Design of the back-up system in Patio 2.12 photovoltaic installation

Depósito de investigación de la Universidad de Sevilla https://idus.us.es/ Esta es la versión aceptada del artículo publicado en: This is an accepted manuscript of a paper published in: Energy and Buildings (2014): 09/2/2024 DOI: https://doi.org/10.1016/j.enbuild.2014.04.030 Copyright: © 2014 Elsevier B.V. All rights reserved. El acceso a la versión publicada del artículo puede requerir la suscripción de la revista. Access to the published version may require subscription. “This is an Accepted Manuscript of an article published by Elsevier in [Energy and Buildings] on [2014], available at: : https://doi.org/10.1016/j.enbuild.2014.04.030” DESIGN OF THE BACK-UP SYSTEM IN PATIO 2.12 PHOTOVOLTAIC INSTALLATION *B. García-Domingo1, M. Torres-Ramírez1, J. de la Casa1, J. Aguilera1, F.J. Terrados2 1IDEA Research Group, University of Jaén, Campus de Las Lagunillas, 23071 Jaén (SPAIN) 2Escuela Técnica Superior de Arquitectura, dpto.: Proyectos Arquitectónicos, University of Sevilla, C/ S. Fernando, 4, 41004. Sevilla, (SPAIN). ! *Corresponding author: Tel.: +34 953 213 306; fax: +34 953 211 967 E-mail address: [email protected] ! ABSTRACT! Andalucía Team presented in the Solar Decathlon Europe 2012 Competition a proposal of a modular, sustainable, self-sufficient housing, Patio 2.12. Inspired by Mediterranean style, Patio 2.12 was composed of four habitable modules around a common space (“patio”). Each habitable module has a photovoltaic system on its roof. Simplicity and modularity determined the design of the photovoltaic system so that, together with a global electrical energy management system, the use of the locally generated electrical energy can be optimized. Amongst others, a remarkable innovation included in Patio 2.12 was the use of an intelligent controlling device, based on an energetic support system that could manage the flows of electrical energy of all elements of the electrical installation integrated in the house. This system allows adapting the electricity availability to the consumption demand, maximizing the amount of photovoltaic energy locally generated and instantaneously consumed.! This paper implements the use of a simulation software model to analyse the electrical energy balance of the photovoltaic electrical installation. This model estimates the electrical photovoltaic generation and the electrical exchanges with the grid and the battery bank, under a determined load profile, and for a specific period of time, using environmental data as inputs to the model. Keywords: Self-sufficient housing, Building-Integrated photovoltaic, Solar Decathlon, Photovoltaic system design, electrical energy balance. 1. Introduction Experts on architecture, photovoltaic (PVi) solar energy and Home automation from Universities of Sevilla, Málaga, Granada and Jaén joined to form the Andalucía Team [2, 3]. Andalucía Team presented in the Solar Decathlon Europe (SDEii) 2012 competition, the prototype called Patio 2.12 [4], inspired by Mediterranean life style as show in Fig. 1. This proposal was based on modularity, sustainability and self-sufficiency housing. So, Patio 2.12 was composed of four habitable modules around a common space (“patio”) that included a PV system on each roof and a global electrical energy management system. The design of the PV system, together with the implemented management system, allows optimizing the use of the locally generated PV electricity, obtaining a higher autonomy from the electrical grid. Figure 1. Inside view of the project Patio 2.12. Members of IDEAiii (Investigation and development in solar energy) research group and students of the University of Jaén, designed, developed and implemented the grid connected PV installation and the global electrical energy management system in Patio 2.12. After the participation of Andalucía Team in SDE 2012, Patio 2.12 got the second award in the general classification on the competition, as well as the first places in contests related to the energy, such as, energy efficiency and energy balance. This paper describes the design principles of the electrical energy systems installed in Patio 2.12. Furthermore, it introduces a simple simulation model to estimate the real performance of the designed electrical system under determined environmental conditions and a specific load profile. The behavior of this model is evaluated by comparison of the real monitoring data obtained during the competition period with the simulated data by the proposed model. Finally, this model is applied to estimate the annual electrical energy balance of the entire PV system for a Typical Meteorological Year (TMYiv) in Madrid.! 2. Design of the PV system 2.1. Premises of the design The participation of the project Patio 2.12 in the SDE competition, made the design to be restricted by a set of rules [5] imposed by the organization of the event. These limitations influenced the PV system design and were referred to the architectural envelope, maximum surface of the housing, maximum ACv (Alternating Current) nominal power of the inverter, and maximum capacity of the battery bank. Apart from these restrictions, to carry out the design of the PV system, some principles were taken into account in order to satisfy the project concepts previously mentioned. ! ! Modular concept. The modular concept was introduced as one of the main basis of the architectural and PV system design. This modular concept defines the architecture of the house as addition of multiple independent areas that make up a whole space. According to the user requirements at any time, the house may change its setting, increasing the possibility of satisfying the space needs of all kind of families. The adopted solution was based on the use of four habitable modules: kitchen, bedroom, living-room, and technical box, all of them around a common nexus “patio”. A PV system was integrated on the roof of each habitable modules. Each PV system was composed of a PV generator, a grid-inverter, and all the necessary security protections. ! Electrical energy autonomy. In other way, it is remarkable the importance of the electrical energy autonomy in the implemented installation. The main objective of the design of the PV system is supplying the consumption needs of the house, being -as much as possiblegrid independent. At the community level, increasing levels of electricity autonomy can deliver social, financial and environmental benefits [6]. To reach this objective, a global electrical energy management system was included as a key element of the electrical installation. At this point, the existence of research works [7,8] with the aim of assessing the energetic, economic and environmental impact of the use of batteries in domestic grid-connected PV systems must be highlighted. ! Optimization of the PV generation use. To achieve the previous mentioned aim, the PV installation included a global electrical energy management system, in order to maximize the amount of electricity generated by the PV installation and consumed by the local loads in the house [9,10,11]. The incorporation of this global electrical energy management system allows the consecution of two main objectives: a) To adapt the consumption to the generation, allowing the displacement of the local demand curve, taking into account the PV electricity locally generated, always within the range of load use preferences of the final user. In the particular case of the SDE contest period, some minimum consumption needs were daily imposed by the organization. These consumption needs were used as inputs to the global electrical energy management system, through a self-designed software tool. According to the prediction of available solar resource and the user consumptions preferences, the intelligent management system decided the optimum time interval to activate these load consumptions. b) To use a backup system, composed of a battery bank and a battery inverter. This backup system allowed that the great majority of the consumption needs were supplied by means of the PV electricity generated in a direct or indirect way (by the use of electric storage). The excess of this PV generated electricity is used to charge the batteries in a first place. After that, and if still having extra electrical energy, this will be injected to the electric grid (only in the case that the battery bank is fully charged). Attending of the State of Charge (SOCvi) of the battery, the PV generation, and the instantaneous local load consumption, the global electrical energy management system controlled the interaction between the different components of the system, to follow the strategy previously introduced. Acting this way, we can take advantage of one of the most important characteristics of PV solar energy: it is a distributed electrical energy. The proposed global electrical energy management system could be applied for residential micro-grids, considering grid tariffs, storage levels and load consumption as system`s control inputs [12]. 2.2. PV system description The house “Patio 2.12” was divided into four independent habitable modules with a “patio” used as nexus of them. Following the modular concept, the installation design consisted of four PV grid-connected systems integrated on the roof of each habitable module. The configuration of each system is shown in Fig. 2. This type of design allows the expansion of the house by simply adding the necessary habitable modules, each one with a fully integrated grid-connected PV system. Figure 2. Configuration scheme of each individual PV system. Interconnection in the Technical Box. ! PV Generator and inverters The PV modules are the most important elements that compose the PV installation. One of the most innovative and efficient PV technologies available in the market was selected for the present installation: Monocrystalline PV modules based on back-contact solar cells-SunPower E20/333 [13]- with 20,4% of efficiency and 333W of maximum peak power. The area occupied by the PV installation was limited by the dimension of the house itself, so that, the election of these PV modules was done due to their high efficiency, which allowed installing the maximum peak power array in the minimum space. The surface requirements of the selected technology were of 4.9m2 per installed kWp. The whole installation was formed of 34 PV modules, resulting a PV generator peak power of 11,322 Wp. The PV installation was divided into four PV systems, incorporating one inverter for each PV system. In this way, the PV systems could independently work between them. There were two different PV array configurations in function of the available area on the roof -useful area to the disposal of PV modules. Fig. 3 shows a real overhead view of PV systems’ configuration. Figure 3. PV installation following the modular concept. Design presented in SDE 2012 competition. The characteristics of each configuration type are shown in table 1. Table 1: Specifications for each configuration considered to the design of the PV systems. HABITABLE MODULE TYPE AVAILABLE AREA ON THE ROOF PV MODULES CONNECETED IN SERIES INVERTER TILT ANGLE TYPE 1 13 m2 8 2kVA grid inverter - SMA SB 2000 HF-30 [14] 8º TYPE 2 14.7 m2 9 2.5 kVA grid inverter -SMA SB 2500 HF-30 [14] 8º The tilt angle of the PV generator was selected according to the rules related to the solar envelope of each house, imposed the latter limits by the competition organization. Concerning to the modular concept, the use of string-oriented grid connected single-phase inverters [15,16] was justified. In conclusion, the grid-connected PV installation integrated in Patio 2.12 project had 11.32kWp of maximum peak power for the PV generator (2 PV systems TYPE 1 and 2 PV systems TYPE 2), as well as 9kVA of inverter nominal power. Anyway, in addition to the possibility of incorporating new habitable modules to the house, using the patio as nexus, it is also possible to use the roof of those selected habitable modules (instead of using all of them), to install a PV generator and incorporate it to the system, attending to the consumption needs of each particular user. This possibility allows the customization of the PV installation, through the suitability of obtaining different PV systems, with different final maximum power, in function of the habitable modules in which these PV systems are integrated in. ! Global electrical energy management system The global electrical energy management system allowed the control of all elements that compose the installation: PV generator, load consumption, grid interconnection and SOC of the batteries. This novel management system was composed of a battery inverter, a battery bank and a self-designed electronic device. The control of this electronic device was made by means of a software tool programmed by researchers of this project. It must be taken into account that this software application did not allow charging the battery from the electrical energy extracted from the conventional grid. In the same way, the electrical energy stored in the battery bank could not be injected to this grid. These limitations were imposed by the rules of the competition and the national electrical codes. The strategy followed by the global electrical energy management system imposes that if there is an excess of PV generated electrical energy, it must be stored in the batteries or injected to the grid if the batteries are fully charged and the consumption needs are covered. In case of deficit of generated PV energy to cover the electrical energy demanded by the local loads, the discharge of the batteries would start to supply the whole consumption needs. If the electrical energy provided by the batteries is not enough, we would resort to the external electrical grid. Using this strategy, the PV electrical energy is available whenever it is needed, even at nights or at grid faults. Due to the great interest caused by these strategies for electrical energy use, recent studies and simulations are currently being developed. These studies are related to the behavior of PV systems working under their two main modes: grid-connected and stand-alone [11][17] [18]. 3. Theoretical description of the implemented simulation model. To study and analyze the electrical energy balance of the entire PV system, a simulation model was carried out. This model is based on ambient temperature and irradiance data in a horizontal plane as input data, in the location of SDE 2012 competition: Madrid. The analysis was established for an entire year (TMY) and for the SDE-2012 competition period, which is that between the 17th and the 28th of September, as described in next sections of the paper. The simulation model implemented in this work is based on the following steps: STEP1: CALCULATION OF THE IN-PLANE GLOBAL IRRADIANCE: Firstly, it is necessary to transform the horizontal global irradiance (G0º) data to real conditions of the implemented PV system [19], in which the PV modules were south-oriented and had a tilt-angle (Gβ) of 8º. STEP 2: CALCULATION OF THE CELL TEMPERATURE: In a second place, it is essential to calculate the cell temperature of the PV generator, from the ambient temperature, knowing the value of NOCTvii (Normal Operation Cell Temperature) parameter [20], which is specified in the manufacturer datasheet: 𝑇!(º𝐶)=𝑇 !℃+!𝐺8°𝑊 𝑚!·!!"# ℃!!" ℃ !"""!! !! (1) Where: • 𝑇!ºC!= Cell temperature. • 𝑇 !℃ = Ambient Temperature. • 𝐺8°W m! = Global irradiance in a plane with 8º of tilt. • NOCT ℃ = Nominal operating cell temperature. In this case, the manufacturer gives a value of 45ºC. ! Although we know the existence of other more appropriate methods to estimate the cell temperature of building integrated PV modules, the NOCT is the unique parameter given by the manufacturer. Anyway, the estimation of the cell temperature by NOCT method gives very good results with a low associated error in building integration with ventilated roof [21], as is in the present case. STEP 3: ESTIMATION OF THE MAXIMUM POWER OF THE PV GENERATOR: Once the operating conditions (Gβ and Tc) of the photovoltaic system were determined, the PM (Maximum power) that can be generated by this PV system, working under these determined conditions, was calculated. Studying the performance of PV systems through the calculation and analysis of their PM, supposing them to be working in the MPPviii (Maximum Power Point) most of their operating time, is a habitual practice. This premise is satisfied due to the function of the inverter of searching and making the PV generator to work in this MPP. To obtain the PV generator PM, the Osterwald method [22] was used. This method allows the determination of the PM, for a determined incident irradiance and cell temperature, using Eq. 2, and considering a minimum irradiance threshold of 50W/m2: 𝑃!𝑊=𝑃!,!"# 𝑊!∗! !!°! !! !"""!! !! ·1+𝛾℃!!·𝑇!℃−25 ℃!!!!!!!!!!!!!!!(2) Where: • 𝑃!,!"# W = Maximum power delivered by the PV generator when working under STCix (Standard Test Conditions). The electric parameters of a PV device under STC are given by the manufacturer. • 𝛾℃!! = Temperature coefficient which expresses the dependence of the maximum power with the cell temperature. In this case, the manufacturer gives a value of 0.0038 ºC-1. STEP 4: MODELLING OF THE ELECTRICAL ENERGY GENERATED BY THE PV SYSTEM: Finally the DCx (Direct Current) electrical energy production of the PV generator (𝐸!",!"# ) is calculated through the integration of hourly values of PM for the particular conditions of in-plane irradiance and cell temperature [23]. E!",!"#!kWh =P !!dt !"# !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!(3) This electrical energy production is decreased when it goes through the different elements of the PV installation due to various losses [24,25,26]. A summary of these losses is shown in Table 2: Table 2 Summary of considered losses. ! Percentage (%) Photovoltaic system Angular and spectral losses 2.86 DC wiring losses 1.50 Mismatch losses 1.50 Dirt losses 5.00 AC wiring losses 2.00 Inverter Maximum power point tracking losses 1.00 DC/AC conversion losses 10.00 It must be taken into account that: o Dirtiness losses were considered of 5% due to the low tilt-angle of the PV generator. o DC/AC conversion losses were considered of 10% according to the instantaneous efficiency curve of the inverters, given by the manufacturer. The final electrical energy injected in the grid,!𝐸!",!"#$ , was obtained using the following expressions, detailed in Fig. 4, in which the losses previously specified are shown in the part of the installation where they appear. Figure 4. Diagram and equations to obtain the electrical energy production of the PV system. 𝐸!",!"# =𝐻8º ∗1−𝐿!"#$ (4) 𝐿!" =1−𝐿!" ∗1−𝐿!",!"# ∗1−𝐿!! ∗1−𝐿!"# ∗(1−𝐿!"") (5) 𝐸!",!"# =𝐸!",!"# ∗(1−𝐿!" ) (6) 𝐸!",!"# =𝐸!",!"# ∗𝜂!"# (7) 𝐸!",!"#$ =𝐸!",!"# ∗(1−𝐿!" ) (8) EDC,INV =E DC,PVG·(1-LDC) EAC,INV =E DC,INV·INV EAC,GRID =E AC,INV·(1-LAC) EDC,PVG =H(8º).(1-LTEMP) In the case of the battery exchange, there were different situations depending on the considered days of the competition. In this way, a daily negative battery-exchange means that the electricity extracted from the battery exceeded the electricity injected in it. Otherwise, a daily positive battery-exchange means that, at the end of the day, the total amount of PV electricity injected in the battery was higher than the electricity extracted from it to supply the consumption needs in absence of PV generated electricity. As in the case of the battery exchange, very good predictions are obtained by the modelling. As the main premise of the PV installation consists of being as grid-independent as possible, one of the most important aspects which must be taken into account in this electrical energy balance study, is the self-consumption index. This index, as presented before, is a useful parameter which determines the global electrical performance of the system. Fig. 12 graphically shows the simulated and measured daily self-consumption indexes for the competition period. Figure 12. Simulated and measured daily self-consumption index during the competition period. According to the data registered during the competition period, the global self-consumption index was of 0.92. Regarding the daily values, a daily self-consumption index of 1 was obtained for three days of this period. This means that, for these three days, all the electricity consumed in the house was supplied by PV solar generation. Additionally, the daily self-consumption index value was higher than 0.90 for nine days during the competition. Fig. 13 shows a comparative analysis of the electrical energy generated and consumed, as well as exchange of electrical energy in batteries and with the electrical grid, for simulated and real measured scenarios, during the competition period. 0.0# 0.1# 0.2# 0.3# 0.4# 0.5# 0.6# 0.7# 0.8# 0.9# 1.0# 17-sep# 18-sep# 19-sep# 20-sep# 21-sep# 22-sep# 23-sep# 24-sep# 25-sep# 26-sep# 27-sep# 28-sep# Self-consump9on#index# Simulated# Measured# Figure 13. Final results at the end of the competition period. Attending to Fig. 13, electricity generated by the PV installation was notably higher than the load consumption of the house. Additionally, the grid exchanges were positive in both measured and simulated cases, what means that more electrical energy was injected to the grid than extracted from it. Apart from that, both battery exchanges (measured and modeled) showed a negative global amount of electrical energy. This situation entails that a higher amount of electrical energy was extracted from the battery than the electrical energy accumulated into it. Table 3 represents the relative errors, in percentage terms (Eq. 11), between the real measured daily values of solar generation, grid exchange, battery exchange and self-consumption index, and the corresponding simulated values, for the competition period. 𝑅𝑒𝑙𝑎𝑡𝑖𝑣𝑒!𝑒𝑟𝑟𝑜𝑟 %=!"#$%&"'!!"#$%&!!"#$%&'()!!"#$%& !"#$%&"'!!"#$%& ∗100 (11)! Table 3 Simulation relative errors for the daily electrical energy balance, in percentage terms. ! Solar Generation Grid Exchange Battery Exchange Self-consumption index 17/09/12 "3.6% "13.6% 2.3% 11.7% 18/09/12 6.1% "4.6% 20.9% 2.9% 19/09/12 7.8% 4.2% 18.5% 3.7% 20/09/12 14.9% 16.0% "2.3% 2.1% 31/09/12 "0.2% "1.7% 4.3% 0.0% 22/09/12 10.7% 10.4% 10.0% 0.0% 23/09/12 "0.4% "8.1% "2.2% 25.0% 24/09/12 3.2% 5.1% "11.4% 0.0% 25/09/12 "0.5% "6.1% 10.4% 1.9% 26/09/12 4.1% 6.3% "1.9% 4.1% 27/09/12 "0.3% "40.7% 14.3% 2.9% 28/09/12 "11.1% "4.3% "4.9% 26.2% GLOBAL 3.9% 0.2% 7.9% 4.1% ! 447.70% 430.87% 136.85% 136.85% 287.89% 287.36% -3.64% -3.37% -50% 0% 50% 100% 150% 200% 250% 300% 350% 400% 450% 500% Simulated% Measured% Electrical%energy%(kWh)% Solar%generaEon% Load%consumpEon% Grid%exchange% BaKery%exchange% As can be appreciated, the final global errors are sufficiently low to consider the proposed model as an accurate tool to predict the electrical energy balance of the designed PV system. 5. Simulation of the electrical energy balance in annual terms ! Finally, this section shows the electrical energy balance of the designed PV system for a TMY in Madrid. In this sense, the simulated performance of the implemented electrical system is shown in monthly and annual terms. This analysis is very useful to take a wider view of the electrical performance of the PV installation, beyond the 2 weeks during which the competition took place. The environmental information provided for the TMY in Madrid was used to estimate the monthly and annual electrical performance of the entire PV system. The load consumptions of the Patio 2.12 during the competition period were taken as the reference to carry out the electrical modeled performance of the system. The simulation model considered that these load consumptions were cyclically repeating going into the whole year. Additionally, as input information to the simulation model, the maximum level of discharge, that the battery bank cannot exceed, was fixed to 30% during the period of analysis. The monthly and the annual electrical energy balance are shown and discussed below. Firstly, the monthly electrical energy balance is shown in Fig. 14. ! Figure 14. Monthly results of the electrical energy balance simulation.! It should be noted that the monthly amount of generated PV solar energy was always higher than the monthly electrical consumption needs. In addition, the monthly grid-exchanges were positive during the whole year. Table 4 shows the monthly and annual self-consumption indexes in order to summarize the global electrical performance of the system. These indexes show the level of achievement of the initial aim of the designed PV installation: Supplying the local loads demand from PV solar energy. 681.25' 770.06' 1,322.50' 1,363.40' 1,734.60' 1,830.30' 1,849.90' 1,700.50' 1,328.20' 1,005.00' 650.26' 505.25' 355.32' 321.87' 359.14' 332.17' 355.32' 351.26' 344.85' 362.95' 335.80' 364.60' 331.12' 363.99' 260.24' 395.58' 901.54' 972.02' 1,318.40' 1,432.30' 1,445.70' 1,445.70' 937.76' 578.90' 264.14' 88.84' 1.47' .2.22' .0.89' 3.27' .0.04' .3.63' 3.38' .2.55' .0.29' 1.51' .0.12' .1.24' .500' 0' 500' 1,000' 1,500' 2,000' 2,500' Jan.' Feb.' Mar.' Apr.' May' June' July' Aug.' Sept.' Oct.' Nov.' Dec.' Monthly'electrical'energy'(kWh/month)' Solar'generaMon' Load'consumpMon' Grid'exchange' BaTery'exchange' Table 4 Annual and monthly self-consumption index during the tried whole year. ! Self-consumption index Jan. 0.82 Feb. 0.86 Mar. 0.91 Apr. 0.94 May 0.93 June 0.94 July 0.95 Aug. 0.95 Sept. 0.93 Oct. 0.87 Nov. 0.80 Dec. 0.70 Annual 0.88 ! The monthly simulated values for the self-consumption index were over 0.90 during seven months. The maximum and minimum values were 0.95 in August and 0.70 in December, respectively. To conclude, Fig. 15 shows the annual electrical energy balance for the designed PV system. Solar generation, load consumption and grid and battery exchanges are depicted in Fig. 15.!! ! Figure 15. Annually results of the electrical energy balance simulation.! The obtained annual results conclude that the present PV installation is able to generate enough electrical energy to cover more than three times the local consumption needs. Moreover, the grid exchange reached an important high value; this situation implies that a big amount of electrical energy was ready to be injected into the conventional electrical grid. The negative value of battery exchange shows that 1.35 kWh were extracted from the battery bank more than injected into it, at the end of the analysis period. 14,741% 4,178% 10,041% (1.35% (5,000% 0% 5,000% 10,000% 15,000% 20,000% Annual%electrical%energy%(kWh)% Solar%genera@on% Load%consump@on% Grid%exchange% BaIery%exchange% It is also worthy to highlight that the annual performance ratio of the PV installation reached a value of 79%, and the average daily and final annual yield were of 3.56 kWh/kWp/day and 1,302 kWh/kWp/year, respectively. 6. Conclusions The participation of Andalucía Team in the International competition of sustainable solar houses –SDE 2012- with the project “Patio 2.12” achieved very good results. This participation encouraged the design and development of a grid-connected PV system whose main function was to satisfy the electrical needs of the house with as much self-consumption as possible. The excellent performance of the system during the competition was remarkable, which resulted in the obtaining of first awards in contests related to the energy, such as, energy efficiency and energy balance. The implemented PV system was composed of very high efficient PV modules. This high efficiency allowed producing enough PV electrical energy to cover, in more than three times, the electrical consumptions needs of the house, only using 55.45m2 of roof surface. The inclusion of a global electrical energy management system, composed of a battery inverter, a battery bank and a self-designed electronic device, allowed managing the electrical energy flows of all the component elements of the PV installation, in a global way. The strategy of electrical energy management permitted to reduce the dependence of the conventional electric grid. In this sense, during the competition period, a self-consumption index up to 0.92 was obtained. By increasing the active participation of the final user on the way of consuming the PV generated electrical energy this self-consumption rate could reach values near to 1. Moreover, this paper introduces a simulation model to estimate the global electrical energy balance of this kind of building integrated PV systems. The tried simulation model requires the environmental conditions and the load consumption as inputs to the modelling. The solar generation, the conventional grid and battery exchanges and the self-consumption indexes were estimated through this simulation model, obtaining fitted results when comparing them with the corresponding real data. Finally, an estimation of the monthly and annual electrical performance of the PV installation was carried out for a TMY in Madrid. The obtained results show that the designed PV installation could satisfy the annual load consumptions needs in more than three times, with a great amount of annual electrical energy injected to the conventional grid. Despite the excellent results obtained in the competition, the early experience extracted from this PV electrical installation shows that the electrical performance of the implemented system could be rather improved. For instance, the inclusion of improved tools related to the prediction of the solar resource must become a key part in this kind of PV systems. These techniques would allow maximizing the use of the generated PV electrical energy and optimizing -reducing- the PV system and battery bank size. Nowadays there are some predictive models based on artificial intelligence techniques that can be used to calculate the evolution of the irradiance for the following days, with the idea of programming the consumption loads in the most suitable period of time, increasing, in that way, the obtained the self-consumption index. Moreover, these proposed strategies could be used to promote the development of the decentralized and distributed generation with renewable energy, reducing the costs associated to the transport and the energetic infrastructures, due to the electrical energy consumption in same the place where it was generated. !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! i PV: Photovoltaic. ii SDE: Solar Decathlon Europe. iii IDEA: Investigation and development in solar energy. iv!TMY: Typical meteorological year.! v AC: Alternating Current. vi SOC: State of Charge. vii NOCT: Normal Operation Cell Temperature. viii MPP: Maximum Power Point. ix STC: Standard Test Conditions. x DC: Direct Current. References [1] http://www.sdeurope.org/. Last access: 11th April 2014. [2] http://www.andaluciateam.org/. Last access: 11th April 2014. [3] http://vimeo.com/48493328. Last access: 11th April 2014. [4] http://www.flickr.com/photos/sdeurope/sets/72157631550799795/. Last access: 11th April 2014. 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