Santosh Rana

An approach to the estimation of the value of agricultural residues used as biofuels

A simple demand side approach for estimating the monetary value of agricultural residues used as biofuels is proposed. Some of the important issues involved in the use of biomass feedstocks in coal-fired boilers are briefly discussed along with their implications for the maximum acceptable price estimates for the agricultural residues. Results of some typical calculations are analysed along with the estimates obtained on the basis of a supply side approach (based on production cost) developed earlier. The prevailing market prices of some agricultural residues used as feedstocks for briquetting are also indicated. The results obtained can be used as preliminary indicators for identifying niche areas for immediate/short-term utilization of agriculture residues in boilers for process heating and power generation.

Using renewable energy technologies for domestic cooking in India: a methodology for potential estimation

An attempt has been made to estimate the potential of using biogas plants, solar cookers and improved cookstoves for domestic cooking in India. Based on 1991 statistics on the bovine population and ownership pattern, the potential number of family size biogas plants comes out to be around 38 million in the optimistic scenario whereas, in the realistic scenario it is around 29 million. The potential of improved cookstoves is estimated at about 90 million and that of solar cookers is estimated at about 75 million.

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).

Automated small tilt-angle measurement using Lau interferometry

A technique for a tilt-angle measurement of reflecting objects based on the Lau interferometry coupled with the moire readout has been proposed. A white-light incoherent source illuminates a set of two gratings, resulting in the generation of the Fresnel image due to the Lau effect. The Fresnel image is projected onto a reflecting object. The image reflected from the object is superimposed onto an identical grating, which results in the formation of a moiré fringe pattern. The inclination angle of moiré fringes is a function of tilt angle of the object. Theory and experimental arrangement of the proposed technique is presented and results of the investigation are reported.

Substitution of energy efficient devices for cooking and lighting in rural areas of Madhya Pradesh

Rural areas in many developing countries, including India, have always been ignored in improving the efficiencies of existing lighting and cooking systems, as well as in developing alternatives. This paper presents the economic performance of new and more efficient systems over the existing ones by using Life Cycle Cost (LCC) and Internal Rate of Return (IRR) methods. The analyses have been performed for 10 surveyed blocks of the State of Madhya Pradesh. The results show impressive returns if the recommended energy efficient systems are installed in the state. The results can form policy guidelines for the implementing agencies/Government organizations for rural energy programmes.

Automated collimation testing using a temporal phase shifting technique in Talbot interferometry.

We propose a quantitative approach toward the detection of collimation of a coherent optical beam. For detection of collimation position of the collimator, a temporal phase shifting technique has been incorporated into Talbot interferometry. The slope of the phase maps depicts the collimation position of the collimator. This technique offers high precision, accuracy, and provides automated output.

Collimation testing by use of the Lau effect coupled with moiré readout

We present an easy, simple, and inexpensive technique for checking the quality of the collimation of optical beams using the Lau effect combined with moiré readout. The experimental arrangement consists of a modified Lau-based interferometer in which a white-light incoherent source illuminates a set of two gratings. A collimating lens is placed between the two gratings such that the self-images of the second grating are formed. The third grating is positioned at one of the self-imaging planes forming moiré fringes. The type of the moiré fringe demonstrates the quality of collimation of the optical beam. The necessary theoretical background is presented and the results of our experimental investigation are reported. The technique can also be used for accurate determination of the focal length of a collimating lens using low-cost components.

Real-time slope mapping and defect detection in bent plates using Talbot interferometry

We demonstrate a simple method for obtaining slope contours of bent plates using Talbot interferometry. The technique has been used to map slope contours of polymethyl methacrylate specimens of different shapes. The Talbot image of a coarse grating is projected onto a specimen such that the self-image is backreflected onto the same grating again. As a Talbot interferometer is basically a grating shearing interferometer, it results in the generation of characteristic slope maps of the specimen under test. Results of the investigation match well with other slope-mapping techniques. Validation of experimental results with theoretical predictions in the case of a cantilever beam specimen has been undertaken. Accuracy of about 4.7% with respect to theoretical predictions is obtained.

Slope measurement of bent plates using double grating shearing interferometry

A grating-based shearing interferometeric setup for slope measurement of bent plates has been proposed. The specimen under test is illuminated by a collimated beam from the laser. Light reflected from the specimen passes through two identical holographic gratings placed in tandem. The grating frequency has been so chosen that the diffracted orders from each grating are separated out distinctly. Two first-order beams diffracted from each of the gratings superpose in space. In the resulting interferogram, the fringes due to slope information of the object are visualized. Mathematical formulation for experimental determination of slope values has been undertaken. Validation of the experimental results with theoretical predictions in case of cantilever beam provides good correlation. The main advantage of the technique has been the realization of very compact geometry without the need for spatial filtering arrangement commonly associated with the grating-based techniques used to date.

Setting sensitivity in collimation testing using Lau interferometry

An improved method for testing the collimation of an incoherent optical beam using Lau interferometry is presented. The experimental setup consists of a white light source and a set of three identical gratings. A source grating G1 is placed in front of a collimating lens. Beyond the collimating lens gratings G2 and G3 are so aligned that the lines of the gratings make a small but equal and opposite angle with the vertical. The self-image of grating G2 is superimposed on the grating G3, resulting in the generation of moire fringes. Decollimation of the optical beam results in a change in the dimensions of the self-image. This change is detected using the magnification effect of the moire method. The horizontal moire fringes are indicative of collimation of the optical beam. Deviation from the horizontal inclination of the moire fringes indicates setting in of decollimation. Theoretical and experimental investigations to determine the sensitivity achievable in this collimation testing technique are undertaken and results of the investigations are reported. Experimental results are in close agreement with the theoretical predictions.