Introduction: A brief history on the evolution of grid technologies.
The Smart Grid is the backbone of all major innovations, policies and regulations included in the power grid since its creation in the 1880’s. The power grid is an electric network of power sub-stations, transmission lines, transformers, and other equipment and facilities used by power suppliers to deliver electricity from the power generation plant to homes and commercial entities.
When power grids started being built for electricity distribution, the demand for devices to measure consumption rose. The need for these devices was to help electricity suppliers in distribution, pricing and monitoring of their services. However, the path from the first provisional devices used for measuring power consumption, to the smart grid technology used today, has been long. Modern smart grid technologies utilize two-way metering technologies that can turn electrical appliances on or off depending on demand and off-peak electricity tariffs.
Earlier grids had their challenges, which needed to be overcome to achieve accurate information gathering about grid behavior. Some of these challenges that were experienced more than a Century ago are strikingly similar to those facing current smart grid technologies.
It all began in 1882 with Thomas Edison’s Pearl Street system located in lower Manhattan. Edison used an electromagnet to carefully adjust a spring that closed and opened contacts thus illuminating a red lamp when line voltage rose or a blue one when it dropped. This indicated to an attendant on stand-by to turn a hand wheel and control the generator’s electromagnet’s field strength to match the generator’s output to the load. To measure electricity consumption, Edison designed a crude meter using two electrodes dipped in electrolyte. When a current was passed through the meter, it caused the transfer of the electrodes’ metal. Consumption was then deduced by weighing both electrodes.
The first electric meter patent was obtained by Samuel Gardiner in 1872 and consisted of an electromagnet that started or stopped a clock but this only indicated the duration of current flow and not the amount consumed. Later in 1883, Hermann Aron obtained a patent for a recording meter showing energy used on a series of clock dials.
It was in 1889 that Elihu Thomson devised the recording wattmeter which immediately became a popular metering technology since it allowed utilities to measure the amount of electricity consumed by customers. However, achieving high precision was still a bottleneck since the braking magnets in these meters were sometimes weakened by power surges caused by lightning storms which meant meters would run faster than usual thus eliciting customer complaints, a problem still seen today with fast-running smart meters.
In the late 1940s, an advertising campaign was launched by General Electric bearing the slogan “Time to Retire Old Watt-hour Meters”. This was to demonstrate the to the losses incurred by utility companies due by slow-running meters caused by overloading. In years prior to electricity suppliers being able to disconnect customer devices during peak periods and reconnect them during low demand periods, load management problems would take care of themselves rather abruptly and in a non-negotiable manner where power lines would simply burn out when demand exceeded line capacity.
As electricity demands on power grids grew through the late twentieth Century, utility companies sought ways to manage peak loads. The costs incurred in building enough capacity to handle peak periods, and which would then be idle during off peak hours led to utilities finding ways of studying demand periods, pricing them accordingly, and encouraging consumers to switch their consumption from peak to non-peak periods. The goal of matching power consumption to power generation required electric meters capable of measuring the time of the day of consumption and also the cumulative consumption. In the 1970s, automatic meter reading devices were introduced, marking the beginning of meters that provided feedback to the utility company which is the basic requirement for any smart grid system. The sensor monitoring and data relaying technologies were derived from the caller-ID technology which had been patented by Theodore Paraskevakos.
All these technological advancements, and more than a Century of development formed the necessary foundations to build the safer, highly efficient and reliable electricity distribution network that would eventually become the smart grid.
The Smart Grid Today: What makes it smart?
The electric power grid is one of the engineering marvels but in the 21st Century there is need to stretch its patchwork nature to full capacity. This creates the need for a new electric grid system built bottom up to accommodate the groundswell of digital technologies and computerized equipment that depend on it. The grid should also be able to manage and automate the increasing electricity needs and arising complexities in the 21st Century.
In a nutshell, the digital technologies that enable duplex communication between the utility company and its customers, and the sensory mechanisms along the transmission lines is what makes the grid smart. Just like the internet, the grid will be composed of various automated controls, computers, and other modern technologies and equipment working together. In this particular case, the technologies work together with the power grid to provide digital responses to the rapidly changing demands for electricity.
How the smart grid works:
The Smart Grid provides a new opportunity to move the energy industry into a new era of efficiency, reliability and availability that will contribute towards economic development and environmental sustainability. During the full transition period, it will be important to carry out testing, consumer awareness, technological improvements, and develop standards, policies and regulations. Information sharing will also be necessary between various projects so as to ensure the benefits envisioned from the Smart Grid are realized.
There are various benefits to reap from the implementation of the Smart Grid and these include improved efficiency in electricity transmission, quicker electricity restoration after power outages and detection of faults in transmission lines. In term of cost efficiency, there will be reduced managements and operations costs for various utilities leading to lowering of power costs for consumers. The peak demand will also reduce thus helping lower electricity rates. In terms of scalability, there will be increased large scale integration of renewable energy systems and the consolidation of consumer-owned power generation systems. Overall security of the grid will also be improved.
In the world today, a small electricity disruption such as a power blackout may cause a ripple effect – a series of failure affecting communications, traffic, banking and security. In winter, blackout cases can lead to failure of home heating systems. The smart grid will thus make the electric power system more resilient and better prepared to deals with emergencies such as earthquakes, storms, terror attacks and other catastrophes. Due to the Smart Grid’s duplex interactive capacity, it will allow for automatic power rerouting when there are outages or equipment failures. This will in turn minimize the amount of outages experienced and their effects when they do occur.
When power blackouts are experienced, the Smart Grid will detect and isolate these incidences, and contain them before they grow into large scale blackouts. New grid technologies will also ensure quick and strategic electricity recovery after emergencies by routing electricity to emergency hit areas first. For example, the grid will utilize customer-owned generators for power production when it cannot be availed by the utilities. The combination of these distributed power generation resources can help a community handle all its power dependent operations and systems such as telephone systems, traffic lighting, and health centers.
In addition the Smart Grid provides a way of addressing the existent energy infrastructure that requires upgrading or replacement. It is also a way to address energy efficiency and increase consumer awareness on the relationship between energy use and environmental sustenance. In addition, it is also a way of increasing national security to energy systems by increasing the amounts of home grown power which is more resistant to natural catastrophes and terror attacks.
Consumer control and the Smart Grid:
The Smart Grid is not only digital technologies and utilities but since it is computerized, incorporated, it serves as an information system and provides various tool to consumers needed to make rational energy choices. This may include services such as online power management thus providing a high level of consumer participation and interaction.
Unlike in the past where consumers needed a monthly statement to know their power consumption habits, the Smart Grid which has various mechanisms such smart meters will allow users track their consumption in terms of amount, time and costs. This will be combined with real time pricing strategies which allow saving costs by using less power when electricity tariffs are high.
Wireless communication and the Smart Grid:
Wireless communication is at the heart of the Smart Grid system and connects users to their provider and power distribution networks. It also enables power companies to acquire critical real-time data which is used for timely and effective decision making thus resulting to more sustainable operations. The possible economic and environmental benefits of the Smart Grid are quite impressive and according to a report by BSR, an environmental consultancy group, smart grid systems can potentially save over 360 million metric tons of Carbon (IV) Oxide emissions in the United States by 2020. This figure is an equivalent of the annual greenhouse emissions of 30 million homes or 70 million passenger service vehicles. The report also showed savings of up to $35 billion due to smart grid implementations.
Wireless communication nodes are the smart grid system’s critical links that gather and process data streams from various sources. These nodes connect smart home appliances to smart meters and ultimately with the grid, and can therefore provide information to consumers about which of their appliances are using energy and at what time. The ability to control these appliances remotely is also provided.
Wireless communication nodes also synchronize with line sensors that detect the amount of power flowing through the system at a given time and then transmit this information to the central operations center. The sensors also show exactly where outages exist and the nodes relay this information back to the utility hub, at the same time triggering technical workarounds which find alternate power transmission routes.
Various utility companies such as Duke Energy in the US now collaborate with wireless network service providers instead of building their own proprietary networks which is a costly affair. Collaboration with wireless networking providers prevents power suppliers from facing the vast array of obstacles that come with the monumental task of deploying wireless network connections. Most of the utility companies outsource public wireless networks since they do not desire to be in the communications industry and because they need to harness already existing wireless capabilities, and expertise provided by wireless networks in terms of network design, implementation and maintenance.
However, while most utility companies make their first steps toward achieving their Smart Grid vision, the beginning of this venture mainly involves Advanced Metering Infrastructure (AMI) systems implementation. To achieve this, the companies must also have separate wireless broadband infrastructures that are capable of delivering high-speed wireless communication 24/7 and enable various additional benefits of the Smart Grid. These additions include delivery of highly sophisticated energy management software, cost-effective AMI data backhaul and enabling real time connectivity within utilities thus improving outage management, service delivery and overall productivity. Essentially, wireless broadband communications networks deployment makes utilities completely “Connected utilities.”
Many power suppliers worldwide have also discovered that partnership with wireless innovators such as IBM and Motorola to implement private wireless broadband networks in their AMI networks makes perfect economic and operational sense.
While public networks are a cheaper option as in the Duke Energy case, there are a variety of factors limiting use of one network to meet all the wireless needs for utility companies AMI options. These factors include variance in requirements between various distribution automation applications, AMI backhauls and lack of coordinated frequency bands. This has led to many utility companies to opting for multiple networks so as to meet the Smart Grid vision. Previously, each business unit selected a network for its application independently but when selecting networks today, the Smart Grid needs of various business units must be accounted for. This paradigm shift for utility companies has led to development of stronger and more favorable business cases to public utility commissions (PUCs) and investors.
There are two major networks required for Smart Grid implementation and these include:
- Backhaul networks: These are low latency but high capacity broadband networks that provide extension for enterprise networks to remote areas thus bringing back data collected from the access networks to the enterprise. Examples of these networks include both wireless and wired point-to-point (P2P), and multipoint networks, microwave and fiber systems. These form the Smart Grid access network backbone.
- Access networks: They are used for remote device communication at the network edge. Examples of these networks are Wi-Fi, Zigbee, Homeplug and other types of meshed networks.
Public versus private networks: A sound business case.
The sample business case shown below for a private versus private wide area network comprising 2,000 AMI collection points, 1,000,000 smart meters and 10,000 Smart Grid devices such as reclosers, capacity banks and switches. The network offers full coverage for each collection point and 1 KB data is read daily from each meter. In the end, a rough amount of $15 is assumed as charges for the cellular broadband data plan. As shown in the figure 1.0 below (courtesy of the Motorola solution brief) the results are quite shocking. The private network only required a one-time CAPEX of $1,380,000 and delivers payback within 7 months of operation while the public network OPEX costs were approximately $2,160,000 in annual fees and accumulated to $10,805,000 in five years’ time.
Fig 1.0 (Chart courtesy of Motorola Solutions Brief)
Operation & Maintenance vs. Capital Investment when selecting wireless networks:
As seen from the data above, private wireless networks are more effective in terms of reducing high backhaul costs and enabling utilities to manage costs. Public Utility Commissions (PUCs) usually treat backhaul costs incurred by use of leased lines as operational expenses thus they are unrecoverable normally. However, building private wireless networks is usually considered a long term capital investment that helps improve service, efficiency, security and reliability. This means a utility can recover various costs incurred for the entire network.
Deploying these networks bring significant benefits since networks from companies such as IBM, Cisco and Motorola usually offer simple installation which can take several days, affordable startup costs and low Total Ownership Costs. Private networks usually offer various benefits such as: extensive coverage even in remote areas, high bandwidth capacities that are scalable thus supporting future growth, utilities can control their networks without depending on public carriers especially during emergencies, improved security and failure tolerance capabilities, and most importantly, recoverable costs due to elimination of recurring costs.
Wireless Communications: Beyond AMI implementation.
While many utility companies are investing a lot of time and other resources in building AMI networks, they are also looking beyond the scope of AMI and discovering that duplex wireless communications are great enablers for the future of the Smart Grid. Companies have begun to use their high speed wireless communication networks for various additional applications to improve service delivery, productivity, Return on Investment (ROI) and security. These expanded applications include:
- Remote monitoring and control: This involves real time monitoring and remote control of various system elements such as sub-stations, power lines, feeder switches, fault indicators, capacitor banks and other physical facilities. While the major deterrent has previously been cost, affordable wireless networks can be simply extended at low costs thus allowing remote monitoring of facilities. This results in fewer cases of disruption and improved power quality management.
- Wi-Fi Hotspots: Wireless communications can help improve productivity by creating Wi-Fi hotspots allowing real-time communication between employees in the field. Field engineers and workers can easily transmit data from a sub-station to the main system directly.
- Load Management and Demand Response Services: Wireless communications enable automatic management and demand response using programs mandated by regulatory agencies. These management programs help reduce energy consumption by sending pricing signals to customers and/or automatically controlling customer appliances such as heaters, water pumps and thermostats. Load management is achieved using programs that utilize wireless broadband in reducing the strain on the grid during peak periods. Small reductions or shifts on the peak load can cause reductions in the need for increased capacity thus reducing the need for building new power plants. These reductions in peak energy consumption can reduce wholesale energy prices which can then be transferred to customers.
Conclusion:
As utility companies work hard to implement Smart Grid solutions and implement AMI systems and wireless communication networks, they are also exploring better energy alternatives and applications to ensure future growth in service delivery, profitability, environmental sustenance and efficiency. The ultimate goal of the Smart Grid is empowering the entire power grid and associated enterprises through fixed and mobile intelligent devices, ensuring high speed duplex connections with virtually all parts of an organization as well as external information sharing. In the end, wireless networks are essential in delivering increased value for the broad range of productive automated applications, equipment and facilities. Connected utilities will thus be able to leverage the AMI system in the Smart Grid to cost-effectively and efficiently meet environmental, regulatory, public service and competitive energy needs today and in the future.
