Comparative experimental analysis of solar thermal energy counters

In order to monitor the energy yield of solar thermal systems, a thermal energy counter with connectivity must he installed. Multiple thermal energy counters and connectivity criteria are available. However, implementation and communication costs differ drastically from one to another. Taking into account market restrictions, in order to widely implement monitoring of energy yield of solar thermal systems these costs should be reduced as much as possible. The paper presents an experimental comparison of the energy yield of a solar thermal system measured with different energy counters at communication time steps of one hour in order to reduce communication costs. These data are compared to those obtained from detailed measuring of the energy Yield with time steps of 1 minute. The evaluated energy counters combine different technologies for the measuring of the flows and temperatures (ultrasound flow sensor, constant flow, single-jet flow meter, vortex flow sensors and RTDs).