Building automation (BA) has a key role to play in the implementation of nearly zero-energy build-ings (nZEB). Building automation is the connector of all the single requirements for nZEB, such as a well-insulated and airtight building shell, efficient HVAC system and a high share of renew-able energy. That is one of the main conclusions of a study prepared by Ecofys for the Leonardo ENERGY initiative. This presentation shortly introduces the functions and potentials Building Automation will have in the transition towards a nearly zero-energy building (nZEB) stock. It also touches on the pathways and actions different stakeholders should take to ensure that the indicated potentials are achieved.

1. 27 January 2015
Role of
Building Automation
related to Renewable Energy in
nearly Zero Energy Buildings
by Markus Offermann

2. © ECOFYS | |
Background
> Electricity consumption in European non-residential buildings has
increased by 74% over the past 20 years
> As of 31.12.2020 the recast of the EPBD requires all new buildings to be
“nearly Zero Energy Buildings”
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Questions
> Which types of buildings offer the best chances to benefit from automation?
> Which type of energy demand and/or which types of renewable energy are
most suited to control?
> What can be done to help policy towards regulations regarding building
automation to
● reduce the energy demand of future non-residential buildings
significantly?
● optimise the use of renewable energy?
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Non-residential building types
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31%
15%
38%
26%
69%
85%
62%
74%
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Office School Supermarket Hotel
Energy consumption
non-residential buildings, Germany
electricity fuel
Typical shares of energy consumption at existing building types*
* in Germany
Data source: Schlomann, Kleeberger et al, 2011: Energieverbrauch des Sektors Gewerbe, Handel, Dienstleistungen (GHD) in Deutschland für die
Jahre 2007 bis 2010. Fraunhofer ISI/IfE/GfK/IREES GmbH/BASE-ING. GmbH. 2011

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Nearly zero-energy buildings
> Energy Performance of Buildings Directive (EPBD):
"Building that has a very high energy performance… [ ]. The nearly zero or
very low amount of energy required should to a very significant extent be
covered by energy from renewable sources, including renewable energy
produced on-site or nearby.“
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Example
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[1] Boermans, Thomsen et al., Principles for nearly-zero energy buildings, Buildings Performance Institute Europe (BPIE), 2011
Nearly zero office building in different European climate zones

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Renewable energy on site
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1. Solar:
– PV
relevant potentials, especially in Southern regions
– Solar thermal collectors
less relevant for most non-residential buildings
(exception e.g. hotels)
2. Wind:
– Not relevant on site
3. Geothermal energy, biomass, energy from waste:
– If available, always available: no special need for control

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Storages
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Short term thermal storages (e.g. thermal building mass)
Seasonal thermal & decentral electricity storages:
=> Economically not feasible
Figure 1 Thermal energy balance and load shifting potential (green arrows) of a nearly zero energy office building in Germ
during one week in January. Source: Ecofys

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Main functions of building automation
> Central, concerted control of all energy related components
> Monitoring and providing feedback
> Load shifting and storage management
> Ensuring thermal comfort
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Central, concerted control of all energy related
components
1. Saving potentials of 50% achievable
Reduction of energy demand heating, cooling and lighting
(e.g. by central control of external blinds)
BUT:
2. Total savings at nZEBs are low
Payback difficult
3. Control also demands energy
e.g. individual room controls critical
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Monitoring and providing feedback
1. To insure the energy consumption meets the calculated
(low) energy demand of the nearly zero energy building
Often there are gaps due to
● insufficient parameter settings and/or
● derivations from planning
2. To encourage the building users to save energy
Usually, the users have no feedback on their energy consumption.
The influence of user behaviour ist estimated to be at least
between 5 % and 30 %.
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Load shifting and storage management
1. Use thermal building masses
At well insulated and heat protected buildings
the thermal energy demand is flexible in time
– solar gains in winter / night cooling in summer
– flexible electricty tariffs can be used,
e.g. to control the heat supply by heatpumps
> Increased grid stability, increased potential of renewable energies
2. Increase the direct usable share of renewables on site (Pv)
Achievable direct total energy coverage
– in Southern Europe up to 50 %
– in Northern regions max. 20 %
> Heat demand coverage small
> Coverage rates can be increased further with batteries
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Ensuring thermal comfort
1. Sophisticated control is required
Especially at nearly zero energy buildings with
– a small thermal mass
– very slow reacting systems,
like floor heating or concrete cooling
> Allowing the implementation of heating and
(ground water) cooling systems with a high efficiency
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Pathways for building automation
with focus on nearly zero non-residential buildings
Central, concerted control of all energy related components
> Sophisticated central systems with producer-independent compatibility are
available (e.g. BACnet), but need to be further developed and supported to
be standard requirement for nearly zero energy buildings
> More transparency concerning the energy demand of (sophisticated) building
automation systems is required
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Proposed actions

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Pathways for building automation
with focus on nearly zero non-residential buildings
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Monitoring and providing feedback
to ensure that the calculated (low) energy demand is met
> Further research to specify the potential gap between paper and reality
> By policy: Development of suitable regulations
> By industry: Development of suitable feedback systems
to the users to encourage them to save energy
> Further research to provide evidence of the potentials and costs
> By industry: Development of suitable feedback systems
Proposed actions

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Pathways for building automation
with focus on nearly zero non-residential buildings
Load shifting and storage management
Energy related use of thermal masses, e.g. to increase free cooling
potentials
> Further research to specifying the potentials for different nearly zero energy
building types in different regions is needed
Grid price related use of thermal masses
> Electricity suppliers should offer (interesting) flexible electricity tariffs
Increase the coverage rates of the energy demand by PV
> Evaluation and publication of best practice examples could increase the
market recognition
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Proposed actions

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Pathways for building automation
with focus on nearly zero non-residential buildings
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Ensuring thermal comfort
> Improvement and development of control mechanisms,
specialized to control slow reacting systems in nearly zero energy buildings
(e.g. by using weather forecasts)
Proposed action

18. © ECOFYS | |
Thank you for your attention
For more information, please contact:
> Markus Offermann
Ecofys Germany
Am Wassermann 36
50829 Cologne
Germany
E: m.offermann@ecofys.com
I: www.ecofys.com
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