Predicted direct solar radiation (ECMWF) for optimized operational strategies of linear focus parabolic-trough systems

Short-Term Forecasts of DNI from an Integrated Forecasting System (ECMWF) for Optimized Operational Strategies of a Central Receiver System

“…In particular, it is during very clean atmosphere periods that the implemented aerosol climatology affects the prediction of DNI more. This has been previously observed with day-ahead forecasts of DNI from the IFS [11,29], where the radiative effects of clouds and aerosols were, respectively, under-or over-estimated by the model, compared to local measurements. For instance, at the EVO station it was found that the predicted mean annual DNI had an overestimation of ≈7%, compared to local measurements [29], being essentially related to an underestimation of the cloud cover.…”

“…Similarly, as performed in [11], continuous measurements of local atmospheric variables, such as air temperature, relative humidity, wind speed, and atmospheric pressure at ground level, were also acquired by nearby standard meteorological measuring equipment. Since atmospheric pressure was not measured at the EVO station and the local wind was disturbed by existing neighboring buildings, not being representative of the measuring location, hourly data from a nearby station (≈4 km apart)-maintained by the Portuguese Meteorology Service (IPMA-Instituto Português do Mar e da Atmosfera)-was used for the considered period of study.…”

“…Moreover, in addition to an improved code that allowed us to reduce computational costs, ecRad was able to reduce numerical noise in cloudy periods, which enabled better DNI predictions than the previous radiative scheme [21]. A recent analysis [11] has shown that improvements of day-ahead forecasts of DNI from the ecRad were attained, in comparison to the previous version (McRad, cycle 41R2). Hourly and daily correlations of 0.87 and 0.91 between predicted and measured data in EVO were found for the same dataset used in the present work.…”

“…In this context, user-friendly software such as the System Advisor Model (SAM) can be used to simulate a CSP plant. This method has been carried out by the authors in a previous work [11], where forecasted data from the IFS was used in the simulation of a linear-focus parabolic trough (PT) system, with a configuration similar to the Andasol 3, a 50 MW e power plant [12] located in Granada (Spain). Although the PT technology has dominated the solar thermal power industry in the last decades, central receiver (CR) units have been emerging, due to the potential that these have for higher efficiency and lower cost.…”

“…In this work, in order to convert DNI values to energy output forecasts of the modeled CSP system, the simulation of a CR power plant similarly configured as the 19.9 MW e Gemasolar thermosolar power plant [15] (located in the province of Sevilla (Spain)), was carried out. The obtained energy outputs based on DNI predictions and local measurements of the simulated CR power plant were assessed and then compared with the results obtained for a PT system [11]. This simulation used the same dataset, i.e., input variables (DNI and meteorological data), as for the PT simulation, being related to the same period and location in Southern Portugal, in which it showed substantial improvements towards the prediction of DNI, due to the new operational radiative scheme of the IFS.…”