S1: Systematic and ceaseless efforts are being made to tap scientifically the abundant solar energy available in the country. P: These include cooking, water heating, water desalination, space heating, etc. Q: A large number of applications in the area have already become commercial. R: Efforts are also afoot to develop economically viable solar collectors for high temperature applications. S: A simple and common mode in solar energy utilization is solar thermal conversion. S6: Installation of solar thermal systems and devices has helped to save or generate energy to the extent of 350 kWh per annum. Find the correct sequence of P, Q, R and S.