Synthesis of DNI time series with sub-hourly time resolution

Abstract

The output of a CSP plant shows a non-linear response to the incoming direct normal irradiance. Due to inertia of the various sub-systems and part-load effects for a proper modelling of their energy yield, information on the DNI with high time-resolution is necessary down to the one minute scale. As this type of data is only scarcely available, tools for the synthetisation of these sets have to be applied. We have adopted a respective procedure for the use in the context of yield prediction. The performance of the procedure is, on the one hand tested for the statistical similarity of measured and synthesised data. On the other hand, the applicability of the synthetic sets is checked by comparing the outcomes of a transient plant simulation model for both types of data. The paper gives results from these tests and draws conclusions concerning further improvements of the scheme for the synthesis.