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Telecom services play a vital role in the socio-economic development of a country. The number of people using these services is growing rapidly with further enhance growth expected in future. Consequently, the number of telecom towers that are critical for providing such services has also increased correspondingly. Such an increase in the number of telecom towers in a country implies a corresponding increase in the electricity demand of the country. Moreover, in view of growing concerns about climate change, it is necessary that the decarbonization of telecom towers is prioritized so as to minimize their carbon footprint. In view of the above, the primary objective of this paper is to provide a comprehensive analysis of various renewable energy-based systems and the advantages they offer for powering telecom towers, based on a review of the existing literature and field installations. Telecom towers are powered by hybrid energy systems that incorporate renewable energy technologies such as solar photovoltaic panels, wind turbines, fuel cells, and microturbines. Utilizing these systems helps to reduce the consumption of fossil fuels and consequently mitigates the anthropogenic carbon emissions. Moreover, information related to growth of the telecom industry, telecom tower configurations and power supply needs, conventional power supply options, and hybrid system combinations and their benefits. Several field installations of renewable energy-based hybrid systems have also been summarized. This review can help to evaluate appropriate low-carbon technologies and also to develop policy instruments to promote renewable energy-based telecom tower power systems. [ABSTRACT FROM AUTHOR]

Selection of condenser cooling technology can affect the financial as well as technical viability of concentrating solar power (CSP) plants. Detailed comparative assessment of three cooling technologies, i.e., wet, dry, and hybrid, is therefore desirable so as to facilitate selection of optimum cooling technology for the plant. Despite the high efficiency of wet cooling technology, considering the fact that the potential plant locations are generally in arid regions suffering from water scarcity, it is imperative to explore and consider other water conserving condenser cooling options. A review and comparison of technical, economic, and environmental aspects of the three condenser cooling technologies for CSP plants have been presented. Adoption of dry or hybrid technology as against wet cooling technology may lead to reduced thermal performance and increased parasitic power requirement resulting in the high cost of electricity generation. However, the same also results in reduced cooling water requirement up to 92% and thus increase the potential of solar thermal power generation considerably as sites in arid areas can also be utilized. [ABSTRACT FROM AUTHOR]

A framework to estimate the potential of solar cooking for institutional level applications is presented. Using the weather data of a given location (such as solar radiation, ambient temperature, and wind speed), the proposed framework estimates the number of days in a year when solar cooking is feasible and consequently the amount of useful energy saved. Around 57% of the annual useful energy required for cooking (5475 TJ/year out of 9562 TJ/year) in the institution-types considered in this study can be met with solar energy. The adoption of solar cooking in these institution-types is expected to save 197 thousand tonnes of LPG annually. The corresponding annual amount of CO2 emissions mitigation is estimated at 592 thousand tonnes. Amongst the six institution-types considered in the study, cooking of mid-day meal (MDM) in government schools of India has the maximum potential of solar cooking. The annual potential of useful energy savings with the use of solar energy for cooking of MDM is estimated at 3881 TJ out of a gross requirement of 6960 TJ/year. The framework developed and approach used in the study can be used for assessment of potential of institutional solar cooking as well as identification of niche areas for immediate intervention in any other country as well. [ABSTRACT FROM AUTHOR]

A review on various aspects of institutional solar cooking is presented. Starting with an overview of energy requirement for cooking, the review includes cooking technologies developed for institutional solar cooking, polices and programs for their promotion and case studies reported in the literature on field level application. State of the art concentrating solar technologies suitable for institutional level cooking includes Parabolic dish, Scheffler dish and ARUN ® dish. Design, construction and operational details of both direct and indirect types of concentrating solar cookers have been discussed. The case studies, mainly from India, included provide useful feedback on the experiences of using large scale institutional solar cooking systems. A Few installations of each type of solar cooker have been reviewed and major findings and observations on various aspects of the same are reported. [ABSTRACT FROM AUTHOR]

In this paper, we estimate the cost reduction potential of parabolic trough based concentrated solar Power systems in India and consequently their implications for levelized cost of electricity. Using the past as well as envisaged global cumulative diffusion of CSP systems and the learning rates reported in the literature, the expected capital cost of parabolic trough based CSP systems in India has been estimated. Present capital cost of parabolic trough based CSP plant in India has been taken as US $2540/kW. Local manufacturing of CSP components and consequently reduced logistics is expected to reduce the capital cost by 14% and 8% respectively. A learning rate of 10% for the global cumulative diffusion in the base case scenario is expected to reduce capital cost to 49% of the present cost by the end of 2050. Present LCOE of US $151/MWh of CSP plant in India is expected to reduce to US $76/MWh by the end of 2050. Provision of 6 hour thermal storage is expected to reduce LCOE of CSP plant in India by 18% as compared to LCOE of CSP plant without storage. Analysis for different learning rates (5%, 10% and 15%) for CSP plant and different discount rates (6%, 8% and 10%) has also been undertaken and results obtained are presented. [ABSTRACT FROM AUTHOR]

For a planner of decentralized renewable energy systems with micro-grids, an accurate load prediction is imperative for proper sizing of the system. For an accurate load projection, the following questions need to be answered: How many households actually get connected to the micro-grid? How much electricity do they actually use? What factors affect their consumption level? How does their consumption level change over time? In this study, an attempt has been made to identify answers to these questions by looking into one of the PV micro-grid rural electrification projects in Sundarban area of West Bengal, India. It is found that the number of beneficiary households has been on increasing trends indicating existence of large potential demands. The monthly electricity consumption of the average household is turned out to be within the range of 0.42–0.66 kW h/day thus not showing any trend of increase over time. In order to identify factors that affect consumption level, a regression model has been developed with two explanatory variables, namely, the total number of connections and the average ambient temperature during supply hours (night). Application of the model would be effective in predicting additional load requirement in case grid extension is planned under the same project to accommodate potential demands. Results of this study would also be applicable to optimization of expansion process of micro-grid systems. [ABSTRACT FROM AUTHOR]

An attempt to assess solar lantern based lighting option for street vendors (often without access to grid electricity) in the city of Dehradun through a questionnaire based survey is presented. Survey results indicate that the vendors are more likely to adopt a lighting device on rental mode that offers the benefit of low operation cost and high reliability. The study points that the city has potential for 10 Central Charging Stations of 1200Wp capacity each. Each station would cater to the lighting needs of 100 vendors. Based on the vendors willingness to pay for lighting services, estimated minimum acceptable daily rental to an entrepreneur operating a station is Rs 3.97. This is about 45% of the average daily rental of Rs 8.90 that the vendors are willing to pay. For daily rental ranging between Rs 4.00 to Rs 9.00, the mark-up for the entrepreneur would range from 16 to 160%. [ABSTRACT FROM AUTHOR]

Development and dissemination of solar energy technologies in India has been aided by a variety of policy and support measures. One of the promotional measures is the provision of financial and fiscal incentives such as capital subsidy, low interest loan and accelerated depreciation related income tax benefits to the users on the purchase of solar energy technologies. In this study an attempt has been made to determine the effective capital cost of solar energy technologies to the user with the provision of financial and/or fiscal incentives. Results of exemplifying calculations for a domestic and an industrial solar water heating system, a solar home lighting system and a solar drying system have been presented and discussed. [Copyright &y& Elsevier]

The choice of condenser cooling option for concentrating solar power (CSP) plants is likely to affect their techno-economic feasibility. In view of this, an attempt has been made to assess relative techno-economics and net life cycle CO 2 -eq emissions mitigation (LCCM) potential for 50 MW nominal capacity wet-cooled and dry-cooled parabolic trough solar collector (PTSC) and dry-cooled solar power tower (SPT) based CSP plants with 6.0 h of thermal energy storage for two potential locations in India. It was observed that though dry cooling is likely to save significant amount of water (∼92%) in PTSC based plants, the same shall result in higher capital cost, higher performance penalty and higher parasitic power requirements leading to around 20% higher levelized cost of electricity (LCOE) as compared to wet-cooled PTSC based plants. It was also observed that the dry-cooled SPT based plants shall be able to deliver up to 4.5% higher annual electricity output and LCOE is also likely to be lowered by 13% than wet-cooled PTSC based plants. Considering emissions embodied and emissions associated with water transport/extraction from the source and water treatment, the estimation of LCCM from the PTSC and SPT based CSP plants have also been undertaken. [ABSTRACT FROM AUTHOR]

An attempt has been made to estimate the unit capital cost of parabolic trough collector (PTC) based concentrating solar power (CSP) plants in India to facilitate their financial appraisal. While reviewing approaches mentioned in the literature, a significant variation is observed in unit capital cost estimates for a 50 MW wet cooled without storage PTC based plant (US $1700 to US $2662 per kW). To internalize the effect of alternate condenser cooling options and thermal energy storage on the unit capital cost, a new approach that is based on inventory of material used and associated costs have been suggested. With the use of this approach, the unit capital cost of a 50 MW wet cooled PTC plant is estimated at US $1734 per kW. Similarly, for the same nominal capacity plant with dry cooling, the unit capital cost is estimated at US $1994 per kW. Moreover, the effects of increased nominal capacity and hours of thermal energy storage on the unit capital cost have also been investigated. • Cost estimates for a 50 MW PTC based CSP plant in India. • Review of potential approaches for estimating capital cost of PTC based CSP plants. • Study of cost implications of condenser cooling options and thermal energy storage. • Effect of the nominal capacity of the plant and hours of storage on the unit cost. [ABSTRACT FROM AUTHOR]

The capital cost of concentrating solar power (CSP) plants is relatively higher amongst other renewable energy-based electricity generation options. To make CSP plants more competitive, different possibilities to reduce capital costs of CSP plants need to be explored while making use of the recent developments in the field. Two potential modalities for parabolic trough collector based CSP plants have been considered in the study – (i) use of large aperture area parabolic troughs and advanced heat transfer fluids so as to operate at higher temperatures (Case-I) and (ii) use of larger aperture area parabolic troughs along with the use of molten salt as both the heat transfer fluid and storage medium (Case-II). The cost reduction potential has been estimated by assessing the impact of proposed changes on the number of components required to be used and consequent reduction in the material requirements in various components of different subsystems of the CSP plant. The likely reduction in capital cost of the parabolic trough collector based CSP plants for a location in India is estimated at 12.3% for Case-I and 29.9% for Case-II. • A review of recent developments in PTC technology to identify cost reduction possibilities. • Estimation of capital cost using advance collectors and heat transfer fluid. • Cost reduction of up to 29.9% is expected using advanced PTC technologies. [ABSTRACT FROM AUTHOR]

An attempt to estimate the potential of solar industrial process heating (SIPH) and corresponding mitigation of greenhouse gas emissions in dairy industry in India is presented. An assessment of availability of solar radiation as well as of the ambient conditions at various locations with milk processing plants has been made. The effect of the choice of design value of direct normal irradiance on the annual performance of solar process heating systems has been studied using model developed for hourly simulation of the performance of solar process heating system. Further, state wise estimates for useful thermal energy delivery and corresponding solar fraction have also been obtained. The total process heating potential in term of useful energy requirement in dairy sector in India has been estimated at 6.40 PJ/annum which reduces to 4.50 PJ per annum if the process heating requirement is restricted to only pasteurization stage of milk processing. The corresponding solar collector area requirement for process heating in dairy industry in India is estimated in the range of 1.54–1.83 million m 2 with the average solar fraction estimated in the range 0.18–0.32. The use of solar energy for meeting milk processing related thermal energy demand is expected to mitigate (32–144 thousand tonnes) of CO 2 emissions annually. [ABSTRACT FROM AUTHOR]