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India has a huge industrial demand for process heating at temperatures that can be provided with commercially available solar collectors. Government of India with support from multi-lateral agencies has initiated an ambitious programme for promoting large scale adoption of Solar Industrial Process Heating (SIPH) in the industrial sector of the country. This paper presents the details of an attempt to study the effect of several existing and potential incentives on the financial attractiveness of SIPH systems in India. A case of solar process heating in dairy industry has been presented to demonstrate the relative efficacy of different incentives on the economics of SIPH systems in terms of their impact on levelized cost of useful thermal energy delivered. Finally, policy implications of the results obtained have been discussed.

An attempt has been made to evaluate the financial feasibility of hybrid power supply option during real-time grid power unavailability (continuous and intermittent) conditions and determine the optimal hybrid power supply configurations for outdoor telecom towers in India. As grid power availability is highly dependent on locations, a review of real-time hourly grid power supply availability for telecom towers at 36 locations in different parts of India has also been presented. Ten different locations across different climatic zones were analyzed, and it was found that duration and continuity (continuous and intermittent) of power outages considerably affect the LCOE of different configurations. So it is imperative that these factors be taken into account when determining the optimal hybrid power system. Solar PV-based hybrid power supply systems were found to have lower LCOE for all power outage conditions both in continuous as well as intermittent with their values in the range of Indian rupees (INR) 6.76–INR 26.32 (US $0.095–US $0.371) per kWh for the optimal cases (1 US$ = INR 76.28 (As on April 27, 2020)). While solar PV with battery is found to be the least cost hybrid power supply options for the telecom towers located in areas with continuous grid power unavailability up to 4 h, a diesel generator also needs to be included for larger hours of continuous grid unavailability. [ABSTRACT FROM AUTHOR]

The contribution of power because of the nonconventional energy sources is enhancing day by day. This gives rise to power converter connected to the grid for an integration and to utilize the nonconventional energy sources economically and efficiently. However, this causes the distortion in the grid voltages and currents. All advanced high precision operating machines and measuring instruments are sensitive to the harmonics of the grid voltages. Therefore, this work illustrates an improved control to supress the grid voltage and current harmonics caused by an integration of non‐conventional energy source and nonlinear loads. An enhanced resonant two‐degree of freedom proportional–integral–derivative (ER‐2‐DOF‐PID) controller is used to extract fundamental components from load currents. It uses a resonant controller in shunt with PI controller to suppress the multi‐order harmonics and steady state error. A DC‐offset is used in parallel of this combination to suppress the sub‐order harmonics. To suppress the peak overshoot during the load transients and insolation changes, a 2‐DOF‐PID controller is used. The presented control is investigated by developing its model in MATLAB environment and this is validated on a prototype developed in the laboratory. The controller is modelled and investigated for stability analysis using a Bode mathematical tool.. [ABSTRACT FROM AUTHOR]

An adaptive approach based on a neural network is presented here for the control of a grid interactive solar power generating system. This control approach is based on a summation and a product neuron, which are used to process the non‐linearity of load currents. A sigmoidal and Gaussian functions are used to linearise the response of summation and product neurons. In this control, the product and summation neurons, and sigmoidal and Gaussian functions are within a single layer, which reduces the complexity of control. This control algorithm is superior over artificial neural network (ANN)‐based control algorithm, which has large number of unknown weights and layers. It reduces the computational burden and complexity of the control algorithm. It shows the inherent improved performance at non‐linear balanced and unbalanced loads. The control of net active and reactive components of the power separately improves the efficacy of the control at unbalanced non‐linear load and reduces the voltage transients in the grid voltages. The ANN‐based control also plays an active role in enhancing the power quality of the grid. The reduced complexity of control and direct power feed forward of photovoltaic array (PVA) to the grid improve the dynamic response of the grid‐connected PVA‐based system. [ABSTRACT FROM AUTHOR]

In a photovoltaic array (PVA) tied grid system, PVA and the grid are connected at AC bus (ACB) to feed the power to the grid and the load connected locally at the ACB. The photovoltaic energy conversion system (PVECS) requires an improved dynamic controller to control the grid voltage harmonics under variable solar power and nonlinear unbalanced load conditions. The conventional filtering controllers are unable to remove the sub‐harmonics and DC‐offset in the input signal. Moreover, their attenuation for the dominant lower order harmonics is unsatisfactory for unbalanced loading conditions and highly nonlinear loads. A MMLSTOGI (mixed multi‐level second and third order generalized integrator) based control is used in this work. It effectively mitigates the dominant lower‐order harmonics and the DC‐offset of load currents and extracts their in‐phase and quadrature‐phase fundamental components (FCs). The PVA is connected at ACB through interfacing voltage source converter (VSC). The DC‐link voltage is ascertained by generating its reference value using an incremental conductance (InC) based maximum power point tracking. The PVA power is feed‐forwarded in the control to enhance the dynamics of the system. The control is validated on a developed model in MATLAB SIMULINK background, and using a developed prototype. [ABSTRACT FROM AUTHOR]

This work presents an improved phase‐locked loop (IPLL)‐based control for grid‐integrated photovoltaic (PV) system (GIPVS). It is used to extract amplitude, frequency, and phase angle of distorted load currents to control PV‐grid‐interfaced voltage source converter (VSC). The VSC controls active and reactive powers at unbalances and distortions in the grid voltages. The control algorithm of VSC includes power feed‐forward term, DC‐link voltage, and grid voltages. The feed‐forward term improves the dynamic performance of a GIPVS and enhances the utilisation of VSC. Three‐phase IPLLs extract the in‐phase components of three‐phase load currents at utility frequency. Further, these in‐phase components of load currents are used for estimation of reference‐grid currents. The proposed IPLL‐based control algorithm offers good dynamic response even under unbalanced load condition. The efficient working of IPLL‐based control algorithm is realised by extracting maximum power from PV‐grid system and through its power‐quality improvement. The perturb and observe (P & O) control algorithm is used for optimum utilisation of a PV array. A developed prototype of PV‐grid system is used to implement an IPLL‐based control algorithm under different operating conditions. [ABSTRACT FROM AUTHOR]

For large-scale dissemination of solar thermal power plants, in countries identified with huge potential, governments are offering various incentives. In an attempt towards studying the effectiveness of various incentives in reducing the levelised cost of electricity (LCOE) delivered by solar thermal power plants in India, this paper presents simple mathematical frameworks that facilitate the determination of the required level of an incentive so as to ensure that the LCOE is within a pre-specified limit. For example, for a 50 MW solar thermal power plant at Barmer (Rajasthan), LCOE of Rs. 9.75 per kWh can be achieved by providing 6.3% viability gap funding or an interest subsidy of 3% or provision of 32% investment tax credits to the equity investor or provision of production tax credits to the equity investor at the rate of Rs. 0.81 per kWh for first 10 years of operation of a plant. [ABSTRACT FROM AUTHOR]

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]

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., (© The Author(s), under exclusive licence to Springer Nature B.V. 2023, Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.)