Dr. Jaspreet Kaur Randhawa

Indian Institute of Technology (IIT), Mandi Kamand, Himachal Pradesh

A Solar Thermal Energy (STE) system uses the Sun's energy, rather than electricity or fossil fuels, to generate low-cost, environmentally friendly thermal energy. This energy is used generally for the following purposes in households/rural/semi-urban areas, primarily : • Solar water purifier/desalination
• Solar cooking
• Solar drying/green house
• Solar water heating

Solar thermal systems differ from solar photovoltaic (SPV) systems, which generate electricity rather than heat. The major problem with above mentioned Solar Thermal Energy systems for small to medium level applications is about effectiveness in applications as these systems are very sluggish and also dependent on Sun availability. Just an instance, box type Solar cooker will be able to cook rice in about 4 hours of good sunny day and almost whole day in partial shaded conditions. Similarly, a small system for water purification/desalination based on evaporation & collection will be able to deliver not more than 2 litres a day on a very good day, despite mineralisation of water is required and not addressed by any other researchers. Water from solar water heating is available in day time only but mostly it is required in early morning hours. Hence, the interests of general public are negative for such beautiful and environmental friendly STE systems. IIT Mandi is situated in hilly region with good sun availability and while pursuing society related projects in nearby region, it became very evident that perception about non-effectiveness is enormous for STE besides little awareness as whole in some areas. Development of simple, cost-effective, easy to operate and maintain, and socially acceptable domestic water purification units. Solar disinfection technologies have been proven as one of the most appropriate point-of-use water treatment (WT) methods, especially in remote regions where access to electrical power and/or chemical supplies are either restricted or unavailable. They can use directly the bactericidal effect of UV radiation or convert the solar energy into heat for thermal pasteurization or distillation, or a combination of both. Hence, the proposed idea of the project is to accelerate the processes happening within Solar Thermal Energy systems by allowing other renewable energy systems like very small wind turbines/fans and high thermal energy storage material, generally available at rural or semi-urban households, to perform reasonably fast, efficiently and effectively. We propose to develop low cost accelerated Highest Quality Water Purification System with added minerals from locally available materials for off-grid applications. The aim of this project aims towards the application of scientific knowledge from various disciplines to have an efficient water purification system. The important contribution will also be to perform suitable cognitive studies to identify hindrance and short-comings in using of solar thermal based systems by general public in Himalayan region and how to include in proposed designs for effective acceptability in society. This innovative approach could lead to low-cost clean water sensors suitable for all solar disinfection technologies, and to high efficient, autonomous hybrid systems that could be used in rural areas with no access to electricity and/or in emergency situations. The
total cost of the hybrid system and the social acceptance will also need to be explored as
the main drawbacks that could affect the deployment of such system.

Increased number of beneficiaries, enterprises with relevant skills in clean energy technologies, business models, etc. Under-served population in rural/semi-urban areas of Himalayan region.

• Testing and linking solar thermal energy via photovoltaic module and other renewable energy sources for better and accelerated system for purifying the water;