Integrating Wind And Solar Energy

Published Date: 02 Nov 2017

Network Visualization.

Figure17:

Figure18:

Introduction:

General overview:

However, the demand has been consistently outstripping the supply even as availability of power has increased due to substantial/ significant investments on the supply side. India faces the challenge of poor reliability and a not up to mark quality of electricity, leading to frequent blackout situation in one part or the other . India has witnessed substantial energy and peak shortages of 8.5% and 11% respectively in the year 2011-12 [1] .

The Indian power sector has been going through evolution, from vertically involved public utilities to unbundled entities, especially with more private assets joining in on the generation side. The changes have brought a steady improvement in efficiency and competition and offer contingency management with better price signals to incentivize the market participants across the value chain. Banking on the inspiration from these changes, India targets to set up substantially high 88 GW of capacity in the 12th plan which may suffice the ever growing demand to a large extent. To better understand the state of the Indian power sector, a deeper analysis of all the three components i.e., generation, transmission and distribution is required.

Figure1: Indian Electricity Generation by Type, 2000-2009

Source: US Energy Information Administration, International Energy Statistics

1.1 Generation

The power generation industry in India is going through rough times. The sector is battling several issues, largely consanguine to fuel shortages, which could slow down the industrious pace of capacity addition witnessed in the past couple of years. In 2011-12, a record capacity addition of over 20,500 MW in a single year was registered in the sector, taking the total capacity addition in the 11th plan period to about 55,000 MW [2] . A significant contribution was reported from the private sector with a share of over 58 percent during 2011-12 and 42 percent during the entire 11th plan period. As on July 31 2012, India’s installed capacity (excluding captive plants) stood at 206,456 MW [3] . Thermal sources continued to dominate accounting for two thirds of the capacity at 137,386 MW, followed by hydropower (19 % or 39,291 MW), renewable energy (12.1 percent or 24,998 MW) and nuclear power (2.3 % or 4780 MW). The traditional power generation industry is at a juncture where the issues like Capacity Additions, enhanced reliability of supply of power and quality of supply which needs to be addressed quickly, are paving way for more investments and easier regulatory norms for absorption of more and more renewable energy in the Indian National Grid. India’s power generation sector is mainly based on thermal plants employing the use of coal. It is ironical that India with the fourth largest coal reserves in the world is perpetually struggling to meet its coal demand by way of deficient coal production because of various policy and infrastructural bottlenecks. The issues faced by the generation sector are:

Coal and gas shortages: Thermal power generation suffered a shortfall of 20 BUs during 2011-12 – 9 BUs and 11 BUs due to a shortage of coal and gas respectively4.

Figure2: All India Installed capacity (as on 30th November 2012)

Source :CEA

Slowdown in hydropower capacity addition: Capacity addition from hydropower sources slowed in the past couple of years. The year on year growth rates declined to 3.8 percent 2011-12 from 7.2 percent in 2006-07. This can be mainly accredited to geological changes, to some extent on local issues, deficiencies in survey and investigation, lack of transparency in the process of award of contracts and inadequacies in project of execution.

Brake in nuclear power: In the post- Fukushima scenario, the opposition to nuclear power in the country has gained ground. Although India has decided

to proceed with its nuclear agenda with greater safety measures, local agitation against the upcoming nuclear projects could adversely impact its

nuclear power ambition

1.2 Transmission:

Figure3: Existing transmission lines and expansion

Source: http://www.metisbs.com/page.php?cid=53

During the 11th plan period (years 2007- 2012 ), open access in transmission had been introduced to promote competition amongst the generating companies who can now sell to different distribution licensees across the country as well as consumers having demand more than 1 MW [4] . The growth of transmission system can be summarized as in figure 4.

Though elaborate and multi faceted legislations such as the Electricity Act, 2003 and IEGC are in place, the effective implementation of these legislations is essential. Greater executing powers need to be bestowed upon the central and the state regulators as well as the system operators. The issues that need to be addressed at present for both public and private transmission project developers are procedural delays in land acquisition; obtaining RoW, environmental and related statutory clearances; and equipment deployment, particularly in hostile terrain.

Figure 4: Growth of transmission system in India

Source: CEA

1.3. Distribution:

Cost Generation and Tariff:

During 2007 to 2011, the overall unit cost had increased by 21% but the rise has not been comparable or even proportionate with the increase in the cost of supply. As a result the gap between the cost of supply and the average tariff has been widening over the years. The financial position of the electricity distribution sector has been a concern for over a decade now. The state owned distribution utilities to remain financially and commercially viable is a million dollar question and is putting at risk the significant investments being pumped into the electricity sector by private and public players.The investment to the tune of 300000 Million US Dollars is the financial risk taken by Indian Public Sector Banking Industry [5] .

The estimated loss of all the State distribution utilities has been estimated at Rs 2.4 lakh crore as of March 31, 2012 [6] .

Distribution companies, mostly state-owned, are mired with about $35 billion in debt [7] .

Tariffs haven't been revised since last ten years leading call for higher subsidies to be inducted in the sub sector to cover costs of inefficiencies, indifference of consumers towards the efficiency of the appliances used by them, augmentation of distribution network to ever changing profile of consumers in terms of quantum of consumption ,spatial, distribution in time and space , nor has electricity theft been checked to the extent that feasible, leading to the accumulated commercial losses to the tune of 35 US$. The electricity distribution losses are huge losses as high as 40% in some states, while the country-wide average is 27 % [8] .

The current AT&C losses vary across state utilities in the range of 12.22%(Himachal Pradesh) to 72.86%( Jammu &Kashmir,to the some extent owing to the fact that the consumers are thinly populated; while the national average was about 26% in the year 2010-11 [9] .

Figure 5:Cost of power supply (paisa/kWh sold)

Source: Annual report on working of state power utilities and electricity departments 2011-12

2. Aging electrical grid of India and its prognosis:

On July 31 2012, India was reeling under the largest electrical blackout in history, affecting an area encompassing about 670 million people, or roughly 10 % of the world’s total population. Three of the country’s interconnected Northern Power Grids crumpled and were left dead for several hours, as blackouts extended almost 2,000 miles, from India’s eastern border with Myanmar to its western border with Pakistan [10] . Such an enormous power failure would pave way for more stringent regulations that need to be adhered to in truest sense to the chain of electricity delivery system in the power sector. Indian authorities should leave no stone unturned to augment the supply chain of electricity delivery system so as the fragile and weary electrical power delivery system of India is mended to the extent that such blackouts do not occur in the future.The primary difference is of adaptability if way blackouts occur in India is compared with that of some other country where electrical supply is far more reliable. The Indian electrical system is conventionally rated as a fragile and an unreliable system lacking considerable self healing and progressive capabilities that tend to have a cascading effect on the overall health of the electrical system. Issues facing India’s electrical system have been discussed rather generously considering they seem to be pivotal to the growth of India’s power sector.

Power Generation and infrastructure:

Experts dealing with the ministry of power reflected on the August 2012 blackout as an accident waiting to happen. The rapid development of the country has put an acute stress on the Indian power delivery chain . It is highly dependent on coal for 70% of its generation and is experiencing perpetual coal shortages. India has about 10 % of the world's coal reserves but output by the near-monopoly Coal India has stagnated,whereas importing coal is far more costlier option coupled with lack of rail connectivity from port to power stations holding up coal supply to power stations [11] .It may sometimes so happens that one more power stations do not have even one day’s coal stock. Such an eventuality is critical to grid security and its uninterrupted continuous operation. Perhaps the biggest challenge, though, is the health of decrepit distribution companies that depend on subsidies and face huge losses from low tariffs and rampant power theft. Together, they are now saddled with debt worth some $35 billion and are increasingly unable to pay for new supplies. Many of the state run electricity companies, which collectively lose $4.5 billion per year, are essentially bankrupt [12] .

Figure6: India’s Coal Production and Consumption

Source: www.gregor.us

Supply, Demand and Unofficial Connections:

Power infrastructure in India cannot be considered capable of providing sufficient and reliable power supply that westerners take for granted. Some 300 million people have no access to electricity since the grid does not reach their areas. While India ranks sixth in the world in terms of overall electricity production and consumption, its population of 1.2 billion means that per capita levels of electricity consumption remains low at just over 500 kWh per person per year,as compared to more than 2,600 kWh in China and nearly 12,000 kWh in the United States [13] .

To efficiently manage the power supply and hence providing quality power to the consumers is an uphill task considering the steady increase in the demand that offsets the demand supply equation. According to government regulations in the country each consumer has to declare the type of connections required by him. Often this is not observed because of the lack of knowledge and non-committal attitude of the consumers to affairs of the distribution company To add to it some consumers operating industrial loads also declare their connections for residential purposes. This practice has a cascading effect and escalates at the end to the DISCOMS that have to bear the losses. Even when India boasts of a highly industrialised economy and the emerging urban lifestyles, the facility of an electrical connection still seems to be out of reach of many, most particularly the residents of slums. This definitely does not mean that slums are looming under dark but that unofficial power tapings are common in such areas.

Blackouts - Planned and Unplanned:

The blackout of July 2012 seems to have its roots in Agra in the state of Uttar Pradesh where transmission lines were carrying twice the permitted load. When the Agra-Gwalior line went down, the effect was a cascade, with lines tripping one after the other. The impact of the blackout was considerable and noticed to a large extent. People were trapped in the metros and lift systems with help reaching them after a long time [14] . The cooling systems came to as grinding halt leaving most of the populace of central India under the mercy of the summer heat with temperatures touching around 37 degree Celsius in certain parts. Massive traffic jams formed in New Delhi as traffic lights went out. Electric crematoria ceased to function. Hundreds of miners were trapped underground. Water supply was heavily impacted. Some hospitals faced major difficulties in the following days. How India differs from western countries is the way blackouts are treated here. In India, the issue is not whether or not there will be a blackout. People know that there will be, often for several hours every day. They prepare for outages and take them head on. The difference is between planned and unplanned blackouts. Planned outages are called rolling blackouts and are a common scene in many places across the country. A rolling blackout also referred to as load shedding refers to an engineering technique employing an intentional electrical shutdown where electricity delivery is stopped for non-overlapping periods of time. Rolling blackouts are a common or even a normal daily event in many developing countries where electricity generation capacity is underfunded or infrastructure is poorly managed. Where outages are scheduled, people adjust their activities accordingly. However, unscheduled disruption is tolerated, so long as it is an organized disruption [15] .

Figure 7: August 2012 blackout Frequency VS Time graph

Source: IIT Bombay

Transmission and Distribution losses:

Figure 8: T&D losses in the system

Source: T&D losses, An Independent study(www.teriin.org)

Environmental ramifications of the power sector:

In India power shortage is not the only issue but its spread is an equally serious issue. Traditionally resources for electricity generation would be foraged using the simple theory of "cheap is good". Although essentially important there are certain other parameters that need to be taken care of such as social, environmental and technological benefits and consequences of the energy sources selection [16] . A figure showing the comparison of different energy sources for life cycle emissions is shown.

Figure 9: Comparison of Life- Cycle Emissions(Tons of carbon dioxide equiv. Per Gig watt Hour)

Source: University of Wisconsin

It can be easily seen that Coal has the maximum global warming potential followed by Natural Gas and others. In a developing country like India the economics of producing electricity is of paramount concern while planning for the type of plant to be installed and commissioned and more so with the abundant supply of coal. However if the consequences of prolonged use of coal for producing electricity on human health and environment and cost as well as efforts required to improve or alter the path of degradation, it seems the initial low cost of using coal seems a strategically bad idea when compared to renewable resources for producing electricity. Taking into account the growing economy of India compared to other countries in the west, switching to a cleaner sources of energy is more of a multi step mechanism rather then a single step. There is an urgent need for transfer of technology and development of other financial instruments from the developed world. India is 145th in the world in the release of 1.25t CO 2 per annum [17] .

3. Prognosis and Smart Grid Introduction:

In an axiomatic sense, our country’s electric power framework that has served us for a long time –known as "the grid" is finally running up against its limitations. Having electricity supply in our homes for most of the time does not mean that the grids capabilities be taken for granted. The establishment of the present electric power system dates back to over a 100 years when the main purpose of the power system was to evacuate power from generating stations employing the use of coal to residential consumers that needed the electricity mostly for lighting purposes. Power generation was localized and built around communities. With the advancement of technology and industry the needs of the civilization grew and ultimately the generation sites also grew to facilatate the needed power. But with the increasing size of the electrical grid, optimisation and complete control couldn’t be satisfied by mere increasing the number of generation sites [18] .Today the electrical power system delivers power to industry, commercial and residential consumers, trying miserably to cope up with the ever growing demand. Systematically the hazards accompanied with relying on an overburdened grid grow in size, scope and convolution with every moment passed. The present limited one way interaction makes it difficult for the grid to respond to the ever changing and rising energy demands of the 21st century .To do justice to the Ministry of Power’s "Vision 2027" involving transformation of the Indian Power Sector into a secure, adaptive, sustainable and digitally enabled ecosystem by 2027 that provides reliable and quality energy for all with active participation of stakeholders, the power infrastructure needs to be upgraded [19] .

Figure 10: Smart Grid over Traditional Grid

Source: International Energy Agency

A smart grid makes the transformation from a traditional one way grid to a highly connected and assertive grid possible by bringing the philosophies, concepts and technologies enabled to the grid. More importantly, it enables the industry’s best ideas for grid modernization to achieve their full potential [20] .

A cloud definition of the smart grid consists of introducing a two way dialogue by which electricity and information can be exchanged by a utility and its customers. It’s a developing network of communications, controls, computers, automation and new technologies and tools working harmoniously to make the grid more efficient, more reliable, more secure and greener. The Smart grid enables newer technologies to be integrated such as wind and solar energy production. The smart grid will soon replace the aging electrical infrastructure and can ensure optimised and green electricity to be used productively. The power system needs in India are not necessarily the same as those in the advanced and industrialized countries. The same goes for the most important power system constraints. Generally, not all smart grid technologies are equally relevant worldwide. In India, the really useful technologies will be those that help constrain peak demand and peak load growth at reasonable cost while cutting losses. There is as yet no internationally unified definition of a smart grid [21] .

4. KEY DRIVERS OF THE SMART GRID IN INDIA:

India is relatively in a preleminary stage of its Smart Grid deployments with many technologies such as advanced metering, still at a very crucial juncture and being reviewed and tested at certain pilots identified in the country. Such technologies are undergoing various trials and advanced testing before they will be deployed all over the country. The coherence of many factors will drive India’s adoption of smart grids such as reducing all technical and commercial losses, resolving the ceaseless supply demand gap, and have a heading to upgrade its infrastructure to a more advanced electricity supply solution to flatter its sustainable, low carbon high growth economic development goals.

Certain factors will drive the adoption of the Smart Grid in India:

Supply shortfalls and Unrelenting Increase in the electricity demand:

Demand especially peak demand of electricity is continuously outpacing the India’s Power supply. With an unmatched growth in the economy and a prosperous industrial arena more and more households are able to afford electrical appliances leading to a fair increase in the demand of electricity. Industries also require a consistently increasing power supplying to match the peaking curves of the industrial growth. Officially India is falling short by around 12% for energy demand while as 16% for peak energy demand. Addressing the needs of the growing economy and satisfying the needs of a developing society are the primary drivers of the adoption of smart grid technologies in India. In India’s high growth economy the demand for electricity is forecasted to grow by about 10 % per year as long as the already present gap isn’t closed.

Figure11: Region wise supply and demand for 2012

Source: CEA yearly reports

Distributed Energy Resources (DER’s) and subsequent loss reduction:

A Smart Grid can make a substantial contribution of reducing losses by allowing integration of DER’s that can allow localised generation hence reducing the transmission and equipment losses. A Smart Grid allows system operators to integrate many renewable energy sources locally which can not only supply energy needs to the local community but also supply power to the grid hence giving a soft spot to the use of natural local resources for the benefits of power supply and cost reduction.

Distributed resources (DR) is a term that envelops both distributed generation (DG) and distributed energy storage (DS). A distributed utility will use both distributed resources and load management to accomplish its goal. To add to it, several compact DG technologies are fast becoming economically feasible. Integration of DG into an existing structure results in several benefits. These benefits consist of line loss reduction, reduced environmental impacts, peak shaving, increased overall energy efficiency, relieved transmission and distribution congestion, voltage support, and deferred investments to upgrade existing generation, transmission, and distribution systems. Benefits are not limited to the utility. Customers also benefit from DG in term of better quality of supply at lower cost. Among the many benefits of distributed generation is a reduced line loss [22] .

Managing the human element in system operations:

Many system reliability predictive methods are based solely on equipment failures neglecting the human component of man-machine systems. These methods do not consider the identification of the root causes of human errors. The reliability and safety of industrial and commercial power systems and processes are dependent upon human characteristics and many dependent and dynamic interactive factors. The consequences of human errors are very diverse and can range from damaging equipment, property, causing injury to personnel or be fatal, to disrupting scheduled system operation, a significant cost to society [23] . Indian contracts for outsourcing are relatively inexpensive and thus labour saving is not a prime driver for Smart Grids in India. AMI (Advanced Metering Infrastructure) would definitely prove pivotal in reducing recording and other errors such as "shade tree" readings or even deliberate errors that are significant reasons for losses. AMI can also bring about a better UI ( User Interface) where the user can participate in a much interactive way and the involvement thus can lead to a better monitoring of the energy usage which can as well reduce the bill and better monitor the peak time usage.

Figure 12: Advanced Metering Infrastructure

Source: https://www.psoklahoma.com/save/SmartMeters/HowSmartMetersWork.aspx

Peak Load Management:

Smart Grid, which is driven by need has a different priority for each country, In the west, It is driven by labour cost, renewable energy, and EV to reduce carbon footprint. For India, managing peak load will be the key driver for its deployment. Energy cannot be stored for long duration in large scale and has to be increased to take care of the demand or the demand reduced. At present, in the west, it is managed by increasing supply through peaker plants, which are managed at high cost and are priced accordingly to the consumer. If India follows the western model, the price of electricity will rise by 35%, a very expensive proposition for a developing country like India [24] . India’s supply demand gap is wide enough to persist for many years. A Smart Grid can allow more "perceptive" load control, directly or indirectly. A Smart Grid can control the appliances switching off the less important ones so as to reduce the usage to prevent peak time shortfall and hence preventing outages and load shedding. This can be done by either communicating to the consumer about the economic pricing incentives in a dynamic manner or by having a real time protocol to allow utilities have a direct control on the devices and setting less important tasks for a time when electricity is cheap and hence acting as a buffer for fluctuations in the peak energy supply. By incentivizing the operation of appliances the consumer can b control the amount of load they are using in a better way. Such measure can to an important extent mitigate the supply-demand gap. Simply by connecting to consumers – by means of the right price signals and smart appliances, for example – a smarter grid can reduce the need for some of that infrastructure while keeping electricity reliable and affordable. As noted, during episodes of peak demand, stress on the grid threatens its reliability and raises the probability of widespread blackouts [25] .

Figure 13: Smart grid provides a two way communication

Source: Smartgridnews.com

Renewable Energy:

The Indian renewable growth story has been performing a constant steep increase in the past couple of decades. Even though a significant contribution to the power generated has been obtained from the hydro power with almost 20 % still being obtained from this sector, it hasn’t progressed much on utilizing the other renewable sources of energy. Recently it has starting foraging into other renewable energy sources. Wind power being the most prominent face of renewable energy for the past decade or so. Since 2010 significant activities in a few other renewable energy sectors such as solar have also been observed. With the inception of the industrious National Solar Mission in 2010 and the consequent successful operation of the initial stages the Indian government has shown its eagerness in harnessing the significant potential that solar presents for India. India can also utilise other renewable energy sources such as small hydro and biomass and there is a huge potential for it. Some segments that show little activity currently - like wave, tidal and geothermal, for instance – have the potential for significant growth in future. As many of the renewable energy sectors are nascent, there is significant need and eagerness from Indian corporate – for technology transfer from companies who are at the cutting edge of clean technology. To successfully integrate clean power from renewable sources such as wind and solar energy, utilities will need a smart grid to manage problems caused by intermittency (the sun and wind only happen during certain times of the day) and distributed power. Spurred by environmental concerns and the desire to tap into all the available sources of power, this move can also be a primary smart grid driver [26] .

Technological Leapfrogging:

A chance to leapfrog into a new future of electricity is perhaps the most intriguing driver for India to address regulations and policies for making the grid "smart". The "smart" in a Smart Grid is an ICT-an area of unique capability in India. For India deployment of a Smart Grid involves not only addressing domestic energy challenges but also executing its policy to become a superpower as it involves technology standardization. India has dedicated research centres and a Smart Grid Task Force (SGTF) working on the deployment of Smart Grids in some pilot cities and then upgraded to a Pan-National scale . Technological standardization is also seen as a critical step toward moving up the value chain and is playing a stronger role in global technology markets [27] .

5. Smart Grid Philosophy:

We are at the crossroads of a great transformation in the way electricity was perceived traditionally. A revolutionary makeover from a centralized, producer controlled network to one that is less centralized and more consumer interactive is on cards. The up gradation to a smarter grid promises to widely affect the industry’s entire business model that consisted of vertically integrated entities and its relationship with all stakeholders in the chain involving and affecting utilities, regulators, energy Service Providers (ESP), technology and control dealers and all consumers of the electric power.

A Smart Grid makes this up gradation possible by bringing the philosophies, concepts and technologies in a common spectrum enabling an internet to the utility and the electric grid. Simply put, a Smart Grid is the integration of ICT (Information and Communication Technology) into the electric transmission and distribution (T&D) networks delivering electricity to consumers using a two way digital technology to enable a more efficient management of consumers end uses of electricity as well as a more efficient use of the grid to identify and correct supply demand imbalances instantaneously and detect faults in a "self- healing" process that improves service quality, enhances reliability, and reduces costs [28] .

6. The Technology of Smart Grids:

With the restructuring and broadening of power sector infrastructure, introduction of new regulations, open sourcing, and increasing the share of renewable energy in energy transactions it has become paramount to design and operate the Indian Grid as a centralized Smart National Grid. The combined total capacity of the centralized grid is estimated to be of the range of 300 GW consisting of about 40-50 GW of renewable generation in the next few years. Integrating the large renewable energy with wind as the main participant is mainly isochronal in nature and would lead to an increase in the complication involved with monitoring and control of such a large grid. Application of advanced synchro phasor technology may to some extent provide the needed interface for the wide area monitoring of such a wide spread grid.

The Smart in a Smart Grid is an ICT that brings together a variety of computing and telecommunications technologies to enable the Smart Grids envisioned benefits become a reality. These technologies encompass a wide range of operations such as detecting and identifying faults and a quick response to power outages, providing consumers with near real-time information on the amount and cost of the power they use, improving the security of the system, and linking all elements of the grid to enable better decision making on the resource use. With continual up-gradation and modifications these technologies will produce more and better quality data which will give the utilities more flexibility and new opportunities to improve their analysis of for example customer load patterns and tariffs and thus offer better services to their customers.

Several of the initiatives that have already been introduced into the system include Supervisory Control and Data Acquisition (SCADA), Distribution Management System (DMS), Distribution Automation System (DA), Energy management System (EMS), Automated Meter Reading (AMR), Outage Management System (OMS), Enterprise Resource Planning (ERP) and Geographical Information System (GIS). Installing latest technology and systems in the power system promises a decrease in loss levels and a subsequent increase in the reliability of the network. Successful Implementation of the Smart Grid would also require introduction on WAMS (Wide Area Measurement System) based technology for achieving grid performance. Installation of Phasor Measurement Units (PMU’s) at the utilities is a prerequisite for WAMS. The existing interface involving SCADA/EMS based grid operation has the potential to provide the steady state view of the power grid only [29] . Dynamic real time measurements and visualization of the power infrastructure which are useful for an optimal working of the grid as well as introducing corrective measure can be realised only with the introduction of PMU based technology.

Smart Grid Deployment is a journey rather than a onetime event. Taking cue from this universally accepted paradigm, India has to observe grass root revolutionary changes in its power infrastructure concerning with its requirement. What a Smart Grid can deliver is driven by need. The US and Europe for instance, care more about labour costs, renewable and electric vehicles. In India, there is evidence that load management, especially the peak, is a major and a primary driver and hence more investments are to be observed related to a superior load management [30] .

Figure 14: Various layers of Smart Grid Infra-Structure

Source: www.datacenterdynamics.com

6.1 Network Operations:

The main difference between the traditional power infra-structure and the Smart Grid will be in the distribution area at the customer/network interfaces. However, in the areas of generation and transmission the role the system operators play will become quite complicated and critical as it will have to ensure an efficient, reliable and integration of other sources of energy. The Smart Grid wil be critically system operators configured. An ancillary support system will be required from sophisticated and technologically advanced energy management systems to oversee and manage all available energy resources and transmission parameters in every part of the system under a broad variety of operating conditions and possible future scenario.

Figure 15: Smart Grid management

Source: www.electricenergyonline.com

6.2 Automated Metering Infra-Structure through Smart Meters:

Smart metering will be a very important focus area for distibution utilties. The main demand driver for this upgradation is the energy accounting backbone created under the Restructured Accelerated Power Development and Reforms programme (RAPDRP). Bringing into picture the vision of introducing a Smart Grid infra-structure, the industry can expect a rise in the demand for metering technologies such as Automated Meter reading (AMR) and prepaid metering. Smart meters will be installed at the customers premises to enable a bi-directional communication between the meters and the Utility meter data management system. This two way communication will enable Utility to understand the demand profile of the customers in near real time. The real time data also allows the customers to monitor and control their consumption. Implementation of tariff of day (TOD) functionality incentivizes customers for demand side management.Smart metering also enables the remote connect and/or disconnect of erroneous customers thus introducing a transparent mechanism and ultimate control. A Meter Data Management System (MDMS) is required to be implemented to interface the SAP-ISU billing system. This system obtains the meter data from the smart meters and is used for various purposes like billing, planning and load forecast etc.Implementation of AMI in India does present a few challenges :

Smart meters are relatively a new concept in the Indian infrastructure and there are a few technical challenges with respect to their customization for Indian conditions like security protocals and at the same time there are no standards yet formulated for smart meters.

Suppliers are not yet prepared to bring smart meters in the Indian market as the technical regulations are not yet harmonized between the utilities and the suppliers and also because of a lack of skilled resources.

Worldwide such projects have been implemented using GPRS and PLC. While as the PLC implementation requires a very high quality of power cable framework which is a relatively new concept for the Indian conditions. GPRS requires enhanced provisioning and a superior service quality from the service providers.

AMI facilitates the collection of data which is critical for utility planning and implementation. Such data also improves the inputs to the retail tariff structure, help with regulatory compliance, and help customers better understand their consumption and plan their usage accordingly [31] .

6.3 Home Area Network:

Even though Home Area Network is not a primary driver of implementing the Smart Grid in India but it provides a definite edge to the idea of complete overhaul of the traditional power system to a grid of the future. A Home Area Network provides the platform for smart devices in a home to communicate directly with the grid and enables the consumers to manage their electricity usage by measuring a home’s electricity consumption more frequently through a smart meter; utilities can provide their customers with much better information to manage their electricity bills. Inside the Smart Home, a Home Area Network (HAN) connects thermostats, refrigerators and other electrical devices to an energy management system. Smart appliances and devices will adjust their run schedule to reduce electricity demand on the grid at critical times and lower consumer’s energy bills [32] .

Figure16: Home Area Network Visualization

Source:www.research.att.com

Wiring:

The basic standard for wiring is Ethernet. Most of the homes in India lack Ethernet running in their structures. The cost and effort of retrofitting a home or a building with new wires is appalling. Speed, reliability and security are often the reasons cited for installing new wires. The demands for most HAN Smart Grid applications are between 10kbps and 500 kbps thus speed doesn’t seem as a working driver for installing new wires but reliability and security are a plausible excuse.

IEEE 802.3 Ethernet

IEEE 802.3 or Ethernet as it is more commonly known is used widely for establishing local networks in offices and certain homes. Systems communicating over Ethernet divide a stream of data into shorter pieces called frames. Each frame contains source and destination address and error checking data so that damaged data can be detected and re-transmitted. Ethernet provides service up to and including data link layer [33] .

Power Line Communication (HomePlug)

HomePlug GREEN PHY (GP) is a low power, robust data communications technology that provides data rates of 4-10 Mbps over a buildings existing electrical wiring. To define the media access control (MAC) and physical layer (PHY) for power line communications in Home Area Networks (HAN) the GP specification is used and has been recently adopted as a profile of the IEEE standard 1901 for broadband over power line networks.

6.4 Fibre Optic Based Communication:

A reliable voice and data communication is a critical aspect of Smart Grid deployment. The need of a capable communication system has substantiated with the introduction of dedicated protection schemes, wide area measurement technology, SCADA system and remote operation. Obtaining real time data of various utilities is a prerequisite for the successful installation and operation of a Smart Grid. At present three basic modes of communication are used in power system operation:

PLCC

Microwave

Fibre Optic

PLCC is an integral part of power system and is used for protection of the power system and providing speech communication in limited area. All of the requirements needed for a capable communication system are met by Optical Fibre Communication (OFC).