Publications

All publications from the ZEN Research Centre are financially supported by the Research Council of Norway through its funding scheme for Centres for Environment-friendly Energy Research (grant no. 257660) and the Centre’s partners.

Our latest scientific publications

All our publications

Woods, Ruth; Thomsen, Judith; Grynning, Steinar; Lolli, Nicola (2020) Electrochromic window system evaluation at Heimdal secondary school
ZEN Memo 28,
NTNU/SINTEF,

News story (2020) Forskere anbefaler klimagasskrav til norske bygninger
Trønder-Avisa,
10 June 2020,

News story (2020) Det er ikke mangel på vindkraft som er problemet
Glåmdalen,
7 May 2020,
further featured in no. of sources: 4,

News story (2020) Derfor sier vi nei
Agder Flekkefjords Tidende,
6 March 2020,
further featured in no. of sources: 1,

News story (2020) Frokostmøte med FutureBuilt: Lavkarbo byggematerialer
Byggfakta,
19 February 2020,
further featured in no. of sources: 1,

10 år med klimagassregnskaper. Hva har vi lært? Vi gjør opp status for den pågående klimadugnaden i byggenæringen og gir deg både matnyttige materialstrategier og hårete favorittprodukter.

Frokostmøtet arrangeres av FutureBuilt, Grønn Byggallianse, FME ZEN og Enova.
Frokostmøtet er fulltegnet. Om du ønsker å stå på venteliste, kan du sende en e-post til futurebuilt@futurebuilt.no

Det er 10 år siden Statsbygg lanserte klimagassberegninger for bygg – og med det et nytt designpremiss som har gitt føringer for materialpaletten i mer enn 50 FutureBuilt prosjekter og en rekke andre klimaforbilder. Resultatet er blant annet biobaserte byggesystemer, flere generasjoner lavkarbon-betong, de første sirkulære bygg-pilotene og nye og innovative lavutslippsmaterialer og produkter.

På frokostmøtet forteller både praktikere og forskere om erfaringene fra de mest ambisiøse forbildeprosjektene. Vi gir deg erfaringer fra 10 år med klimagassberegninger, materialstrategier for reduserte utslipp, oversikt over redskaper og verktøy for klimasmarte materialvalg, og anbefaler både dypøkologiske og stuerene produkter for utbyggere og arkitekter som ønsker å ligge i front.

Program

08.00 Frokost

08.30 Velkommen! Stein Stoknes, FutureBuilt

08.35 10 år med klimagassberegninger – hva har vi lært? Marianne Wiik, SINTEF Community/ZEN

08.45 Materialstrategier for reduserte utslipp Eivind Selvig, Civitas

08.55 Tre eller betong – eller: Ja, takk. Begge deler! Christofer Skaar, SINTEF Community/ZEN

09.05 Veidekke bygger med «ekstrem-lavkarbonbetong» Nils Ivar Nilsen og Karl Christian Martinsen, Veidekke

09.15 Anskaffelse av lavutslippsbyggematerialer – ECOproduct og Grønn materialguide Katharina Bramslev, Grønn Byggallianse

09.25 Stuerent – 10 klimavinnere Rolf Hagen, Context

09.35 Dypgrønt – 10 radikale klimaløsninger Rolf Jakobsen, Gaia

09.45 Enova støtter lavutslippsløsninger i bygg Jan Petter Amundal, Enova

09.50 Dialog

10.00 Takk for i dag!

I etterkant av frokostmøtet arrangeres det en innovasjonsworkshop for spesielt inviterte. Workshopen er del av prosessen med å utvikle FutureBuilt 2.0.

Praktisk informasjon

Dato: Tirsdag 25. februar Sted: Ingensteds, Brenneriveien 9, Oslo

Arrangementet er gratis og åpent for alle, men påmelding er nødvendig. Påmelding på FutureBuilt sine sider. Det blir servert frokost. Vi oppfordrer alle til å gå, sykle eller reise kollektivt til frokostmøtet.

Frokostmøtet vil også bli streamet.


News story (2020) I et kupert grunnfjellsområde som Agder vil vindkraftverk medføre varige terrenginngrep, og gjerne i de mest uberørte delene av naturen
Agderposten,
21 January 2020,

Askeland, M. (2020) Web-based solution for eTransport
ZEN Memo 25,
SINTEF,

Sartori, I., Sørensen, Å.L. (2020) ZEN-case Energisystem Risvollan
ZEN Memo 24,
NTNU/SINTEF,

Analyse av energisystemsløsninger, kostnader og
beslutningsprosess for Risvollan borettslag.


ZEN Report 20,
NTNU/SINTEF,

Calculation of Key Performance Indicators of Energy and Power in Ydalir

Ydalir is the name of a development area located northeast of the centre of Elverum. The area is one of
the pilot areas in FME ZEN with ambitions of becoming a Zero Emission Neighbourhood (ZEN). At
the end of the construction period the area will have a new school, a kindergarten, and about 700
residential units. There are high ambitions for the development of Ydalir. For Ydalir to fulfil the ZEN
definition, it must be energy efficient, and the emissions from the area must be reduced. The emission
reductions in Ydalir will be achieved through building according to the Norwegian passive house
standard (NS 3700/NS3701), by using district heating, and by installing photovoltaic (PV) solar panels.

The development of the definition of a Zero Emission Neighbourhood (ZEN) and the development of
assessment criteria and key performance indicators is an ongoing process that will last throughout the
program period of FME ZEN. This work will enable an assessment of the performance of the ZEN pilot
areas. Based on the draft for the ZEN definition, the assessment criteria and KPIs (per 2019) can be
divided into the following categories: GHG Emissions, Energy, Power, Mobility, Spatial qualities,
economy and innovation.

Constructing Ydalir as a ZEN will have positive impacts on energy consumption, the peak load,
and the utilization of the local electricity grid.

The purpose of this report is to test the indicators on energy and power on a ZEN-pilot in the planning
phase. The suggested energy KPIs and power KPIs have been tested for Ydalir for the year 2035. It is
assumed that the area will be fully operational by this time. Two scenarios have been created for Ydalir,
2035: the first scenario represent the current expectations for the pilot area and is called the «ZEN
Scenario». The second scenario represent the reference project, or the «Business as usual» (BAU) case
for the development of Ydalir. This is called the «Baseline Scenario». The KPIs for Energy and Power
have been calculated for Ydalir for both scenarios.

This analysis shows that the KPI net energy demand can be reduced by 27 %, the total import of energy
can be reduced by 30%, and the combined peak load for electricity and heating can be reduced by 24%
in the ZEN-scenario compared to the Baseline Scenario.

Annual energy use and emissions from the use phase can be significantly reduced if the development
turns out as expected, if all developers follow the master plan, and if the use of transport by car is reduced
as expected. The testing of the KPIs used in ZEN within the categories Energy and Power shows that
there is a need for further work on system boundaries, the reference scenario, and finding standard
methodologies.

Involved ZEN-partners in this study have been SINTEF, Elverum Vekst, and Elverum municipality.


Matthias Haase, Nicola Lolli and Kari Thunshelle (2020) Renovation concepts for residential buildings
ZEN Report 19,
NTNU/SINTEF,

This study looks at the challenges and opportunities in the deep energy renovation market with prefab elements. An analysis of 39 European projects was conducted, and the results where structured in three topics.


Nuijten, Anne (editor) (2020) Innovasjonsarbeid i FME-ene
ZEN Memo 23,
NTNU/SINTEF,

Denne memoen er resultatet av arbeidet i 2019 og beskriver for FME-ene ZEN, NTRANS, HydroCen, CINELDI, HighEFF, NCCS og SUSOLTECH hvordan FME-ene jobber med innovasjon og hva resultatene er så langt.


Moazami, Amin (2019) Climate Robust Buildings: Towards Buildings with a Robust Energy Performance Under Climate Change
PhD thesis,

Bergsdal, Håvard (2020) Environmental assessment of ventilation systems in buildings
ZEN Report 22,
SINTEF,

Nordström, Tobias; Rokseth, Lillian; Green, Sylvia; Manum, Bendik (2020) ZEN spatial indicators: Evaluation of Kommunedelplan 3 (KDP 3) for Fornebu
ZEN Report 21,
NTNU,

Nordström, Tobias; Rokseth, Lillian; Green, Sylvia; Manum, Bendik (2020) ZEN spatial indicators: Evaluation of parallel assignments for Sluppen
ZEN Memo 20,
NTNU,

Nordström, Tobias; Rokseth, Lillian; Green, Sylvia; Manum, Bendik (2020) ZEN spatial indicators: Evaluation of Bodø-vest
ZEN Memo 19,
NTNU,

News story (2019) Kjære NTE!
Namdalsavisa,
31 December 2019,
further featured in no. of sources: 1,

Jacobsen, Terje (2019) Forbudt å kreve nullutslipp og plusshus
Teknisk Ukeblad,
19 November 2019,
further featured in no. of sources: 1,

Yu, Xingji; Georges, Laurent; Knudsen, Michael; Sartori, Igor; Imsland, Lars Struen (2019) Investigation of the Model Structure for Low-Order Grey-Box Modelling of Residential Buildings
Proceedings of Building Simulation 2019: 16th Conference of IBPSA,
8 p.,

Walnum, Harald Taxt; Lindberg, Karen Byskov; Sartori, Igor. (2019) Influence of inputs knowledge on Grey-box models for Demand Response in Buildings
Proceedings of Building Simulation 2019: 16th Conference of IBPSA,

Tomasgard, Asgeir; Gustavsen, Arild (2019) Kutter utslipp, sparer nettleie
Dagens næringsliv,
4 January 2019,

Satola, Daniel; Houlihan Wiberg, Aoife Anne Marie; Gustavsen, Arild (2019) Towards Zero Emission Residential Buildings (ZEBs) in a Humid Subtropical Climate. Analysis Emissions from Energy Use and Embodied Emissions from Materials in Referential Locations According to Obligatory Residential Energy Codes and Using Generic LCA Data Sources
Proceedings of the 11th International Symposium on Heating, Ventilation and Air Conditioning (ISHVAC 2019),

Haase, Matthias; Rønneseth, Øystein; Thunshelle, Kari; Georges, Laurent; Holøs, Sverre Bjørn; Thomsen, Judith (2019) Review of building services solution fitted for a low emission building stock in urban areas
Proceedings of the 40th AIVC Conferenece. 8th TightVent Conference. 6th Venticool Conference. From energy crisis to sustainable indoor climate – 40 years of AIVC,

Backe, Stian; Kara, Güray; Crespo del Granado, Pedro; Tomasgard, Asgeir. (2019) Local Flexibility Markets in Smart Cities: Interactions Between Positive Energy Blocks
IAEE International Conference,

PhD Thesis,
NTNU, Trondheim,

The transition to a sustainable energy system requires a shift to intermittent renewable
energy sources, which call for increased flexibility on the demand side. Heat pumps
offer the possibility to couple the electricity sector and the heating sector, and when
connected to thermal energy storages, they can provide demand side flexibility.
This thesis investigates the flexibility potential of residential buildings in
Scandinavia, and more specifically in Norway. In this regard, three different
boundary levels are considered: power grid level, building level, and heat pump
system level.
At the power grid level, a methodology to evaluate the hourly average CO2eq. intensity
of the electricity mix, while also considering electricity trading is developed. In
general, the CO2eq. intensity of the electricity mix may indicate the share of renewable
energies in the mix. The proposed method is based on the logic of input-output
models and avails the balance between electricity generation and demand. This thesis
shows that it is essential to consider electricity imports and their varying CO2eq.
intensities for the evaluation of the CO2eq. intensity in Scandinavian bidding zones.
Generally, the average CO2eq. intensity of the Norwegian electricity mix increases
during times of electricity imports since the average CO2eq. intensity usually is low
because electricity is mainly generated from hydropower. This hourly CO2eq. intensity
can be used as a penalty signal for demand response strategies applied to residential
heating.
At the building level, the flexibility potential of predictive rule-based controls
(PRBC) in the context of Scandinavia and Norway is studied. For this purpose,
demand response measures are applied to electricity-based heating systems, such as
heat pumps and direct electric heating. In one case study, the demand response
potential for heating a single-family residential building based on the hourly average
CO2eq. intensity of six Scandinavian bidding zones is investigated. The results show
that control strategies based on the CO2eq. intensity can achieve emission reductions
if daily fluctuations of the CO2eq. intensity are large enough to compensate for the
increased electricity use due to load shifting. Furthermore, the results reveal that
price-based control strategies usually lead to increased overall emissions for the
Scandinavian bidding zones as the operation is shifted to nighttime when cheap
carbon-intensive electricity is imported from the continental European power grid.
In another case study, the building energy flexibility potential of a Norwegian singlefamily
detached house is investigated using PRBC. Four insulation levels are studied
for this building: (1) passive house, based on the Norwegian standard for residential
passive houses, (2) zero emission building, based on the LivingLab located at the
Gløshaugen Campus at NTNU, (3) TEK10, based on the Norwegian building
standard from 2010, and (4) TEK87, based on the Norwegian building standard from
1987. The three PRBC investigated aim at reducing energy costs for heating, reducing
annual CO2eq. emissions and reducing the energy use for heating during peak hours.
This last objective is probably the most strategic in the Norwegian context where
cheap electricity is mainly produced by hydropower. It is shown that the price-based
control does not generate cost savings because lower electricity prices are outweighed
by the increase in electricity use for heating. The implemented price-based control
would create cost savings in electricity markets with higher daily fluctuations in
electricity prices, such as Denmark. For the same reasons, the carbon-based control
cannot reduce the yearly CO2eq. emissions due to limited daily fluctuations in the
average CO2eq. intensity of the Norwegian electricity mix. The PRBC that reduces the
energy use for heating during peak hours turns out to be very efficient, especially for
direct electric heating. As an example, for the ZEB insulation level and direct electric
heating, the price-based control reduces the energy use during peak hours by 18%,
and the carbon-based control by about 37%. The control strategy dedicated to reduce
the energy use during peak hours leads to a 93% reduction. For air-source heat pumps,
the control of the heat pump system is complex and reduces the performance of the
three PRBC. Therefore, it is suggested to model a heat pump system with enough
detail for a proper assessment of the building energy flexibility.
The model complexity required to adequately describe the heat pump system
behavior with regards to demand response of residential heating is investigated on
the heat pump system level. In the course of this thesis, the influence of the modeling
complexity of the heat pump system control on distinct energy-related and heat pump
system-related performance indicators is studied. The results prove that the modeling
complexity of the system control has a significant impact on the key performance
indicators, meaning that this aspect should not be overlooked. If the heat pump
operation is investigated in detail and a high time resolution is required, it is shown
that a PI-controller leads to a smoother operation than a P-controller, but tuning of
the controller is highly recommended. It is shown that the choice of the controller (P
or PI) is not crucial as long as the control signal to the heat pump is not of importance
and power is not investigated at very short time scales. Regarding demand response
measures, a strong interaction between the prioritization of domestic hot water and
the control of auxiliary heaters significantly increases electricity use of a bivalent
mono-energetic heat pump system, if demand response is performed for both,
domestic hot water and space heating. The electricity use for heating is only slightly
increased if demand control using predictive rule-based control is performed for
space heating only.
To summarize, energy flexible buildings can play a major role in the transition
towards a more sustainable energy system. The use of the hourly CO2eq. intensity as
a penalty signal for demand response strategies applied to residential heating, can
facilitate achieving the emission targets of the European Union. At the building level,
different objectives of demand response, such as reducing operational costs, reducing
CO2 emissions or increasing system efficiency are often incompatible and thus
difficult to achieve at the same time when using PRBC. When aiming at a realistic
control of the heating system of a single building, it is found that heat pump controller
tuning and DHW prioritization of the heat pump are two significant aspects that
should be considered regardless of the control strategy applied. The combination of
heating system, heat distribution system, system control and building envelope is
always case-specific and it is suggested that future work focuses on the design of a
heat pump system that considers energy flexibility. In this PhD thesis, standard sizing
of a heat pump system that is operated in an energy flexible way is applied.
Keywords
Energy flexibility; hourly CO2eq. intensity; demand response; demand side flexibility;
predictive control; rule-based control; heat pump system; heat pump modeling; model
complexity; direct electric heating; time-varying CO2eq. intensities; time varying
electricity prices; Scandinavian power market


Master Thesis,
NTNU, Trondheim,

The paper aims to investigate how a net zero energy building could be optimised in order to shift to net zero emission building by balancing greenhouse gas (GHG) emissions from the operational energy use and materials embodied emissions with those from onsite renewable energy in the tropical rainforest climate of Singapore.
The first net Zero Energy Building in Singapore, SDE4, is taken as the case study. Guided by Norwegian ZEB guideline, the principles of the Life cycle assessment (LCA) methodology are used to calculate the total GHG emissions profile of the case study, which focuses on operational emissions and materials embodied emissions. The system boundary for LCA includes the embodied emissions from materials for the transport of materials (A4) and replacement (B4) of new materials in addition to the production stage (A1-A3). These calculations provide an overview of the emissions profile of the Singaporean net zero energy building is provided, outlining the need to address the high embodied emissions. More importantly, the main emissions drivers, concrete and steel, are revealed from the results.
Based on the results, potential emissions reduction measures are discussed, and an emission-reduced scenario is proposed and calculated to demonstrate the improvement. The final result showed that, for the case study, on-site renewable energy generation could compensate for the operational emissions and materials embodied emissions if sufficient emissions reduction strategies have been adopted. In conclusion, the net zero energy building is possible to be shifted into net zero or low emission building with the implementation of emission-reducing design strategy, despite the rather challenging climate and situation in Singapore.