, gaps which are more pronounced for SNG. Results show that the gas mix and the price are key in consumer evaluations. Labels and feedstock are less relevant, regionality and supplier type almost neglectable. Biomethane is clearly favored over SNG, which comes as a surprise given the past controversy over food vs. fuel. Our results call for raising consumer awareness and standardizing information in order to improve decision-making.

Benefit Analysis and Comparison of Electric Heating System for Municipal Central Heating

Electric heating can not only relieve the pressure of municipal central heating but also help to solve the problem of wind and light abandonment, which is an important direction for the future development of central heating. To maximize the comprehensive benefits, this paper constructs three kinds of electric heating systems. According to the comprehensive benefit evaluation of technical, economic, and environmental aspects, the comprehensive optimal scheme is selected. An office area in Beijing is taken as an example to determine the optimal scheme of electric heating and heating supplement. The results show that the comprehensive benefit of the heat pump + phase change accumulator system is the best, but the environmental benefit needs to be further improved. To promote the pace of electric heating and heating supplement, the government should increase the subsidies for electric boiler technology. At the same time, clean energy power supply enterprises should improve the trading mechanism of the electric heating market and reduce the price of clean energy heating.

Strategies for supplying enterprises with energy in the context of changing coal prices on the Polish market - The effect of the war in Ukraine

The primary fuel carrier of energy in the Polish economy is hard coal. Due to such a high share in the energy balance, it is important to guarantee stable and predictable prices for this raw material and to ensure the possibility of its availability. Climate and energy policy and the international context have a significant impact on shaping the framework of the national energy strategy. The long-term vision of striving for the EU climate neutrality by 2050 and stimulating regulatory mechanisms have an impact on the achievement of effects in the coming decades. The implementation of the 2030 climate and energy targets in the EU is crucial for a low-carbon energy transition. The objective of the article is to present, for the Polish domestic market, the PSCMI index of a group of indices for benchmark prices of thermal coal produced by domestic producers and sold in the domestic energy market and the domestic heat market. The article discusses indices for coal sold in the domestic market for power generation (PSCMI 1) and heating (PSCMI 2). Price trends and analysis of price changes for these indices between 2020 and 2022 are also analyzed. The adopted scope of the conducted research was taken into account in the period of the greatest boom in price and index changes, which was caused by various external factors.

Artificial Intelligence Methods for Analysis and Optimization of CHP Cogeneration Units Based on Landfill Biogas as a Progress in Improving Energy Efficiency and Limiting Climate Change

Combined heat and power generation is the simultaneous conversion of primary energy (in the form of fuel) in a technical system into useful thermal and mechanical energy (as the basis for the generation of electricity). This method of energy conversion offers a high degree of efficiency (i.e., very efficient conversion of fuel to useful energy). In the context of energy system transformation, combined heat and power (CHP) is a fundamental pillar and link between the volatile electricity market and the heat market, which enables better planning. This article presents an advanced model for the production of fuel mixtures based on landfill biogas in the context of energy use in CHP units. The search for optimal technological solutions in energy management requires specialized domain-specific knowledge which, using advanced algorithmic models, has the potential to become an essential element in real-time intelligent ICT systems. Numerical modeling makes it possible to build systems based on the knowledge of complex systems, processes, and equipment in a relatively short time. The focus was on analyzing the applicability of algorithmic models based on artificial intelligence implemented in the supervisory control systems (SCADA-type systems including Virtual SCADA) of technological processes in waste management systems. The novelty of the presented solution is the application of predictive diagnostic tools based on multithreaded polymorphic models, supporting making decisions that control complex technological processes and objects and solving the problem of optimal control for intelligent dynamic objects with a logical representation of knowledge about the process, the control object, and the control, for which the learning process consists of successive validation and updating of knowledge and using the results of this updating to determine control decisions.

Rethinking the governance of geothermal power industry: The roadmap for sustainable development

The European geothermal heating market, at one time dominated by only a handful of countries, is set to experience a purple patch in the coming years as governments scramble to find an affordable alternative to expensive gas-fired heating. The primary focus of this study will be to investigate what effect will worldwide governance factors and economic growth on the geothermal energy output among the 27 European Countries from the time being 1996 to 2021. Using the autoregressive distributed lag, the findings shows that a significant increase in the geothermal energy industry sustainability can occur in European Union 14 (EU14) emerged economies using worldwide governance factors than in EU13 emerging economies. Among additional factors, instability in the political realm, regulatory issues in the area of quality, accountability, and voice-related issues, and the ability to curb corrupt practices contribute more positively to geothermal energy sustainability in EU14 emerged economies than in European Union 13 (EU13) emerging economies. On the other hand, government effectiveness contributes more positively to geothermal energy sustainability in EU13 emerging economies than in EU14 emerged economies. The finding implies that geothermal power sustainability in EU region countries can be significantly increased by mounting the level of worldwide governance determinants to achieve Energy Union aims by 2030. This will finally be spread to combat climate change and environmental pollution. All observations on projected calculations are valid. The confirmation was achieved with the aid of the three estimators used in the study which are the pooled mean group estimator, the mean group estimator, and the third one was dynamic fixed effect approach. This study recommended that these European countries need to put more effort in terms of being effective in worldwide governance indicators which will help in goal attainment at the societal and environmental levels. Those in charge of making laws in the European countries should get more engaged in worldwide governance scopes as this will assist in facilitating the security and sustainability of geothermal energy generation. Those in charge of making policies in the EU countries should as well lay more emphasis on the strategies that could be cointegrated and as well sustainable toward worldwide governance fractionation toward the achievement of the sustainability of geothermal power and this will drastically reduce the need or dependence on fossil fuel and emissions coming from carbon dioxide in the future time.

Application of an intelligent method for hydrogen-based energy hub in multiple energy markets

Use of different energy carriers together, known as an energy hub, has been a hot topic of research. The hub manager manages the energy in the hub and supplies the energy demanded by the consumers. Herein, a multi-carrier energy storage system comprising a thermal energy storage system, ice storage system, and hydrogen storage system is considered for a multi-carrier energy system to exploit their economic benefits. The proposed combined cooling, heating and electricity microgrid not only participates in the electricity, gas and heat market to meet the needs of electricity, heating and cooling, but also can use the new hydrogen power technology used in the hydrogen storage system to increase the efficiency of the whole system participate in the market. In addition, a multi-energy demand response model is used as a new concept of demand response on electrical and thermal loads, which provides more options for multi-energy end users in energy management policies. To cover the uncertainty of the existence of different energy sources in the used model and the price of electricity, a new method has been used. The LHS sampling is used to develop diverse scenarios, and the backward scenario reduction method is adopted to decrease the number of scenarios. To solve the objective function and optimization, the metaheuristic whale algorithm improved by a local search algorithm is utilized. The main goal is to reduce the operation costs of the multi-energy carrier system. The obtained results show that the hydrogen storage utilization and multi-energy demand response can reduce the system operation cost by 6% for the studied experimental system. Furthermore, as the uncertainty budget increased, the total cost of operations increased by 10%. This is because the level of planning conservatism increases with each increase in the uncertainty budget.

Optimal bidding strategies of advanced adiabatic compressed air energy storage based energy hub in electricity and heating markets

Integration of power and heating systems can not only improve energy efficiency but also reduce the peak generation capacity by narrowing the gap between peak and valley demands. Advanced adiabatic compressed air energy storage (AA-CAES) is a large-scale and environmental-friendly storage technology that can supply heat and power. It can be adopted as an energy hub that integrates electricity and heating systems. This paper studies the strategic behavior of an AA-CAES based energy hub in deregulated electricity and heat markets. Firstly, a heat market clearing model with elastic thermal demands is developed, and the impact of demand elasticity on the stability of the heat market is analyzed. Secondly, based on the proposed heat market model, a bi-level optimization model is established to explore the strategic bidding and scheduling of the merchant AA-CAES based energy hub in both markets. Through exploiting the weakly coupling structure of the bi-level problem, a special decomposition method is proposed to compute the market equilibrium. The optimal response of the lower-level power/heat market clearing problem is analytically expressed by multi-parametric programming techniques, where the bidding strategies are parameters. With the lower-level parameterized solution, the original complex joint optimization problem is transformed into a small-scale mixed integer quadratic program with only a few binary variables, and thus can be solved efficiently. Case studies verify the proposed model and method. Results show that the AA-CAES based energy hub/heat market is conducive to an 8.6%/22.5% reduction in the operation cost of the heat market/energy hub.

Renewable energy of wastewater heat recovery.

Wastewater heat recovery (HR) is one of the renewable energy sources. The associated harmful environmental, health, and social effects of traditional biomass, fossil fuel, and other polluted sources have enhanced the growing interest in the search for an alternate cleaner energy source globally. The major objective of this study is to develop a model to assess the impacts of wastewater flow (WF), the temperature of wastewater (TW), and internal temperature in sewer pipes (TA) on the performance of HR. Sanitary sewer networks in Karbala city of Iraq were chosen as a case study in the present research. Statistical and physically based models such as the storm water management model (SWMM), multiple-linear regression (MLR), and structural equation model (SEM) were used for this purpose. The model outputs were analyzed to assess the performance of HR in the context of changing WF, TW, and TA. The results showed that the total amount of HR from wastewater in Karbala city center during the 70 days was 136,000 Mw. The study clearly showed that WF in Karbala played a major role in HR. Basically, the heat from wastewater is CO2-free and represents a significant opportunity for the energy transition in the heating market.

Domestic Solar Heating: Historical Development, System Description,Social Aspects, and Future Prospects

With the advancing technology, there are many well-developed domestic solar systems with two main categories: activeheating systems and passive heating systems. This paper focuses on a functional heating system which includes solarwater and air heating systems. The main physical principles are solar thermal energy and heat transfer, implementedon solar collectors and heat exchangers. As for the environmental aspect, domestic solar heating systems can reducegreenhouse emissions, alleviating global warming. Moreover, with the increasing demand for renewable energy due tothe rising awareness of environmental protection, the marketing size of solar energy has become larger. Solar heatingsystems have been a fast-growing technology in many countries over the last decade. Compared with other energy, theprice of solar energy is considered the cheapest, which can help consumers save around $5,000 with a payback time of 5years. Therefore, the solar heating market will expand in the future because of carbon emission reduction and increasingefficiency.

Implementation of a new pricing mechanism in the heat supply market

The article notes the lack of investment in heat supply market, which leads to increased wear and tear of both heat sources and heating networks, huge heat losses and non-competitiveness of district heating systems. A proposal is being considered to implement a new model of the heat market in all regions of Russia and to switch from direct state regulation of tariffs for heat energy (capacity) to contractual tariffs, the maximum level of which is determined by the “alternative boiler house” method. However, for those regions where the existing tariffs for heat energy (capacity) are higher than the established limit levels using the “alternative boiler house” method, the authors propose the use of other approaches and methods of tariff regulation, in particular, examples, advantages and disadvantages of using energy service contracts, tariff regulation based on method of return on invested capital, new legislation in terms of obtaining long-term loans for the modernization of infrastructure from the National Welfare Fund and the Housing and Utilities Reform Assistance Fund.

Evaluating the role of waste-to-energy and cogeneration units in district heatings and electricity markets

This paper investigates the activity of a multi-utility that uses Waste-to-Energy (WtE) and cogeneration (COG) plants to provide services in the heat and in the electricity markets. We assume that it employs WtE and COG units to participate in the day-ahead and real-time electricity markets and, with the support of heat-only units, it satisfies the heat demand of local district heating areas (DHAs). We use stochastic programming to develop three linked problems that describe the sequence of the decision process regarding the operation of WtE and COG facilities: (i) the first problem considers the point of view of the multi-utility that defines the day-ahead and the real-time heat scheduling of its plants and the maximum amount of electricity that WtE and COG units can offer in the day-ahead electricity market, taking into account the uncertainty of the real-time heat demand; (ii) the second problem models the day-ahead electricity market cleared by the Power Exchange, where the electricity dispatch of WtE and COG units is limited by the maximum power offers defined in step (i); and (iii) given the heat and power schedules respectively determined in steps (i) and (ii), the last problem describes the activity of theTransmission System Operator that re-dispatches WtE and COG outputs and decides their participation in the reserves and the real-time electricity markets, incorporating uncertain electricity demand and renewable power generation. Italian data are taken to investigate the operation of the WtE and COG plants under different assumptions. A reference analysis shows that these facilities obtain stable revenues from the heating market, but those from the electricity markets are very variable and mainly derives from reserve procurement. In addition, we perform two sensitivity analyses: in the first one, where we consider high natural gas and CO_2 prices, the use of WtE and COG units increases to substitute gas-fueled plants with a consequent increase of their profits; in the second one, which describes an electricity market with a high renewable penetration, the activity of these facilities becomes more irregular because of the augmented penetration of intermitted renewable generation.