DTE Energy is a visionary utility that was looking for a lower cost solution to get more real-time reliability data out of its distribution grid, particularly on older legacy and poorly performing circuits to improve reliability by predicting and preventing outages and have better situational awareness to safely restore power faster and better plan their capital investments around aging assets about to fail.
DTE Energy, headquartered in Detroit, Michigan, is one of the nation’s largest diversified energy companies, delivering electricity to 2.1 million customers.
DTE Energy wanted to move away from traditional Fault Current Indicators (FCIs) and instead bring back real-time fault data with waveform capture that could be analyzed to predict grid outages, provide notifications of momentary outages ("momentaries") and alert crews to line disturbances. Having the capability to monitor the distribution network was a desire the team held for some time.
“Up until now this type of solution was just too expensive. Now that the technology has caught up and is integrated at the right price point, getting data from the grid through sensors makes business sense. We are now of the mindset to monitor
everything," Vince Dow, Vice President, Distribution Operations, DTE Energy.
Equally important was the impact of installation and maintenance requirements. DTE Energy needed to find a solution that was easy to install and would not require them to shut down circuits during installation. In addition, DTE Energy wanted a battery-free and maintenance-free solution.
They had been using battery-powered FCIs but these were expensive to maintain and lacked communications. FCIs required crews to drive long circuits looking or blinking, flashing LED indicators that were often difficult to spot and provided no real-time situational awareness to crews.
Finally, DTE Energy, like most North American utilities, found retrofitting old substations was as expensive as rebuilding a new substation. They hoped by finding a less expensive monitoring solution with built-in wireless communications, they could provide planners and asset managers with the critical data they needed, without having to rebuild substations.
DTE Energy deployed Tollgrade’s LightHouse MV Smart Grid Sensors and Predictive Grid Analytics platform at key substations and feeders within its extensive distribution network. This solution offered a number of advantages:
• LightHouse Sensors were extremely lightweight and easy to install. Because Tollgrade holds the design patent for the way sensors clamp onto the line, crews only need to use the hot-stick once during installation which was an advantage over other solutions that were heavier and required multiple screws to clamp sensors onto the line.
• LightHouse Sensors are inductively powered from the line; they require no batteries or solar panels and have a Mean Time Before Failure (MTBF) of 20 years. They are maintenance-free, require no calibration and are much more reliable than solar panels or batteries.
• The real-time data gathered from Tollgrade’s MV Sensors to the LightHouse SMS software could be used to predict faults, respond to outages and monitor assets to more strategically plan their capital investments.
HOW IT WORKS
Data from the Tollgrade MV Smart Grid Sensors is sent to LightHouse Sensor Management System (SMS) software for analysis and then pushed to DTE Energy’s Data Historian, Geographical Information System (GIS) and Distribution management System (DMS) to provide crews with live, situational awareness about grid conditions.
With this data, crews can get real-time diagnostics about what caused the faults. They can also get ahead of outages by investigating equipment failures, momentaries and line disturbances (e.g. trees brushing against power lines) before they cause a power failure. All of this data is captured, classified and analyzed by the LightHouse SMS software first and this gives DTE Energy the predictive capabilities to avoid future outages.
Currently, DTE Energy is in the process of integrating the LightHouse platform into its pre-existing wireless mesh network provided by ABB Tropos as part of its Itron advanced metering infrastructure (AMI) system. By using the same wireless network, DTE Energy can further leverage its investment to improve reliability and get the visibility needed to proactively manage their grid.
DTE has seen tremendous cost savings from its LightHouse deployment, not only in reduced drive times and crew overtime, but in other unexpected ways as well. For example, instead of long lead time and costly substation upgrade, now with the Tollgrade LightHouse solution it takes only a couple of thousand dollars to monitor a substation remotely. Additionally, the ability to integrate LightHouse into the existing wireless RF Mesh network saves money by leveraging the communications infrastructure that the company had already deployed.
With LightHouse Smart Grid Sensors, DTE Energy gets real-time data about the location of outages so crews can more quickly and accurately locate them. This saves crew time, reduces expensive truck rolls and allows DTE Energy to restore power faster. By using the Predictive Grid Analytics capabilities of the LightHouse solution, they can begin to avoid outages, saving an estimated $10,000 per event.
When a storm hits, information from smart grid sensors can be used to improve crew safety by showing the status of the load on the portion of the grid they are working on. By knowing what portions of the network are de-energized, crews can more safely work on the network. Once repairs are complete, crews get confirmation that power is successfully restored.
Before LightHouse, DTE Energy did not have a good way to monitor its legacy network in real- time to know what the assets uses were. The information from LightHouse Smart Grid Sensors is helping DTE Energy justify what equipment to fully replace and what is functioning properly. Having this visibility is a key advantage that has changed its asset management and operations strategy, helping DTE to make more strategic decisions about how to best allocate capital investment across their network.
In June 2014, Tollgrade worked with the Clinton Global Initiative (CGI) to make this project a Commitment of Action that pledges to bring comprehensive grid modernization in Detroit. The project will show how other utilities can take the same proactive measures DTE Energy is standardizing on their network to:
• Increase the number of outages avoided
• Decrease customer minutes without power
• Decrease frequency of power outages
• Save costs by avoiding outages
• Save costs by restoring power faster
The commitment entitled, “Building a Predictive Grid for the Motor City,” was featured on stage at the 2014 CGI Americas meeting during the closing plenary session moderated by President Bill Clinton, founding chairman of the Clinton Global Initiative and 42nd president of the United States. This project will eliminate nearly 500,000 customer outage minutes from the DTE Energy network and create greentech jobs in the U.S. Both Tollgrade and DTE Energy were recognized for their outstanding contribution by the Clinton Global Initiative.