With an increasing number of PV systems of various scales, real-time irradiance monitoring at every system location becomes costly. Therefore, using a suitable network of sensors has practical relevance. Setting up monitoring stations is often a stepwise procedure, where a batch of sensors can be installed or removed each time. In this paper, I outline the procedure for irradiance monitoring network redesign by deriving criteria for expanding and reducing the network. A monitoring network with 24 stations in Singapore is used in the empirical part of the paper. In addition, a nonparametric covariance estimation technique which handles both anisotropy and heterogeneity is promoted. (C) 2017 Published by Elsevier Ltd.