Residential heat pump as flexible load for direct control service with parametrized duration and rebound effect

Abstract

This paper addresses the problem of an aggregator controlling residential heat pumps to offer a direct control flexibility service. The service consists of a power modulation, upward or downward, that is activated at a given time period over a fixed number of periods. The service modulation is relative to an optimized baseline that minimizes the energy costs. The load modulation is directly followed by a constrained rebound effect, consisting of a delay time with no deviations from the baseline consumption and a payback time to return to the baseline state. The potential amount of modulation and the constrained rebound effect are computed by solving mixed integer linear problems. Within these problems, the thermal behavior of the building is modeled by an equivalent thermal network made of resistances and lumped capacitances. Simulations are performed for different sets of buildings typical of the Belgian residential building stock and are presented in terms of achievable modulation amplitude, deviations from the baseline and associated costs. A cluster of one hundred ideal buildings, corresponding to retrofitted freestanding houses, is then chosen to investigate the influence of each parameter defined within the service. Results show that with a set of one hundred heat pumps, a load aggregator could expect to harvest mean modulation amplitudes of up to 138kW for an upward modulation and up * Corresponding author Email address: emeline.georges@ulg.ac.be (Emeline Georges) (DOI:10.1016(DOI:10. /j.apenergy.2016 to 51kW for a downward modulation. The obtained values strongly depend on the proposed flexibility service. For example, they can decrease down to 2.6kW and 0.4kW, respectively, if no rebound effect is allowed. Accepted in Applied Energy

Power-to-Heat for Renewable Energy Integration: Technologies, Modeling Approaches, and Flexibility Potentials

“…Besides deriving results on the potentials of power-to-heat, several of the reviewed articles distinctly discuss model formulations [44,46,57,47,38,28,59,54,66,49,31,32,51,39,41,42,43,36,70]. Section 5 discusses some specific examples in more detail.…”

“…While the first two are cost minimization models, energyPLAN seeks to minimize consumption of fossil fuels. Other objectives comprise welfare maximization [66], the minimization of residual load variability [61] or some kind of flexibility maximization [38]. Most models apply linear programming (LP) or mixed-integer linear programming (MILP) to carry out the optimization.…”

“…While most of the reviewed models have an hourly time resolution, many do not cover all hours of the year, but make use of some time aggregation strategy. Few models have a sub-hourly resolution [56,38,66].…”

“…In order to capture higher efficiency in part-load mode and larger flexibility for load following of variable-speed heat pumps, Georges et al [38] suggest a piece-wise linearization of the non-linear problem described by Verhelst et al [69]. Salpakari et al [70], who analyze the use of large-scale heat pumps in district heating networks, constrain heat pump use on the network's exogenous supply temperature and allow operation only below 90 • C. The COP is then treated as a constant parameter, which might be a justified assumption in the context of large-scale heat pumps with a stable heat energy source.…”

Non-intrusive load monitoring under residential solar power influx

“…For such applications, knowing only the non-critical loads that can be shed and critical loads that needs to be maintained of a house is sufficient [41]. So, in such occasions, user signs an agreement with the utility defining a set of appliances as non-critical appliances (E.g.…”