about storage processes

[Ville_O]

Our model has 96 sub-annual time slices (representing 4 seasons and 24 hours in a season). If we assume a daily loss-% of 0.2% for the thermal storage tank, then based on the example above STG_LOSS should be daily loss-%/(G_YRFR*DAYS^-1) = 0.002/(4^-1*24^-1*91.25^-1) = 17.52? However, if we use this value for the STG_LOSS parameter, we get an error "Error at line 126534: rPower: FUNC DOMAIN: x**y, x < 0" when running the model. How can we fix this issue?