DS Automation, Achievements, and Case Studies: US DOE SGIG Program
Written by Hossam A. Gabbar
A Distribution System is a key segment in the energy and power system. With the ongoing efforts in modernizing the power grid and leading towards a Smart Grid, the efforts in focusing on strengthening the distribution segment have gained focus. As per a Report Card on America’s Infrastructure, Distribution infrastructure struggles with reliability and 92% of all outages occurring along these segments. So, we need implementation of relevant programs, technologies and solutions to strengthen the DS grid to enhance reliability and resiliency in the changing scenario of regulatory compliance, DER penetration, and others.
The U.S. Department of Energy (DOE) launched the Smart Grid Investment Grant (SGIG) program consisting of $3.4 billion dollars of funding from the American Recovery and Reinvestment Act (ARRA), which was further matched with an additional $4.5 billion in industry investment. There were 99 SGIG projects that received a total of $7.9 billion in new smart grid technology and equipment for transmission, distribution, metering, and customer systems. Their major objectives were to modernize the electricity system, strengthen cybersecurity and improve interoperability. Projects under this program began in 2010, and the program was completed in 2015. A final report was submitted with achievements, case studies, lessons learned leading to future trends and opportunities in Distribution automation (DA) technologies and systems, including advanced sensors and self-healing controls, advanced metering infrastructure (AMI), including smart meters and two-way communications networks and customer systems, including programmable communicating thermostats (PCT), and direct load control devices (DLC) that enable utilities to offer time-based rates and incentives.
By integrating Distribution Automation (DA) with AMI (Automated Metering Infrastructure), utilities reduced outage duration, limited customer inconvenience, and reduced labor hours and truck rolls for outage diagnosis and restoration. Many utilities reduced the number of affected customers by as much as 55% and reduced the total customer minutes of interruption by up to 53 percent using “self-healing” FLISR capabilities (Fault Location, Isolation & Service Restoration).
The following are details on a few successful projects and case studies along with relevant benefits explains the significance and need of adopting and deploying such technologies on the distribution system to enhance reliability and overall efficiency.
The deployment of the SGIG program created 12,000 direct jobs in the smart grid ecosystem of manufacturers, IT, and technical service providers, and created another 35,000 full-time equivalent positions throughout vendor supply chains. Under this program, $2.19B was spent on Distributions System technologies, $4.44B on Advanced Metering Infrastructure and $780M on Customer System technologies. Additionally, 82,000 intelligent automated devices were installed, and 16M smart meters were installed.
SGIG Technology Deployment Segments
Regarding Distribution System technologies and devices, 45% was spent on field devices, 25% on communication equipment and 22% was spent on Data management systems. In terms of field devices, 9,107 Automated Feeder switches, 11,033 Smart Relays, 13,037 Automated Capacitors, 10,665 Automated Voltage Regulators, 20,263 Transformer Monitors, 4,447 Automated Feeder monitors and 13,324 remote Fault Indicators were installed.
Distribution Automation technologies provided advanced capabilities for operators to detect, locate, and diagnose faults. For example, FLISR-fault location, isolation, and service restoration technologies helped automate power restoration in seconds by automatically isolating faulty areas of the grid and switching some customers to adjacent healthy feeders. In many cases, FLISR helped reduce the number of affected customers outage durations by half or even more.
In one such case study, it helped the operators restore system-wide power about 17 hours earlier than without DS Automation after a weather-related event. In another case, the utility was able to restore power 36 hours faster and reduce the amount of affected customers from 70,000 down to 33,000. One utility was able to restore service three days faster than estimated during a storm and automatically restored power to about 37,000 customers in less than five minutes using automated feeder switching. In other successful project, there was an estimated a 55% drop in the average outage duration (SAIDI) and a 58% decrease in the average number of interruptions (SAIFI) across its system using DS Automation upgrades.
There was a great deal of success deploying automated Recloser devices. One utility estimates its investments in substation and line reclosers saved customers more than $935,000 in one year, and they will continue to save a total of $20.7 million through the next 6 years.
In other case studies and successful projects, installing sensors on key components and devices along the power grid like transformers and others to monitor equipment health and parameters helped improve reliability and huge savings for the utility. The technology provided real-time alerts for abnormal equipment conditions and data for new analysis tools for utility engineers to improve preventative maintenance and equipment repairs and replacement. One such utility project prevented an outage for 15,000 customers and avoided $1.0M in restoration costs by identifying and repairing a transformer before it failed.
Volt/VAR Optimization: VVO and CVR Projects
Voltage/volt–ampere reactive (volt/VAR control) and conservation voltage reduction (CVR) technology using automated station and in-line capacitors and voltage regulators helped to improve phase balancing and reactive power compensation and to optimize voltage levels on distribution circuits. These enhanced capabilities can minimize voltage levels and reactive power levels to reduce electricity requirements for real and reactive power during peak periods or for longer periods of time. These capabilities have enabled SGIG utilities to maximize existing assets, reduce line losses, and save customers energy.
One utility used its voltage control and reactive power management technologies to increase its 4kV unit substation capability by 2.8%, resulting in a net savings of $15.7 million. It also reduced primary losses on its 4 kV systems by 2.3% under peak conditions. Another utility estimates that a five-year CVR project on 65% of feeders can achieve energy savings of 2-4%, and net power cost savings of $470,000 to $1.2 million per year.
Automated Metering Infrastructure: AMI and Smart Metering Project
AMI deployment has a lot of benefits, including reducing losses and deferring capital investments with effective load management techniques. AMI services saved about $316 million in labor and O&M costs for 19 SGIG utilities over 3 years. One utility under the SGIG program was able to defer capital investment in 170 MW of peaking generation by expanding enrollment in its time-based rate program with AMI/Smart Metering devices. One utility realized a 65% decrease in annual meter operations costs (from $450,000 to about $156,000 per year) from smart meter deployments.
A pre-pay program and automated connection/disconnection capabilities on smart meters also contributed to a 50% reduction in unpaid bill write-offs for a utility and automated meter reading reduced estimated billing by more than 90%.
Demand Side management & Demand Reduction Using PCT (Programmable Communicating Thermostats), Direct Load Control (DLC) and Other Methods
Customers participating in demand-side management programs piloted at 10 utilities reduced their peak demand by up to 23.5%, which saved customers up to $500 annually, depending on the types of rates offered. Another utility averaged annual savings of $191.78 for residential customers and $570.02 for commercial customers, and reduced load by offering variable peak pricing to about 4,670 participating customers.
Environmental Impacts & GHG Emissions
All the above DS Automation, AMI/Smart Metering and other technology deployment reduced CO2-equivalent emissions by 17,510 metric tons over a nearly 4-year reporting period by avoiding truck rolls previously required to read meters, detect outages, and confirm restoration.
With increasing adverse weather-related events impacting the power grid reliability and quality and majority outages happening on the already aging distribution segment of the power grid, there is an urgent need to pay extra attention to this sector and deploying more such technologies and devices for Distribution Automation. The above successful projects and case studies further strengthen the business case for initiating and implementing such programs on continuous basis.
For further details, discussions or questions on any such subject, please contact the author:
BSEE, SMIEEE, P.Eng. Sr. Advisor, Power System & DS Grid Modernization Chair
IEEE Smart Grid Technical Activities Committee
This article was edited by Jorge Martinez.