scholarly journals Energy/Exergy Conversion Factors of Low-Enthalpy Geothermal Heat Plants

2021 ◽  
Author(s):  
Henning Francke
Keyword(s):  
Conversion Factor ◽  
Operating Cost ◽  
Electric Heating ◽  
Electrical Energy ◽  
Energy System ◽  
Heat Pumps ◽  
Electricity Sector ◽  
Geothermal Heat ◽  
System Perspective ◽  
Useful Heat

Abstract From the system perspective, a geothermal heat plant is not only a source of heat, but, in case of liquid producing wells producing liquid brine, also a sink for relevant amounts of electricity, consumed mainly by the pump(s). This electricity demand is usually not given much attention, although being decisive for operation costs and offering chances for demand side management as a variable consumer. From the perspective of an integrated energy system, geothermal installations basically move energy from the electricity sector into the heat sector. So do electrical compression heat pumps, whose performance is rated by the COP, the ratio between useful heat and invested energy and useful heat, the COP. This study transfers the COP concept to geothermal sites, by defining and determining the energy conversion factor quantity (i.e. relative auxiliary energy or operating cost of heat provision expressed in electricity) for a selection of mostly German geothermal sites. Based on heterogenous data consisting of operational values for some sites and theoretical estimations for others, the calculated ε range from 12 to 116. In analogy, the concept is extended to the exergy conversion factor ζ, which is calculated to range from 1 to 36. A comparison with alternative heat provision technologies, such as heat pumps (COP ≤ 6) or simple electric heating (ε ≈ 1), quantifies the potential service geothermal plants can render to the grid by converting electrical energy into useful heat. This study aims at quantifying the potential benefit of geothermal plants on for the electric grid.

scholarly journals Energy/Exergy Conversion Factors of Low Enthalpy Geothermal Heat Plants

2021 ◽  
Author(s):  
Henning Francke
Keyword(s):  
Conversion Factor ◽  
Operating Cost ◽  
Electric Heating ◽  
Electrical Energy ◽  
Energy System ◽  
Heat Pumps ◽  
Electricity Sector ◽  
Geothermal Heat ◽  
System Perspective ◽  
Useful Heat

Abstract From the system perspective, a geothermal heat plant is not only a source of heat, but, in case of liquid producing wells producing liquid brine, also a sink for relevant amounts of electricity, consumed mainly by the pump(s). This electricity demand is usually not given much attention, although being decisive for operation costs and offering chances for demand side management as a variable consumer. From the perspective of an integrated energy system, geothermal installations basically move energy from the electricity sector into the heat sector. So do electrical compression heat pumps, whose performance is rated by the COP, the ratio between useful heat and invested energy and useful heat, the COP. This study transfers the COP concept to geothermal sites, by defining and determining the energy conversion factor quantity (i.e. relative auxiliary energy or operating cost of heat provision expressed in electricity) for a selection of mostly German geothermal sites. Based on heterogenous data consisting of operational values for some sites and theoretical estimations for others, the calculated ε range from 12 to 116. In analogy, the concept is extended to the exergy conversion factor ζ, which is calculated to range from 1 to 36. A comparison with alternative heat provision technologies, such as heat pumps (COP ≤ 6) or simple electric heating (ε ≈ 1), quantifies the potential service geothermal plants can render to the grid by converting electrical energy into useful heat. This study aims at quantifying the potential benefit of geothermal plants on for the electric grid.

Energy/Exergy Conversion Factors of Low Enthalpy Geothermal Plants

2021 ◽  
Author(s):  
Henning Francke
Keyword(s):  
Performance Indicator ◽  
Energy System ◽  
Heat Pumps ◽  
Electricity Sector ◽  
Not Given ◽  
Geothermal Heat ◽  
Operation Costs ◽  
Integrated Energy System ◽  
Useful Heat ◽  
Selection Of

Abstract A geothermal heat plant is a not only a source of heat, but, in general, also a sink for relevant amounts of electricity, consumed mainly by the pump(s). This electricity demand is usually not given much attention although being decisive for operation costs, but also offering chances for demand side management as a variable consumer. From the perspective of an integrated energy system, geothermal installations basically move energy from the electricity sector into the heat sector, similar to compression heat pumps. The main heat pump performance indicator is the ratio between invested energy and useful heat, the COP. This paper transfers the COP concept to geothermal sites, by defining and determining the quantity for a selection of mostly German geothermal sites.

scholarly journals Evaluating the Potential Contribution of District Heating to the Flexibility of the Future Italian Power System

Energies ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 584
Author(s):  
Chiara Magni ◽  
Sylvain Quoilin ◽  
Alessia Arteconi
Keyword(s):  
Power Systems ◽  
Power System ◽  
Large Scale ◽  
District Heating ◽  
Energy System ◽  
Heat Pumps ◽  
Electricity Sector ◽  
Potential Contribution ◽  
The Future ◽  
Promising Solution

Flexibility is crucial to enable the penetration of high shares of renewables in the power system while ensuring the security and affordability of the electricity dispatch. In this regard, heat–electricity sector coupling technologies are considered a promising solution for the integration of flexible devices such as thermal storage units and heat pumps. The deployment of these devices would also enable the decarbonization of the heating sector, responsible for around half of the energy consumption in the EU, of which 75% is currently supplied by fossil fuels. This paper investigates in which measure the diffusion of district heating (DH) coupled with thermal energy storage (TES) units can contribute to the overall system flexibility and to the provision of operating reserves for energy systems with high renewable penetration. The deployment of two different DH supply technologies, namely combined heat and power units (CHP) and large-scale heat pumps (P2HT), is modeled and compared in terms of performance. The case study analyzed is the future Italian energy system, which is simulated through the unit commitment and optimal dispatch model Dispa-SET. Results show that DH coupled with heat pumps and CHP units could enable both costs and emissions related to the heat–electricity sector to be reduced by up to 50%. DH systems also proved to be a promising solution to grant the flexibility and resilience of power systems with high shares of renewables by significantly reducing the curtailment of renewables and cost-optimally providing up to 15% of the total upward reserve requirements.

scholarly journals Linear Optimisation of a Settlement Towards the Energy-Plus House Standard

Energies ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 210 ◽  
Author(s):  
Matthias Slonski ◽  
Tobias Schrag
Keyword(s):  
Energy Efficiency ◽  
Open Source ◽  
Energy Efficient ◽  
Electrical Energy ◽  
Energy System ◽  
Heat Pumps ◽  
Building Type ◽  
Energy Plus ◽  
Linear Optimisation ◽  
House Standard

Future buildings will use technologies that are either well-known, innovative, or a combination thereof in order to be environmentally friendly and feasible at the same time. To evaluate and compare such systems through simulation, adaptive tools need to be available. This paper describes a conceived method for planning quarters and settlements. The novelty of this work emerges from the combination of a building simulation with a linear economic optimisation of the energy system, to achieve the energy-plus house standard for a settlement. Furthermore, the tools applied are adaptive or open source. In this article, a hypothetical basic example is given for a predefined idealised settlement, which consists of 132 single-family houses of one building type. The hourly demand for electrical energy and heat is established for three energy-efficiency classes for the building type with a dynamic simulation in MATLAB/SIMULINK using the CARNOT toolbox. This toolbox is also used to calculate the specific electrical energy production by photovoltaics. The components for the energy system of the settlement are implemented in the open source linear optimisation tool URBS. An economic optimum for the energy system of the settlement is found for each of the energy efficiency classes for an accumulated energy demand of the buildings. In this way, a lossless energy hub between the buildings is assumed. The results of the conducted simulations indicate that the optimal ratio of air/water to ground/water heat pumps shifts towards air/water heat pumps with more energy efficient houses. This is due to the lower specific investment costs, which outweigh the operational costs when less energy is required. The lowest costs for the entire energy system are for the one with the most energy efficient settlement. This is the case, as the costs for the higher energy standard of the buildings are not considered in the calculations. The behaviour of the optimisation is tested and discussed through a sensitivity analysis for one efficiency class. By presenting this simple, comprehensible example, an impression of the possible applications for this methodology is conveyed.

scholarly journals Impact of Grid-Scale Electricity Storage and Electric Vehicles on Renewable Energy Penetration: A Case Study for Italy

Energies ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1303 ◽  
Author(s):  
Sara Bellocchi ◽  
Michele Manno ◽  
Michel Noussan ◽  
Michela Vellini
Keyword(s):  
Electric Vehicles ◽  
Low Cost ◽  
Energy System ◽  
Heat Pumps ◽  
System Perspective ◽  
Electricity Storage ◽  
Italian Case ◽  
Electrochemical Storage ◽  
Power To Gas ◽  
Storage Technologies

Storage technologies are progressively emerging as a key measure to accommodate high shares of intermittent renewables with a view to guarantee their effective integration towards a profound decarbonisation of existing energy systems. This study aims to evaluate to what extent electricity storage can contribute to a significant renewable penetration by absorbing otherwise-curtailed renewable surplus and quantitatively defines the associated costs. Under a Smart Energy System perspective, a variety of future scenarios are defined for the Italian case based on a progressively increasing renewable and storage capacity feeding an ever-larger electrified demand mostly made up of electric vehicles and, to some extent, heat pumps and power-to-gas/liquid technologies. Results are compared in terms of crucial environmental and techno-economic indicators and discussed with respect to storage operating parameters. The outcome of this analysis reveals the remarkable role of electricity storage in increasing system flexibility and reducing, in the range 24–44%, the renewable capacity required to meet a given sustainability target. Nonetheless, such achievements become feasible only under relatively low investment and operating costs, condition that excludes electrochemical storage solutions and privileges low-cost alternatives that at present, however, exist only at a pilot or demonstration scale.

scholarly journals An Approach to Short-Term Control of Integrated Energy Systems with Load-Controlled Consumers

2019 ◽  
Vol 217 ◽  
pp. 01001
Author(s):  
Valery Stennikov ◽  
Evgeny Barakhtenko ◽  
Oleg Voitov
Keyword(s):  
Storage Systems ◽  
Energy Systems ◽  
Electric Heating ◽  
Energy System ◽  
Heat Pumps ◽  
Short Term ◽  
Integrated Energy Systems ◽  
Heating And Cooling ◽  
Functional Features ◽  
Heat Loads

Modern cities and industrial centers boast a developed energy infrastructure including fuel, electric, heating, and cooling systems. The integration of many separate system into a single technological complex can provide new functional capabilities, the application of more advanced technologies for operation, and the establishment of integrated energy systems. Such systems have a multidimensional structure of functional features and properties of development. The control of integrated energy systems with load-controlled consumers represents an urgent and a rather challenging task. The paper is concerned with an approach to short-term control of integrated energy systems with load-controlled consumers. Planning the daily electricity and heat loads is performed for an integrated energy system, including energy storage systems and electric water heaters, electrical shiftable loads of individual consumers as well as power generation by additional electricity and heat sources (PV systems, wind turbines, heat pumps). The optimal daily profiles are obtained based on the initial profiles of electricity and heat loads, photovoltaic generation and optimal profiles of using electricity and heat storage systems and shiftable load. Optimal daily electricity and heat load profiles differ greatly from the initial ones, which provides a reduction in the energy costs for the consumer.

scholarly journals Sustainable Residential Energy Supply: A Literature Review-Based Morphological Analysis

Energies ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 432 ◽  
Author(s):  
Stefan Arens ◽  
Sunke Schlüters ◽  
Benedikt Hanke ◽  
Karsten von Maydell ◽  
Carsten Agert
Keyword(s):  
Energy Supply ◽  
Energy Demand ◽  
Morphological Analysis ◽  
Energy System ◽  
Heat Pumps ◽  
Electricity Sector ◽  
Residential Energy ◽  
Electricity Grid ◽  
Vehicle To Grid ◽  
Mode Shift

The decarbonization of the energy system will bring substantial changes, from supranational regions to residential sites. This review investigates sustainable energy supply, applying a multi-sectoral approach from a residential site perspective, especially with focus on identifying crucial, plausible factors and their influence on the operation of the system. The traditionally separated mobility, heat, and electricity sectors are examined in more detail with regard to their decarbonization approaches. For every sector, available technologies, demand, and future perspectives are described. Furthermore, the benefits of cross-sectoral integration and technology coupling are examined, besides challenges to the electricity grid due to upcoming technologies, such as electric vehicles and heat pumps. Measures such as transport mode shift and improving building insulation can reduce the demand in their respective sector, although their impact remains uncertain. Moreover, flexibility measures such as Power to X or vehicle to grid couple the electricity sector to other sectors such as the mobility and heat sectors. Based on these findings, a morphological analysis is conducted. A morphological box is presented to summarize the major characteristics of the future residential energy system and investigate mutually incompatible pairs of factors. Lastly, the scenario space is further analyzed in terms of annual energy demand for a district.

scholarly journals Techno-Economic Analysis of Power-to-Heat Systems

2021 ◽  
Vol 238 ◽  
pp. 03003
Author(s):  
Alberto Vannoni ◽  
Alessandro Sorce ◽  
Alberto Traverso ◽  
Aristide Fausto Massardo
Keyword(s):  
Large Scale ◽  
Renewable Energy Sources ◽  
Large Fraction ◽  
District Heating ◽  
Electrical Energy ◽  
Energy System ◽  
Heat Pumps ◽  
Point Of View ◽  
Thermal Source ◽  
Economic Point

The heating and cooling sector, responsible for a large fraction of greenhouse emissions, may have a large scale impact on the energy system evolution contributing to smart industrial and domestic electrification; at the same time the recent increase of renewable energy sources installation, posing a threat in terms of grid stability, makes available a considerable amount of clean and cheap electrical energy during peak hours production. Power to heat technologies constitute a promising solution to face both these issues reducing the electric demand variability and decarbonizing the heat production. Large vapor compression heat pumps are a reliable technology able to compete, under the economic point of view, with the heat-only-boilers in order to serve district heating networks. Performance and economic profitability of a compression cycle is strongly dependent on available thermal source and the temperature of water delivered to the network. The present work explores and compares performance and economic indicators under different installation conditions, considering compression heat pumps employing four different fluids: a traditional HCF (R134a) and three natural fluids, ammonia (R717), butane (R600), and propane (R290), often preferred nowadays to HCFs due to the lower global warming potential.

scholarly journals Optimal operation of regional integrated energy system based on demand-side load response

2020 ◽  
Vol 213 ◽  
pp. 02005
Author(s):  
Peng Fang ◽  
Cui Mao ◽  
Yuping Chen ◽  
Shan Zhou ◽  
Rui You ◽  
...  
Keyword(s):  
Operating Cost ◽  
Electric Heating ◽  
Energy System ◽  
Optimal Operation ◽  
Energy Utilization ◽  
Utilization Rate ◽  
Demand Side ◽  
Side Load ◽  
Load Response ◽  
Integrated Energy System

The integrated energy system (IES) has the advantage of improving energy utilization and promoting energy flexibility. From the perspective of demand-side load response, this paper establishes demand-side power, thermal load response, and natural gas demand response models, and then constructs the objective function of the lowest operating cost of the regional IES for combined electric heating and gas supply, using Cplex to perform optimization. Finally, a typical northern park is taken as an example to analyze and verify the feasibility of the model and algorithm. The analysis of the case shows that considering the electric heating gas demand side response will be better than not considering or considering only the single and both responses, not only can reduce operating costs, achieve peak reduction and valley filling, but also reduce abandonment of wind and energy, and increase energy utilization rate.

scholarly journals Life Cycle Cost of Heat Supply to Areas with Detached Houses—A Comparison of District Heating and Heat Pumps from an Energy System Perspective

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3266 ◽  
Author(s):  
Moa Swing Gustafsson ◽  
Jonn Myhren ◽  
Erik Dotzauer
Keyword(s):  
Life Cycle ◽  
Life Cycle Cost ◽  
Probability Distributions ◽  
District Heating ◽  
Energy System ◽  
Heat Pumps ◽  
Local Conditions ◽  
System Perspective ◽  
Alternative Scenarios ◽  
System Life

There are different views on whether district heating (DH) or heat pumps (HPs) is or are the best heating solution in order to reach a 100% renewable energy system. This article investigates the economic perspective, by calculating and comparing the energy system life cycle cost (LCC) for the two solutions in areas with detached houses. The LCC is calculated using Monte Carlo simulation, where all input data is varied according to predefined probability distributions. In addition to the parameter variations, 16 different scenarios are evaluated regarding the main fuel for the DH, the percentage of combined heat and power (CHP), the DH temperature level, and the type of electrical backup power. Although HP is the case with the lowest LCC for most of the scenarios, there are alternatives for each scenario in which either HP or DH has the lowest LCC. In alternative scenarios with additional electricity transmission costs, and a marginal cost perspective regarding the CHP investment, DH has the lowest LCC overall, taking into account all scenarios. The study concludes that the decision based on energy system economy on whether DH should expand into areas with detached houses must take local conditions into consideration.

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