Institutional and community solar cooking in India using SK-23 and Scheffler solar cookers: A financial appraisal

Financial appraisal of two solar cookers (SK-23 and Scheffler dish) that may be used for institutional/community cooking is presented. For each solar cooker type, three different categories in terms of performance and cost as prevailing in the market have been considered. Annual numbers of solar cooked meals and consequently the values of several measures of financial performance are estimated for three locations in India with varying climatic conditions. As per the estimates obtained in this study a SK-23 solar cooker can cook from 39% to 60% of the meals during the year while, the corresponding range for Scheffler dish based solar cooker is from 59% to 85% at these locations. The discounted payback for SK-23 varies 6.2-9.2 years while the same for Scheffler dish varies from 9.5 to 11.7 years. The financial attractiveness of SK-23 is adversely affected by its poor performance in high wind, while the relatively higher capital cost of the Scheffler direct cooker apparently makes it financially unattractive. Thus, there is an urgent need to encourage research and development on solar cookers to reduce their cost and also to improve performance.