A solar thermal collector system is installed at a house in London to partly cover the domestic hot water (DHW) needs. The solar thermal collector modules are mounted on the roof inclined at 40 with orientation towards South. The monthly mean daily solar radiation on the inclined plane of the solar collectors in April is 4.711 kWh/m and the monthly mean ambient temperature 10.9C. Assume a solar thermal collector system configuration with 2 flat plate solar collector modules with the following technical characteristics: FR(Ta)n = 0.76 FRUL 4.73 W/mK Ac =2.24 m per module The total DHW load (LDHw) for heating up water from the mains cold water temperature of 13C to the desired hot water temperature of 60C, including the losses in the pipes and in the 250 litres hot water tank for April is LDHw = 465 kWh. Assume that FR/FR=0.95 and (Ta)/(ra)=0.90 n Estimate the percentage of load coverage f by the solar collector system for the month of April using the f-chart method. Enter the value of f in % rounding to 1 decimal place.