Dynamic whole system testing of combined renewable heating systems – The current state of the art
The state of the art for dynamic whole system test methods using “hardware in the loop” concepts is described based on three different approaches that are currently used at four different test institutes. The methods were applied for testing solar thermal systems in combination with fossil fuel boilers (heating oil and natural gas), biomass boilers, and/or heat pumps. All three methods were able to show the performance of combined heating systems under transient operating conditions. The methods often detected unexpected behaviour of the tested system that cannot be detected based on steady state performance tests that are usually applied to single components. A harmonized approach for whole system tests may lead to new test standards and improve the accuracy of performance prediction as well as reduce the need for field tests.