Solar Thermal System Evaluation in China

Table 9

Test results for a solar water heating system.

Number	Ambient temperature; °C	Solar irradiation; MJ/m^2	Useful heat gain; MJ	Total energy consumption; MJ	Efficiency of solar collecting system	Solar energy fraction	Consumed hot water; m^3
1	25.9	7.82	239.4	697.2	0.33	0.34	7.81
2	27.3	12.74	474.1	977.3	0.40	0.49	7.54
3	28.4	20.48	942.3	941.6	0.50	1.00	7.93
4	30.2	17.96	839.4	838.6	0.51	1.00	8.05