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Summary of Smart Grid: Benefits and Issues
Md. Golam Rahman, M. Fahad Bin Ramim Chowdhury, Md. Abdulla Al Mamun, Md. Rakib Hasan, Sayeed Mahfuz
Abstract— Electricity has a staggering importance in our daily life and economic development. Efficient transmission and distribution of electricity is a fundamental requirement for every society. Shortfall in power generation due to increased power demand to meet up the industrial requirements is causing several social and economic difficulties. As things stand now, the current grid is struggling to keep up. Smart Grid, an upgrade of current system which is more reliable, efficient, affordable, secured and environment friendly, is the solution of this growing concern. It is believed that Smart Grid will take us towards energy independence and environmentally sustainable economic growth. In this paper some key features of Smart Grid has been discussed. The benefits and potential barriers to create a Smart Grid are alsoexplained.
Index Terms— AMI, challenge, demand response, distributed generation, eco-friendly, efficiency, electricity market, smart grid
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here are many definitions of Smart Grid and different people have different views to define it. The brief defini- tion of Smart Grid, as proposed by the European Technol-
ogy Platform, is- “A Smart Grid is an electricity network that can intelligently integrate the action of all users connected to it—generators, consumers and those that do both—in order to efficiently deliver sustainable, economic and secure electricity supplies” [15]. National Institute of Standard and Technology (NIST) defines it as- "A modernized grid that enables bidirec- tional flows of energy and uses two-way communication and control capabilities that will lead to an array of new function- alities and applications” [16]. According to US Department of Energy’s modern grid initiative, “A Smart grid is the technol- ogy that incorporates advanced sensing technologies, control systems and integrated communications into the existing elec- tricity grid”[17]. Basically it is the digital upgrade of current power grid by modernizing and digitalizing the generation, transmission and distribution of power and by introducing active participation of the consumer.
Smart Grid itself is a big idea. The total concept doesn’t end with the modernizing the transmission or communication network. The idea of modernizing electricity network includes the ability to reduce power consumption at the consumer end during peak hours (Demand side management), enabling grid connection of distributed generation, incorporating grid ener- gy storage for distributed energy, providing opportunity to integrate renewable energy and eliminating failures such as widespread power grid cascading failures. The increased effi- ciency and reliability of the smart grid is expected to save con-
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Md. Golam Rahman. E-mail: schools.goals@yahoo.com
M. Fahad Bin Ramim Chowdhury. E-mail: fahadramim@gmail.com
Abdulla Al Mamun. E-mail: smnnew@gmail.com
Md. Rakib Hasan. E-mail: Rizvej@hotmail.com
Sayeed Mahmuz. E-mail: sayeedm2@gmail.com
sumers money and help reduce CO2 emissions by establishing
an eco-friendly power network.
To get a better idea about what is Smart Grid and what it is not let’s look at Table 1.
TABLE 1
COMPARISON BETW EEN EXISTING POWER GRID & SMART GRID
Source: [1] [2]
The current climate demands change in the way electricity is supplied. The current social and economic situation is driving us towards Smart Grid. The driving factors are briefly de- scribed below.
As the demand of energy is ever increasing we need secure supply of fuel. If we look at the oil price trend, since the Islamic revolution in Iran in 1979, the price is always increasing and fairly unstable. Another major problem is that all the fossil fuels are limited. Inside next 120 years all major sources of fossil fuel will be finished [3]. So depending on non renewable fossil fuel makes our economic growth vulnerable. Integrating more fossil fuel can solve the problem. Smart Grid provides ideal opportunity to integrate Renewable into the
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system.
We live in the age of free market economy. Free Market Econ- omy allows different companies to invest and compete with each other. This competition will drive the price down which will benefit the consumers. This will also encourage the ven- dors to invest more for advancement in technology.
Typical fossil fuels cause the emission of gases like CO2, SO2 and other pollutants which are causing severe environmental damages. The U.S. CO2 emissions from energy consumption alone totalled 1,340 million metric tons during the first quarter of 2012 [4], which contributes almost 41 percent of the CO2 emissions from fossil fuels in the United States and 34 percent of all greenhouse gas emissions [5]. So we need fuels and technology which are green and eco friendly. Smart Grid pro- vides ideal opportunity to achieve that.
Smart Grid combines IT, power engineering, communication technology, material science etc. Recent advancements in these fields will encourage the growth of Smart Grid.
Grid optimization is another key feature of Smart Grid. Geo- graphic Information System (GIS) helps us to design the net- work efficiently which will ensure asset optimization. GIS is widely used to optimize maintenance schedules and daily fleet movements. Typical implementations can result in a sav- ings of 10 to 30 percent in operational expenses through reduc- tion in fuel use and staff time, improved customer service, and more efficient scheduling [6]. Advanced two way communica- tion will also ensure greater efficiency.
Power quality determines the fitness of electrical power of the electrical devices. Poor Power Quality like voltage sag, transi- ent voltage, flicker, spike, presence of harmonics etc. increase cost, down time and reduce competitiveness, life of device. So it’s really important to provide clean power. Smart Grid can improve the Power Quality using back to back inverter and FACTS devices which satisfy our needs.
The technology areas – each consisting of sets of individual technologies – span the entire grid, from generation through transmission and distribution to various types of electricity consumers. Some of the technologies are actively being de- ployed and are considered mature in both their development and application, while others require further development and demonstration. A fully optimized electricity system will de- ploy all the technology areas described here. However, not all technology areas need to be installed to increase the “smart- ness” of the grid.
Advanced metering infrastructure (AMI) refers to a system that collects, measures and analyses energy usage by enabling data to be sent back and forth over a two-way communica- tions network connecting advanced meters (“smart meters”) and the utility’s control systems [7]. AMI provides utilities unprecedented system management capabilities, allowing for the first time the possibility of having consumers/end-users make informed, real-time choices about their energy usage (acting as a gateway technology to the “smart home”). Millions of smart meters are currently being deployed around the globe. There are two main components of any AMI system:
- The physical smart meter itself, which replaces older mechanical meters unable to communicate
- The communications network necessary to transport the data that the meter generates
critical, “peak” times, on demand [8]. Contracts, made in ad-
vance, specifically determine both how and when the utility
(or an acting third-party intermediary) can reduce an end us- er’s load.
Demand response is a win-win solution for utilities and customers. At times of peak energy demand, Demand Re- sponse is a cheaper, faster, cleaner and more reliable solution than adding a peaking power plant. While concerns for the environment are increasing in the U.S. and the EU, the fact that both the utility and the consumer save money will be key driver in the mass adoption of demand response programs.
The integration of renewable energy and distributed genera- tion sources at mass scale is one of the most revolutionary as- pects of a smarter grid. While many of the renewable energy solutions – such as wind and solar – have been around for decades, what has been lacking is the proper infrastructure to support their introduction in an impactful way. Smart Grid technologies will change this, as smarter grids attempt to fix the scale-management problem. The continued development of true “plug and play” interoperability will promote the same wide-spread deployment in renewables and distributed gen- eration that occurred with personal computers and cell phones, bringing a profound transformation to electric genera- tion in the coming decade [7].
Various types of communications media are used in today’s electric grid, including copper wiring, optical fiber, power line carrier technologies, and wireless technologies. Using these
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media, it is possible to deploy Substation Automation, an ex- cellent first step in integrating grid communications. Howev- er, Substation Automation does not yet fully integrate with the other features that will modernize our power grid [9].
Phasor Measurement Unit (PMU), also known as Synchro- phasors give operators a time stamped snapshot of the power system using a common time source for synchronization. Time synchronization allows synchronized real-time measurements of multiple remote measurement points on the grid [1]. PMUs ensure voltage and current with high accuracy at a rate of 2.88 kHz. They can calculate real power, reactive power, frequen- cy, and phase angle 12 times per 60 Hz cycle. The actual sam- pling rate used to achieve this output is 1.4 MHz [10]. Popular- ly referred to as the power system’s “health meter”, PMU sample voltage and current many times a second at a given location, providing an ‘MRI’ of the power system compared to the ‘X-Ray’ quality available from earlier Supervisory Control and Data Acquisition (SCADA) technology. Equipped with Smart Grid communications technologies, measurements tak- en are precisely time-synchronized and taken many times a second (i.e., 10-60 samples/second) offering dynamic visibility into the power system [11].
The smart home represents the convergence of energy effi- cient, controllable appliances and real-time access to energy usage data. This integration of smart devices and smart grid enables customers to proactively manage energy use in ways that are convenient, cost effective, and good for the environ- ment.
Home Area Networks (HAN) are a major part of Smart Grid. A network within the home that enables devices and major appliances to communicate with each other and dynam- ically respond to price signals sent from the utility, relaying whether or not electricity is currently expensive.
One of the most discussed and anticipated “applications” of Smart Grid is the introduction of the plug-in hybrid electric vehicle (PHEV). PHEV’s larger battery, relative to the previ- ous generation (plug-less) hybrids, will allow for both the pos- sibility of storing electricity, which might otherwise go unused (ideally from renewable, intermittent sources), and of feeding stored energy back into the electric grid, in periods of high demand, serving as a back-up source of power for the electric grid [7].
The key features of Smart Grid are given bellow-
Smart Grid with the help of real time sensors like PMU can detect the health of the power. With the self healing ability Smart Grid can anticipate, detect and react to faults or outages
using PMU and automatic control center. It also uses intelli- gent sensors which can start, stop or reroute power flow to avoid further problems.
One of the main features of Smart Grid is bidirectional power flow. One can be a consumer and provider at the same time. Dynamic pricing will encourage users to use less power in the peak hours, which will reduce the peak demand. This behav- ior will ultimately lead to the unity Load Factor which is de- sirable.
Smart Grid network and control system is designed such a way so that it is very strong against cyber attacks. Real time monitoring using PMU allows the operators to anticipate pos- sible problems, so the preventive measures can be taken. Dis- tributed generation and microgrid also ensures security of supply.
Using Geographic Information System (GIS), we can design efficient network using minimum transmission network and other equipments. It will enable condition and performance based maintenance. Smart grids will also improve efficiency through reduction in technical and non-technical line losses.
Distributed Generation (DG) means decentralized generating units in place of centralized network. The major benefits of distributed generation can be divided into two categories: economic and operational [12]. From an economic point of view, distributed generation provides power support when load increases during peak demand periods, thus reducing interruption that may lead to system outages. It also reduces the peril of investment, due to the flexibility of its capacity and installation placement. DG cuts operational costs when in- stalled close to the customer load because it avoids upgrading or setting up a new transmission and distribution network, thereby providing a cost saving. The use of local renewable energy sources (RES) will help to reduce dependence on im- ported fossil fuels and decrease internationally escalating en- ergy prices.
A smart grid involves consumers by engaging them as active participants in the electricity market. It will help empower utilities to match evolving consumer expectation and deliver greater visibility and choice in energy purchasing. It will gen- erate demand, for cost-saving and energy-saving products. Smart grids will help educate the average consumer, foster innovation in new energy management services and reduce the costs and environmental impact of the delivery of electrici- ty.
The energy conservation and improvements in end-use effi- ciency enabled by the smart grid can reduce significant
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amount of CO2 emission. The Pacific Northwest National La- boratory (PNNL) has issued a report in which carbon savings from introduction of smart grid technologies are estimated, looking ahead to the year 2030. PNNL located in Richland, Washington and operated by Batelle for the U.S. Department of Energy, puts direct carbon savings from equipment like smart meters at 12 percent, and indirect savings from things like stronger grid support for renewable electricity generation at 6 percent [13]. Environmental improvements can be ob- tained by managing the peak load through demand response rather than spinning reserves. Smart grid will reduce trans- mission and distribution loss besides controlling theft, ensur- ing better availability in rural areas and increasing reliability and quality of supply in urban areas. Reducing these losses would require an investment ranging from $20,000 (reactive power compensation, phase shifting transformer) to $75,000 (power electronics steering and control) per MW [14]. Smart grid system gives a continuous feedback on electricity use, which enables the consumers to adjust the usage in response to pricing and consumption and thereby reduce annual CO2 emissions. Optimised use of existing generation, transmission and distribution through this system reduces the new infra- structure constructions.
Several challenges present themselves for smart grid devel- opment-
Huge amount of capital investment is needed to initiate the journey of Smart Grid. So we need significant financial re- sources/ investments to create the necessary distributed net- work and other establishments.
Financial resources are not the only obstacle to initiate Smart Grid. Political bodies of the country play an even bigger role. We need a willing government and effective energy policy for a successful implementation of Smart Grid.
Some older equipment must be replaced as it is incompatible with smart grid technologies. This may present a problem for utilities, regulators as well as to the consumers.
Consumer education and participation is an important com- ponent of the successful implementation of the Smart Grid. A significant portion of the Smart Meter benefits rely upon con- sumer engagement. So the consumers have to be educated and intelligent to get the maximum benefit.
Costs could be higher than projected because the standards and protocols needed to design and operate an advanced me- tering infrastructure are still in a state of flux. Thus, invest-
ments made now, before the standards are settled, have a higher risk of obsolescence.
Digital communication networks and more granular and fre- quent information on consumption patterns raise concerns in cyber-insecurity and potential for misuse of private data.
Smart Grid uses hi-tech devices all over the network. Technol- ogy is never at a standstill, in fact it is moving as fast as ever. So the Smart Grid has to be able to absorb modern and ad- vanced technology.
The Smart grid, although a revolutionary being, has to have some weak spots, which should be of our utmost concern. The companies and manpower working behind the setup of the grid, has to deal with some unexpected occurrences and haz- ards the grid has to overcome. These are—
- Attacks of cyber thieves
- Weak Base
- Inefficient Control System
- Corrosion
- Smart Meter Authentication
- Blackouts
The smart grid is a very complex and sophisticated system. To cover the controlling program of the whole grid system, a lot of equipments are required, which are compatible with the system.
The whole discussion, we tried to introduce and discuss some key features of Smart Power Grid. It is still in a primary stage. The whole power community is busy with researching and developing smart power grid system which is no longer a theme of future. The new technology associated with smart grids offers the opportunity to improve the quality and relia- bility of the power experienced by the consumers. However, it will also introduce a number of new challenges. But these new challenges should definitely not be used as arguments against the development of smart grids as Smart Grid will play the most vital role in turning the conventional and aged power system to an intelligent and modern grid of the 21st century and lead us towards energy independence.
The author would like to express his appreciation to Md. Maruf Hossain, Chowdhury Akram Hossain and Taskin Jamal for providing valuable inputs and support for writing this paper. The author is, of course, responsible for the contents.
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