Energy Saving Public Swimming Complex In Finland Suvi Karirinne 1,a, Petri Konttinen 2,b, and Jukka Kotiniemi 3 1 Faculty of Energy and Construction, Satakunta University of Applied Science, Tiedepuisto 3, Pori, FI-28600, Finland 2 Aurubis Finland Oy, Kuparitie 5, FI-28330, Pori, Finland 3 Technical Service Centre, City of Pori, Yrjönkatu 6, FI-28101, Pori, Finland a suvi.karirinne@samk.fi, b p.konttinen@aurubis.com ABSTRACT In this article, the process for the realization of energy-sparing public swimming complex is presented. This energy-stingy public swimming complex represents a new approach and energy-generating models in tackling the climate change. The public swimming complex uses solar energy systems in energy generation and recovery, as the first public swimming complex in Finland. The public swimming complex has a total of 560 m 2 of solar panels and collectors on its roof hidden from view. Additionally, an area of 80 m 2 of solar energy collectors is fully architecturally integrated in the cladding copper material on the south-facing façade. This is the first pilot site in the world that incorporates the fully architecturally integrated solar energy system called Nordic Solar. Solar heat collectors generates 120,000 kwh of energy for the complex, covering 5 % of the annual heat requirements of the public swimming complex and corresponding to the annual energy need of six average detached houses in Finland. Photovoltaic panels produce around 45,000 kwh or 3 % of the electricity consumed by the building. The building has been designed to save energy: it recovers heat from exhaust air and shower water. When the indoor pool is closed from public during summer, the basic functions of the complex are maintained by solar power and heat, whereas during normal opening hours solar power is used as a complementary energy source in generating electricity and heating the pool water. KEYWORDS: Photovoltaic Systems, Solar Thermal Systems, Building Integration 1. INTRODUCTION In the light of future temperature SRRES scenarios, B1, A1B and A2 presented in IPCC s AR4 report (G.A. Meehl et al., 2007, N. Nakicenovic et al. 2000) no matter what our technological choices for energy production or transportation are, global temperature increase is inevitable. We, as societies, can however affect, through our actions and choices, whether this increase in global temperature is 2 or 5 degrees Celsius at the end of the present century. Climate change and the resulting global warming are mainly due to the increase in the amount of GHG emissions in the atmosphere. Finland as a member of the European Union (EU) has to meet the so called 20-20-20-targets, which are part of the climate and energy package and were set as binding legislation by the European Parliament, which aims to ensure the European Union meets its ambitious climate and energy targets for 2020 (Communications of European Commission, 2007). These targets set three key objectives for 2020, namely 20% reduction in GHG emissions from 1990 level by 20%, raising the share of energy consumption produced from renewable resources up to 20%, and improving the overall energy efficiency by 20% by the year 2020. Energy efficiency increasement targets were speeded up by the energy efficiency directive launched by the commission at 2010 (European Parliament, Directive 2010/31/EU), in which it is stated, that all the new build public buildings have to be near zero energy buildings by the year 2019. This directive sets high demands for
municipalities and their officials, since for example in Finland s case, the built environment (without construction and transportation sectors) accounted for 38 % of the final energy use and 32 % of the GHG emissions in Finland in 2007 (The Finnish Innovation Fund 2010). In this article, the process for the realisation of energy-stingy public swimming complex is presented. This energy-stingy public swimming complex represents a new approach and energygenerating models in tackling the climate change. The public swimming complex uses solar energy systems in energy generation and recovery, as the first public swimming complex in Finland, and as such constitutes a major environmental action. The Pori model represents a new approach by Finnish cities and municipalities for stopping climate change. 2. DESIGN AND ENGINEERING PROCESS OF THE SOLAR ENERGY SYSTEMS The design and engineering process of this public swimming complex is an excellent example of the co-operation done between three parties, namely private corporate experts, public city officials, and university researchers and educators. 2.1 Starting point The public swimming complex was decided to be built by the city board to celebrate the City of Pori s 450 th jubilee at 2011. At the stage when solar energy systems were considered as a potential technology for energy production in the public swimming complex, the architectural and technical basic design and engineering were already done (figure 1). This obviously set some restrictions for the solar energy system s building integration and limited the possibilities e.g. in solar energy system size. Figure 1. Architectural basic design of the public swimming complex in the city of Pori. At the beginning of the solar energy system design process, several possibilities in system orientations, system sizes and technologies, installation options and investment costs were cautiously scrutinized together with the city officials, university s and corporate solar energy experts, project s architect and construction engineer. During this process, three main objectives for the solar energy system integration were set, namely 1. Maximum solar energy system operation age, 2. Maximum solar energy yield of the chosen system, and 3. Minimal solar energy system cost. Architectural basic design set only one limitation, namely that the solar energy systems must be hidden from the street view and
may not be visible in the façade view. From the technical basic engineering s point of view, the biggest challenge for the solar thermal system engineering was the fact that the public swimming complex was to be connected to the district heating network. As a result of several design and engineering iteration rounds with the mentioned restrictions and main objectives taken into account, the first version of the solar energy system design was produced (figure 2). No solar energy systems here. Solar thermal flat plate collectors Photovoltaic system Figure 2. First draft of the solar energy systems design. Due to requirement of maximum solar energy system operation age and the limited roof space available (Onto the roof, above the 50 meter full length pool, no solar energy system installation was possible), the solar thermal system was designed first and the space left over was decided to be filled in with photovoltaic panels. The south facing façade was designed to be partially covered with the Aurubis Finland s Nordic Solar façade integrated solar thermal system, making the public swimming complex the first building in the world, in which the Nordic Solar-system is piloted in real size and environment. 2.2. Architecturally integrated solar thermal copper façade Facade integrated solar thermal system, Nordic Solar Aurubis Finland s architecturally integrated solar thermal copper façade, Nordic Solar, can in practice be installed to façade in such a manner, that no thermal collectors are visible from the outside (figure 3). Since spring 2010 the pilot functionalities and energy yields of different patinas for solar thermal heating have been studied. On the basis of obtained results the system has been developed further. In the proto we can see the pyranometers and wind sensors. Operating results have been technically good, short energy yields even at -18 C at full sunshine during wintertime have been gained. The pilot has provided annual heat 280-450 kwh/m 2, depending on the type of prepatinated copper. Temperature provided by the collectors is well suitable e.g. for preheating of domestic hot water, and is best suited for typical low-temperature applications, such as spas and indoor swimming pools.
Figure3. Proto environment of the Nordic Solar architecturally integrated solar thermal façade. Energy yields even at -18 C at full sunshine during wintertime have been gained. 2.3. Detailed design and engineering process In the second phase, also HVAC, electrical and water treatment engineering experts were involved in the solar energy system engineering process and the first design version draft was adjusted with the restrictions set by already existing architectural basic design and technical basic engineering. During this process the orientation of the roof and facade PV modules and solar thermal collectors were finetuned and possible shadowing effects were calculated. At this phase, some alterations to the basic design and engineering were done. For example, the roof s support structures were recalculated due to the extra load caused by the mass of solar thermal and photovoltaic systems and the aluminium grid structure designed for solar thermal and photovoltaic systems fastening and installation. This metal grid structure was designed since no entries through the roofing material were allowed. Positioning of the solar energy systems onto roof were also verified. Also the location of solar thermal systems pipelines and their entries, as well as the location of fire walls and hatches, were adjusted and their possible impacts on solar energy system design were calculated. In the case of shadowing effect calculation, realisation of the future city planning and especially the planned apartment house city block to the western side of the swimming complex were taken into consideration as well. According to the shadowing simulations and calculations, shadowing caused by the highest apartment houses would lead to annual 5% decrease in solar energy yield for the photovoltaic and solar thermal systems situated on the roof. This decrease in annual solar energy yield was compensated by choosing more efficient photovoltaic panels and flat plate collectors. The calculated percentual energy yield loss was higher for the façade integrated solar thermal system. However, this loss was not compensated, but was considered as a feasible compromise between maximum energy yield and city architecture. The result of the detailed design and engineering process for the solar thermal systems is presented in figure 4.
Figure 4. Solar heating system in the public swimming complex in Pori. Solar thermal systems consist of 200 m 2 roof flat plate collectors and 78 m 2 of Nordic Solar façade integrated solar thermal system. Total power of the flat plate collectors is 140 kw and they are calculated to generate a total of 100, 000 kwh of energy for the complex. Total power of the façade integrated Nordic Solar thermal system is 56 kw and it was calculated to generate 15-23, 000 kwh of energy. So all together, solar thermal systems produce energy corresponding to the annual total energy costs of six average detached houses and covering 5 % of the annual heat requirements of the swimming pool complex. Solar heating process flow chart is presented in figure 5. Solar thermal systems are designed to pre-heat the pool water. Figure 5. Solar heating process flow chart. Technical realisation was similar for both façade integrated and roof thermal systems (figure 6). Both systems were divided into separate collector fields. Every separate collector field was insulated with temperature resistant flow metering valve to adjust and balance the flow in the piping and with sluices to insulate the system from the main swimming complex systems in the case of an emergency. Furthermore the beginning of every collector field was equipped with a 10 bar safety valve for preventing any pipeline breaks. For every collector field, sensor pockets with sensors were installed to measure the collectors inlet temperatures.
Facade integrated collector system Roof installed collector system Figure 6. Technical realisation of the façade integrated and roof installed solar thermal systems. In the case of the PV system, the peak power for the photovoltaic system was designed to be 50 kw p and the system consists of 360 m 2 (240 pieces) of c-si panels with the installation angle on 45 (figure 7). This PV system produces approximately 45 000 kwh energy annually or 3 % of the electricity consumed by the building. Energy produced by the PV system corresponds to the annual total energy costs of two average detached houses. 360 m 2 (240 pieces) c-si panels Figure 7. Photovoltaic system in the public swimming complex in Pori. During the summertime, when the indoor swimming pool is normally closed, the basic functions of the complex will be maintained by solar power. When the swimming pool complex is open, solar energy will be used as a complementary energy system for heating the pool water and for the electricity consumption. The total cost for the swimming complex s solar energy systems including installation stood at 590,000 euros. 3. FROM DESIGN INTO REALISATION After detailed design and engineering process, the project realisation started with determining the procurement procedure. Contract interfaces were defined and requests for quotations were prepared. Solar energy systems were decided to be purchased as own separate acquisitions. During the procurement process, special attention was paid to the qualifications of the possible suppliers.
3.1. Experiences and lessons learned Being a piloting project in solar energy system integration into swimming complex environment, both positive and negative experiences, as well as lessons learned were recorded during the process. In the media, the general attitude towards this project was extremely positive. What comes to the architecture and the location of the swimming complex, they suited extremely well for solar energy system integration. Project s architect and all of the designers and engineers had very positive attitude towards utilisation of solar energy, regardless of the caused extra work. Swimming complex s solar energy systems are also a learning environment for the environmental, electrical, and automation engineering students in Satakunta University of Applied Science and in this way strengthens the local solar energy technology application and integration education. Since the solar energy system integration was realised only after the swimming complex s basic engineering and architectural design were already done, it had some negative impacts on the project. Some technical problems relating to the already fixed positioning of the heat exchangers caused extra costs and heat losses in the form of extra-long pipelines. Except for the Nordic Solar thermal system, fully architecturally sound building integration was not possible for the PV and flat plate collector solar thermal systems. In Finland there is not much experience in coordination of large solar energy system integration projects and improvements concerning the overall project management have to be made. As one result of this swimming complex project, a model of the solar energy system procurement and project management procedure was realised for the future use in the projects of the City of Pori. The final result from the private corporate - municipal university -joint design, engineering and procurement process can be seen from the figure 8, in which the completed public swimming hall is presented. Figure 8. Completed public swimming complex in the city of Pori. 3.2. Solar system operation in the swimming complex Satakunta University of Applied Science with its solar energy RDI-team is metering and following the energy yield from the swimming complex s solar energy systems (figure 9). Swimming complex was opened to the public in September 2011. During the first autumn, the solar energy system operation was optimised for PV system and during the first full operational year, the total PV power obtained from the system was approximately 43,000 kwh. The result is quite near the approximated 45,000 kwh annual energy production for the PV system. Because of warranty issues related to nonsolar HVAC components elsewhere, the operation optimisation was a longer process for both of the solar thermal systems. First results from the solar thermal systems were obtained from the flat plate collector system situated on the roof in May.
Total solar energy power obtained from ST and PV systems kwh,wm -2 10000 9000 8000 7000 6000 5000 4000 3000 2000 1000 0 Jan Feb Mar Apr May Jun July Aug PV [kwh] 1,93 198,635082,55163,47456,5 6670 6998,86197,53770,81117,9 307,1 0,4 64,1 113 5927,86634,37910,3 ST [kwh) 0 0 0 0 3846,96916,54628,2 4795 2408,2 0 0 0 8,1 233,6 5159,65364,59514,7 radiation [W/m2] 525 1001 1127 1243 1181 1369 1253 1270 1241 1007 720 313 646 912 1154 1244 1229 Sep Oct Nov Dec Jan Feb Mar April May Figure 9. Total solar power obtained so far from the swimming complex s solar energy systems. Façade integrated Nordic Solar thermal system s operation optimisation was finished in May because of the earlier mentioned non-solar HVAC component warranty issues. Due to the longer system optimisation times, it is too early to make any conclusions relating to the real operation of the solar thermal systems, since the first year, when both of the ST systems (plate collectors and façade integrated systems) are simultaneously operational, will be the year 2014. 4. SUMMARY The solar energy solutions designed for Pori s new pool complex are unique in Finland. The project embraces the latest technology, the development of renewable forms of energy, research and innovations, plus education for future specialists in the field. Even though this solution only replaces a part of the complex s requirements for district heat and electric power, nevertheless the Pori model represents a new approach by Finnish cities for stopping the climate change. What comes to the real operation of the solar energy systems, the amount of energy obtained from the PV system during the first full operation year corresponds well with the design and calculations made. For the solar thermal systems, it is too early to make any conclusions about the real operation, since the first full operation year for the both systems will be the year 2014 because of nonsolar HVAC component warranty issues. REFERENCES Communications of European Commission, Communication from the commission to the council, the European parliament, the European economic and social committee and the committee of the regions, Limiting Global Climate Change to 2 degrees Celsius - The way ahead for 2020 and beyond, p.5, 2007. European Parliament, Directive 2010/31/EU, Official Journal of the European Union, 2010, L153/21 Finnish Innovation Fund, Energy use and greenhouse gas emissions in the Finnish built environment (in Finnish), 2010, pp.11-16 G.A. Meehl and T.F. Stocker (lead authors), Global Climate Projections in H.L. Miller (ed.), Climate Change 2007: The Physical Science Basis, contribution of working group I to the fourth assessment report of the IPCC s report, Cambridge, UK, and New York, Cambridge University Press, 2007, p. 766. N. Nakicenovic and R. Swart eds., Special report on Emissions Scenarios: A Special Report of Working Group III of the IPCC, Cambridge, UK: Cambridge University Press, 2000, p. 570.