Jonas Hinker

On the problem formulation of model predictive control for demand response of a power-to-heat home microgrid

In this paper, MPC problem formulations for demand response of a power-to-heat residential microgrid are investigated. Two demand response operation strategies using MPC are proposed and thoroughly evaluated. The simulation results indicate that the problem formulation always poses a trade-off between comfort of the inhabitants, peak power reduction at point of common coupling and CPU time for the optimizer. These aspects have to be taken into consideration for a roll-out of demand response technology for residential buildings. While for the case presented in this paper, a quadratic objective function is the most promising one, the necessity of further investigations is derived from the results.

VLX: A novel virtual localization extension for geographical leash-based secure routing in indoor Wireless Mesh scenarios

Emergency and rescue organizations are giving Wireless Mesh Networks (WMNs) increased attention as the key technology to realize network connectivity anywhere, anytime with simplicity and low cost. The WMNs capability for self-organization significantly reduces the complexity of network deployment and maintenance, and thus requires minimal upfront investment. On the other hand, this characteristic makes WMNs prone to a new type of attacks, namely wormhole. While geographical leash-based secure routing such as PASER provides protection against wormhole in outdoor scenarios, in indoor scenarios, this method is ineffective since the geographical position of nodes is not always known (no GPS). For this end, we propose in this paper an efficient security extension (VLX) to secure WMNs routing against wormhole in indoor scenarios using a novel virtual localization technology. We extend the secure routing protocol PASER with our novel approach and evaluate it in different scenarios. The results show that VLX has negligible to no side effect in outdoor scenarios. It provides nearly the same level of security indoors as geographical leashes outdoors. It grants legitimate indoor nodes access to the network despite the lack of their geographical information. It has a light overhead and it is not sensitive to low outdoor to indoor node ratios.

How thermal comfort affects the energy-efficiency gap in residential buildings

Up until now, thermal comfort metrics are mostly used to design heating, ventilation and air conditioning (HVAC) systems in office buildings. Studies indicate that the demand in the building sector amounts to approximately 40%, while residential demand amounts to roughly 25% of the total energy demand. Notwithstanding, the role of the interaction of occupants and their corresponding comfort and discomfort remain unknown - especially in residential situations. This work thus contributes to the understanding of the issue of thermal comfort in residential buildings. This is achieved by extensively discussing the application of thermal comfort for small groups of people and by systematically deriving new requirements that also make a novel multi-agent simulation (MAS) approach necessary. By explicitly modelling the detailed steps of an occupant simulation, we lay a sound foundation to explain the variation in the energy consumption of dwellings and to reveal the impact of social influences.

Portfolio flexibility plots: Matching thermo-electric demand and supply in planning and dispatch

The integration of efficient supply technologies like electric heat pumps and combined-heat-and-power (CHP) plants into multi-energy-systems is of growing interest. However, typical off-the-shelf systems like CHP units and industrial heat pumps are characterized as single-degree-of-freedom systems, which means the interaction between electric and thermal power input/output is well-defined and cannot be altered. In this work, the technically feasible working points of individual plants are translated into a mathematical set representation, which can then be visualized in Portfolio Flexibility Plots (PFP). The proposed PFPs reveal a new degree-of-freedom of partially uncoupled thermal and electric supply. This flexibility can be exploited to derive efficient supply portfolios under consideration of exact technical constraints and arbitrary time-varying supply tasks.

Impact assessment of inhabitants on the economic potential of energy efficient refurbishment by means of a novel socio-technical multi-agent simulation

Purpose / Context – Studies of building design and economic feasibility for energy-efficient refurbishments often utilise average temperatures for the heated space in a dwelling. As even small deviations have a significant impact on the resulting energy demand, an occupant-centred simulation is necessary for more precise evaluations and recommendations. Methodology / Approach – An Agent-based model (ABM) with only two agent types was derived. On the one hand, the technical view is included by means of a building agent that resembles a multiroom building. On the other hand, individual inhabitant agents are able to interact with the building agent to make sure they feel comfortable with resulting climate conditions in the rooms they occupy. To model realistic behaviour, inhabitant agents are negotiating about temperature setpoints and change e.g. their level of clothing if necessary. Results – It is possible to derive realistic demand situations from different types of household under consideration. Both resulting temperature levels and heat demand differ significantly from one household composition to the other. The insulation level of the building has an impact on these figures which has to be analysed in detail. Key Findings / Implications – In fact, the reference temperatures given in current technical standards do not reflect the behaviour of occupants. Therefore, the potential for energy demand reductions and corresponding economic feasibility have to be considered on a more individual per-household basis. Originality – The proposed agent model was designed from scratch and closes the gap between technical and social view in an integrated socio-technical perspective.