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The production of low-cost wind generation through decentralized power stations in India is discussed.

The evaluation of the financial aspects of biomass gasifier power projects for the decentralization of power supply in India, based on the usage of dual fuel engines and 100% producer gas engines, isn presented.

- An improved equation form for computing the glass cover temperature of flat-plate solar collectors with single glazing is developed. A semi-analytical correlation for the factor f - the ratio of inner to outer heat-transfer coefficients - as a function of collector parameters and atmospheric variables is obtained by regression analysis. This relation readily provides the glass cover temperature ([T.sub.g]). The results are compared with those obtained by numerical solution of heat balance equations. Computational errors in [T.sub.g] and hence in the top heat loss coefficient ([U.sub.t]) are reduced by a factor of five or more. With such low errors in computation of [T.sub.g] and [U.sub.t], a numerical solution of heat balance equations is not required. The method is applicable over an extensive range of variables: the error in the computation of [U.sub.t] is within 2% with the range of air gap spacing 8 mm to 90 mm and the range of ambient temperature 0 [degrees] C to 45 [degrees] C. In this extended range of variables the errors due to simplified method based on empirical relations for [U.sub.t] are substantially higher.

The performance of a box-type solar cooker can be represented in terms of two figures of merit, [F.sub.1] and [F.sub.2]. The second figure [F.sub.2] is a controlling factor in the sensible heating of a load. The present work validates [F.sub.2] by computing this figure from experimental data by two different procedures and comparing the results. An attempt has also been made to provide some guidelines for selecting a suitable temperature interval for determination of [F.sub.2]. The results of some experiments to study the effect of number of pots and the load on [F.sub.2] have also been presented. It is recommended that for standardization tests should be conducted at full load.

A generalized analytical equation for the top heat loss factor of a flat-plate collector with one or more glass covers has been developed. The maximum computational errors resulting from the use of the analytical equation with several simplifications are + or - 5 percent compared to numerical solution of the set of heat balance equations. The analytical equation is considerably more accurate than the available semi-empirical equations over the entire range of variables covered. An additional advantage of the proposed technique over the semi-empirical equations is that results can be obtained for different values of sky temperature, using any given correlation for convective heat transfer in the air gap spacings, and for any given values of fluid (air in the present case) properties.

An approximate method for calculation of the hourly output of a solar still over a 24-hour cycle has been studied. The hourly performance of a solar still is predicted given the values of the insolation, ambient temperature, wind heat-transfer coefficient, water depth, and the heat-transfer coefficient through base and sides. The proposed method does not require graphical constructions and does not assume constant heat-transfer coefficients as in the previous methods. The possibility of using the values of the heat-transfer coefficients for the preceding time interval in the heat balance equations is examined. In fact, two variants of the basic method of calculation are examined. The hourly rate of evaporation is obtained. The results are compared to those obtained by numerical solution of the complete set of heat balance equations. The errors from the approximate method in prediction of the 24-hour output are within + or - 1.5 percent of the values from the numerical solution using the heat balance equations. The range of variables covered is 5 to 15 cms in water depth, 0 to 3 W/m squared K in a heat-transfer coefficient through base and sides, and 5 to 40 W/m squared K in a wind heat-transfer coefficient.

Byline: M.R. Nouni, S.C. Mullick, T.C. Kandpal Results of a techno-economic feasibility evaluation of some micro-hydro power (MHP) plants being planned and implemented for remote village power supply in the state of Uttaranchal in India are presented. The capital cost of MHP plants in the capacity range of 20100 kW (including cost of local transmission and distribution system), investment requirement per unit of rated capacity, and relative cost of different components of MHP plants have been analysed. Unit cost of delivered electricity from the MHP plants has been estimated. Discounted payback period, benefitcost ratio, net present value and internal rate of return for an MHP plant have also been determined. Breakeven values for useful life, plant load factor, and unit cost of electricity to the user for the same MHP plant have also been estimated.

Focuses on the correlations for surface temperatures of the glass cover for the estimation of heat-transfer coefficients in upward heat-flow in solar collectors with single glazing. Proposed method for prediction of temperature of inner and outer surfaces of glass-cover; Effect of absorption of solar radiation in glass; Individual heat-transfer co-efficients.