Low-efficiency, rice-husk-based furnace-boiler systems are generally used for meeting thermal energy demand of paddy parboiling in India. Shortages in rice-husk availability are met
with fuels such as coal, furnace oil, etc. Besides steam at low pressures, paddy parboiling oper-ations require hot water at temperatures up to 90°C. The financial feasibility of supplementing the energy supply for parboiling of paddy through the use of solar water-heating systems has been assessed. Typical results indicate that as long as the opportunity cost of rice husk is less than Rs lOOO/tonne, a solar water-heating system is not financially attractive.