Heterogeneous resource management in energy hubs with self-consumption: Contributions and application example

Abstract

The energy hub concept and modeling methodology are widely employed tools for solving resource conversion and storage scheduling problems. For instance, industrial clusters might benefit from determining the suitable time to operate their facilities and to sell electricity to the public power grid, according to legal, economic or environmental factors. In this paper, novel elements are introduced in order to more accurately represent real plants and to reduce the amount of decision variables. The major innovation is to consider devices consuming a resource which is not related to the quantity of output produced, by attaching binary decision variables to certain energy hub outputs. Secondly, a path vector is defined to take into account the flows of resources within the system instead of employing a variable for each branch between the components. The third innovation consists of an additional vector to express the amount of output resources sold from the energy hub, including constraints for those resources which are exported and imported through the same medium. An extended energy hub model is first proposed and then applied to a real plant example, including multiple and heterogeneous resources and performing a comparison between days with different demands, weather conditions and electricity prices. The results obtained in the selected scenarios demonstrate a logical operation scheduling, and therefore validate the proposed approach.

Economic dispatch of a bioclimatic office building considering thermal energy, electricity and water demands

“…The model set up for simulations, and the economic dispatch problem, are based on the general approach presented previously by some of the authors of this work in [14], which has been adapted for the structure of the CIESOL building, see Fig. 2.…”

“…Thus, is only an actual consumption if the impulsion pump is activated ( , ) for maintaining the required pressure on the water flow (which is assumed to happen any time a tap is opened, or the storage tank is charged). Furthermore, each device is numbered in order to establish the equations of the system as in [14].…”

“…It must be remarked that is a vector that depends on the system's structure and allows a linear formulation of the problem. In order to represent all the resources flows, it contains as many variable as possible paths between the inputs and the outputs (readers are referred to [14] for clarification), so that equation 3relates input vector (whose variables split into the different paths) with vector .…”

Generalised control-oriented modelling framework for multi-energy systems

“…including bidirectional power flow and splitting of energy flow at any point in the converter arrangement). Recent contributions based on the energy hub that also aim to address some of these issues are [15] and [16]. However, while both address the issue of arbitrarily complex uni-directional flow paths across an energy hub, neither address the possibility of bi-directional power flow through, or within a hub as is the case with the approach proposed herein.…”

“…The particular MES considered in this case study has been chosen as it demonstrates most features of the modelling framework as well as highlighting the superiority of the proposed approach over existing methods. In particular, it is not possible to represent the energy conversion topology, shown in Figure 3, as a single hub using existing energy hub approaches, even using the recent modifications in [15] and [16], due to the presence of bi-directional power flow within the arrangement. The non-energy hub approach reported in [21] requires the user to distinguish between inputs and outputs referred to sources and clients in [21] when modelling bidirectional power flow in which case, as described in Section III, it is entirely possible for a given interface to act both as an input and an output.…”