Jessen Page | EPFL Graph Search

Jessen Page was born in Dubai (UAE) in 1975. After attending school in Bulle (Switzerland) he studied physics for two years at the University of Konstanz, Germany, before joining the University of Fribourg in Switzerland. He graduated in June 2002 and joined the Solar Energy and Building Physics Laboratory 4 months later. He has been working on the EU funded SUNtool project since its launching in January 2003.

Optimization based approach to assist the transition of large energy users to low temperature networks

Francesca Belfiore, François Maréchal, Alberto Mian, Jessen Page

Distric Energy System (DES) represents a promising opportunity to improve energy efficiency and boost the decarbonization of the European energy sector. If most of the studies focus on small consumers typically located within urban areas, large energy users like hospitals, university campuses or airports, constitute complex and unique systems with great potential for energy and cost savings. The aim of this work is to propose a robust method to optimize the preliminary design and operation of local DES characterized by complex non-residential buildings. Decision variables include the optimal set of technologies to be installed (type, size, location), their operating schedule, together with temperature and configuration of the thermal network. Focus is given to heat pumping technologies and in particular to the comparison between different degrees of centralization and respectively, decentralization. The mathematical model is based on a Mixed- Integer Linear Programming (MILP) formulation including a set of heat cascade constraints to ensure the feasibility of the heat exchanges. A case study is generated to represent a building-stock constituted by large non-residential buildings, connected to a central plant through an existing network infrastructure. The users differ for power and temperature demand, both estimated as linear function of the ambient temperature. Results show that the optimum degree of decentralization is highly influenced by the distribution of the heat demand among the users at the different temperatures. Therefore, the use of local heat pumps to upgrade the heat produced by a central unit does not always translate in operating cost savings. For the case study presented in this work it is shown that if the lowest temperature user covers 66% or more of the total demand a decentralized configuration is the most cost effective solution.

Curran Associates, Inc.2020

The optimum is not the goal: Capturing the decision space for the planning of new neighborhoods

Sébastien Cajot, François Maréchal, Jessen Page, Nils Christian Schüler

This article presents the development and application of a methodology that employs optimization not to seek the single or few optimal plan(s) but to provide planners with a systematic overview of their decision space. As urban development projects are not only subject to decisions of planners but to those of many actors, the insight about how different actors would decide based on the decisions of the planners, should enable planners to already adapt their decisions to ensure that final project targets are reached. The existence of different decision makers is considered via a multiparametric mixed-integer linear programming (mpMILP) approach. Along with the methodology a model was developed, which incorporates multiple domains and scales. Those domains include social, environmental, form, energy and economic aspects. The considered scales range from single floors up to a neighborhood. Model and methodology were applied to a greenfield development project. Two practical questions are answered, which address the impact of planning decisions about (a) the building density and the sustainability of the energy supply on costs of different actors, and (b) the building density and the share of parks on the view on a landmark. The capturing of the decision space revealed trade-offs in terms of chosen energy supply system and urban form, respectively. The presented computational method forms part of the decision support tool URBio which shall assist urban planning.

2018

IntegrCiTy - D2.3 Report - Enabling and integrating a common IT structure: Definition of a back-end layer architecture

Gillian Jean Bernard Basso, Luc Girardin, François Maréchal, Jessen Page

The concept of the IntegrCiTy platform is built around the development of a single application as a suite of independent software: project partners will mutualize a certain number of tools that shall be integrated in the IntegrCiTy platform. Therefore, a robust modularized "microservice" architecture is proposed which allows parallel integration and development of independent services. The back-end is composed of a message broker that enables the communication between the front-end, the database and the environments (decision-support environment, co-simulation environment). The front-end (user interface) is the communicating tool with the user. The back-end thus connects applications, user devices (as clients) and data to each other, as components of a larger application. It uses asynchronous messaging for decoupling applications by separating sending and receiving data. The EPFL is developing and hosting the message broker of the back-end using RabbitMQ server and Protobuf format. RabbitMQ is an open source message broker software that implements the Advanced Message Queuing Protocol (AMQP) and Protobuf is a simple method to serialize structured data. Unlike monolithic application, the proposed architecture requires the use of an inter-service communication protocol and the development of a wrapper for each service of the Platform. Wrappers have to be developed by the partner responsible of the related service (i.e. software) and are therefore part of the corresponding WP. For every server-wrapper, the developer must provide the documentation required to allow the communication with other client-wrappers. The documentation derives from the specification of the existing software integrated in the project and should take the form of a Protobuf “prototype file”. This report describes the proposed architecture allowing the communication between the different software of the IntegrCiTy platform, based on AMQP. A simple application case is provided as a proof of concept of the proposed back-end technology

IPESE-EPFL2017