This paper considers the effects of various working patterns on the low-temperature solar heat utilization for UK industry. For this purpose, a specially-designed system was developed and used to construct a computer program entitled SOLGEN. It combines a straight-through, open-loop working cycle with a closed-loop storage circuit. System simulations indicated that, in the case of a single working day, the maximum unused solar heat output is only 4Â·7% of the total daily output. Annual outputs based on a five-day working week showed that 30Â·5% of the unused generated heat can be retrieved coupled with an overall reduction in unit cost of about 10%. Characteristic trends were also developed for the shole range of alternative regimes and working patterns for industry in the UK.