@article {70,
	title = {Evaluation of energy flexibility of low-energy residential buildings connected to district heating},
	journal = {Energy and Buildings},
	volume = {213},
	year = {2020},
	pages = {109804},
	publisher = {Elsevier},
	abstract = {Energy flexibility is a cost-effective solution to facilitate secure operation of the energy system while integrating large share of renewables. Thermal energy infrastructure is a great asset for flexibility in systems with widely developed district heating networks. The aim of the present work is to investigate the potential for low-energy residential buildings to be operated flexibly, according to the needs of district heating system. An apartment block is studied, utilizing the storage capacity of thermal mass as storage medium. Two sets of data are utilized: heat load of Greater Copenhagen and dynamic heat production cost which is used as a price signal for the scheduling of the heating use in the building. Scenarios with different control signals are determined in order to achieve load shifting. The findings show that pre-heating is highly effective for load shifting and peak load reduction. During morning peak load hours, energy use is reduced in all scenarios between 40\% and 87\%. Although with load shifting higher energy use may occur, it occurs mostly at times when the city heat load is lower and heat production is less expensive and less carbon-intensive. Indoor temperature has a wider range and/or more fluctuations, yet remains within acceptable limits.},
	keywords = {Building thermal mass, District heating, Energy flexibility, Heating demand},
	doi = {10.1016/j.enbuild.2020.109804},
	author = {Foteinaki, Kyriaki and Li, Rongling and Thibault Q. P{\'e}an and Rode, Carsten and Jaume Salom}
}
@article {81,
	title = {Heating system energy flexibility of low-energy residential buildings},
	journal = {Energy and Buildings},
	volume = {180},
	year = {2018},
	pages = {95{\textendash}108},
	publisher = {Elsevier},
	abstract = {Energy flexibility is proposed as a cost-effective solution facilitating secure operation of the energy system while integrating large share of renewables. With strict building regulations in Denmark, newly built buildings are low-energy buildings. In order to identify the role of low-energy buildings in the energy system, we investigated the physical potential for flexibility and analysed the thermal storage capacity existing inherently in the structural mass. Two building types were studied: single-family house and apartment block. The aim is to quantify the energy that can be added to or curtailed from each building during a time period without compromising thermal comfort. Different scenarios (starting time and duration), building design characteristics and boundary conditions were studied. The findings showed that low-energy buildings are highly robust and can remain autonomous for several hours. Although for individual buildings the available energy for curtailment is limited, if many buildings are aggregated energy flexibility becomes significant. The potential for storage in the thermal mass is considerable. The analysis presented high dependence of flexibility potential on boundary conditions (ambient temperature, solar radiation, internal gains) and underlined the importance of envelope insulation. Heat losses govern the potential for flexibility, while the walls{\textquoteright} thermal mass has a secondary influence.},
	keywords = {Building thermal mass, Demand response, Energy flexibility, Low-energy building, Thermal energy storage},
	doi = {10.1016/j.enbuild.2018.09.030},
	author = {Foteinaki, Kyriaki and Li, Rongling and Heller, Alfred and Rode, Carsten}
}
