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The rapidly depleting fossil fuel reserves with rising greenhouse gas levels (GHGs) in the atmosphere necessitate exploring alternate sustainable energy options. Biofuels from microalgae are emerging as a viable renewable energy resource owing to their inherent characteristics of higher biomass and lipid yield per hectare compared to other terrestrial bioenergy feedstocks. In this context, the present communication highlights the prospects of microalgal biofuel and other value-added products produced in a decentralized microalgal biorefinery in the flood plains (gazani lands) of the west coast of India. The spatial extent of potential sites for diatom cultivation estimated in three districts along the Indian west coast was 1940 ha. The opportunities for establishing biorefineries using diatoms as renewable bioenergy feedstocks were investigated through species prioritization, seasonal availability, tolerance, and biochemical composition analyses. Nitzschia and Amphora sp. were prioritized for lab-scale productivity studies based on their tolerance and macromolecular composition. When cultivated in a prototype biofilms-based bioreactor designed using gravel stones as substrates, Amphora sp. Yielded 16 times more productivity (0.56 g L−1) than conventional shake flask cultures. Design of a diatom biorefinery and its mass budgeting considering 100 kg dry biomass yielded ∼15–24 kg of biodiesel. Techno-economic assessment of biodiesel with value-added products of glycerol, biogas, and biofertilizer demonstrated a biodiesel production cost of 30.08–59.52 INR/kg of biodiesel. Harvesting cost in a hybrid mode using mechanized scrubbers and manual labour was estimated as 20 INR/kg of biomass. [Display omitted] • Evaluate the potential of diatoms as a source of biofuel with value-added products. • Biochemical composition and feedstock availability assessment across seasons. • Design and implementation of prototype algal reactor. • Economic feasibility assessment and mass budgeting of the diatom biorefinery. • Promising scope for a diatom biorefinery along the Indian central west coast. [ABSTRACT FROM AUTHOR]

Energy plays a prominent role in human society. As a result of technological and industrial developments, the demand for energy is rapidly increasing. Existing power sources that are mainly fossil fuel based are leaving an unacceptable legacy of waste and pollution apart from diminishing stock of fuels. Hence, the focus is now shifted to large-scale propagation of renewable energy. Renewable energy technologies are clean sources of energy that have a much lower environmental impact than conventional energy technologies. Solar energy is one such renewable energy. Most renewable energy comes either directly or indirectly from the sun. Estimation of solar energy potential of a region requires detailed solar radiation climatology, and it is necessary to collect extensive radiation data of high accuracy covering all climatic zones of the region. In this regard, a decision support system (DSS) would help to estimate solar energy potential considering the regions’ energy requirement. This article explains the design and implementation of DSS for assessment of solar energy. The DSS with executive information systems and reporting tools helps to tap vast data resources and deliver information. The main hypothesis is that this tool can be used to form a core of practical methodology that is resilient and can be used by decision-making bodies to assess various scenarios. It also offers means of entering, accessing and interpreting the information for the purpose of sound decision-making. [ABSTRACT FROM AUTHOR]

Abstract: Increasing negative effects of fossil fuel combustion on the environment in addition to limited stock have forced many countries to explore and change to environmentally friendly alternatives that are renewable to sustain the increasing energy demand. Changing to renewable sources and implementation of effective conservation measures would ensure sustainability. Currently, wind energy is one of the fastest developing renewable energy source technologies across the globe. Wind energy is an alternative clean energy source compared to fossil fuel, which pollute the lower layer of the atmosphere. It has the advantage of being harnessed on a local basis for application in rural and remote areas. In order to tap the potential of wind energy sources, there is a need to assess the availability of the resources spatially. Mapping potential sites for tapping wind energy in Karnataka (a federal State in India) is the focus of this study. The study employs the geographical information system (GIS) to map the wind energy resources of Karnataka state and analyse their variability considering spatial and seasonal aspects. Considering these, the present status of the potential is assessed and maps of locations suitable for tapping wind energy have been prepared. A spatial data base with data of wind velocities has been developed and used for evaluation of the theoretical potential through continuous monitoring and mapping of the wind resources. The study shows that the average wind velocity in Karnataka varies from 0.85m/s in Bagalkote to 8.28m/s in Chikkodi during the monsoon season. Chikkodi, in Belgaum district, has high wind velocity during the period May to September with a peak value of 9.18m/s in July. Agroclimatic zone wise analysis shows that the northern dry zone and the central dry zone are ideally suited for harvesting wind energy for regional economic development. [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]