ModSCO – Building Performance Assessment Based on IPMVP Protocol

Within the last decade, the European Union (EU) has developed policies aimed at accelerating the cost-effective renovation of existing buildings, with the vision of a decarbonised building stock by 2050.

One of the potential measures to target this objective and enhance the energy efficiency (EE) of buildings is Energy Performance Contracting (EPC). However, there are different risks and barriers opposing the uptake of EPC such as process complexity, lack of information, uncertainty about post-renovation energy performance, access to finance, lack of trust in Energy Service Companies (ESCO), and lack of skilled professional, fragmentation of value chain and unclear financial mechanisms.

One way to tackle the barriers posed by the aforementioned uncertainties is the utilisation of Measurement and Verification (M&V) protocol. M&V is a procedure which measures and analyses data needed to verify and report energy savings within a system or a whole facility. M&V underpins and enhances a standards-based approach to the implementation of energy conservation measures (ECM’s). Guidelines regarding the M&V protocol are provided by the International Performance Measurement and Verification Protocol (IPMVP®). This protocol defines a standards-based approach to estimate the potential and actual savings and can be used to quantify the payments to all stakeholders throughout the EPC process. In verifying the results of energy efficiency, water efficiency, and renewable energy projects, the IPMVP® provides four options referenced from A–D. One of the main recommendations of the IPMVP® guidelines is that the M&V costs does not exceed 10% of the average annual savings achieved through its application. Additional cost limits are provided by M&V guidelines, such as the M&V handbook, where the cost limits range from a minimum of 1% of the annual measured savings for the IPMVP® Option A to a maximum of 10% for the IPMVP® Option D.

Option D is the development of a calibrated computer simulation model that supports detailed analysis of various ECM’s. This option also provides a big opportunity to evaluate the savings of each ECM or multiple ECMs and thus, to test the best renovation scenario to apply to a building.

The high computational time, the complexity, the cost of the model implementation, and the uncertainty of the model parameters means this procedure is not a popular method adopted by IPMVP® and in general for thermal prediction of existing buildings in the deep-renovation process. All issues aforementioned also carry the increasing cost burdens of this option that usually exceed cost limit recommendations.

Two alternatives from this purely physics modelling approach (white-box) can be found in a purely empirical approach (black-box) and in a synthesis of White and Black box modelling approaches into a grey-box modelling approach.

ModSCO Tool Role Within Sphere Ecosystem

The ModSCO tool is the acronym for Model-Supported Control. ModSCO uses Reduced Order Grey Box Models (ROM) developed with the MODELICA ® language. It offers standardized performance assessment methods in order to analyse and optimize building performances by applying control settings, testing envelope retrofit packages and evaluating the savings by using IPMVP method.

In the SPHERE platform, a potential user of ModSCO initiates a baseline energy consumption request for a project. Then the user will be redirected to a web browser app (Figure 1), which is currently under development within the IRUSE group at NUIG.

Figure 1 – Modsco web interface

The web application allows a smoother input gathering process to generate the simulation model. Once the model is generated, the same web application will provide a monthly baseline period energy consumption of a full year for a pre-defined building.

The Neanex portal handles the building asset data and links it with 3D model geometry, within the SPHERE ecosystem. It enables adding semantic information and linking documents to the building 2D and 3D model geometry. The integrations between NEANEX portal and ModSCO facilitates the data workflow (automatically retrieving specific data) and reducing the possible mistakes, in order to not overcome the 10% cost limit range imposed by IPMVP standard.

Written by Federico Seri and Alessandro Piccinini from NUIG, based on the article “ Piccinini, A., D’Angelo, L., Seri, F., Deane, C., Sterling, R., Costa, A., … & Keane, M. M. Development Of A Reduced Order Model For Standard-Based Measurement And Verification To Support ECM.”