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Abstract: An energy resource that is renewed by nature and whose supply is not affected by the rate of consumption is often termed as renewable energy. The need to search for renewable, alternate and non-polluting sources of energy assumes top priority for self-reliance in the regional energy supply. This demands an estimation of available energy resources spatially to evolve better management strategies for ensuring sustainability of resources. The spatial mapping of availability and demand of energy resources would help in the integrated regional energy planning through an appropriate energy supply–demand matching. This paper discusses the application of Geographical Information System (GIS) to map the renewable energy potential talukwise in Karnataka State, India. Taluk is an administrative division in the federal set-up in India to implement developmental programmes like dissemination of biogas, improved stoves, etc. Hence, this paper focuses talukwise mapping of renewable energy (solar, wind, bioenergy and small hydroenergy) potential for Karnataka using GIS. GIS helps in spatial and temporal analyses of the resources and demand and also aids as Decision Support System while implementing location-specific renewable energy technologies. Regions suitable for tapping solar energy are mapped based on global solar radiation data, which provides a picture of the potential. Coastal taluks in Uttara Kannada have higher global solar radiation during summer (6.31kWh/m2), monsoon (4.16kWh/m2) and winter (5.48kWh/m2). Mapping of regions suitable for tapping wind energy has been done based on wind velocity data, and it shows that Chikkodi taluk, Belgaum district, has higher potential during summer (6.06m/s), monsoon (8.27m/s) and winter (5.19m/s). Mysore district has the maximum number of small hydropower plants with a capacity of 36MW. Talukwise computation of bioenergy availability from agricultural residue, forest, horticulture, plantation and livestock indicates that Channagiri taluk in Shimoga district yields maximum bioenergy. The bioenergy status analysis shows that Siddapur taluk in Uttara Kannada district has the highest bioenergy status of 2.004 (ratio of bioresource availability and demand). [Copyright &y& Elsevier]

Burgeoning dependence on fossil fuels for transport and industrial sectors has been posing challenges such as depletion of fossil fuel reserves, enhanced greenhouse gas (GHG) footprint, with the imminent changes in the climate, etc. This has necessitated an exploration of sustainable, eco-friendly and carbon neutral energy alternatives. Recent studies on biofuels indicate that algal biomass, particularly from marine macroalgae (seaweeds) have the potential to supplement oil fuel. Marine macroalgae are fast growing and carbohydrate rich biomass having advantage over other biofuel feedstock in terms of land dependence, freshwater requirements, not competing with food crops, which were the inherent drawback of the first- and second-generation feedstock. The present communication reviews the macroalgal feedstock availability, screening and selection of viable feedstock based on the biochemical composition, process involved, scope and opportunities in bioethanol production as well as technology interventions. The prospect of bioethanol production from algal feedstock of Central West Coast of India has been evaluated taking into account challenges (feedstock sustenance, technical feasibility, economic viability) in order to achieve energy sustainability. The green algae exhibited growth during all seasons and highest total carbohydrate was recorded from green seaweed Ulva lactuca (62.15 ± 12.8%). Elemental (CHN) analyses of seaweed samples indicate 25.31–37.95% of carbon, 4.52–6.48% hydrogen and 1.88–4.36% Nitrogen. Highest carbon, hydrogen and nitrogen content were recorded respectively from G.pusillum (C: 37.95%), G.pusillum (H: 6.48%) and E.intestinalis (N: 4.36%). Green seaweeds are rich in cellulose content (>10%) compared to other seaweeds (2–10%). Higher cellulose content was estimated in U.lactuca (14.03 ± 0.14%), followed by E.intestinalis (12.10 ± 0.53%) and C.media (10.53 ± 0.17%). Cellulose is a glucan present in green seaweeds, which can easily be hydrolysed through enzyme and subsequently fermented to produce bioethanol. Lower sugar removal in acid hydrolysate neutralization process (Na 2 CO 3) was recorded in U.lactuca (39.8%) and E.intestinalis (14.7%). Highest ethanol yield of 1.63 g and 0.49 g achieving 25.8% and 77.4% efficiency in SHF (Separate Hydrolysis and Fermentation) and SSF (Simultaneous Saccharification and Fermentation) process respectively was recorded for green alga E. intestinalis. Image 1 • Reviews the macroalgal feedstock availability, screening of viable feedstock based on the biochemical composition and process. • Scope and opportunities in bioethanol production as well as technology interventions. • Evaluated algal bioethanol prospects considering feedstock sustenance, technical feasibility, economic viability with energy sustainability. • Prioritization of potential macroalgal feedstock for bioethanol production based on biochemical composition. • The green algae exhibited growth in all the season and highest total carbohydrate in Ulva lactuca (62.15 ± 12.8%). • Highest ethanol yield of 1.63 g and 0.49 g achieving 25.8% and 77.4% efficiency in SHF and SSF process respectively was recorded for green alga E. intestinalis. • Potential sites identified in estuary for large scale algal cultivation. [ABSTRACT FROM AUTHOR]

Sustainability of a bioenergy project depends on precise assessment of biomass resource, planning of cost-effective logistics and evaluation of possible environmental implications. In this context, this paper reviews the role and applications of geo-spatial tool such as Geographical Information System (GIS) for precise agro-residue resource assessment, biomass logistic and power plant design. Further, application of Life Cycle Assessment (LCA) in understanding the potential impact of agro-residue bioenergy generation on different ecosystem services has also been reviewed and limitations associated with LCA variability and uncertainty were discussed. Usefulness of integration of GIS into LCA (i.e. spatial LCA) to overcome the limitations of conventional LCA and to produce a holistic evaluation of the environmental benefits and concerns of bioenergy is also reviewed. Application of GIS, LCA and spatial LCA can help alleviate the challenges faced by ambitious bioenergy projects by addressing both economics and environmental goals. [ABSTRACT FROM AUTHOR]