Puerto Rico’s latest island wide power outages revealed weaknesses that all electric utilities, including those in the continental United States, need to address.
What Happened in Puerto Rico?
Puerto Rico is an island that is 40 miles wide and 110 miles long with an area of 5,325 square miles. This is about the size of Connecticut. The electric energy grid consists of 450 miles of 230 KiloVolt power lines and 500 miles of 115 KiloVolt power lines with 6000 Megawatts of energy production capacity at twelve coastal power generating facilities.
On April 16, 2025, Puerto Rico experienced an island-wide power outage, the second in just over four months. The island’s power grid was never fully restored after it experienced catastrophic damage from Hurricane Maria in 2017. Then in 2022, Hurricane Fiona again created blackouts across the island.
After Hurricane Maria, pundits explained that the problem was that the electric grid in Puerto Rico is old and poorly maintained. Well, eight years later, not enough has changed. To no one’s surprise, local power authorities said the latest outage “appears to have been caused by a combination of factors, including a ‘failure in the protection system as initial trigger’ and vegetation on a transmission line.”
How Does this Apply to the Continental US?
While the continental United States is significantly larger than the island of Puerto Rico, the grid is comparative in age and functionality. Many grid components in use today were installed in the 1970s and 1980s and are only updated when at the point of failure. Grid component failure and widespread power outages are common when hurricanes hit states like Florida and Louisiana. A key difference is that these states are connected to the much larger power grid that spans the US to the east of the Rocky Mountains. Because of this, continental states can receive grid support from adjacent states in times of crisis, via linemen to repair downed lines or energy when major energy production facilities are offline.
In comparison, Puerto Rico’s grid is isolated and therefore much more susceptible to outages. Arguably, portions of the continental US power grid are just as old as Puerto Rico’s electric grid. Either major grid overhaul or inventive grid enhancements are essential to keeping the grid functional through worsening storms, increased energy consumption, and other demands on the grid in the near future.
Major grid overhaul will be expensive and time consuming. Instead, I strongly recommend inventive enhancements to reduce wide area blackout risks, including:
- Investing in research and development of cutting edge technologies.
- Developing advanced, dynamic models.
- Implementing enhanced protective systems.
- Studying the successes of other industries.
These enhancements, outlined in more detail below, are a more cost effective means of improving the functionality and increasing the lifespan of existing grid infrastructure, while reducing the risk of wide area blackouts. They can be implemented across the continental US, as well as on islands like Puerto Rico, to prevent outages when grid collapse is imminent or restore power when grid collapse has occurred.
Before enhancements can be implemented, it is essential that electric utilities encourage their engineering staff to become focused on the future of blackout prevention, rather than be content to continue the status quo.
Future-focused Engineering Staff: Study and Plan
Future-focused electric utility engineers will become aware of best practices that are used in other industries. In particular, the nuclear power industry should be studied as an example of best practices for electric utilities. After issues occur, the possibility of similar events occurring at other nuclear power plants is evaluated. This type of frequent evaluation is essential for electric grid infrastructure.
For example, future-focused engineering staff would seek to mitigate long standing concerns around FIDVR (Fault Induced Delayed Voltage Recovery) that first occurred in Pasadena, CA in the 1970s. To do so, engineering staff would develop models to predict FIDVR, and implement technology to mitigate FIDVR before multi-state blackouts occur.
In addition, future-focused engineering staff could develop methods to
- Reduce protective relay system misoperations to less than 1 in 1000 operations (currently misoperations occur around 6 in 100).
- Use short circuit voltage profiles to evaluate impacts on customer load.
- Include FIDVR in load models.
- Split the electric grid into predetermined energy islands when collapse is imminent.
- Shed load using undervoltage and power factor as design parameters when collapse is imminent.
- Ensure that inadvertent operation of a single air break switch operating mechanism or a single ground switch operating mechanism cannot result in a three phase fault on a high voltage system.
- Ensure that unlikely, but known to occur, failures are addressed.
- Control the flow of energy across East-West and North-South transmission lines.
- Enable voltage recovery within eight milliseconds of fault initiation.
Cutting Edge Technology Reduce Blackout Risks
Electric utilities need to invest in research and development of the cutting edge technology needed to mitigate protective relay failures. When old electromechanical relays were replaced with microprocessor based relays, certain enhanced capabilities of microprocessor based technology were overlooked. New tools and capabilities can be added to microprocessor based relays to mitigate the risk of wide area blackouts like those seen in Puerto Rico.
Cutting edge technology includes:
- Series capacitors and series inductors that are inserted to match transmission line impedances.
- Solenoid inductors that instantaneously restore voltage to pre-fault levels.
- Distribution line voltage compensators that enable bidirectional energy flow.
Advanced Models Help Utilities Prepare
Advanced system models are needed to establish firewalls that prevent system collapse. Electric utilities continue to use load flow programs that were developed by IBM in the 1960s. These models are appropriate for steady state conditions, but not for dynamic conditions when collapse of the power grid is imminent.
Today’s computers have the capability to model the response of energy production sources, motors, laptop computers, solar panels, electric vehicle chargers, etc. as a function of power system voltage and frequency. In technical terms, today’s computers have the capability to calculate the impact of Fault Induced Voltage Collapse on the stability of the electric energy grid. With a concerted effort, advanced system models could be developed in as little as six months and broadcast throughout the electric utility industry in less than a year.
Advanced models need to:
- Dynamically model customer loads using fault voltage and fault duration as key performance indicators.
- Simplify FIDVR analysis using time biased recovery voltage models.
- Recognize that energy efficient lightbulbs stop working when voltage drops below 90 volts for more than eight milliseconds.
- Recognize that air conditioners stall when voltage drops below 70% for more than 100 milliseconds.
- Recognize that uninterruptible power supplies actuate in data centers when voltage drops below 70% for 32 milliseconds.
- Include electric vehicles as energy sources.
- Accurately represent traditional energy sources, renewable energy sources, electric vehicles, customer loads, and customer preferences on an hourly basis.
Yes, this last point means that 8,760 base models would be developed, significantly more than are currently in use. Today’s advanced computational capability, in particular AI’s ability to select and leverage data as prompted by future-focused engineering staff, will result in phenomenal new models.
Enhanced Protective Systems Prevent System Collapse
With advanced system models, enhanced protective systems that include unused electrical parameters can be used to establish firewalls. Today, microprocessor relays open circuit breakers when short circuits occur. They are not intended to establish firewalls that ensure recovery. Advanced protective systems will include features to:
- Reduce misoperation to less than 1 in 1000.
- Recognize that grid collapse is imminent and determine which facilities to shed before collapse occurs.
- React to anomalies that are precursors of collapse.
The goal is to implement advanced protective systems that ensure that the backbone of the energy grid remains intact when severe perturbations occur.
Study Successes in Other Industries
The Nuclear Regulatory Commission (NRC) requires that the nuclear power industry include design base threats, degraded grid voltage, and physical separation of redundant electrical systems in their design considerations checklist. The electric utility industry needs to follow their lead.
One of the main reasons that the electric system disturbance that occurred in the Washington, D.C., area on April 7, 2015 did not result in a multi-state blackout was the actuation of degraded grid voltage schemes at nuclear power plants in Maryland. Thanks to the requirements of the nuclear power industry, the electric grid avoided total collapse in Washington, D.C. and the surrounding area. This fact appears to have been overlooked by the electric utility industry.
Other industries can also provide helpful insights for electric utilities. The oil and gas industry routinely installs pressurizing stations to increase pipeline capacity. Are pressurizing stations the fluid equivalent of static var compensators? The railway industry replaced bolted rail with welded rail to increase speed. Are railroad tracks similar to transmission line conductors when thermal expansion is a consideration? These important considerations must be studied by electric utility professionals.
Electric Grid: The Highway Analogy
Electric utilities need to think of their power grids as energy highways and develop tools that ensure recovery within 8 milliseconds when a fault occurs. Power system faults are comparable to potholes in highways: dips in voltage create bumps in the energy highway. When permitted to persist, potholes can cause major damage to roadways and vehicles; likewise, faults that persist for more than 8 milliseconds can lead to wide area blackouts.
When cutting edge technology is installed, advanced models are studied, and enhanced protective systems are implemented, power system fault “potholes” can be shortened to only a minuscule bump in the road.
With these enhancements in place, future wide area blackouts like those experienced in Puerto Rico can be avoided. It is essential that electric utilities replace silo mentality with creative innovation and future-focused staff. To do so, they must provide resources and encouragement to engineering and operations staff so that fundamental shifts in technology can be pursued and implemented before 2035.