Adrien Desportes

The engineering of solar power applications, such as photovoltaic energy (PV) or thermal solar energy requires the knowledge of the solar resource available for the solar energy system. This solar resource is generally obtained from datasets, and is either measured by ground-stations, through the use of pyranometers, or by satellites. The solar radiation data are generally not free, and their cost can be high, in particular if high temporal resolution is required, such as hourly data.

In this work we present an alternative method to provide free hourly G(α,β) data for the whole European territory through a web platform. We provide hourly G(α,β) data with a spatial resolution of 1 data/(12x12km2). The method that we have developed makes use of two completely different and independent sources of information to estimate the solar irradiance. First, the PV systems are used as sensors that measure the tilted solar irradiance from the power output that is read at their energy meters. Second, the combination of clear-sky simulations and weather conditions data is used to generate solar irradiance. These methods allow obtaining solar irradiance data which accuracy is at least as good as satellite-based solar radiation data, or even better.

The results are publicly available for free through a web interface that is available from the website of PV CROPS. To our knowledge, this is the first time that hourly solar irradiance data are made available online, in real-time, and for free, to the public.

The number of solar photovoltaic (PV) systems installed in Europe has drastically increased over the last few years, mostly thanks to the advantageous feed-in tariffs set in by each country’s government. A relatively little fraction of the energy production data of these PV systems has been analysed, and
as a consequence, there still remain wide gaps in the knowledge of the real-world performance of these PV systems. This feedback from the field is nevertheless important for the future development of the PV industry and for the establishment of new renewable energy development programmes by the respective governments.

We have analysed the operational data monitored at more than 31,000 PV systems in Europe. These installations comprise residential and commercial rooftop PV systems distributed over 9 different countries, including multi-megawatt PV plants installed in the South of Europe. The PV systems were installed between 2006 and 2014. The mean Energy Yield of the PV systems located in the four reference countries are 1115 kWh/kWp for France, 898 kWh/kWp for the UK, 908 kWh/kWp for Belgium, 1450 kWh/kWp for the PV plants in Spain mounted on a static structure, and 2127 kWh/kWp for those mounted on a solar tracker in Spain. We suggest that the typical PR value for the PV systems installed in 2015 is 0.81. We have observed that the performance of the PV system s tends to increase when the peak power of the PV systems increases. We have found significant performance differences as a function of the inverter manufacturer, and the PV module manufacturer and technology. We have found an improvement of the state-of-the-art, in the form of an increase in performance in the yearly integrated PR of around 3 to 4% over the last seven years, which represents an increase of about 0.5% per year.

The wide disparity in yearly integrated performance ratio, between 0.6 and 0.9, implies that there is a difference of some 30% between the best and the worst performers. Ideally, the PV sector should aim at reaching PR values over 0.84 for most of the PV systems to be installed in the future. More quality controls and further improvement in the state of the art are therefore a very promising option towards a leap in overall performance, which could lead to an average value of PR over 0.84, representing an improvement in performance around 10%, and a corresponding reduction in LCoE of the same order of magnitude.

We have tried to cast some light on some of the numerous questions concerning the performance of solar PV systems in Europe. We have based our analysis on the operational data monitored at more than 31,000 PV systems in Europe. These installations comprise residential and commercial rooftop PV systems distributed over 9 different countries, including multi-megawatt PV plants installed in the South of Europe. The PV systems were installed between 2006 and 2014. The mean Energy Yield of the PV systems located in the four reference countries are 1115 kWh/kWp for France, 898 kWh/kWp for the UK, 908 kWh/kWp for Belgium, 1450 kWh/kWp for the PV plants in Spain mounted on a static structure, and 2127 kWh/kWp for those mounted on a solar tracker in Spain. We suggest that the typical PR value for the PV systems installed in 2015 is 0.81. We have observed that the performance of the PV systems tends to increase when the peak power of the PV systems increases. We have found significant performance differences as a function of the inverter manufacturer, and the PV module manufacturer and technology. We have found an improvement of the state-of-the-art, in the form of an increase in performance in the yearly integrated PR of around 3 to 4% over the last seven years, which represents an increase of about 0.5% per year.

O método descrito neste artigo detecta problemas operacionais nos sistemas fotovoltaicos integrados aos edifícios (BIPV) baseado apenas nos dados de produção de energia, não exigindo o conhecimento das condições de operação. O procedimento, aplicado em diversos sistemas BIPV na Europa, identifica as variações anormais de um indicador de desempenho a partir de comparações entre instalações vizinhas e similares.

Detecção de falhas em sistemas integrados a edificações.