Austria - Demo Center 2 I CSSL Lab

Demonstration Center 2

Stegersbach

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The Austrian demo center was launched in October 2021 as part of the solar.one building in Stegersbach, in the south of Burgenland. It is part of a larger competence center for renewable energy, which uses a range of different sector coupling and city storage technologies.

These include:

storing electricity in a Li-Ion and a saltwater battery.
storing heat and cool air in thermal heat storages.
heating and cooling the building thanks to a heat exchanger system/core activation
Equipment for mobile storage for electric vehicles

All these technologies are regulated by monitoring equipment (temperature and presence monitoring) as well as a load and flexibility management system to ensure the building receives the heat and electricity it needs.

By using this approach, the demo center is addressing a key problem. In typical photovoltaic systems, surplus solar energy is fed into the grid for a relatively low price and during times of limited sunshine, all (electric) energy has to be supplied from the grid. With the solutions tested in the demo site, a lot more of the energy generated can be used on site, considerably increasing the self-consumption ratio. In addition, the sector coupling solutions (heat pumps, EV charging) also allow for the utilization of electric energy in other sectors, like heating and mobility, which further increases the proportion of self-consumed energy.

While the PV system is not part of the demo site but of the whole competence center, it is still important to note that the entire building – which can host 200 people – has a generational capacity of 177 KW. This means that it can be entirely energy positive and depend solely on renewable energy sources. Since this amount of energy is sufficient to cover its own needs, the building could also hypothetically supply neighbouring buildings with excess PV power.

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Ventilation

Water tank storage

Air-water heat pumps

Energy monitoring

Lighting

Power storage - battery

E charging infrastructure

PKV-Photovoltaic system

E charging infrastructure

For the most part, the individual functional areas are situated on the ground floor and meet the requirements of ÖNORM B 1600. The roofs are partly designed as extensive green roofs (with vegetation) and partly as Kalzip roofs with photovoltaic equipment. The technical rooms are each arranged at the bottom of the roof. The facade largely consists of a mullion-transom facade with PV elements. Floor-to-ceiling photovoltaic elements and transparent fixed glazing with inserted ventilation wing elements alternate between each other. A thermal insulation composite system is used in some areas.

The PV system feeds the main systems of the building, controlled by the energy management, whereby the highest possible utilization of renewable energy is guaranteed via the energy storage.

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The components are conditioned by means of surface heating (concrete core temperature control, ceiling, underfloor heating). Four air / water heat pumps in a cascade connection with a nominal output of approx. 10 kW (total = 40 kW) are used. The individual heat pumps have a reverse function in order to be able to provide a corresponding supply of cold. The heat pumps are located on the roof of component B and coupled with a hot water storage tank and a cold storage tank.

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In the battery room of component B, three battery systems with a storage capacity of ranging from 30kWh to 100kWh are realized for storing electricity. Storage systems based on lithium-ion technology, redox flow technology and saltwater technology are used.

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The battery system operates in combination with the PV installation and the EV Charging station and is controlled in a way that allows the operation in the most optimal way.

The charging station is smart, which dynamically adapts to the current consumption of the building and the condition of the battery and also benefits from the additional power of the solar power plant when available.

Without a smart adjustment of the charger consumption, the system would fall apart, as the power of the charger is relatively high compared to the installed power of the building.

The charging station will then be ready to be connected to the back-office system, which is in the application with 300,000 charging stations across Europe.

The operation of the entire system is visible in the web interface, where the conditions of production and energy consumption of the smart facility can be seen. The production and consumption data can be seen also here at the CSSC Lab platform.

The system operates in the optimal cost mode, which means: first consumers use solar energy, then energy from the battery and only then energy from the grid.

In case of excess production, the system works in such a way that the energy is stored first in the stationary battery or in the car battery, and only then the surplus energy is sent as part of the self-supply package to the network.

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Building has the possibility to store heating and cooling energy within heat water tank storage and cold water tank storage. These are available for energy consumption from other heating/cooling systems within the demo-center.

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A central ventilation device, consisting of a base frame, panels made of galvanized sheet metal with heat and sound insulation, supply and exhaust air flap with actuator, air filter, rotary heat exchanger and integrated heat pump, with a supply and exhaust air volume flow of 6,500 is used for mechanical ventilation of the components m³ / h used.

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Different e-charging infrastructure facilities for charging e-vehicles will be implemented on the site. The power range of the charging points is 3.7kW, 11kW, 22kW or 50kW (AC and DC technology), whereby the connection between the vehicle and the charging infrastructure is made using wired technology.

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The interior lighting of the property is realized exclusively with lights based on LED technology. In the outdoor area, LED mast lights are used to illuminate the driveway and parking area, as well as LED building lighting.

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Based on the use of the latest technologies and systems (highly efficient PV modules, use of electricity and heat storage, building core activation …) a comprehensive energy concept was developed for an entire office building, to make sure that all energy needed for the building (electricity, heating, cooling) can be supplied by the installed PV panels. The whole building is energy positive, which means it produces more energy than is consumed on site. The building is equipped with an energy management system for operation, which can also be integrated into higher-level systems – for example in the context of energy communities or energy-plus districts. For this purpose, an interface to the VPP (= Virtual Power Plant) already in operation in Oberwart (Oberwart Loadshift project) is planned.

The building is designed and engineered consistently in BIM systems (= Building Information Modeling), the data models generated in the process are also updated during operation and kept up to date in order to ensure that the building is operated with optimized energy consumption. The entire building is automated on the basis of the BIM data models, so that many functionalities run in the background without impairing the convenience of the users.

A comprehensive monitoring system continuously monitors generation and consumption (at 15-minute intervals) and regulates the energy demand based on current and forecast usage and occupancy of the individual rooms. The PV system feeds the main systems of the building, controlled by the energy management, whereby the highest possible utilization of renewable energy is guaranteed via the various energy storages.

According to the overall concept, the competence center will play a central role in a renewable energy community or in a plus-energy district and it is planned to be able to use the surplus energy generated in the building across the district in the future. For this reason, the PV system was not dimensioned with the individual building in mind but made larger and the entire existing roof and facade area as well as the roof areas of the carports were used.

One main goal of the project is to considerably increase the self-consumption of the buildings PV installation, supplying all the buildings energy needs from its own, self-generated power. With the different storage solutions that will be installed in solar.one, a lot more of the generated energy can be used on site, considerably increasing the self-consumption ratio. The sector coupling solutions (heat pumps, EV charging) also allow the utilization of electric energy in other sectors, like heating and mobility. This further increases the ratio of self-consumed energy. Solar.one is not only a net-positive building, where a lot of energy is generated and supplied to the grid (and being basically lost for the building and region), the project aims to show that with the intelligent utilization of storage and sector coupling most of the generated energy can be used on site and directly used by the building and its users. As such the utilization of locally generated renewable energy can be substantially increased. PV generation is volatile, as it depends on the sun shining. This traditionally means, that surplus energy that cannot currently be used on site, is fed into the grid for a comparably low compensation. Also, if there is no sunshine, all (electric) energy has to be supplied from the grid. With the storage and sector coupling solutions deployed on the site, the majority of the generated electricity can be used – even in times when the sun doesn’t shine.

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The project planning for the whole building started in 2018, construction of the building started in Q4/2019. First offices in the building where ready to use in Q4/2020.

The whole building was designed and engineering with BIM technology (started in 2018), and as such a digital twin of the building is available at the end of the engineering process. The whole design and engineering effort was closely coordinated between the building architect, the BIM design team, the building utility design and the building energy design. Construction of the building started when the principal detail design was finished in Q4/2019. The following components have been installed in the solar.one building as part of the CSSC Lab project: thermal storage (heat and cold), battery storage (Li-Ion and Na-Ion), building core activation (utilizing the bulk mass of the building as thermal storage), EV – charging infrastructure, monitoring and load management system. Project management for the engineering phase was done by Energie Kompass GmbH, this included the design of the buildings energy and storage systems. Within these tasks the buildings PV system, the battery and thermal storages and the charging infrastructure have been defined and engineered. Project management for the construction phase was done by solar.one IMMO GmbH & CoKG. There was no general contractor for the project, all needed coordination and project management tasks have been done by the investing company, solar.one IMMO GmbH & CoKG.

The CSSC components have been installed into the building as the construction progressed. The planning for the CSSC part started in July 2020 with CSSC components installed in Q4/2020 to Q2/2021. The grand opening of the solar.one building and site is planned for October 2021. As a first part the thermal storages and the building core activation have been installed in the building and commissioned in March 2021. The second commissioned part was the monitoring and load management system in March 2021 as well. The battery storages and the EV charging infrastructure have been installed after the main building construction was finished in Q2/2021.

Biggest difficulties in the project were the coordination of the various design and engineering tasks, that have been carried out by different companies. In order to create a building where the energy system is deeply integrated in the core building functionality a close cooperation between the building architect, the PV engineer, the heating and cooling system engineer and the civil engineer had to be ensured. As all systems and components are linked on the building monitoring and load management systems a major ICT component was also part of the overall projects. Energie Kompass GmbH did lead the overall engineering process, with additional expertise coming from external suppliers and engineering partners. Ensuring a proper information flow, management of documentation revisions and communicating design decisions to all involved parties proved to be the major challenge in the process. A major boon in this context was the decision to use BIM as a design tool. This provided a digital model on a central data server where all involved parties could work together and the design status was always documented in a central place.

Feasibility study and detailed planning of demo-center

07/2020 – 09/2020

Technical specification of components

09/2020

Procurement of components

10/2020

Purchase and delivery of components

03/2021

Installation of components

05/2021

Initial operation of demo-center

06/2021

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The whole solar.one investment amounts to approximately 3.6 million Euro. The investment was made based on a business plan, with the objective of creating a sustainable business case. This business case for the project is primarily renting out office space and event locations (seminar and workshop rooms, an event hall, coffee shop). The demonstration character of the whole building will be used to host a range of events, workshops and congresses on topics of the energy transition, which will generate a revenue stream in addition to renting out office space to local companies and startups.

The investment for CSSC components (storages, monitoring, load management and charging

infrastructure) amounts to about 200.000 EUR, with half of this sum being claimed under the CSSC project.

Indicators for the period from 01.01.2022 – 31.08.2022.

Key Figures
Investment Cost	Approx. 197.000 €
CAPEX	Approx. 240.000 €
OPEX	Negligible within operation period (no maintenance needed)
Autarky Grade	33% cummulated over 8 months
Self Consumption Grade	78% cummulated over 8 months
Total Energy Production	111.298 kWh
Total Li-Ion Storage utilization	20.020 kWh
Total Na-Ion Storage utilization	18.900 kWh
Total Hot Water Storage utilization	13.100 kWh
Total Cold Water Storage utilization	7.000 kWh
Total charging sessions	144 recharges, 4.900 kWh charged
CO2 Savings	20.033 kg (*)

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The thermal storages serve the main purpose to generate energy flexibilities to allow a time delay between energy consumption and energy generation. The energy generation is done with the buildings PV panels and electric current is converted to thermal energy using heat pumps.

KPI-T1: Annual Thermal Flexibility The annual thermal flexibility shall be defined as the thermal energy amount, measured in kWh, that is stored between the time of generation (i.e., loading of the storage) and time of consumption over the period of one year. As thermal storages will be loaded from the buildings PV-generated electricity (via heat pump), this flexibility directly increases the PV – self consumption by the respective amount.

KPI-T2: Total annual thermal loading cycles The total annual thermal loading cycles shall be defined as number of loading and emptying of the thermal storage over one year These 2 KPI will be utilized for the two thermal storages, i.e., the hot water storages and the cold-water storage.

The electric battery storages also serve the purpose to generate energy flexibilities to allow a time delay between energy consumption and energy generation. The batteries will be mainly used to utilize PV generated power at times with low or no PV – generation (e.g., during the night).

KPI-E1: Annual Electric Flexibility The annual electric flexibility shall be defined as the electric energy amount, measured in kWh, that is stored between the time of generation (i.e., loading of the storage) and time of consumption over the period of one year.

KPI-E2: Total annual electric loading cycles The total annual electric loading cycles shall be defined as number of loading and emptying of the electric storage over one year These 2 KPI will be utilized for the two electric storages, i.e., the Li-Ion battery as well as the Na-Ion battery.

The buildings PV system will provide the electric power needed for charging EVs that are parked on site. The battery storages will provide the needed buffer to ensure that only self-generated power is used. Within the CSSC-Lab two charging point will be installed, one for AC charging (type 2 charger) and one for DC fast charging (CCS charger). KPI-M1: Total annual charged energy, AC This KPI shall give the total annual energy amount that is charged on the AC charging unit. KPI-M2: Total annual charged energy, DC This KPI shall give the total annual energy amount that is charged on the DC charging unit.

The main purpose of the monitoring and load management systems is to maximize the utilization of the self-generated PV power in the building.

KPI-LM1: Annual self-consumption ratio This KPI shall be defined as the ratio of self-consumption in %, measured as the amount of self-consumed electric energy divided by total amount of electric energy generated.

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Description

The solar.one site as a whole is a plus-energy office building, showing and demonstrating cutting edge technology in the field of PV, building integrated PV, energy storage, sector coupling and energy efficiency. It will also show advantages of greening buildings, with the roof areas greened with a mix of suitable plants and grasses. The solar.one is a competence center for renewable energies, and is hosting the offices of the Innovation Lab act4.energy and its parent organisation Energie Kompass GmbH.

However, not the whole solar.one site is part of the CSSC lab, which has a focus on storage and sector coupling solutions. As such, part of the CSSC project are the battery storages (Li-Ion and Saltwater), thermal heat storages, sector coupling to E-Mobility (charging infrastructure) as well as coupling power2heat, utilizing the activated building core (heat exchanger system). The building is equipped with monitoring equipment (temperature and presence monitoring) as well as a load and flexibility management software to ensure optimal utilization of storage and sector coupling solutions.

Furthermore it is planned to integrate the building into a regional, renewable energy system. The building is equipped with an energy management system for operation, which can also be integrated into higher-level systems – for example in the context of energy communities or energy-plus districts. For this purpose, an interface to the VPP (= Virtual Power Plant) already in operation in Oberwart (Oberwart Loadshift project) is planned.

The building is designed and engineered consistently in BIM systems (= Building Information Modeling), the data models generated in the process are also updated during operation and kept up to date in order to ensure that the building is operated with optimized energy consumption. A comprehensive monitoring system continuously monitors generation and consumption (at 15-minute intervals) and regulates the energy demand based on current and forecast usage and occupancy of the individual rooms.

The PV system feeds the main systems of the building, controlled by the energy management, whereby the highest possible utilization of renewable energy is guaranteed via the various energy storages. According to the overall concept, the competence center will play a central role in a renewable energy community or in a plus-energy district and it is planned to be able to use the surplus energy generated in the building across the district in the future. For this reason, the PV system was not dimensioned with the individual building in mind but made larger and the entire existing roof and facade area as well as the roof areas of the carports were used.

The entire building is automated on the basis of the BIM data models, so that many functionalities run in the background without impairing the convenience of the users.

Building data

The entire object consists of a series of components with their respective functional units. The individual components are triangular in plan and each have roof surfaces that are inclined in opposite directions. A basement is not planned for the construction project at hand.

The respective components are made up of the following functional areas:

Component A:

Ground floor: roofing of the main entrance with storage

Component B:

Ground floor: foyer, representation, social room, library & meeting, sanitary area, technical area
Upper floor 01: office gallery

Component C:

Ground floor: office area, kitchenette, laboratory, technology

The main access to the above-mentioned property is in the area of the Glorietteweg / Herrschaftsweg intersection. Another access is planned via a cul-de-sac from Glorietteweg. A total of 44 parking spaces (including 4 barrier-free parking spaces) are created on the property, with all parking spaces being prepared for the subsequent expansion of EV-charging station units.

Building

For the most part, the individual functional areas are arranged on the ground floor and meet the requirements of ÖNORM B 1600. Only in component B is an office gallery on the upper floor, which can be reached via a single flight of stairs. The clear width of these stairs is designed for a possible retrofitting of a stair lift.

The roofs develop from the landscape like a desk and are designed partly as an extensive green roof and partly as a Kalzip roof with photovoltaic equipment. The technical rooms are each arranged in the low areas of the roof, where the smooth transition from roof to landscape takes place. Climbing on the roofs is prevented at the base by means of climbing protection, and controlled access to the roofs is guaranteed via a lockable access door.

The facade consists largely of a mullion-transom facade with PV elements. Floor-to-ceiling photovoltaic elements and transparent fixed glazing with inserted ventilation wing elements are arranged alternately. A thermal insulation composite system is used in some areas. The exact arrangement of the facade elements can be found in the attached submission plans in the views. The use of the rooms can be found in the attached floor plan.

Photovoltaic systems

The photovoltaic system serves as a demonstration object for innovative photovoltaic solutions. The overall photovoltaic concept is therefore based on various module assembly solutions and inverter concepts. Both facade systems, in-roof systems, elevations on the green roof and carport systems are used.

Overall energy concept of the building and integration of CSSC solutions

The building is planned consistently in BIM systems (= Building Information Modeling), the data models generated in the process are also updated during operation and kept up to date in order to ensure that the building is operated with optimized energy consumption. A comprehensive monitoring system continuously monitors generation and consumption (at 15-minute intervals) and regulates the energy demand based on current and forecast usage and occupancy of the individual rooms.

The PV system feeds the main systems of the building, controlled by the energy management, whereby the highest possible utilization of renewable energy is guaranteed via the energy storage. According to the overall concept, the competence center will play a central role in a renewable energy community or in a plus-energy district and it is planned to be able to use the surplus energy generated in the building across the district in the future. For this reason, the PV system was not dimensioned with the individual building in mind but made larger and the entire existing roof and facade area as well as the roof areas of the carports were used.

The entire building is automated on the basis of the BIM data models, so that many functionalities run in the background without impairing the convenience of the users.

Energy Monitoring

The whole building is equipped with a range of sensors for energy monitoring. This includes temperature, CO2, humidity and presence sensors among others.

All data is processed in a central energy monitoring and control system.

The energy monitoring system provides the data base for the load and flexibility management system that is utilized to maximize the efficiency of the installed CSSC technologies.

Load and Flexibility Management

The building is designed as a plus energy building and is planned to supply surplus energy as needed to other consumers in the region. In order to manage the loads and flexibilities accordingly, a load management system will be implemented.

This load management system is also key to the operation and management of the installed storage solutions in order to achieve the highest efficiency in utilizing the storage capacities.

Heating and Cooling

The heat pumps are located on the roof of component B and coupled with a hot water storage tank and a cold storage tank.

Hot Water Production

The hot water preparation takes place decentrally by means of electrical energy (electric instantaneous water heater). The electricity is generated on the buildings PV installation.

Ventilation

Technical data ventilation unit:

Volume flow of supply air: 6.500 m³/h

Volume flow of exhaust air: 6.500 m³/h

El. Power consumption: 12 kW

Sound power level Lw: 70,5 dBA (at frequency = 250 Hz)

Used refrigerant (WP): R410A

Refrigerant charge: ca. 8 kg

Power Storage

E-Charging Infrastructure

Storage and Sector Coupling Technologies

The solar.one building will be a showcase for a variety of storage and sector coupling applications. These technologies play a vital role in the energy transition, as they allow for optimal utilization of locally generated renewable energy sources.

There are two major challenges with the utilization of local renewable energy sources, that become more and more pronounced the higher the fraction of renewables is in the total energy mix is. First of all, lot of renewable energy sources (like wind and sun) are volatile and do not provide a constant rate of energy generation. Second there are also seasonal fluctuations in the energy generation as seen with solar, wind or hydropower.

To account for the volatility and seasonal fluctuations storage systems do play a major role, as does sector coupling. While energy storages (long term or short term) can account for volatility and fluctuations, the sector coupling technologies allow a surplus electrical (or thermal) energy generation to be used in a wide variety of applications, transforming one type of energy (electricity) in another (e.g. heat).

Within the Stegersbach demo site of the CSSC Lab project a variety of CSSC solutions will implemented, tested and demonstrated:

Battery Storages
- Li-Ion technology as well as Na-Ion technology are implemented
Thermal Storage
- Heat and cold storage (water based) in combination with heat pumps and heat exchangers will be implemented
Sector coupling
- Power2heat sector coupling, utilizing PV power for heating and cooling
- Power2mobility sector coupling, utilizing PV power for charging of electric vehicles

Lessons learnt

During the course of the project, which included parts of the design process, the building and implementation phase as well as the first 18 months of operation a couple of lessons have been learned:

Design phase lessons:

During the engineering phase the proper dimensioning of storage sizes in relation to the buildings energy demand and load profile was a main learning in the project.
Due to the innovative nature of the building, there was no direct reference material available and assumptions needed to be made on several steps of the design process. Especially the building core activation is a rather new technological concept and its interplay with the heat pump and heat exchanger system had to be newly explored.
A learning from this step is that if there are possibilities to do simulations during the design phase, it will have major benefits.

Implementation phase lessons:

As always with big construction projects, project and site management as well as proper construction supervision are critical
As many of the components installed (battery storages, charging infrastructure, …) are not quite yet industry standard, contractors may not have sufficient experience when installing and commissioning these parts. Make sure to choose contractors with sufficient expertise but also provide good documentation, instructions and manuals to allow for properly installed and commissioned equipment.
Many of the equipment traditionally belongs to different trades and different contracting partners (electrical installation vs. HVAC installation for example). However all these belong to a modern buildings energy system and have to work smoothly together.
Make sure that contractors communicate accordingly and have a proper site supervision to provide an overall guide line to get all parts working as a coherent system.

Operation phase lessons:

The energy system of the solar.one building consists of several different parts (PV, batteries, heat pumps, thermal and battery storages) that are supplied by a variety of different vendors. Many of these systems do come with their own proprietary controls and interfaces.
Integration all these proprietary systems into a coherent building management system has been more difficult than anticipated. Interoperability does not always work as advertised and getting a proper data a control flow between all the different equipment is still an ongoing task. While the building and its energy system do work exceptionally well, there are occasional bugs and inconsistencies that need to be ironed out further on.
A major learning here is to have one organization fully in charge for data and control systems and have all equipment vendors comply to interoperability standards requirements of the overall system

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