Heuristic optimization of clusters of heat pumps: A simulation and case study of residential frequency reserve

The technological challenges of adapting energy systems to the addition of more renewables are intricately interrelated with the ways in which markets incentivize their development and deployment. Households with own onsite distributed generation augmented by electrical and thermal storage capacities (prosumers), can adjust energy use based on the current needs of the electricity grid. Heat pumps, as an established technology for enhancing energy efficiency, are increasingly seen as having potential for shifting electricity use and contributing to Demand Response (DR). Using a model developed and validated with monitoring data of a household in a plus-energy neighborhood in southern Germany, the technical and financial viability of utilizing household heat pumps to provide power in the market for Frequency Restoration Reserve (FRR) are studied. The research aims to evaluate the flexible electrical load offered by a cluster of buildings whose heat pumps are activated depending on selected rule-based participation strategies. Given the prevailing prices for FRR in Germany, the modelled cluster was unable to reduce overall electricity costs and thus was unable to show that DR participation as a cluster with the heat pumps is financially viable. Five strategies that differed in the respective contractual requirements that would need to be agreed upon between the cluster manager and the aggregator were studied. The relatively high degree of flexibility necessary for the heat pumps to participate in FRR activations could be provided to varying extents in all strategies, but the minimum running time of the heat pumps turned out to be the primary limiting physical (and financial) factor. The frequency, price and duration of the activation calls from the FRR are also vital to compensate the increase of the heat pumps’ energy use. With respect to thermal comfort and self-sufficiency constraints, the buildings were only able to accept up to 34% of the activation calls while remaining within set comfort parameters. This, however, also depends on the characteristics of the buildings. Finally, a sensitivity analysis showed that if the FRR market changed and the energy prices were more advantageous, the proposed approaches could become financially viable. This work suggests the need for further study of the role of heat pumps in flexibility markets and research questions concerning the aggregation of local clusters of such flexible technologies.Comisión Europea 69596

供給と需要側を考慮した電源システムのモデリングと評価

Modelling and optimization of sustainable power system and energy network are becoming complex engineering. Demand side resources also need to be planned considering characteristics of district energy supply scenario. This research first analyzes the feasibility of VPP based on scenario of Chongming Island. VPP focuses on expansion of renewable energy and upgrade of efficient appliances, results verify the effectiveness of the VPP concept. Then investigates the techno-economic viability of high variable renewable integration. PV-PHS dispatch scenarious are carried out with constraints, PHS effectively recovers the suppression and decreases the PV power levelized cost. Introduction PV-PHS shifts merit order curve to right, decreasing power generating cost. Thirdly, cost and environmental benefits of optimal designed decentralized energy systems were investigated. Scheduled distributed energy resources could be optimized to benefit the public grid. Performance of dynamic price is investigated based on the social demonstration project experiment. Finally, the conclusions are provided.北九州市立大

Decentralization in the electricity system: At the household, community and city levels

Recent years have seen a rise in the number of implementations of small-scale generation and storage technologies for electricity and heat at different levels in the energy system. This trend towards decentralization of the system is driven by rapid decrease in technology costs, as well as the intentions expressed by various stakeholders to contribute to a carbon-neutral energy system. This thesis investigates the investments and operation of generation and storage technologies at three levels within the energy system: i) residential Prosumer households, which use photovoltaic (PV)-battery systems to supply and shift their electricity demand; ii) Prosumer communities, in which prosumer households share electricity; and iii) Smart integrated cities, which make use of interconnections between the electricity, heating, and transport sectors.Three techno-economic optimization modeling methods are utilized to study technology investment and dispatch, self-consumption of electricity and heat at different levels of decentralization, and the interactions that occur between decentralized systems and the centralized electricity system. Prosumer households are modeled by combining a household electricity cost optimization model and a northern European electricity system dispatch model. The optimization model developed to study prosumer communities directly compares the PV-battery system investments and operations in individual prosumer households and in prosumer households within a community. The city energy system optimization model is designed to analyze interconnections between the urban electricity and heat (and in future work, also transport) sectors.It is shown that prosumer households under the current Swedish tariff system experience a strong incentive to self-consume PV-generated electricity within their households and experience a weak incentive to operate their battery systems such as to reduce operational costs within the electricity system. Being part of a prosumer community can provide the highest monetary benefit to prosumer households for the purpose of reducing the connection capacity to the centralized system. Prosumer communities exhibit different patterns of electricity trade to the centralized system than individual prosumer households, due to local balancing of electricity within the community. On the city level, the installation of local generation and storage technologies for electricity and heat can reduce the stress on the connection to the centralized electricity system. Thus, local electricity generation can help to meet increases in electricity demand and demand peaks at the city level, stemming from city growth or electrification of energy use within the city. An interaction between the electricity and heating sectors in the city energy system can in the modeling results be seen in, for example, the utilization of power-to-heat technologies, which often use electricity during low-cost hours. Storage systems for electricity and heat are utilized within the city to shift electricity and heat between different periods