Is ModSCO an innovative tool? A short literature review on available Grey-box model based tools in the field of building simulation

In the previous article “ModSCO – Building Performance Assessment Based on IPMVP Protocol”, the scope, the barriers, the main features of ModSCO tool within the SPHERE platform were described, including the modelling approach, which is based on Grey-box theory. 

A critical review reported in Li, Y. et al. (2021) describes the fundamentals of different building simulation modelling approaches, and underlines that the grey box approach has potential to solve simulation problems in which white & black box approaches are not suitable. Nevertheless, the author’s review concludes that mostly the grey-box models lack a user-friendly software package for wider adoption, as per not expert users.

ModSCO is a unique tool that uses Reduced Order Grey Box Models (ROM) developed with the MODELICA ® language, also equipped with a Graphical User Interface (GUI). It will allow standardized performance assessment method to analyse and optimize building performances by applying control settings, testing envelope retrofit packages and evaluating energy savings by using International Performance Measurement and Verification Protocol (IPMVP).

The next section reports a brief analysis regarding tools currently available, which are also based on Grey-box modelling approach, than a comparison to ModSCO is included as well. First of all, a features selection process has been conducted to allow a proper comparison between the different tools available in literature. The selection process lead to the following features:

  1. Simplified calculus of model parameters of a building for a not expert user 
  2. Output compliance with IPMVP protocol 
  3. Quality of the simulation model calibration process using real data following IPMVP protocol
  4. Ready to use tool (not under development)
  5. Presence of a GUI

Table 1 shows an extension of the study performed reported in Li, Y. et al. (2021) where several tools are described and compared, considering the criteria mentioned previously. Table 1 reports for each tool a marker in case a certain feature is satisfied by the tool and a brief description of the tool itself.

Tools features and short description

Tool 12345Description
OpenBuild   X It is a Matlab tool for design and simulation of advanced controlled. It generates the RC model from Energy+ models.
BLDG X X It is a Matlab toolbox for control-oriented building simulator implemented for simple buildings.
BRCM   X The Building Resistance-Capacitance Modeling is a Matlab Toolbox that simplify the physical modeling of buildings for MPC generating RC models.
Energy Performance calculatorXX   Toolbox that simulates the thermal behaviour of the building using a resistor-capacitor (RC) model. The model is based on the ISO 13790 standard and the python tool is under development. The MS excel version of the tool is working and ready to use.
ISOmodelXX X It is a C++ implementation of the reduced order model of the ISO 13790.
CTSM-RX  X CTSM is a tool for estimating embedded parameters of stochastic grey-box models. The former is accessed through the programming language R, while the latter runs under Matlab.
TEASERXX X Tool that generates reduced-order models for building and urban-scale energy modelling. The model generated needs a Modelica solver environment (e.g. Dymola) to be used. A web interface generates the Modelica Model.
Gray-Box toolbox and FastBuildings Modelica LibratyXX X Toolbox that allows the parameters estimation of the Modelica FastBuildings library gray box models using Jmodelica with a Python front end interface. The tool is focus on MPC and forecasting of temperature and heating load.
MPCpyXX X It is an open source python based software platform that facilitates the testing and implementation MPC using Jmodelica for parameter estimation and solving.
ModestPyX  X It is a Python based parameter estimation package for Functional Mock-Up Interface (FMI)-compliant models. It is mostly used with grey-box models. A user friendly graphical interface is planned.
IDENTX  X It is a MATLAB graphical user interface in to estimate the RC models of building envelopes from the measurement data.
Tools features and short description

Table 1 shows that the majority of the tools are used for Model Predicting Control (MPC). Only few tools uses simplified methods to estimate the building performance (i.e.  Energy Performance calculator, ISOModel). The TEASER tool (Remmen et al. 2018) estimates building performance, but it needs the licence of a software as Dymola to be used. It is also unclear how all these tools could be incorporated into a formal estimation of building energy savings under the IPMVP protocol guidelines. In particular, the tools showed in Table 1, do not have a clear workflow to calibrate the simulation model using real data, considering also that a user-friendly interface for data input and a clear reports of results are missing as well.

ModSCO is a web tool, which allows an accurate estimation of energy savings following IPMVP protocol guidelines. In addition, a user-friendly GUI and the tool background engine allows the evaluation of energy performance of a building within the right accuracy, even where building technical data are uncertain or partially not available. From this brief analysis, it is clear that the SPHERE platform with the adoption of ModSCO, would be able to provide innovation in the field of building simulation and performance assessment.

References

Li, Y. et al. (2021) ‘Grey-box modelling and application for building energy simulations – A critical review’, Renewable and Sustainable Energy Reviews, 146, p. 111174. doi: 10.1016/j.rser.2021.111174.

Remmen, P. et al. (2018). TEASER: an open tool for urban energy modelling of building stocks’, Journal of Building Performance Simulation. Taylor and Francis Ltd., 11(1), 84–98. Doi: 10.1080/19401493.2017.1283539

Written by  Federico Seri and Alessandro Piccinini, from NUIG National University of Ireland, Galway

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