Institut Nachhaltigkeit und Energie am Bau
Dauerhafte URI für die Sammlunghttps://irf.fhnw.ch/handle/11654/10
Listen
5 Ergebnisse
Ergebnisse nach Hochschule und Institut
Publikation Multi-agent based simulation of smart building cluster for electric grid stabilization(IOP Publishing, 21.11.2019) Hall, Monika; Geissler, Achim; Wache, HolgerWith the increasing number of photovoltaic systems and heat pumps in buildings existing substations of the electric grid could be overloaded. A multi-agent based simulation of a building cluster studies the impact of building flexibility in regard to the residual substation load. Each building announces its available flexibility, e.g. "heat pump can be switched off/on". A master coordinator evaluates all incoming offers and decides which offers are accepted. This reduces the residual load at the substation. This paper presents results from a study of the impact at the substation of a smart urban building cluster with different penetration scenarios of heat pumps, photovoltaic systems, batteries and electric vehicles. It is shown that a high penetration of heat pumps and photovoltaic systems violates the substation's limits for the studied building cluster. Batteries cannot reduce the peak utilization. The master coordinator's load shifting options are limited.01A - Beitrag in wissenschaftlicher ZeitschriftPublikation The impact of different energy balancing methods on Net Zero Energy Buildings(03.10.2017) Hall, Monika; Geissler, AchimTo date, the building energy balance is typically based on annual values. If the annual PV-yield equals the overall annual energy demand, the building is called a Net Zero Energy Building (NZEB). Of course, this balancing approach does not take into account that PV-yield and electricity energy demand do not necessarily occur at the same time. However, Swiss standards and the building label Minergie have begun to address this issue. The Swiss standard SIA 380:2015, and the Minergie recast 2017 include self-consumption/grid-interaction in the energy balance. Currently, for the energy balance PV-yield and electricity demand are usually weighted with the same primary energy factor. Minergie 2017 retains this, but SIA 380:2015 features different (asymmetrical) primary energy factors for import from and export to the grid. This necessarily has a large impact on the resulting energy balance. The primary energy factor for import from the grid depends on the chosen type of the power mix in the grid. If this factor is higher than the primary energy factor of the PV-system, a larger PV system than when using symmetrical factors is required in order to fulfil the NZEB balance. The impact of balancing method of SIA 380:2015 and Minergie-A on a Net Zero Energy Building are discussed. It is found that the newly introduced definitions for the building energy balance have a large impact on the grid interaction.04B - Beitrag KonferenzschriftPublikation Different balancing methods for Net Zero Energy Buildings - Impact of time steps, grid interaction and weighting factors(Elsevier, 2017) Hall, Monika; Geissler, AchimAdding large photovoltaic systems to buildings is becoming more and more popular. To date, the self-consumption/grid interaction is not typically part of the energy balance. The choice of symmetric or asymmetric primary energy factors has an impact on the balance. The primary energy factor for import from the grid depends on the chosen type of the power mix in the grid. If this factor is higher/lower than the primary energy factor of the on-site PV-system, a larger/smaller PV system than when using symmetrical factors is required in order to fulfil the NZEB balance.01A - Beitrag in wissenschaftlicher ZeitschriftPublikation Net zero energy balance for high-rise buildings(Advanced Building Skins, 2016) Hall, Monika; Geissler, AchimMultifamily dwellings and office buildings with a square and a stretched footprint with up to 40 floors are considered for a net zero energy balance. A wide range of parameters is investigated in regard to their impact on the zero energy balance. The main results gained by the simulation based research described above can be summarized as follows: Only the HVAC zero balance can be achieved for up to 40 floors for all variants studied but one. The five main parameters in regard to achieving a HVAC or TE zero energy balance are, efficient electric devices and lighting, low heat demand, the type of heating system, the actually available area for PV and the overall efficiency of the PV-System. The results show that a net zero energy balance for HVAC only or for total energy can be achieved for large multifamily dwellings and office buildings of up to 40 floors. To this end, however, apart from a well-insulated building envelope, electronic devices, lighting and PV systems with a very high efficiency are necessary. With further improvements in the efficiency of devices, lighting and PV-systems, reaching the "zero" will become easier.04B - Beitrag KonferenzschriftPublikation Optimization of concurrency of PV-generation and energy demand for a heat pump comparison of a monitored building and simulation data(2015) Hall, Monika; Geissler, AchimMonitoring data of a small, well-insulated residential building shows that the electricity consumption of the heat pump amounts to approx. 30% of the total electricity consumption of the building. Shifting duty cycles of the heat pump into the daytime would therefore be a possible means to greatly increase the concurrency of electricity production and consumption and reduce the grid interaction without an expensiv e technical effort. Experimentally, the duty cycle of the heat pump is limited to daytime from 10 am through 7 pm. The monitored data shows this is sufficient to heat the building and the domestic hot water. Interesting questions that arise are e.g. if such run-time limitations can also be used with a heavy (concrete) and a lightweight (wood) construction and if further reduction of the run-time is possible. Reducing run-time even more would further increase self-consumption and reduce grid interaction. The impact of the thermal mass of the construction and the limiting of the run-time are investigated by transient thermal building simulation. The simulation model with constructions “as built” is calibrated based on measurement values from temperature sensors in the living rooms and the measured heating demand of all three apartments. Simulation results are evaluated based on thermal comfort criteria in the living rooms of each apartment. The results obtained show that for the construction types “as built” and “heavyweight” no differences in resulting thermal comfort are to be expected. Construction types “ as built” and “heavyweight” show good robustness in regard to the limitation of the run-time of the heat pump. The construction type “lightweight” cannot be used with limited run-times of the heat pump without a significant drop in thermal comfort as defined by the metrics used. The paper gives detailed results for the mentioned construction types and 4 different run-time scenarios.04B - Beitrag Konferenzschrift