M. S. Sodha

Solar drying systems and their testing procedures: A review

Abstract Solar drying systems of different designs have been reviewed. All components of solar drying systems have been considered. The testing procedures for solar dryers have also been reviewed. An attempt has been made to present the material in a self-consistent manner.

Optimal mix of renewable energy resources to meet the electrical energy demand in villages of Madhya Pradesh

Abstract Electrification of villages from the main grid leads to large investments and losses, and this forms the basis of decentralized electricity generation. The objective of the present paper is to evolve different strategies in which the electrical energy demand of various villages of Madhya Pradesh (India) is met at minimum cost by utilizing renewable energy resources, thereby making them self-sustainable in their electrical energy needs. The renewable energy technologies considered are biomass based power generation, biogas based power generation and solar photovoltaics. The villages are categorized into five categories on the basis of the resource technology combination capable of meeting their demand at the lowest cost. The demand of villages of category (1) is met by biogas based technology only. The per unit electricity cost (PUEC) of these villages lies between Rs. 4.1 and Rs. 5.7/kW h. For villages of category (2), where demand is met by a combination of biogas and biomass technologies, the PUEC lies in the range Rs. 4.1 to Rs. 5.8/kW h. The PUEC of villages of category (3), where demand is met by biomass based technology only, lies in the range Rs. 4.7 to Rs. 8.2/kW h. The PUEC of villages where demand is met by a combination of biogas, biomass based power generation and PV technology, varies between Rs. 4.7 and Rs. 18.0/kW h (category 4). Category (5) includes those villages that do not have an appreciable amount of biomass or dung, and hence their demand is solely met by PV systems. The PUEC of these villages varies between Rs. 16.1 and Rs. 21.3/kW h. It is found that villages that have good biogas potential correspond to the lowest PUEC. This is sufficient indication for having energy policies in countries, like India, based on bioenergy (biogas and biomass).

Testing procedures for solar air heaters: A review

There are numerous designs of solar air heaters available in the literature [N. K. Bansal, R. Chandra and M. A. S. Malik, Solar air heaters. In Reviews of Renewable Resources of Energy (Edited by M. S. Sodha, S. S. Mathur and M. A. S. Malik). Wiley Eastern, New Delhi (1984) (Ref. [1]); M. S. Sodha, N. K. Bansal, A. Kumar, P. K. Bansal and M. A. S. Malik, Solar Crop Drying. CRC Press, Cleveland, Ohio (1987) (Ref. [2]). Therefore, there is a need for a repeatable test method independent of outdoor environmental conditions and test location. Various experimental techniques have been described so as to allow the net thermal output of an irradiated solar air heater array to be reproduced indoors. The effect of air leaks has been incorporated into the performance equations. The other well known testing procedures have also been described. A method for generating design data for solar air heaters is described.

Sizing of a multi‐tank solar water heater

The thermal performance of a multi-tank solar water heating systems under different climatic conditions, has been characterised by the solar fraction i.e. the fraction of needed energy, available from sun. An earlier model of Sodha et al. (1984) has been validated with experimental observations on different models of solar water heating systems. This model and the concept of solar fraction have been used to size the system for different climatic regions of country represented by Jodhpur (hot and dry), Srinagar (cold), Bombay (warm and humid), Mount Abu (cool), Delhi (composite) and Bangalore (moderate).

Effect of coal properties on the specific coal consumption in a typical thermal power station in India

Abstract The effect of various coal properties like ash content, moisture content, fixed carbon and calorific value on specific coal consumption in a typical thermal power station in India is analysed. It is observed that the specific coal consumption is a strong function of moisture content, ash content and fixed carbon. For the Panipat Thermal Power Station (the one considered in the present analysis), it is observed that, for an increase in moisture content by 2%, the specific coal consumption increases by about 8%. If, however, the ash content is increased by 2%, the specific coal consumption increases by about 5%. It is also observed that, for a 4% increase in fixed carbon, the specific coal consumption decreases by about 25%.