Page 29 - European Energy Innovation - winter 2018 publication
P. 29
Winter 2018 European Energy Innovation 29
BUILDING EFFICIENCY
to retrofit measures which focus on technology to cover space heating
individual building upgrades: and domestic hot water demands.
• At individual building level, • Some technologies, e.g. deep Stijn Verbeke
unfavorable conditions might geothermal energy, are only
limit the uptake of renewable applicable at a very large scale.
energy measures such as solar Geothermal installations are well
PV, solar hot water boilers and known in geographic regions where
ground sourced heat pumps. At high temperatures are readily
larger scales, there will be more available at the earth’s surface,
opportunities to install these such as in Iceland and in northern
technologies in optimal conditions, Italy. In a pilot project in Belgium,
e.g. with respect to available VITO is successfully demonstrating
and accessible surfaces with that geothermal energy can
a favorable orientation, limited also be a viable technology in
external shading, etc. many other places. From the 3.5
kilometres deep boreholes of this
• Some renewable energy plant, heat is extracted at 125°C,
technologies such as wind which enables the conversion into
turbines or combined heat and electricity via an Organic Rankine
power plants are strongly affected Cycle (ORC). The excess heat will
by economies of scale, and are be further distributed to buildings,
seldomly viable at the level of an greenhouses and industries
individual building. through a district heating grid.
• District heating and cooling Given the large range of available for example define areas for which
networks can be an alternative technologies and the broad diversity the preferential choice is a rollout of
to individual fossil-based heat or of existing districts, we need a novel district heating and cooling networks,
cold generators. These networks approach to urban energy system whereas in other areas all-electric
allow to connect multiple heat planning. An optimal future urban solutions can be preferable. This can
or cold generators to ensure an energy system will require an apt affect the desired retrofit levels for
optimal production mix. Fourth combination of energy efficiency the buildings in the district. Another
generation district heating and measures, energy generation and the outcome of such analysis would
cooling networks are designed to capacity to balance energy flows, e.g. better be that specific buildings
work at low temperature gradients, through storage or flexible control are rather to be replaced by new
increasing their efficiency and of energy demands. By combining constructions than retrofitted, even
enabling the utilisation of various energy sources and energy when we take into account the
renewable energy and residual vectors and by aggregating demands environmental impact of building
heat and cold sources from at larger scale levels, peaks can be materials.
industry, datacenters, etc. smoothened out and the system can
be operated more efficiently than on Secondly, the temporal aspect
• In a future energy system with individual building level. of the energy system design is
intermittent generation from critically important. This incorporates
distributed renewable energy Three important aspects need to be fluctuations of demand and supply
sources, storage will be an covered to have an effective urban to define an optimal mix of energy
important factor to help balance energy planning: generation and storage assets. But
the demand and generation equally essential is the longer time
profiles. For many types of Firstly, urban energy planning horizon when upgrading an existing
dedicated thermal, electrical requires a spatial analysis to adapt urban area. Building retrofits are
or thermo-chemical storage to local needs and conditions: space executed gradually over a period
equipment, implementation constraints, locally available excess of many years, installing a district
at district level can be more heat from industry or biomass, the heating network can be jointly
promising due to scale effects. state of the building stock, local executed with major roadworks,
As demonstrated in various demand profiles, etc. An in-depth residual heat sources might become
case studies, seasonal thermal spatial analysis of the assets and unavailable over time, etc. District
storage can even become a viable potentials of the urban areas can
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