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Electric utilities break a sweat over summer

For most of us, the arrival of summer is celebrated with ice cream, sunburns and barbeques with friends.  Unfortunately, for utility companies tasked with delivering power to their consumers reliably and cost-effectively, warmer weather can often leave them in a cold sweat.

The combination of stormy weather patterns, rising temperatures and increased demand for power creates a ‘triple whammy’ for energy companies, which can have a dramatic effect on their operations and ability to supply power to customers without interruptions.

On top of having to cater to the surge in electricity consumption from air conditioning, utilities also have to cope with the consequences hot summer days put on the electric network, including sagging power lines from thermal expansion and equipment failures, both of which are triggers for power outages.

Hot summer days add stress to the electrical grid

Summer time often translates into a significant increase of power usage to make our everyday living more pleasant both at home and at work as temperatures rise to uncormfortable heights. In a 2015 study published in Proceedings of the National Academy of Sciences, researchers found that the adoption of air conditioning is likely to boom, which will eventually drive residential electricity usage up 83 percent over the rest of this century. Residential consumers show by far the largest seasonal variance in electricity use, with air conditioning contributing to a massive swing of some 67 billion kilowatt-hours between minimum and maximum demand.

These needs during the summer months put an enormous strain on the electric grid, ramping up the load on circuits and transformers and increasing the risk of blackouts and brownouts. When circuits become overloaded, the excessive current can cause circuit breakers to trip and equipment on the distribution network to deteriorate which can lead to power interruptions and impacts on reliability.

Heavily loaded transformers regulate voltage less effectively, which results in reduced bus voltages. This additional voltage drop is more of an issue during  peak summer temperatures because the system’s voltage is already low due to the high demands on the grid.

Staying cool with smart grid sensors and predictive grid analytics software

Increasingly, utilities are deploying network monitoring solutions, such as Tollgrade’s LightHouse® platform, which combines smart grid sensors and predictive grid analytics software to proactively monitor distribution circuits. This approach enables utilities to take proactive steps to identify fault types and get increased visibility at their rural substations by aggregating load information from their feeders and substation transformers. Using Tollgrade’s Predictive Grid Analytics software, utilities can turn the data collected by the overhead power line sensors into actionable business intelligence, both for their own operational efficiency and for the benefit of their customers.

Case study: Summer Peak Demand Season – Power Outage Disaster Averted

Utilities are often forced to operate transformers up to and beyond their expected life spans. As mentioned in a ‘Managing Aged Transformers article, “asset managers are diagnosing and monitoring the condition of critical and problematic units, and then ranking the transformers by condition to deal in the near-term with the units that affect utility operations the most.” However, that methodology is not always reliable, as a large utility located in the North East region of the U.S. found out last summer.

The utility company deployed Tollgrade Smart Grid Sensors in 2012 to monitor their network, specifically near their substations. Cognizant that one of their substation transformers was nearing its load rating, the NE utility decided to move some of its Tollgrade’s smart grid sensors closer to the substation prior to the start of summer 2015.

On a number of occasions throughout July, August and September, Tollgrade’s Sensor Management System (SMS) software triggered the overload monitoring alarms as a result of increased electricity demands. To the utility’s engineer’s amazement – and the belief that the transformer had a few additional years before it reached capacity – loading was almost 14% above the transformer’s rating.

The load profile clearly showed that the electric load would spike suddenly for a couple of hours and then settle back down, not damaging the transformer. Nevertheless, the LightHouse system made the company aware of the need to take action to either reduce loading at that particular substation or to install a larger transformer. 

With the addition of smart grid sensor data, the utility discovered an unsuspected overloading issue and was able to react before it caused a power outage. In addition, because the team had interval load data (every 15-minute for the entire summer) they were able to persuade the company’s management as well as the Public Utitilty Commission to release additional budget to replace the over loaded transformers before service interuptions occurred.

This case study proves that with a grid monitoring platform utilities are able to better identify the root of problems and understand how to manage their system in the optimal way. LightHouse possesses the unique ability to capture waveforms so engineers can analyze events in their network. By providing waveforms to understand the true nature and location of faults, utility distribution engineers can proactively respond to outages and momentaries and support the overall health of the grid.

Equipped with the right information, utilities and network operators can implement cost-effective and rapid improvement plans to identify aging or failing equipment.

In addition to monitoring assets as the peak summer months approach, once the LightHouse sensors are installed utilities can take advantage of its fault detection capabilities to identify exactly where faults, momentaries and outages occur.  With sensors in place, distribution engineers can more affordably retrofit intelligence into the distribution network, quickly fix problems and make better-informed decisions during times of peak demand which will significantly reduce the risk of power outages.

Summer should be an exciting season when everyone is able to shed their normal stress and enjoy this beautiful time of year.  With the advancement of scalable monitoring solutions, utilities are finaly able to properly plan and react to dynamic summer grid conditions, making the season more enjoyable for everyone involved.

Free download. For more information on how to detect, locate and prevent power outages, download our white paper: Predictive Grid Analytics: Bringing our electric grid into the 21st century.

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