Studying more eco-friendly mobility in a Fribourg neighborhood
Charles Jeanbart brings mobility to the autonomous solar house. © Alain Herzog/EPFL
Summer series on student projects (5) – Charles Jeanbart's semester project brings the question of mobility into the Solar Decathlon, an inter-university competition to design an autonomous solar house.
It is impossible to envision an energy autonomous house without considering the related question of personal mobility. This is not just for the sake of consistency: it's the challenge posed by the Solar Decathlon. In this inter-university competition, teams will design, build and operate a fully autonomous, solar-powered house. The Swiss Team, which includes EPFL, was selected alongside 13 others and is now preparing to present its design in Denver (USA) in 2017. Charles Jeanbart, a Master’s student in civil engineering, is working on the question of mobility, simulating solutions that are both electric and shared and that use fewer vehicles.
What is unique about the Swiss project is that it’s not simply a theoretical exercise. Following the competition in Denver, the house is designed to be brought back to Fribourg and set up there, possibly in the Beaumont neighborhood. It will be connected to existing buildings and readily accessible to the public, with the aim of helping acquaint people with new forms of energy, consumption and mobility. Jeanbart chose the Beaumont neighborhood as the basis for his analysis of how existing vehicles could navigate the energy transition.
He began by estimating the number of vehicles in the neighborhood: around 1,670 for 4,000 residents. He then envisioned a scenario of electric or hybrid vehicles needing to be recharged frequently. Jeanbart, who is part of EPFL’s Transport and Mobility Laboratory, factors into his analysis the frequency and length of trips, when they take place during the day and on which day of the week, and he excludes longer trips. For his simulation, he chose two scenarios, one in which the cars can be charged wherever they are parked and the other in which they can only be charged at home with a home charger.
A step towards smart grids
“The goal is to determine the electricity demand at certain periods during the day,” said Jeanbart. “The first scenario shows that the peak charging curve corresponds – with a slight gap – to traffic peaks. This is mostly during the day, from 8am to 5pm. In the second scenario, which is more realistic, the peak is at the end of the day and in the evening." Not ideal for recharging cars with solar energy.
Jeanbart's work presents a simplified overview of the recharging needs of electric cars in the neighborhood of one city. “The model should be improved, taking the assumptions even further," said Jeanbart. “What I have in mind is to build this into a smart grid – an intelligent system that comprises energy production, storage and consumption – in order to make consumption and production more efficient.”
This exercise is particularly relevant in the context of the Solar Decathlon, which dovetails nicely with the thrifty, parsimonious vision of the 2000-watt society. Under this vision, individuals use no more than 48 kWh per day, or 2,000 watts in constant power, which is equal to the global average in 1990. The Swiss average is currently around 5,500 watts. “To achieve this, switching to electric cars and reducing the number of cars through car-pooling won’t be enough. We will also have to scale back our mobility needs by developing the local network,” said Jeanbart.