N. V. Joshi

Present and prospective role of bioenergy in regional energy system

Bioenergy is the energy released from the reaction of organic carbon material with oxygen. The organic material derived from plants and animals is also referred to as biomass. Biomass is a flexible feedstock capable of conversion into solid, liquid and gaseous fuels by chemical and biological processes. These intermediate biofuels (such as methane gas, ethanol, charcoal) can be substituted for fossil based fuels. Wood and charcoal are important as household fuels and for small scale industries such as brick making, cashew processing etc. The scarcity of biofuels has far reaching implications on the environment. Hence, expansion of bioenergy systems could be influential in bettering both the socio-economic condition and the environment of the region. This paper examines the present role of biomass in the regions (Uttara Kannada District, Karnataka State, India) energy supply and calculates the potential for future biomass provision and scope for conversion to both modern and traditional fuels. Based on the detailed investigation of biomass resource availability and demand, we can categorise the Uttara Kannada District into two zones (a) Biomass surplus zone consisting of Taluks mainly from hilly area (b) Biomass deficit zone, consisting of thickly populated coastal Taluks such as Bhatkal, Kumta, Ankola, Honnavar and Karwar. Fuel wood is mainly used for cooking and horticulture residues from coconut, arecanut trees are used for water heating purposes. Most of the households in this region still use traditional stoves where efficiency is less than 10%. The present inefficient fuel consumption could be brought down by the usage of fuel efficient stoves (a saving of the order of 27%). Availability of animal residues for biogas generation in Sirsi, Siddapur, Yellapur Taluks gives a viable alternative for cooking, lighting fuel and a useful fertiliser. However to support the present livestock population, fodder from agricultural residues is insufficient in these Taluks. There is a need to supplement the fodder availability with fodder crops as successfully tried in Banavasi village by some progressive farmers.

Domestic energy consumption patterns in Uttara Kannada District, Karnataka State, India.

Abstract Energy planning of any region should be based on existing levels of energy consumption. Sectorwise disaggregated information of energy usage is developed for the Uttara Kannada District to assist in the regional energy planning exercise. This paper provides comparative analyses of village level domestic energy consumption patterns across coastal, interior, hilly and plain zones considering regional and seasonal variations. Cooking, water heating and space heating are the major end use activities. The results, based on eighteen months of field research in five taluks of Uttara Kannada, reveal that the average energy consumption norm does vary significantly for cooking and water heating in various seasons across the zones. Among the five taluks, 90 villages (out of 119) and all divisions of Kumta town in the Kumta taluk and 190–220 randomly selected households in selected villages of Sirsi, Mundgod, Siddapur and Ankola were studied. A survey of 1304 households from 90 villages in the Kumta taluk shows that most of them still use traditional stoves for cooking (97.92%) and water heating (98.3%). Average consumption (kg/person/day) for cooking ranges from 2.01±1.49 (coastal) to 2.32±2.09 (hilly). Seasonwise cooking fuel wood requirement for coast and hilly zones, ranges from 1.98 and 2.22 (summer) to 2.11 and 2.51 (monsoon), respectively, while for water heating (for bath and washing), it ranges from 1.17±0.02 (coast) to 1.63±0.05 (hilly). Seasonal variation is evident from the range 1.12 and 1.53 (summer) to 1.22 and 1.73 (monsoon) for coastal and hilly zones, respectively. Analysis of other sources of energy for domestic purposes shows that kerosene is used for cooking and lighting in the coast. Kerosene consumption (l/person/month) for cooking ranges from 0.05 (hilly) to 0.34 (coast) and for lighting ranges from 0.75 (coast) to 0.99 (hilly). Availability of bioresources in hilly zone is the main reason for less consumption of kerosene for cooking. In the hilly zone, electrification of all households has not been possible, as they are scattered. Because of the erratic supply during all seasons (especially monsoon), electrified households also depend on kerosene for lighting. Based on fuel consumption norms (regionwise, seasonwise and end usewise), (a) the total fuel wood required (cooking, water heating, space heating, jaggery making and parboiling) works out to 1.668,698.23 tonnes/year, (b) the electricity demand, excluding irrigation, is about 32.65 million kWh/year and (c) the kerosene demand for cooking and water heating is about 15.86 million litres per year.

Wind energy potential assessment in Uttara Kannada district of Karnataka, India

Availability of wind energy and its characteristics at Kumta and Sirsi in Uttara Kannada District of Karnataka has been studied based on primary data collected at these sites for a period of 24 months. Wind regimes at Karwar (1952–1989), Honnavar (1939–1989) and Shirali (1974–1989) have also been analysed based on data collected from India Meteorological Department (IMD) of respective meterological observatories. Wind energy conversion systems would be most effective in these taluks during the period May to August. The monthly frequency distributions of wind speed have been analysed for Kumta and Sirsi where hourly wind speed recording is available. It is shown that two parameter Weibull distribution is a good representation of the probability density function for the wind speed. Energy Pattern Factor (EPF) and Power Densities are computed for sites at Kumta and Sirsi. With the knowledge of EPF and mean wind speed, mean power density is computed for Karwar, Honnavar and Shirali. Our analyses show that the coastal taluks such as Karwar and Kumta have good wind potential. This potential, if exploited would help local industries and coconut and areca plantations. Premonsoon availability of wind energy would help in irrigating these orchards and makes the wind energy a desirable alternative.

End use efficiencies in the domestic sector of Uttara Kannada District

End use efficiency experiments conducted in some households of Masur village (based on 4 days experiment) of Kumta taluk show that there is scope for saving 27-42% of energy by switching to improved devices, which are designed to maximise combustion rate (of fuel, ensuring the presence of sufficient oxygen), radiant heat transfer (from fire to vessels, keeping them as close to fire as possible), convection (to pass maximum hot gas over vessels, reducing drafts), conduction (heat is concentrated near the vessels by using insulating material for the stove) and user satisfaction (with user friendly design). The thermal performances of improved stoves designed at our Institute (ASTRA) have also been studied in the field. Irrespective of type of fuel, community, etc., improved stoves show significant saving in fuel. By switching to energy efficient devices 450,548 to 700,853 tonnes of fuel wood can be saved per year in the district.

Hydroelectric resource assessment in Uttara Kannada District, Karnataka State, India

The amount of power available at a given site is decided by the volumetric flow of water and the hydraulic head or water pressure. In hydro schemes, the turbines that drive the electricity generators are directly powered either from a reservoir or the ‘run of the river’. The large schemes may include a water storage reservoir providing daily or seasonal storage to match the production with demand for electricity. These schemes have been producing power in Karnataka for many years, with the first hydroelectric station built in 1942. The majority of them are in Uttara Kannada district. Due to environmental constraints, further construction of storage reservoirs is limited and attention has been focussed towards developing environmental friendly small-scale hydro schemes to cater for the needs of the region. In this paper, the assessment of potential carried out in the streams of Bedthi and Aghnashini river basins in Uttara Kannada district of Western Ghats is discussed. Potentials at five feasible sites are assessed based on stream gauging carried out for a period of 18 months. Computations of discharge on empirical/rational method based on 90 years of precipitation data and the subsequent power and energy values computed are in conformity with the power calculations based on stream gauging. It is estimated that, if all streams are harnessed for energy, electricity generated would be in the order of 720 and 510 million units in Bedthi and Aghnashini basins, respectively. This exercise provides insight to meeting the regional energy requirement through integrated approaches, like harnessing hydro power in a decentralized way during the monsoon season, and meeting lean season requirements through small storage, solar or other thermal options. Net energy analyses incorporating biomass energy lost in submergence show that maximization in net energy at a site is possible, if the hydroelectric generation capacity is adjusted according to the seasonal variations in the river’s water discharge.

Optimal design of hydroelectric projects in Uttara Kannada, India

Abstract The planning of water resources depends on the type and size of projects, the ecological factors involved, etc. Emphasis is placed on presenting an overview of water resources through meteorological, hydrological, ecological and economic data. Economic data include all costs and benefits, specifically those hitherto under estimated, environmental social costs and benefits. This study was carried out on the Bedthi and Aghnashini rivers in the Uttara Kannada district of the Western Ghats region, Karnataka State, India. It is estimated that 720 and 510 million kWh of electricity can be generated in Bedthi and Aghnashini River basins, respectively, if all the streams are harnessed. Focusing on land submergence impact, a model is proposed to minimize submergence and maximize net energy in a region with seasonal power generation, reservoir storage capacity (to meet the regions demand during all seasons) and installed generation capacity as the decision variables. Net energy analyses incorporating biomass energy lost in submergence show that maximization in net energy at a site is possible if the hydroelectric generation capacity is adjusted according to the seasonal variations in the rivers water discharge. A Decision Support System (DSS) used for optimal design of hydroelectric projects in Uttara Kannada district is discussed.

Biofuel Production Along with Remediation of Sewage Water Through Algae

The current study aims to formulate an alternative cost-effective sustainable wastewater treatment option for towns and cities in India through a comparative assessment of the treatment efficacy of mechanical treatment systems, facultative pond-based systems, and man-made lake systems based on physico-chemical and biological parameters. The key treatment parameters were analysed along with the assessment of total annual cost for operation of facultative pond and mechanical treatment systems. The results show that lake systems performed well under higher organic load with the removal efficiency of 70 % chemical oxygen demand (COD), 73 % total nitrogen (TN) and 22 % total phosphorus (TP). However, facultative pond-based systems were effective in the removal of up to 93 % suspended solid (SS) and 82 % biochemical oxygen demand (BOD). The conventional mechanical treatment removed 98 % SS, 74 % COD and 63 % BOD and is ineffective in the removal of nutrients. Furthermore, wastewater algae growing in lakes and ponds showed better lipid content (25–28 %) with suitable fatty acids (C16–C18 > 90 %). The FAME analysis showed high C16:0 (>40 %) followed by C18 fatty acids that further provides scope for algal biofuel generation to meet the regional energy demand. This necessitates an efficient algal capture mechanism to free the final treated effluent from algal BOD and solids and use of algal biomass as viable energy alternatives. Nutrient-integrated treatment efficiency (NITE) based on physical, chemical and biological factors has been devised for evaluating treatment efficiencies. Based on these efficiencies and cost of organic matter and nutrient removal for domestic wastewater treatment options, the best results were obtained for the lake and facultative algal pond-based systems which would be highly effective in Indian context and pave a way for sustainable wastewater treatment with resource recovery.

A decision support system for optimal design of hydroelectric projects in Uttara Kannada

The first hydropower plant in Karnataka state, India, was set up at Shivanasamudram in 1902. Gradually, the capacities of hydropower plants became very large due to increased electricity demand. Large-scale hydroelectric plants now contribute significantly to meeting the states and the nations demand for electricity. Most of Karnatakas hydroelectric plants are located in Uttara Kannada district. Construction of large reservoirs is restricted due to environmental constraints and necessitates the development of ecologically sound alternatives to cater for the needs of the region. The planning of water resources depends on type and size of projects, the ecological factors involved, etc. Emphasis is placed on presenting an overview of water resources through meteorological, hydrological, ecological and economic data. Economic data includes all costs and benefits, specifically hitherto underestimated, environmental social costs and benefits. This study was carried out in Bedthi and Aghnashini rivers in Uttara Kannada district of the Western Ghats region, Karnataka state, India. An estimated 720 and 510 million kWh of electricity can be generated in Bedthi and Aghnashini river basins if all the streams are harnessed. Focusing on land submergence impact, a model is proposed to minimize submergence and maximize net energy in a region, with seasonal power generation, reservoir storage capacity (so as to meet the regions demand during all seasons) and installed generation capacity as the decision variables. Net energy analyses incorporating biomass energy lost in submergence show that maximization in net energy at a site is possible, if the hydroelectric generation capacity is adjusted according to the seasonal variations in the rivers water discharge. A decision support system (DSS) used in water resource planning for electricity generation is discussed in this paper.

Algae-Based Biofertilizers: A Biorefinery Approach

Current perturbations in the agrarian economies and the agro-environment have sparked concerns regarding the future food security and a dire need for sustainable agricultural practices without jeopardizing the environmental assets. One such major requirement for an agrarian society is a resilient nutrient source for agriculture. In this regard algal cells that are cosmopolitan in nature with unparalleled characteristics of high biomass productivity, high photosynthetic efficiency and ability to grow in barren and non-arable lands are attractive. They grow in a wide range of water systems especially the ones that are highly enriched with salts (saline) and nutrients (eutrophied) and in numerous contaminated and polluted systems as urban wastewaters. Apart from these primary benefits, the algal route also offers important byproducts that can be further used as value-added products in industries and as C neutral commodities that help to evade climate change by negating greenhouse gas emissions. The most important aspects are its efficiency as a biofertilizer that dynamically improves the soil health and its physicochemical behaviour. The wastewater-grown algal microflora is exceptional in imparting the appropriate mineral nutrient mix with essential vitamins and plant growth promoters together with increasing the water holding capacity of the soil. Algal communities from wastewaters with optimal NPK ratio and secondary nutrients are therefore model biofertilizers. They can be substitutes of the conventional chemical fertilizers due to its ubiquity, enhanced metabolic flux, short generation time and inherent capabilities to transform inert N into plant-available N (N fixation). All the above-mentioned characteristics, techno-economic feasibility and environmental benefits make algae the most beneficial and demanding bioresource of the twenty-first century.