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31st European Photovoltaic Solar Energy Conference and Exhibition; 3107-3111, 2006 the International Building Exhibition (IBA) started in Hamburg under the device “Cities new building”. One Part of the IBA Program was “Cities in climate change”. In these part the question of combining climate protection with urban growth should be answered. For this, a working group started to develop the “Energy atlas for Hamburg-Wilhelmsburg”. There, different scenarios of the future energy demand were developed, potentials for energy saving and energy efficiency were identified and concrete step for the realization of these scenarios were shown. 2012 the “Island-Power study Hamburg-Wilhelmsburg” was realized. These study replied the question of the dynamic between energy demand and supply in 2050 under consideration of the realization of the Excellence- Scenario from the Energy-Atlas, including storage technologies and load management. The simulated scenarios showed that the 100%-Renewable-Energy-supply that was calculated as a yearly balance in the “Energy-Atlas” is not accessible in form of a local autarky. The high fluctuation of the electricity supply in the dynamic scenario tends to high surpluses and deficits. System operators are confronted with a complete new situation; higher load and the changing of the load flow direction are crucial. 2014, the Island-Grid-Study followed, to show whether todays lowvoltage and middle voltage grids are able to transport the electricity under the aspect of load flow changes and high power production from the PV side installed in the city quartiers of the future.

31st European Photovoltaic Solar Energy Conference and Exhibition; 3102-3106, The distributed nature of the solar resource indicates that photovoltaic (PV) generation is particularly suited for distributed generation (DG) and it will be among the major driving forces towards a paradigm shift of the traditional distribution segment. This research proposes an analysis framework to guide engineers in the assessment of PV power sources impacts when connected to distribution networks, to assist in network access studies and to help utilities on defining adequate grid codes. A probabilistic approach based on a probabilistic load flow model suited for radial distribution systems analysis is implemented. Uncertainties about load and generation parameters, which are relevant in order to assess operational and planning issues, can be represented, mainly, uncertainty about system active and reactive power loads and due to PV generation. In this paper, active power losses, voltage unbalance and the influence of R/X parameter are investigated. Simulation results obtained indicate that the approach adopted gives a consistent framework for evaluating the different operation scenarios that arise on practice.

31st European Photovoltaic Solar Energy Conference and Exhibition; 3112-3116, Load duration curve (LDC) and output duration curve (ODC) are a very useful graphic tools to analyze the behaviour of an electric system both for demand purposes and for generation ones, respectively. Despite that, the use of this tool is not much extended in photovoltaics systems, not even in grid connected PV systems. However, its utilization may provide us with interesting information for the assessment of the PV system operation, such as: peak power reached, energy yield, energy time distribution, etc. Therefore this type of curves can be very useful both for the analysis of the PV system operation and for the comparison among different PV systems or to perform studies related to energy planning and grid penetration of PV electricity. Regarding the latter issue, it is presented how the use of ODC can determine the maximum demand coverage through photovoltaics in large electricity grids. In the cases studied, the maximum photovoltaic coverage has resulted to range between 18.7% and 29.9% of the annual energy demand without including storage and without surplus photovoltaic generation. An interesting new concept is presented: Half Energy Line. This line can be successfully used to analyze the behaviour of a photovoltaic installation or system.

31st European Photovoltaic Solar Energy Conference and Exhibition; 2952-2954, By end of 2014, about 88 GW of photovoltaic electricity systems have been installed, producing 2.8% of all the European electricity consumed [1]. This exceeds already the target of 84.4GWp set by Europe's Member States in their National Renewable Energy Action Plans (NREAP) delivered to the European Commission in 2010. However, deployment of PV is very varied across Member States, either due to different ambitions in the original NREAPs, or due to the different weight renewable energy plays within a Member-State's general energy policy. Regarding PV deployment, Europe is still far from implementing a European Renewable Energy Union. Whilst technical barriers have been very successfully reduced by European and international standards development, regulatory differences across Member States are increasing and lead to a situation where PV has achieved a electricity share of almost 8% in some countries, between 1% and 2% in many others, or none at all. The presentation will examine a number of facts which explain Europe's situation in the deployment of PV towards the 2020 renewable energy target, will substantiate the assessment by providing robust data and will provide recommendations to harmonize Member States deployment policies.

31st European Photovoltaic Solar Energy Conference and Exhibition; 3135-3136, PV will play a major role in the global renewable energy portfolio. However, PV generation profile often does not match with the consumption profile, in particular under moderate climate conditions: In these regions, consumption is highest during the winter period, while PV generation is highest during the summer period. This mismatch is even more pronounced by the present working and holiday behavior: A considerable part of the population leaves for holiday during the summer period and thus additionally reducing consumption in a market with energy overproduction, thus causing additional costs for electricity system management. Usually, inefficient and costly technical measures are under consideration to overcome that problem: Seasonal storage for PV power or even PV curtailment. This paper shows the shift of the holiday season as a new, effective and non-technical load-shifting measure: Fast implementation, low costs, additional benefits (such as less infrastructure costs: less office heating, less healthcare costs, more bicycles instead of cars & public transport., thus reducing CO2 emissions).

31st European Photovoltaic Solar Energy Conference and Exhibition; 3124-3128, National and international climate objectives provide a massive expansion of clean energy resources in the upcoming decades. As a consequence, the increasing number of renewable energy systems and the decreasing number of conventional power plants lead to the inevitable step of taking over system responsibility for photovoltaics (PV). The research project PV-Regel addresses the system responsibility for PV by developing new concepts and by determining suitable market conditions for providing control reserve with PV systems. First investigations show that PV systems with appropriate communication and control capabilities can easily be combined to virtual power plants and are very dynamic and precise in providing negative and positive control reserve even without additional energy storages. One challenge is the verification method of the provided control reserve. The validation of the method ‘available active power’ will be part of the project PV-Regel. A prototypal PV inverter, which has already been developed, shows the feasibility of this method. Even the required accuracy can be satisfied by PV systems.

31st European Photovoltaic Solar Energy Conference and Exhibition; 2945-2951, Integration in the power system is becoming a limiting factor to the further development of photovoltaics. Proper quantification is needed to evaluate both issues and solutions; the share of annual electricity demand is widely used but we found that some of the metrics which are related to power rather than energy better reflect the impact on networks. Barriers to wider deployment of PV into power grids can be split between local technical issues (voltage levels, harmonics distortion, reverse power flows and transformer loading) and system-wide issues (intermittency, reduction of system resilience). Many of the technical solutions to these issues rely on the inverters as actuators (e.g., for control of active and reactive power) or as interfaces (e.g., for local storage). This role requires further technical standardisation and needs to be taken into account in the planning of power networks. Forecasting, storage, and combination with other renewable sources are interdependent solutions to solve the intermittency issue. Finally, we found that PV is also an opportunity to reduce some investment required to upgrade existing power networks. Through integration with micro-grids and hybrid generators, it can form the basis of novel power systems.

31st European Photovoltaic Solar Energy Conference and Exhibition; 3092-3098, The application of stationary battery storage systems in distribution grids can serve different purposes. Especially in grid areas with a high photovoltaic penetration, storage systems can increase the level of self-sufficiency for consumers using privately owned photovoltaic systems as well as offload the grid in times of high photovoltaic generation in order to reduce necessary grid reinforcement. A further application scenario is provision of control power for stabilizing the grid frequency. Storage systems can fulfill single individual abovementioned tasks as well as a combination of several ones, which may result in a variety of different load curves for the storage system. As the aging behavior of the battery cells is strongly influenced by load profiles, the storage application will severely influence lifetime of storage systems. In order to investigate the aging behavior dependent on the application mode, the load curves resulting from the different applications given above are raised for a battery aging simulation. This study presents aging behavior for lithium-ion cells with NMC technology. As a result, the deterioration rate of this cell type is determined dependent on the different application modes. On the basis of these outcomes, conclusions regarding the aging behavior for the different applications are drawn.

31st European Photovoltaic Solar Energy Conference and Exhibition; 2955-2972, The installed capacity of photovoltaics (PV) is rising steadily. Most PV is installed in highly electrified countries as on-grid systems. Further, there are reams of small off-grid systems in rural areas of developing countries. Due to this, reliable installation rates for PV are available only for a small number of countries. For the end of 2014 SolarPower Europe reports 178,391 MWp of globally installed PV capacity, giving clear national specific data for 21 countries. IEA PVPS gives a number of 176,965 MWp installed by providing detailed data for 34 countries, 24 of which coming from official sources in IEA PVPS member countries. This paper gives an overview of installed PV for all countries in the world, predicated based on the examination of publically accessible data. Furthermore, an analysis of the development of cumulative PV capacities in recent years is given. Resulting from this evaluation, PV installations are localized in 190 countries, representing 177,600 MWp.

31st European Photovoltaic Solar Energy Conference and Exhibition; 3087-3091, This work analyses the economic framework of Smart Grid for the consumer as a microgenerator, by usage of Photovoltaic generation exploring the modularity of this solution. Methodologically are considered the effects in the relations with the smart grid regarding the technical, commercial and regulatory affairs, based on the normative approach aiming the possibilities and barriers for the viability of this form of microgeneration. The results shows that, even with the demanding side providing the project, it’s in the distribution framework that this relation is commercially affected, as the distribution company remains responsible for the primary energy supply, obligated to bear the heavy costs of the distribution network infrastructure, as well as shall face a decrease on their income due to microgenerating consumers. Thus, it’s validated through a simulation, that only regulating credits to be used by the consumers is insufficient, as there are further points to be improved in order to effectively disseminate cogeneration for residential consumers, despite their great solar potential.

31st European Photovoltaic Solar Energy Conference and Exhibition; 3117-3123, This study provides an update of the 2014 paper “Quantitative Analysis Of The Merit Order Effect From Photovoltaic Production In Key European Countries” from M.Gourvitch, M.Gouzerh, M.Masson and Ms Orlandi. It provides a method to quantify the savings in a set of European countries over the past 9 years as a result of the decrease in electricity spot market prices observed when PV plants feed electricity into the grid. The study confirms the previous finding that the total electricity demand retreated by PV production is well correlated to market prices, following a stable exponential curve. It proposes a calculation of what the additional energy payments would have been necessary, had there been no PV production on the geographical market constituted by Germany, Austria, France, Switzerland and Italy (GAFSI). Such gain is called the Merit Order Effect (MOE). The level of the MOE depends widely on how the demand profile is well correlated with the PV production. The cumulative gain over the period 2006 to 2014 reaches € 26 Bn for the whole GAFSI region. On average, the wholesale prices would have been 3.7% higher over the 9 year period, had there not be PV electricity fed into the grid. The paper also brings confirmation on the proposition that the magnitude of the MOE decreases when the penetration of PV in the energy mix increases.

31st European Photovoltaic Solar Energy Conference and Exhibition; 3129-3134, In South Africa, embedded PV is at retail grid parity today. It is even cost-competitive to alternative new-build options (“new-build parity”). Many electricity customers are therefore already installing embedded PV. This would lead to an uncontrollable “under the radar” market for embedded PV, with potentially unsafe practices. Furthermore, it would lead to bankruptcy of many electricity distributors due to lost margins owed to self-consumed PV energy. It is better to embrace the development as an immense opportunity for quick, inexpensive ramp-up of significant amounts of additional energy supply. The CSIR Energy Centre therefore developed a Net Feed-in Tariff concept, in which electricity distributors are made financially indifferent to embedded PV, and the business case for the PV owner is de-risked at the same time. This all at no net costs to the system as compared to alternative new-build options. The concept is currently being discussed with the relevant government departments, the PV industry and with the regulator for potential implementation.

31st European Photovoltaic Solar Energy Conference and Exhibition; 3099-3101, The increasing penetration of electricity generation from Renewable Energy Sources (RES) ask for an active integration of such sources in the grid. In this paper a project is presented aiming to propose and test solutions for such matters. During Q4-2014 the integration works of a NaNiCl2 battery energy storage system has been completed [1], the battery being installed in a 10MW PV power plant in Sicily. Activities of testing and performance monitoring are explained.

31st European Photovoltaic Solar Energy Conference and Exhibition; 2973-2981, Today’s almost fully non-sustainable global energy system needs to be transformed towards a 100% sustainable basis. Solar photovoltaic (PV) is considered by a growing base of organizations and researchers as a backbone technology for global energy supply in the decades to come. Global energy scenarios of the recent years are compared in their level of acknowledging the significant role of solar PV. Using logistic growth functions it is possible to extrapolate the trend in the various studies to the years 2050 and 2100. The studies can be distinguished in a group of progressive and conservative ones. The reports of the IEA set the lower limit of all studies. The three most progressive studies are from the WBGU, the IEA PVPS and the Solar Economy scenario published in this paper. The Solar Economy scenario is based on a stabilized population which may require by the end of this century about 400,000 TWhel for all energetic needs. The PV share of TPED among the studies varies between 3-73% in the year 2100 when the currently available long-term forecasts are being compared. According to the Solar Economy scenario a PV share of up to 40%, would lead to a total installed capacity of up to 93 TWp and annual installations of up to 2.3 TWp for harvesting sustainable energy on a cost level of about 11-12 €/MWh in the global average. The global energy problem might be easier solvable than most people expect today.

31st European Photovoltaic Solar Energy Conference and Exhibition; 2996-3001, After the nuclear power plant accidents on March 11, 2011, there are ongoing serious discussions on the future energy demand-supply in Japan. Beside the discussions, a Feed-in Tariff program for renewable energy was launched in July of 2012. More recently, the Japan government announced the Strategic Energy Plan, in April 2014, and it announced the long-term energy demand and supply outlook in July, 2015. The power system in Japan consists of 10 systems, of which 9 areas, excluding the Okinawa in southern islands, are interconnected by AC 500kV and DC +/-250kV and DC back-to-back interconnections. We have been analyzing and evaluating Japan’s future power demand and supply using a tool, ESPRIT and we also developed a new demand and supply analysis tool. In this paper, we used these tools to model Japan’s power systems in 2030. Based on the long-term outlook of energy demand and supply, we analyzed demand and supply balance of Japan’s interconnected power systems. The analysis considered enhancements of interconnection operation, and selection between economic load dispatch and priority load dispatch for renewable energy generation. The enhancements of interconnection operation from isolated systems, and energy exchanges to additional LFC balancing capability exchange reduced curtailment of PV and wind generation in the scenarios studied. Priority load dispatch also reduced curtailment but increased fuel costs. The results show that with enhanced interconnection operation, there will be moderate renewable power generation curtailment under a penetration scenario of 103 GW of PV and 32 GW of wind

31st European Photovoltaic Solar Energy Conference and Exhibition; 2989-2995, This paper is the result of research undertaken by CAT Projects and the Australian Renewable Energy Agency (ARENA) in 2013-2014, investigating the impacts of solar radiation variability on the stability of electrical grids with medium penetration PV generation. The analysis takes into account the distribution of PV generators throughout the grid, with the hypothesis that the impact of weather variability is mitigated by dispersion of PV across a greater geographical area. Although there is an assumption that large multi-nodal electricity grids are inherently stable (i.e. do not experience large variances in supply), and that the addition of significant PV input and associated intermittency potential could cause disruptions that would increase the risk of operational problems, results from this project indicate the opposite. Notably, the Alice Springs grid (which is analogous to many other grids in regional and remote areas, as well as many sections of larger electricity networks) encounters a significant level of load variance as part of normal operation. In other words, such networks already accommodate a high degree of variability without compromising on operational outcomes.

29th European Photovoltaic Solar Energy Conference and Exhibition; 4024-4029, Remote/off-grid applications were the first terrestrial markets for PV and dominated from the late 1970s until the late 1990s when grid connected markets were created by economic incentive policies. These large markets have driven PV down the experience curve and brought prices for PV systems down by at least two orders of magnitude since the late 1970s. This paper examines how the vastly improved economics of PV combined with improvements in application and information technology, improved economies in emerging market countries, and innovative business models are creating a new growth of off-grid remote markets for PV.

29th European Photovoltaic Solar Energy Conference and Exhibition; 4151-4152, Highly concentrated photovoltaics (PV) in distribution grids lead to reverse power flows and high voltages at the generation sites. This paper is an introduction to results from research, development and demonstration that have been achieved within the European Commission-funded demo project MetaPV. They illustrate how such control can be organized and implemented effectively for large numbers of inverters in a real distribution grid. The project results show how the hosting capacity of a distribution grid for PV can be strongly increased by active voltage control from the side of the PV inverters. In grids with continuously increasing PV penetration, this can serve to postpone grid reinforcement or even to substitute for it. Consolidated recommendations and lessons learned will be published in March 2015. In the meantime, a large amount of detailed technical results is available on the MetaPV project website.

29th European Photovoltaic Solar Energy Conference and Exhibition; 4014-4017, We present a study of the possible self-consumption of PV electricity by individual households. The study is based on electricity consumption time series data from 144 households in Ulm, Germany. PV power estimates using solar radiation data from satellite are used to calculate the instantaneous PV power self-consumption for each household under a number of scenarios. The results show that with a PV system producing 1/3 of the total annual electricity consumption, the self-consumption may reach 60-90% of the PV electricity while for a PV system producing the same annual energy as the consumption, the self-consumption is reduced to 20-40%. Adding battery storage may significantly increase PV self-consumption. For a PV system producing half the annual consumption, the percentage of self-consumption increases from 40-60% to 70-85%, with a storage size of 3kWh per kWp of PV system.

29th European Photovoltaic Solar Energy Conference and Exhibition; 3894-3900, This study builds on a 2013 paper from M.Gourvitch, M.Gouzerh, M.Carton and M.Masson on “Quantitative analysis of the merit order effect from photovoltaic production in Italy”. This study proposes a method to quantify the savings incurred by the end consumers in a set of European countries over the past 8 years as a result of the decrease in electricity spot market prices observed when PV plants feed electricity into the grid. The 2013 study showed that the total electricity demand retreated by PV production is well correlated to market prices, following a stable exponential curve. Estimating such curve enables to calculate what the additional energy payments would have been had there been no PV production. Such gain, called merit order effect, has varied over time. This study will research whether the same effect can be seen in other European countries, France, Germany, Austria and Switzerland. The authors have run Monte Carlo simulations on a large number of irradiation profiles and showed that the merit order effect does not depend much on the PV penetration rate but rather on the electricity demand profile, and therefore on how well it correlates with the PV production profile. The social gain expressed per MWh of PV electricity fed into the grid gets close to 100 €/MWh, and has exceeded € 20 Bn at the country scale over the past 7 years. Also, average wholesale prices would have been 3% (or 1.5 €/MWh) higher had there been no PV production. If that money could be captured by the government, it could be used to finance support schemes and grid infrastructure works for instance.

29th European Photovoltaic Solar Energy Conference and Exhibition; 3878-3885, Due to the high amount of installed solar power systems in Europe and especially Germany, the low-voltage distribution grids reach their maximum capacities during periods of high insolation. As an alternative to gridreinforcement, local battery storage systems can be used to store the surplus generation and limit the feed-in power of the solar power systems. For this purpose, decentralized PV home-storages in single households as well as larger stationary battery systems supplying a whole local grid area can be called into action. In this paper, a grid-compatible storage operational strategy is simulated using standard load profiles and statistically generated realistic load profiles for use with both storage types. The goal of this research is to investigate a grid-compatible and also economic storage operation when using centralized large-scale batteries instead of PV home-storage systems in a low-voltage distribution grid with a high degree of decentralized PV-generation. Results show that large-scale systems provide advantages regarding grid-related operation as well as economic feasibility and therefore represent a useful alternative to home-storage systems. Additionally, it can be shown that depending on which storage type is simulated, different requirements are imposed. The simulation of decentralized home-storages needs real load profiles in order to receive realistic results, while the operation of large-scale battery storages can be simulated using standard load profiles.

29th European Photovoltaic Solar Energy Conference and Exhibition; 4018-4023, Distributed generation and self-consumption contribute to sustainable energy systems, opening up new opportunities for employment, financial security and further liberalization of the electricity market. Net Energy Metering (NEM) can, in a decisive way, contribute to make these goals feasible. The emergence, in recent years, of new concepts, technical developments and systems may gradually lead to an evolution, from traditional electricity generation, to a model where distributed electricity generation, mainly for small power facilities, starts to become effectively integrated in the network as an efficient component of production and management. A case study of an installation -a 2240 Wp energy self-sufficient facility in a detached house in Burgos, Spain- is analyzed in the context of recent Spanish legislation, as well as its economic and energetic consequences for both the individual user and the energy system. Our study makes precise reference to the guidelines published in the long-awaited Spanish legislation in this area.

29th European Photovoltaic Solar Energy Conference and Exhibition; 4153-4155, The problem of evaluating the greenhouse gas emissions and energy return on energy invested for an electricity system with a high level of installed PV is discussed and proposed solutions are put forward. A novel consequential lifecycle assessment (CLCA) approach is described that assess the impacts of PV at three distinct but interrelated levels. Firstly energy and material flows from raw materials through to end of life disposal or recycling PV products including panels, inverters and batteries. Secondly, changes to electricity distribution networks where the aggregate effects of PV require new infrastructure assets or new management and control approaches. Thirdly there are effects on the operation of the centralised electricity grid, both in terms of power flows into the grid and in terms of reducing from the grid at certain times through self consumption of PV output. The challenges of evaluating the impacts a distributed electricity generating technology in aggregate on a future electricity system require inter-disciplinary use of life cycle assessment, detailed scenario development and power system analysis.

29th European Photovoltaic Solar Energy Conference and Exhibition; 3866-3870, With significantly reduced PV electricity feed-in tariffs it became challenging to implement and operate grid-connected residential solar PV in the majority of the European countries by 2014. The decline in investment costs did not keep track with the decline in feed-in tariffs regulated on national level. New legal and fiscal barriers further slowdown PV system implementation. This framework fostered the development of a new business model in Germany that allows end-users pooling their electricity under one roof and to market it directly within the building’s grid. In consequence PV electricity, starting from low digit kW level installations, may again become economically viable. In the pilot case discussed herein direct marketing of PV energy increases annual revenues by 9% while lowering electricity costs for the tenants. And there is a further benefit for the society: peaks in production and demand are minimized and the transformation process in the energy sector is supported.

29th European Photovoltaic Solar Energy Conference and Exhibition; 4156-4160, Solar photovoltaic technology (PV) is playing a rapidly growing role in the UK electricity system with an increase of around 5GW capacity between 2010 and 2014. This work examines potential pathways towards ambitious levels of PV in the UK in order to investigate the impacts, drivers and opportunities for PV in the UK’s future energy mix. This includes a concurrent consideration of policy drivers such as climate change, fuel affordability and security of supply issues together with the impact upon existing energy generation, transmission and distribution infrastructure. For two PV expansion scenarios, a whole-system approach is presented in which a specific-use case is defined and a classification framework (or ontology) is proposed. The ontology provides the basis for subsequent quantitative, multi-domain analysis of future outcomes using a probabilistic technique based on Bayesian statistics. Analytic results based on the analysis of the impacts of wide-sale PV penetration upon a key socio-economic indicator (fuel affordability) are presented, both with and without household energy storage present as a self-consumption facilitator. The potential benefits of this approach in dealing with multiple-domain uncertainties is discussed, whereby multiple criteria such as carbon emissions, energy transmission and generation system impacts and socio-economic impacts can be evaluated for various future PV development pathways, and the implications of the outputs of the research for various stakeholders (including policy makers) are described.

29th European Photovoltaic Solar Energy Conference and Exhibition; 3871-3877, This paper investigates the profitability of PV battery systems that aim to reduce the electricity purchased from the grid of households. The economic feasibility is assessed based on the approach of calculating the mean electricity cost of the household equipped with a PV battery system. The study focuses on the main question: What is the break-even point of the battery system price at which residential PV battery systems become economically viable in Germany? This is analyzed by determining the limit of profitability in terms of required battery system price, which makes the investment in a PV battery system under given circumstances profitable. The impact of different economic input parameters on the required battery system price was studied for a defined reference case. The results reveal that the major factor is the interest rate, followed by the PV system price, retail electricity price and feed-in tariff. Nevertheless, several uncertainties with regard to the economic assessment exist. However, assuming that the calculated required battery prices will be achieved in the future; investing in a PV battery system is financially more attractive than purchasing the entire electricity demand from the grid.

29th European Photovoltaic Solar Energy Conference and Exhibition; 3994-3999, During the past four years, national experts from 11 institutions around the world have worked together within Subtask 3 – High penetration solutions for central PV generation scenarios – in order to identify best practice scenarios for a technically and economically improved grid integration of PV focusing on aspects at a power system level. The study, in order to envision the future PV penetration into a power system in the scope of transmission system level, reviewed the impacts of PV Penetration, the countermeasures for system operation and augmentation planning, and market design including the impact of other variable renewable generation. The study also reviewed the state-of-art methodology of power system operation planning and augmentation planning.

29th European Photovoltaic Solar Energy Conference and Exhibition; 4038-4043, From 2004 to 2010, and supported by a becoming legislative framework, the photovoltaic industry in Spain reached an unprecedented success, placing the country as a worldwide reference in the technological development in this area, but the Spanish crisis and the electrical tariff deficit existing in the country, made the government to legislate by means of reducing the feed-in tariffs applied to these systems, even with retroactive effects. As a consequence of this restrictive legislation, with the last Royal Decree published in June 2014, the economic investment in PV has changed from an attractive initial profitable scenario to a limit situation in regards to the original finance of the installations. With the last governmental actions, it will not be possible to cover the loans at which the PV plants were financed under the framework of the Spanish RD 661/2007. The estimated profitability for those PV installations built under the aforementioned Royal Decree has changed from 10.14% (in 2007) to an imposed IRR of 7.48% and just a 5.4% for the forthcoming new ones. In this paper the variations of the forecasted profitability scenario made in 2007 for the current year (2014) are analyzed based on the data of a real PV system located in the South of Spain.

29th European Photovoltaic Solar Energy Conference and Exhibition; 3886-3893, This paper examines possible operating options of a grid-connected hybrid energy system (HES), including a photovoltaic (PV) system. Different technologies are examined, including fluctuating renewable energy sources (RES), especially PV and wind power, electrical energy storage (EES) and a biomass power plant. The aim of the work is to illustrate an optimal system design in combination with a most cost-effective operation of such a power plant. An existing optimization model is extended in order to analyse the operation and design of a hybrid energy system. The system design and operation is optimized under technical, economic and regulatory constraints within a single model. This optimization model is able to provide a market-oriented operation of the hybrid system under the consideration of energy demand, renewable energy resources and achieved market prices. The paper focuses on the cost-efficient electrical supply of an industrial company by the optional use of renewable energy sources at a location in Germany. Various scenarios are analysed to better define the properties and the sensitivity of the model. Thus, effects of external technical and economic conditions, such as variable market prices or fixed self-consumption, are examined for plant operation and system design. With the help of this work, it is shown under which conditions the investment in a HES with RES for an industrial company is optimal and how such a hybrid plant would be operated in the ideal case.

29th European Photovoltaic Solar Energy Conference and Exhibition; 4034-4037, The benefits of hybridising two solar technologies are not clear at first sight. Combining the low cost electricity generation by photovoltaics (PV) with the cheap thermal energy storage option available to concentrating solar thermal power (CSP) plants is what makes this package interesting. In this work we simulate hybrid power plants over the course of one year using historical hourly weather data on the input side and synthetic load data on a national level on the output side. In addition to examining pure PV-CSP plants we also consider adding wind power and direct battery storage to the mix. The economics of such combinations are determined and compared. The results show that PV-CSP hybrids are a viable option to provide an output profile following national electricity demand. We also show that when allowing a wide range of power generation and storage technologies, at any given location many different combinations lead to levelised electricity costs not too far above the minimal possible costs for any renewable power source.

29th European Photovoltaic Solar Energy Conference and Exhibition; 4000-4004, The Island-Power Study of Hamburg-Wilhelmsburg was done in order of the International Building Exhibition (IBA) Hamburg in 2013. The Study is a dynamic simulation of a 100% Renewable Energy Concept that was developed by the Scientific Advisory Board Cities and Climate from 2010 to 2012. The question to answer in the frame of this study was to convert a non-dynamic renewable energy balance for the city-quarter Hamburg-Wilhelmsburg into a dynamic system, which shows the load flows of Power and the demand and supply of Power and Heat in a high timely solution.

29th European Photovoltaic Solar Energy Conference and Exhibition; 4009-4013, In the foreseeable future, sustainable electrical energy systems should be capable to handle up to 100% of renewable energy share in the electricity grid. Due to the recent price drops, PV will play a major role in the global renewable energy portfolio. The technical implications of this development (also referred to as "energy transition" in Germany) in all areas of electricity supply (generation, transmission, distribution, operation management) are manifold and consequently lead to a new system design. For the effective integration of PV the major challenges are volatile generation given by sun’s position and actual weather conditions, as well as load level. On one hand, the article addresses the generation side by adapting PV power plants to load requirements (e.g., via azimuth and tilt angle modification to achieve peak power output during periods of high demand, via thermal conditioning of PV modules, via smart site selection or via a combination of complementary energy sources) and on the other hand the article discusses several possibilities of load management (e.g. load shifting, inducements, load adaptation, appropriate market design).

29th European Photovoltaic Solar Energy Conference and Exhibition; 4030-4033, In this paper we explore the value of a big data approach to the solar PV market in The Netherlands. As a pilot we choose a specific area on a scale of 200.000 inhabitants. Available data sets from different sources depicting a variety of relevant parameters were brought onto the same Geographical Information System base. We demonstrate how this approach can help in understanding, planning and controlling the energy system.

28th European Photovoltaic Solar Energy Conference and Exhibition; 4809-4814, A new concept of PV grid-parity is presented for three typical case studies in Germany and Italy by including the fixed costs of the electricity bills. The electricity bills have been analysed for residential and tertiarysector users: in Germany the fixed costs are negligible, whereas in Italy the common loads of apartment blocks are heavily charged by the cost of the available power. The grid-parity problem is analysed as an investment in which the net present value provides the convenience or not of the installation of a PV plant. The main results take into account the different economic situation in the Countries by the interest rates of 3-5 % in Germany and 4-9 % in Italy. The grid-parity for dwelling houses is close to be reached in South of Germany/Italy; the grid parity is achieved in Munich for the users in apartment-blocks, while it is unrealistic to be reached in Italy with the current tariff situation; the grid-parity is reached in South of Germany/Italy for the tertiary-sector users.

28th European Photovoltaic Solar Energy Conference and Exhibition; 4497-4503, By considering the opportunity of using the surfaces left free by a wind farm structure to install a complementary PV plant, it is expected to lead to important synergies during the lifetime of the global system. Furthermore, from the production profile point of view, on a utility scale, the combination of wind and solar photovoltaic (PV) plants can lead to a more stable and more reliable energy source by taking advantage of the frequent complementarities of the two plants. Obviously, the mutual interference, due to the co-existence of the two plants, leads to a possible reduction of the load factor for each plant and these interactions have to be considered at an early stage for optimizing the combination design. In this paper, it is presented the analysis of the design aspects for the combination of wind and PV plants to increase their overall technical/economical effectiveness. Finally, with a real project case, it is shown the effectiveness and the expected promising effects of the described solution.

28th European Photovoltaic Solar Energy Conference and Exhibition; 4787-4792, In the context of rising energy costs, the direct marketing of solar electric energy generated by PV systems becomes increasingly interesting for households. For this, usually, standardized energy production profiles of south orientated, roof mounted PV systems are compared to the corresponding standard load profile. There, a balance sheet cover of the energy consumption and production is normally chosen for reference. Typically there results a ratio between consumption on-site and PV energy generation of 30 %. This value is well established in the meantime. Commerce and industry has to face increasing costs for energy, too. There, especially potentially rising costs for CO2-certificates may fuel this issue. At the same time, generation costs for electric energy generated by PV systems decreases, which leads to more and more commerce and industry direct consumption schemes. The present paper investigates the ratio of consumption on site as well as that of the autarky – ratio of PV energy consumption – considering different energy production and load profiles of commerce and industry. Influences on the generation profiles due to site-specific meteorology, PV plant layouts and PV system “performances” are accounted for as well as effects arising from different load profiles.

28th European Photovoltaic Solar Energy Conference and Exhibition; 4793-4796, Solar electricity is the most promising new source of electricity in the world1. The idea to produce solar electricity in southern European regions and in northern Africa to serve Europe has been discussed for decades2. The paper shows that solar electricity can now be produced cheaper and more effective in high alpine places in mid Europe.

28th European Photovoltaic Solar Energy Conference and Exhibition; 4753-4757, In a mature photovoltaic (PV) market where feed-in tariffs have declined, managing of the hosting capacity of the distribution grid becomes essential by maximizing the utilization of PV. One way to increase hosting capacity is to increase self-consumption of the self-produced PV power. This paper investigates the effect of an alternative year-round daylight savings time (DST) – where the time of the entire society is changed relative to the sun - on the level of self-consumption in terms of solar fraction and load fraction of PV power both on householdand national level. Household electricity use was modeled with a Markov-chain model, PV power production was modeled from solar irradiance data, and the national level was simulated using national electricity data. Results show that one hour year-round DST shifted ahead might increase self-consumption by a fraction of one percentage point for a net-zero energy household. For a 30 GWp PV installation on a national scale with a 140 TWh annual electricity use one hour DST shift ahead had almost no effect on self-consumption. The optimal self-consumption of PV power on the national level was concluded to be the current DST setup.

28th European Photovoltaic Solar Energy Conference and Exhibition; 4773-4782, Islands, as isolated territories usually far from the mainland, have extra costs compared to continental areas in their access to conventional energy sources. In spite of the fact that islands are hardly ever granted with this kind of energy, depending on the site, they normally have plenty of renewable energy resources. In this work, photovoltaic systems integration on islands is analysed from the residential viewpoint, taking into account some examples of regulations in force on some islands, as well as in discussion for their implementation in the near future, the goal is to investigate the economics of the results for different combinations with regard to existing conventional generation, together with the achievement of certain percentages of photovoltaic energy penetration, also considering some aspects in the optimisation of their electrical energy management as a whole. In this way, considering a base case of a typical residential load in a hypothetical island, sensitivity studies using the HOMER software package are performed to analyse different scenarios that may arise in islands around the world, mainly regarding economics in photovoltaic systems integration. General conclusions are reached for a comparative analysis of the considered scenarios.

28th European Photovoltaic Solar Energy Conference and Exhibition; 4758-4761, The majority of photovoltaic (PV) systems installed in Europe is connected to the grid. Next to technical issues, such as grid saturation or dimensioning effects, a decrease of feed-in tariffs puts the concept of feeding and drawing electric energy into/from the grid into question. The storage of produced electric energy and its subsequent usage onsite could - under certain circumstances - become a feasible solution for both existing and future installations. In some countries, feed-in tariffs already award self-consumption and dedicated incentives are at the moment under discussion. The aim of this study is to find out and understand the conditions thereof, based on the monitoring data of two different building-integrated PV (BIPV) plants: one roof-integrated (Milland Church in Brixen-Bressanone, Italy) and one façade-integrated system (Ex-Poste building in Bozen-Bolzano, Italy). The balancing of electric energy production and consumption of the buildings is presented on a monthly and hourly basis respectively, including selfconsumption rate and load duration curves. Different scenarios for the maximization of the self-consumption of PV generated electric energy are analyzed.

28th European Photovoltaic Solar Energy Conference and Exhibition; 4527-4534, With continuously increasing penetration of variable generation, the power system needs are changing and so is the need for ancillary services (AS). In time of high generation, PV and wind will be required to participate in AS provision. In this matter, the integration of forecasting confidence intervals into system operation planning is a much more relevant factor than the natural variability itself. This paper introduces a new straightforward approach to generate day-ahead confidence intervals, adjust them to intraday, and adapt this approach to the provision of ancillary services. As a result, the authors quantify the costs of AS provision by PV. The cost is expressed as unused PV generation due to curtailment which is needed to ensure the provision of upward reserve services with a certainty that is acceptable for the TSO. Furthermore, the paper quantifies how far the provider of ancillary services can benefit from larger sizes and wider spreads of its portfolios and how far the reduction of lead contracting times of the AS can reduce costs of unused electricity. Results on the loss due to the contracted reserve power are crucial to determine the competitiveness of PV as an AS provider, therefore the authors make several recommendations on the needed market changes to achieve this. The work presented in this paper has been conducted in the framework of the European funded project, REserviceS.

28th European Photovoltaic Solar Energy Conference and Exhibition; 4733-4749, The installed capacity of photovoltaic (PV) is rising steadily. Most PV is installed in highly electrified countries as on-grid systems. Further there are reams of small off-grid systems in rural areas of developing countries. Due to this, reliable installation rates for PV are available only for a small number of countries. For the end of 2012 EPIA reports 102,156 MWp of installed PV capacity giving data for 50 countries, whereas 2,098 MWp are not allocatable to specific countries. IEA-PVPS provides data for 89,500 MWp installed in 23 countries. This Paper gives an overview on installed PV for all countries in the world, being predicated on the examination of public accessible data. Furthermore, an analysis on development of cumulative PV capacities in recent years is given. Resulting from this evaluation, PV installations are localized in 190 countries claiming 98,988 MWp.

28th European Photovoltaic Solar Energy Conference and Exhibition; 4515-4526, High PV utilization ratios in buildings, i.e. the consumption of most of the PV energy within the building premises, can reduce the energy losses in distribution networks, and mitigate overvoltages and transformer overloadings. For this reason, some countries have adopted, or are discussing, regulatory instruments to motivate local utilization of PV energy. In this paper, we investigate the potential of maximizing the PV utilization ratio using small-scale batteries and flexible thermal loads. We propose four rule-based control algorithms for batteries and heat pumps, and calculate the building energy flows and PV self-consumption ratios on an annual basis using the commercial software Polysun. Based on the results, we provide insights on the potential of thermal and battery storage for PV self-consumption maximization and indicate synergies among them. Also, we identify the battery capacities that maximize the savings over the investment lifetime for different combinations of battery capital costs and PV feed-in tariffs (FITs). The results show that maximizing PV self-consumption can be an interesting business case due to the decreasing trends in battery costs and FITs.

28th European Photovoltaic Solar Energy Conference and Exhibition; 4490-4496, In the past few years the PV sector has experienced a very rapid increase in terms of installed capacity. PV was the 1st source of electricity installed in Europe in 2011, with 21.6 GWp of new power generation capacity. As comparison to other technologies, during the same period of time there were only new capacity of 9.6 GW for wind power plants, 9.7 GW for gas power plants, 2.1 GW for coal power plants, 0.6 GW for large hydro power plants and a decommissioning of 1.1 GW of fuel oil power plants and 6,2 GW of nuclear power plants. Based on these figures, PV has been seen as a potential and feasible electricity source in Europe. In the upcoming years the installed capacity of PV has to further increase to reach the “20-20-20” binding targets of 20% of RES in energy consumption until 2020, which corresponds to 30-35% of the electricity demand from RES, according the Renewable Energy Directive (2009/28/EC) and beyond, until 2050, to achieve the targets of the Energy Roadmap 2050. According to the High RES scenario of the Energy Roadmap 2050, the share of RES in electricity should reach 75% in gross final energy consumption and 97% in terms of electricity production. Among the other renewable power technologies, PV will provide a relevant contribution to reach these ambitious European targets. To achieve such contribution from RES electricity, several key challenges need to be further addressed. At the time being, the status quo in the field of electricity generation is still based on a centralized concept, where electricity producers from small-scale renewable energy systems, such as photovoltaic systems, are forced to adapt their needs, in terms of legal and regulatory framework, grid access and market design rules, to the infrastructures developed to support a centralized approach for electricity production. The PV parity project aims at defining an appropriate policy and legal framework to ensure a sustainable PV market growth. To reach this ambitious target, during the PV Parity project, European and National policy makers have been provided with objective and transparent recommendations to implement support schemes to ensure that PV will become competitive with other electricity sources in Europe and to go beyond the PV competitiveness, in order to ensure a sustainable PV market growth until 2020, 2050 and beyond.

28th European Photovoltaic Solar Energy Conference and Exhibition; 4805-4808, The ability of PV solar energy for a massive integration in a big electricity grid depends on the availability of the solar resource, on the availability of photovoltaic installations and on the grid capacity to host and transport the electricity output. But even if there is enough solar resource, photovoltaic installations and power grid, demand and PV generation may not be coupled, either in magnitude or in time, producing a limited energy contribution to the grid. This work is aimed to identify the theoretical limit imposed by the electricity demand for the network penetration of solar photovoltaic, without storage or considered international exchanges. It proposes a method based on idealized demand and PV generation curves and the best case scenario for the surrounding conditions. Knowledge of these limits will allow us to have a clear reference for power sector planning and to provide confidence on the feasibility of the integration of future PV projects in the electrical system and the match of the PV generation capacity with the electricity demand. With the proposed methodology it wil be possible to determine the maximum PV contribution to the electricity mix and to provide further tools to improve the energy planning for a determined territory, regardless of storage or exchanges between power grids.

28th European Photovoltaic Solar Energy Conference and Exhibition; 4508-4514, In order to reach high penetration levels of distributed PV electricity generation in the distribution grids, without overvoltage and other grid related problems, different concepts for peak shavings will have to be introduced. One possible way to alter the PV electricity generation profile, and at the same time increase the selfconsumption, is by installing PV panels in alternative orientations to avoid a large peak production at noon. In this study the qualitative and quantitative effects of PV installations in alternative orientations is investigated. Three different theoretical neighborhoods with different building orientations are studied at three different PV penetration levels. The results show that with a low PV system price the highest PV potential is found in neighborhoods where the building are placed so that the main roof orientations are east-west rather than north-south. The neighborhood where the buildings are east-west oriented reaches the highest solar fraction and the highest total electricity production at a given upper limit of the maximum peak power injected to the grid. However, in order for the neighborhood with east-west oriented houses to be truly favorable, also from an economical perspective, the PV system prices need to be lower than today and/or the electricity market price needs to be lower during mid day peak generation hours.

28th European Photovoltaic Solar Energy Conference and Exhibition; 4504-4507, By analyzing several scenario “archetypes”, the German Federal Environment Agency (Umweltbundesamt, UBA) has shown that a future 100% renewables-based power generation is technically and ecologically feasible. Three radically different scenarios were developed in order to study the technical and ecological feasibility of Germany switching to an electricity supply based entirely on renewable sources by 2050 and thus represent extreme points of a solution space. Apart from different generation structures, the studies assume different degrees of connection and interchange between regions in Germany as well as between Germany and other countries within a Pan-European network. Within the different generation structures, however, PV plays a crucial role in all three scenarios as a main pillar in the electricity system. This approach was chosen in order to show that on the way to a low carbon or even carbon neutral society there are a number of possible paths within the solution space, depending on political and social priorities.

28th European Photovoltaic Solar Energy Conference and Exhibition; 4767-4772, PV rooftop systems can produce a significant proportion of daily household needs, yet that relies on the careful design of the system and the time of energy use. With reducing FiT (feed-in-tariff) values (IPART, 2012a) and Federal supports across Australia, it makes little sense to install larger PV (Photovoltaic) systems on residential rooftops, where most of the electricity generated would be exported directly to the grid. This study aims to study the benefits, both financial and technological, of adding storage to existing rooftop distributed PV systems for residential households in Sydney, Australia. A mathematical model was constructed to analyse and manipulate the available data. It was concluded that addition of storage resulted in a significant reduction in the peak hour energy consumption; hence alleviating the need for expensive network upgrades, while increasing financial returns from the renewable energy system, from an end user point of view. Significant reductions in returnon- investment and increase in yearly financial savings were observed.

28th European Photovoltaic Solar Energy Conference and Exhibition; 4797-4799, For a fast deployment of PV in Europe, well-suited regions have to be determined and developed for PV power plants. Alpine regions provide high solar irradiation within central Europe. Applying newest bifacial technology allows exploiting the high solar irradiation available in alpine regions and taking advantage of several additional benefits leading to a higher overall performance. First results of a bifacial test module operated and measured in pre-alpine regions in Switzerland show an additional gain of around 15% from the backside of bifacial PV modules compared to conventional PV modules, a gain of up to 27% during winter days with reflections of solar irradiation from snow on the ground, an increase of performance of about 10% due to temperature effects and an overall higher solar irradiation in alpine regions of up to 50% compared to lower regions in Switzerland. All these effects are complementary and not excluding. A higher share of power production during winter half year of up to 45% contributes to a reduced need of seasonal storage for high penetrations of PV but is not yet rated.

31st European Photovoltaic Solar Energy Conference and Exhibition; 2982-2988, The low-voltage distribution grid Dettighofen, Germany, was analysed regarding load flows and the voltage behaviour due to decentralised PV power generation. High load flow fluctuations of 400kW within 25 minutes were observed in the more critical western part of the grid. During the night, the average base and the peak load obtained from the medium voltage grid was 55.8kW and 150kW, respectively. On certain days, the transformer (400kVA) fed with rated power into the medium-voltage grid. The relative voltage rise on the transformer was between 2% and 3%. A critical situation was found at a distribution box with two long stubs and a total PV installation power of 99.3kWp. The load flows caused a relative voltage rise of 4.5% on a day with clear sky and there was a voltage peak slightly above 110% on a day with high fluctuating irradiance. In a second step, load flow simulations with NEPLAN were performed to analyse three different voltage reducing measures. The relative voltage rise could be reduced by 3% with an active power curtailment ratio of 70% together with reactive power control (cos of 0.95 and cos of 0.9 at P>13.8kW). Peak shifting with battery storage leads to the same reduction if the power which exceeds 40% of the rated PV power is shifted. The average costs of limiting the active power to 70% are 1.45ct/kWh compared to 3.11€/kWh for peak shifting with commercial available lead-acid batteries. This is due to the low number of storage cycles resulting in high costs.