Integration of building flexibility into future energy systems

The societal objective of the project is to enable more informed decisions concerning the design and operation of building energy systems. Heating and cooling of buildings is responsible for approximately 50% of the final energy consumption in the EU, and it is 75% fossil fuel-based. Meanwhile, wind and solar power are already the lowest cost sources of carbon-free electricity in many regions of the world. However, their generation is variable and they would benefit from flexible consumption of electricity. Flexible consumption of electricity in buildings (later ‘building flexibility’) could increase the value of variable power generation and decrease the use of fossil fuels for buildings.
The scientific objective is to produce high quality estimates on the full costs and benefits of building flexibility, from individual buildings to the larger energy system. As the benefits can be highly dependent on the circumstances, the project also seeks to understand the underlying dynamics between building flexibility and a wide range of possible influential factors arising from the larger energy system.
The overarching research method is a rigorous combination of tools from different spatial and temporal scales: 1. detailed simulation of building physics and rule-based control of building energy devices, 2. optimization based model predictive control for buildings and groups of buildings, 3. distribution grid models to pinpoint possible bottlenecks, and 4. large scale energy system models presenting the dynamics of power generation and consumption across energy sectors while including competing sources of flexibility. The research data will contain the presentation of these four system levels in a manner that allows conclusions about the whole building stock. The expected results are optimized solutions for building flexibility. Among other things, we expect to demonstrate the trade-offs between energy efficiency and building flexibility, show the cost-effectiveness of collective heating of groups of buildings (instead of individual buildings or district heating), and provide a new point of view for the power market participation of buildings through the integrated optimization approach.
The project aims to impact policies and regulations for building energy efficiency and building flexibility. By advancing the state-ofthe-art, the project could also impact the future solutions for the modelling and control of energy devices in buildings.

Collaborative partners
VTT Technical Research Centre of Finland
Tallinn University of Technology
Aalto University

Funding
Academy of Finland

The energy sector is the primary source of greenhouse gas emissions in our society, and needs to undergo massive changes in order to achieve current climate targets. Digitalization and the electrification of heating and transport are seen as promising ways of reducing the emissions of said sectors, as well as help mitigate the variability of wind and solar power. Researchers at VTT and Aalto University aim to study the benefits of harnessing the untapped potential for flexible energy use in buildings by combining detailed building simulation, household energy management systems, and large scale energy system modelling into a single framework. The results will improve our understanding of energy flexibility in buildings, as well as its relation to energy efficiency and competing sources of flexibility in the energy system. Furthermore, these insights can be valuable for new business models and policy, and help transition our society towards a more sustainable future.