technologies. Solar power in India has an ambitious ... 500kV HVDC lines and back-to-back links. ... 2014, the Indian Grid became the largest synchronously.
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Recent Trends in Sustainable Development of Renewable Energy Dr.S. Elangovan Assoc. Prof., EEE Department, Jansons Institute of Technology, Coimbatore, India. Abstract— Sustainable development is the optimum use of natural resources and adoption of advanced technologies. Solar power in India has an ambitious target and is expected to achieve grid parity by 2022. The national grid is a hybrid AC/DC transmission system. This operates synchronously with five regions including the North-East with 765kV and 400kV AC with +/500kV HVDC lines and back-to-back links. Renewable energy sources viz. wind power integration pose technical challenges to the grid, including reactive power and stability. Hybrid AC/DC Micro grid consists of conventional AC grid in combination with a DC grid. Power sources to the Micro grid can be any combination of renewable sources. An emerging trend is that home loads are moving towards DC. Transport sector is witnessing the growth of hybrid electric cars and buses. Electric buses run on Li-ion batteries due to their technical advantages. Alternatively, Ultra capacitors are used when fast-charging is required. Energy-efficiency is becoming more relevant in all areas eg. Motors and transformers. The Indian Standard for distribution transformers has been revised in Nov. 2014 to bring it on par with corresponding International Standards. Keywords— Emerging Trends; Energy-efficiency; Hybrid AC/DC Power system; Micro-grid; Renewable Energy; Sustainable Development; Transport sector.
lighting, TV (LED/LCD). DC motors are extensively being used in various home appliances: ceiling fans (brushless DC motor), air-coolers, refrigerators and washing machines. Air pollution is a major problem faced in our cities mainly due to diesel driven vehicles. Electric buses are a good alternative in the public transport sector to tackle this problem. Two major technologies must be mentioned here. The first is Li-ion battery technology with its advantages of high specific power and specific density. Another technology in electric buses uses Ultra capacitors which can be charged and discharged quickly which is a major advantage. This paper attempts to trace some of the emerging trends in the Indian context.
II.RENEWABLE ENERGY Sun is an abundant source of renewable energy. The combination of Solar-DC and Electric vehicles is seen as a great opportunity for India to reduce air pollution and combat Climate change [1]. Realizing this, the Indian Government has set an ambitious target for 100 GW of solar energy by 2022 [2]. Refer Fig.1. The concept of grid parity for solar implies that the cost of solar power generation is equal to the cost of power generated from conventional sources eg. Coal.
I.INTRODUCTION Sustainable Development, Renewable Energy and Climate change are so closely inter-related that it is difficult to discuss these separately. If we trace the technological advances in the electrical field in the last few decades, we can be proud that we have embraced these technologies whether it is HVDC or Solar/Wind or Smart grid. In Jan. 2014, the Indian Grid became the largest synchronously operating grid in the World. Many technical challenges still lie ahead: Access to electricity, Large-scale Grid integration of renewable sources, Electric Vehicles. Micro grids with multiple energy sources feeding AC and DC home loads at distribution level are envisaged in the future power scenario. Energy-efficiency and energy conservation are being actively promoted by the Government. This point is illustrated in this article by focusing on energy-efficient distribution transformers. Home appliances are becoming more efficient: eg. LED
Fig. 1. Solar Energy Target by 2022 The latest bids for solar power called by Tamil Nadu (TN) witnessed the lowest bid at Rs. 6.48 per unit. The commercial tariff in TN is Rs. 7 per unit. Another example is Rajasthan where the lowest bid was Rs. 6.45
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as against the commercial tariff of Rs. 5.50 in that state [3]. So, grid parity for solar power may be reached sooner than expected.
III. CLIMATE CHANGE Globally, there is a concerted effort to move away from fossil fuels. India is a signatory to the Paris Climate change Agreement of Dec. 2015. As per the requirements of this Agreement, India has submitted to the United Nations Framework Convention on Climate Change, (UNFCCC) a strategy for reducing emissions. This document, known as India’s Nationally Intended Determined Contributions (INDC) [4], outlines a definite plan of action and outcomes covering a wide range of sectors. According to INDC, about 40% cumulative installed capacity will come from non-fossil fuel based energy sources by 2030 and all the measures will reduce emissions intensity of GDP by 33 to 35% in 2030 from 2005 levels. Recently, International Energy Agency has published a special report titled “India Energy Outlook” [5]. CO2 gas is taken as the base for comparison of Green House Gas (GHG) emissions and the unit is 1 tonne of CO2. India’s emissions can be viewed in two ways: First in terms of the volume of CO2 emitted: India (2.47 billion tonne CO2) is the fourth largest emitter of GHG next to China, (10.7 billion tonne CO2) Russia and the USA. Secondly in terms of the per capita basis (ie., the total volume of CO2 divided by the country’s population). As a comparison, India’s per-capita emissions (1.9 tCO2) are extremely low, at one-fourth that of China’s (7.7 tCO2). It was at 1.5 tCO2 in 2013 (around 1/3rd the global average). According to projections, it will reach 3.2 tCO2 in 2040 compared to the global average of 4.1 tCO2. This is illustrated in Fig.2 [4].
loss of 0.9 W/kg at 50 Hz and a maximum flux density of 1.7 Tesla are available in India. This, together with advanced computerized design techniques has contributed to the advent of “energyefficient” distribution transformers. The Indian Standard 1180 (2014) specifies the maximum permissible losses at 50% and 100% loading conditions for mineral oil filled distribution transformers starting from 16 kVA upto 2500 kVA rating and 33 kV primary voltage. There is excellent export market potential for energy-efficient distribution transformers. Indian distribution companies are also becoming increasingly aware of its benefits in the longrun. The distribution loss is projected to come down to 16% by 2040 from the current level of 20%[5].
V. TRANSPORT SECTOR Air pollution is a major problem facing Indian cities due to an increasing trend in motorization. Hence there is a need to promote public transport with clean sources such as Electric buses. A recent report prepared by the Global Green Growth Institute and Centre for Study of Science, Technology and Policy has recommended a widely used technique known as the “Avoid-Share-Improve” framework [for achieving alternative mobility solutions. [6].
Fig. 3. Avoid-Shift-Improvement(ASI) Framework
Fig. 2. GHG emissions in 2013 and 2040
IV. ENERGY EFFICIENCY It is necessary to understand why energy-efficiency is important now more than ever. With the advances in various technologies, new products and services are introduced in the market. In the electrical industry, distribution system loss is a major area of concern. A major portion of the system losses occur in the distribution transformer. Cold-rolled Grain-oriented (CRGO) steel lamination contributes to the fixed loss component, while the variable part is due to I2R copper loss. Core loss is a function of the quality of steel lamination and its thickness. Laminations of 0.23 mm thickness with a low hysteresis
Fig. 4. Li-ion cell (Source: Karlsruhe Institute of Technolgy) PM2.5 denotes particles (dust or due to vehicular emissions) of size less than 2.5 microns and is considered to be most harmful to health. The National Ambient Air Quality Standards(NAAQS) has set an annual average 149
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limit of 40μg/m3, whereas the World Health Organization(WHO) has a more stringent limit of 10μg/m3. Petrol and diesel vehicles are designated as Bharat Stage followed by a numeral. Higher the stage, more stringent is the Standard. BS III norms (350 ppm sulphur content in exhaust) were withdrawn in Apr. 2010. BS IV norm (50 ppm) was made mandatory from Apr. 2017. BS V norm may be skipped and a more stringent BS VI is proposed from April 2020 [6]. Li-ion batteries have proven to be the most promising for electric vehicles. They combine a high specific power (300 Wh/kg), a high energy density (90 – 140 Wh/kg) and a low self-discharge rate over time. Additionally, their low weight and endurance of high temperatures make them suitable for usage in Electric buses. Li-ion batteries are able to endure approximately 1000 – 1500 loading cycles. The batteries consist of an oxidized cobalt material on the cathode and a carbon based material on the anode. Lithium salt is used as the electrolyte. Refer Fig. 4. However, Liion batteries are still expensive in production. Also, the electrolyte is highly inflammable and it requires a sufficient battery management system [7].
VI. MICRO GRIDS The Indian power grid is on the threshold of a great revolution. The high voltage grid consists of 765kV AC and +/- 500kV HVDC lines and back-to-back links. Large scale integration of solar and wind renewable energy sources is gaining momentum with a dedicated Green Energy Corridor [8]. At the distribution level, micro-grids are evolving with home loads catered to by both ac and dc lines. The dc lines can act as an uninterruptible power supply in case of partial failure of ac supply (brown-outs) [1]. Smart grid can be defined as the evolution of a new power grid encompassing Information and Communication Technologies (ICT). It includes the use of smart meters (digital energy meters), and Advanced
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meter infrastructure (AMI). Smart grid at the transmission level involves the use of Phasor Measurement Units (PMU) for improving power system stability [9].
VI.CONCLUSIONS In this paper, Sustainable development is possible by adopting a multi-pronged approach to the development and adoption of new technologies. Unless R&D is done in-house, we will be forced to pay for the high technological costs e.g., Highly efficient solar panels. India has a vast pool of engineering talent which can be harnessed in the areas of R&D. This is a slow and painful process but will pay rich dividends in the long-run.
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[7]. [8]. [9].
Ashok Jhunjhunwala, “Solar DC and Electric Vehicles – An Opportunity for India” IST E-magazine Sun & wind energy magazine, Aug 2017, www.sunwindenergy.com. UNFCCC, “India’s intended nationally determined contributions – working towards climate justice”, Dec 2015. International Energy Agency, “India Energy Outlook – World energy outlook Special report”, 2015. Global Green Growth Institute and centre for study of science, technology and policy(2015), “Electric buses in India: Technology, Policy and benefits,GGGI, Seoul, Republic of Korea. Michael Benz, “Techview report – Electric buses – Fraunhofer MOEZ”, European business and technology Centre (EBTC), 2015. Report by Central Electricity Authority, “Large scale Grid integration of Renewable energy sources – way forward” Nov 2013. India Country Report – Research, Development, Demonstration and Deployment of smart grids in India, Govt. of India, Ministry of Science and Technology, New Delhi, June 2017.
