Parimita Mohanty

Solar Radiation Fundamentals and PV System Components

Solar PV technology has emerged as one of the most matured and fast evolving renewable energy technologies and it is expected that it will play a major role in the future global electricity generation mix. Keeping the rapid development of the PV technology into consideration, this chapter systematically documents the evolution of solar PV material as well as the PV applications and PV markets. It also provides insight into the trend in batteries and inverters used for solar PV applications. Furthermore, a comparative analysis of different PV technologies and its development is summarized. The rest of the chapter aims at providing a comprehensive analysis of solar radiation measurement and modelling techniques to assess the availability of solar radiation at different locations. The chapter presents comprehensive information for solar energy engineers, architects and other practitioners.

Enterprise GIS and Smart Electric Grid for India's power sector

Smart Electric Grid is an important as well as intelligent element towards the development of an energy independent and environmentally sustainable society. Although there is no universal definition for Smart Grid, it has various functionalities towards modernization of the electrical grid by using digital systems and addressing disturbances via automated prevention and various other novel ideas. But a smarter grid needs a real-time analysis of the network. Therefore to provide accurate scientific decisions, the idea of integrating enterprise Geographic Information System (GIS) with Smart Electric Grid presented in this paper so as to make the grid apt in advanced decision making. It also helps in modelling the workflow of a network by understanding the relationship between network and surroundings and by controlling all parts of the grid. With the increasing demand of electricity in almost every sector, power sector utilities of India need to perform more effectively and in efficient manner. For this purpose, a Smart Electric Grid along with enterprise GIS is one of the evolutionary idea which can facilitate a cleaner environment, efficient load management and fully automated systems. GIS enabled system also helps to establish a link between the surroundings, the consumers and the grid and thus making it proficient in automation and efficient energy consumption and customer awareness by maintaining a relational database including all the required spatial information. The main objective of this study is to showcase the integration of enterprise GIS with Smart Electric Grid to provide an end-to-end solution for the utilities to improve the efficiency of the electrical system, enable intelligent demand side management and enhance energy security through sustainable business model.

Installation of roof-top solar PV modules and their impact on building cooling load

It has been shown by many researchers that over a long term there has been a slow but steady rise of ambient temperature within the Indian sub-continent. Due to an increased economic prosperity there has been an accompanied increase in the urban heat island effect. Furthermore, urbanisation of large cities in India has also led to higher population densities. The above factors had the combined effect of a significant increase of cooling load of buildings. The high density of dwellings and other building construction has resulted in shading of walls. However, the flat roof spaces are exposed to an uninterrupted solar radiation regime and this in turn leads to generation of high sol-air temperatures which cause higher cooling loads. Presently, it has been argued that roof spaces are one of the major contributors to building cooling load. In this article, the reasons behind the phenomenal rise in the installation of air-conditioners in India are reviewed. The dual role of roof-top PV systems in electricity generation and reduction of building cooling load due to the shading they provide is then investigated. For this purpose, the CIBSE method to obtain sol-air temperature with solar radiation and outdoor ambient temperature has been used. Sol-air temperature for five key Indian locations (Delhi, Bhopal, Ahmedabad, Bhubaneswar and Chennai), based on the recently presented data by the NREL-India Meteorological Department consortium, were then obtained. A computer simulation routine was presently developed for solving the classical transient heat conduction problem with hourly sol-air temperature data and roof construction details provided to the routine. This program was executed to obtain the cooling load profile for each of the five Indian locations for the respective design day. Practical application : The present work reviews the reasons behind the phenomenal rise in the installation of air-conditioners in India. The dual role of roof-top PV systems in electricity generation and reduction of building cooling load due to the shading they provide has been investigated. The computer simulation demonstrated that the energy required for roof-induced cooling load decreased between 73% and 90% after installation of the PV system. The method used in this work has the advantage that it enables the user to obtain cooling load estimates using a general transient heat conduction approach. Moreover, all software was developed within MS-Excel environment, this is also an additional advantage as the cost associated with purchase and training of proprietary building energy software can be prohibitive for many consultants who are based in developing countries.

Smart Design of Stand-Alone Solar PV System for Off Grid Electrification Projects

Solar PV has seen a remarkable growth across the globe with the total PV installation now exceeding several gigawatts (GW). The technology has the versatility and flexibility for designing systems in different regions, especially in remote rural areas. While conventionally straightforward designs were used to set up off-grid PV-based systems in many areas for a wide range of applications, it is now possible to adopt a smart design approach for the off-grid stand-alone solar PV system. A range of off-grid system configurations are possible, from the more straightforward design to the relatively complex, depending upon power and energy requirements, electrical properties of the load, as well as on site specificity, and available energy resources. The overall goal of the off-gird system design should be such that it can give maximum efficiency, reliability and flexibility of the system at an affordable price. In this chapter, the three basic PV systems, i.e. stand-alone, grid connected- and hybrid-systems are briefly described. Assessment of energy requirement including load profiling, load distribution and load categorisation is provided in a lucid way. That is then matched with a section on solar resource availability. Furthermore, a systematic approach has then been presented regarding sizing and designing of the above systems. Guidelines for selection of PV components and system optimisation are provided. Owing to the natural variance of the solar resource there is a critical need for storage batteries to satisfy energy demand during nocturnal and overcast periods. Furthermore, under a highly variable cloud regime there is a frequent demand for charging and discharging of battery in a PV system. So, the type of battery used in a PV system is not the same as in an automobile application. Detailed guidelines for selection of battery are therefore also provided.

Smart Systems and Smart Grids for Effective Governance of Electricity Supply in India

Despite several reform measures, the electricity sector in India is grappling with multiple challenges including significant system losses, supply shortages, demand management and integrating renewable energy into the system network. At the same time institutional arrangements and relations have also transformed and consumers are asserting their demand for improved quality and services through the regulatory process. Both utilities and policy makers see Information and Communication Technology (ICT) as an important tool in meeting growing aspirations in the electricity sector. Many state utilities have improved their interaction with consumers through IT enabled web-based systems. Some are providing billing, payment and grievance redressal facilities online. Utilities also see significant use of ICT in improving operational efficiencies, theft detection, mapping of assets, managing load, outage management, etc. Integration of all urban basic services as envisaged under a smart cities, requires collection and analysis of electricity consumption data on real-time basis. Most utilities have deployed, automated meter reading (AMR) systems, prepaid meters and time of day meters for large revenue industrial consumers. In future, advanced Metering Infrastructure (AMI) compatible smart meters are expected to facilitate two-way communication between utilities and consumers. A Smart Grid Vision for India has been drafted to ‘transform the Indian power sector into a secure, adaptive, sustainable and digitally enabled eco-system that provides reliable and quality energy for all with active participation of stakeholders’. With part funding from the central government, state utilities are experimenting with smart pilot projects and if successful and effective, these pilots would be rolled out in a bigger way. The Energy and Resources Institutes (TERI’s) recent initiative on making a renewable-based mini-grid smart showcases the possibility and utility of smart technologies in load management and reduced need for human intervention. The drive for smart grids and smart cities would certainly improve quality of civic life. However, it would require huge investments, resources and greater co-ordination between state level electricity providers and city governments. The investments envisaged will result in greater stress on state and city governments and ultimately on consumers. Hence, policy makers and regulators will have tread cautiously and weigh the costs and benefits of the smart initiatives in light of the equity objectives of the country.

Approach for Designing Solar Photovoltaic-Based Mini-Grid Projects: A Case Study from India

Having the largest rural population in the world, India confronts a huge challenge for rural electrification, especially for electrifying remote, forested and tribal habitations. Solar Photovoltaic-based mini-grids have emerged as a viable option for the provision of electricity in such remote rural locations, where grid extension is either not techno-economically feasible or electricity supply is intermittent. Very often such projects are purely technology-driven and several attempts at delivering electricity services to such remote locations have not succeeded, owing to the lack of adequate attention given to important socio-economic factors such as promotion of livelihoods or the creation of strong local institutions that can own, operate and manage the project over its lifetime. This chapter aims to present an interdisciplinary framework for the development of mini-grid projects in remote rural locations, developed from field experience of actual implementation of projects by TERI. Using this framework as a guide, TERI has commissioned solar photovoltaic-based mini-grids in a cluster of five villages in the state of Odisha. The detailed design methodology, including modifications to standardised practices in order to customise and improve the performance of these solar mini-grids is presented in this chapter as a case study. It is expected that the process followed and the resulting design will serve as a useful guide for renewable energy practitioners and researchers working in remote rural locations for provisioning of electricity services.

On-field performance assessment of power converters of solar PV system under different operating conditions

Renewable Energy (RE) system, specifically Solar Photovoltaic (SPV) systems are expected to have a significant impact on the power scenario of many countries across the world in near future. Although most of the RE systems are not technologically new, they have received increased attention because of their ability in providing peak power demand, backup power, improved power quality and reliability to the power grid etc. All the RE systems require specific power electronic converters to convert the power generated into useful power that can be directly interconnected with the utility grid and/ or can be used for specific consumer applications locally. The roles of these power converters become very critical, particularly when it is used in one of the most expensive energy generating sources such as solar PV. These power converters need to be designed optimally in order to provide maximum energy efficiency, ensuring reliability and safety of the overall solar PV system. For this purpose, the performance of the power converter at different operating conditions has to be assessed and subsequently the findings can be provided to the system design community for designing and developing appropriate power converters for different solar PV systems. The paper will present the on-field performance assessment of the power converters used in the experimental setup of a 7kWp(kilo-Watt Peak) solar PV system in one of the research facilities of TERI. Currently the 7kWp SPV system is connected to the local distribution grid through a DC-DC converter with MPPT and an inverter. It is used to meet the continuously varying daytime load of the research facility. The paper will bring out the experimental research findings of the actual setup under different operating condition to show how well the PV system is able to meet the local loads.

Electric vehicles: Status and roadmap for India

Abstract In India, transport sector is one of the fastest growing sectors. Within this sector, two-wheelers are the dominating sector, which accounts for almost 75% of total vehicle in country. These increasing numbers of vehicle raise the local challenges such as congestion on road and deterioration of air quality. Currently, transport sector is one of the major contributors of CO 2 emission and as per 2012–13 data; the transport sector is responsible for 14% of Indias energy-related CO 2 emissions. An assessment carried out by Central Pollution Control Board surveyed that 75% cities are at very high risk of PM 10 levels. Out of these, 50% of cities have critical level of NOx as well. Road transport, which is the main mode of transportation in India, has experienced increased activities in terms of increase in the number of vehicles. This is because as household income increases, the need to use an improved form of mobility also increases and households tend to move from nonmotorized to motorized form of mobility. The Indian auto industry is one of the largest in the world with an annual production of 23.37 million vehicles in financial year (FY) 2014–15, following a growth of 8.68% over the last year. The automobile production grew at compound annual growth rate of 10.5% over the last 10 years in India and is expected to grow at the same rate in near future. The chapter presents the overview of the programmes and policies with respect to electric vehicle in India.

PV System Design for Off-Grid Applications

Solar photovoltaic (PV) technology has the versatility and flexibility for developing off-grid electricity system for different regions, especially in remote rural areas. While conventionally straight forward designs were used to set up off-grid PV-based system in many areas for wide range of applications, it is now possible to adapt a smart design approach for the off-grid solar PV hybrid system. A range of off-grid system configurations are possible, depending upon load requirements and their electrical properties as well as on site-specific available energy resources. The overall goal of the off-gird system design should be such that it should provide maximum efficiency, reliability and flexibility at an affordable price. In this chapter, three basic PV systems, i.e. stand-alone, grid-connected and hybrid systems, are briefly described. These systems consider different load profiles and available solar radiations. A systematic approach has then been presented regarding sizing and designing of these systems. Guidelines for selection of PV components and system sizing are provided. Battery energy storage is the important component in the off-grid solar PV system. Due to load and PV output variations, battery energy storage is going to have frequent charging and discharging. So the type of battery used in a PV system is not the same as in an automobile application. Detailed guidelines for selection of battery are therefore also provided. At present, most of the world-wide PV systems are operating at maximum power points and not contributing effectively towards the energy management in the network. Unless properly managed and controlled, large-scale deployment of PV generators in off-grid system may create problems such as voltage fluctuations, frequency deviations, power quality problems in the network, changes in fault currents and protections settings, and congestion in the network. A possible solution to these problems is the concept of active generator. The active generator will be very flexible and able to manage the power delivery as in a conventional generator system. This active generator includes the PV array with combination of energy storage technologies with proper power conditioning devices. The PV array output is weather dependent, and therefore the PV power output predictability is important for operational planning of the off-grid system. Many manufacturers of PV system power condition devices are designing and developing new type of inverters, which can work for delivering the power from PV system in coordination with energy storage batteries as conventional power plant.

PV Component Selection for Off-Grid Applications

Although component selection is one of the major tasks of the PV system design and installation, it is often overlooked and poorly integrated within the thought process. This particular aspect needs to be given special attention and awareness ought to be created amongst the installer. This chapter deals with the guidelines, methodology and approaches that need to be adopted for the appropriate selection of the components used in the solar PV-based off-grid application. These approaches are developed based on the state-of-the art system design as well as field experience and extensive research work carried out by the authors in this sector. This chapter will help readers in understanding the importance of each component of the solar PV system which may significantly affect its performance. Further, it will guide the implementers and designers in proper selection of the solar PV components for off-grid applications.