The “grid” refers to the interconnected system of power generators, transformers, and distribution lines which provide electricity to our homes and businesses. To get an idea of its complexity, imagine having a simple gasoline powered generator which supplies your home. This would not be very efficient, but it would work if properly sized and connected. Periodically, you would have to live with no electricity while you serviced your generator, and occasionally you might blow the circuit breaker when several high power loads were switched on simultaneously. Suppose your next door neighbor had a similar system and experienced the same problems with temporary outage from servicing and sudden high loads. Together, you decided to interconnect your two systems to provide better reliability. A great idea, but it WILL NOT WORK because the two generators are not synchronized to provide the exact same voltage, frequency, and phase. Now consider the situation in Mexico where the government power company CFE connects many different power plants located hundreds or thousands of miles apart to millions of homes spread out across the country. Their goal is to provide at least 99.95% reliability. That is 5 hours of outage per year. This is a daunting challenge which in Mexico is made more difficult by the fact that electricity generation and distribution is even more politicized than in the US. (If you doubt it is politicized in the US, read Shorting the Grid by Meredith Angwin).
If we lose the grid, we lose not only the electricity in our homes, but also nearly everything else we depend on. In Mexico, we are used to occasional outages of a few hours, but if these last more than a few days, we may lose perishable food in the refrigerator and freezer. If our water is supplied through a cistern, the pump that supplies pressurized water to the house will not work, and at best we will have low pressure (and unfiltered) water from the tinaco on the roof until that runs out. Gasoline will not be available for our cars because the gas pumps are electric. In a few days, water will run out as SAPASMA will no longer be able to pump it, and their water towers will run dry. Stores will be empty of food and essential supplies after a few more days because there will be no new deliveries. After a week or so, civil society will collapse. If you want to read more about what life would be like, read the novel One Second After by William R. Forstchen or any of the dystopian novels by Mathew Bracken.
How likely is it that a power outage of this duration could happen? In my opinion, it is about 50%. And considering the consequences, it is worth taking some measures to survive it. Think of this preparation as an insurance policy. Fortunately, in Mexico, it is easier to do this than in most places in the US.
Grid Vulnerabilities
Weather and natural disasters (hurricanes, lightning, earthquakes, etc.) can take out a portion of the grid for days or weeks at a time. The best example was probably the Mexico City earthquake of 1985. About half the population was without electricity for weeks. Emergency relief for such disasters is generally available within a few days. The grid has good lightning protection.
Terrorism is a significant concern. Substation transformers are vulnerable to high powered rifles. Replacing them can take weeks or months as they are very expensive (millions of dollars) and difficult to transport and there are not that many spares. Recent attacks occurred in San Jose, CA in 2013 and in Moore County, NC in 2022. Power was lost to thousands of homes for about 4 days. A more widespread coordinated attack would not be repaired so quickly. High voltage transmission lines are also vulnerable since they pass through uninhabited areas. Three of the four lines leaving the Palo Verde nuclear plant in Arizona were shorted out in 1986 by terrorists using only ropes and chains.
Solar Flares are very common but not usually severe. However, very large ones can occur. The largest on record was the Carrington Event in 1859 which was about a hundred times the intensity as those that are typically experienced. Another large one occurred in 1989. What happens is that a solar eruption sprays a large cloud of charged particles into space. If these intersect the Earth, they will interact with the Earth’s magnetic field and produce a voltage gradient along the surface. If a long wire (like a high voltage transmission line) lies along the path of this gradient, a current will be induced into the line. The currents can be very large and they are direct current (DC) rather than alternating current (AC). This means that the transformers connected to the lines can be saturated and damaged by overheating. This did not occur of course in 1859 but it did in 1989. It takes a solar flare about 3 days to reach the Earth, so in theory, transformers could be disconnected to protect them.
Electromagnetic Pulses (EMPs) are produced by detonation of a nuclear weapon above the Earth’s atmosphere. This of course is an act of war, but it is a practical and tested weapon of mass destruction. An EMP actually consists of three pulses. E1 is an extremely short but powerful pulse that can directly damage semiconductor electronics such as those used to sense over-currents and over-voltages at substations to protect the transformers. E2 is a medium duration pulse that induces voltages similar to a lightning strike. And E3 is a longer duration pulse that produces a DC current similar to but shorter than a solar flare. It can last from seconds to minutes while the solar flare currents can last from hours to days. Nuclear EMP was demonstrated in a program called Starfish Prime when a high altitude nuclear bomb was detonated in 1962 and the lights in Hawaii were affected 1000 miles away!
Cyberattacks against the US electrical grid occur very frequently, but fortunately they have not been successful to date. In December 2015, the Ukrainian grid was successfully cyber attacked and resulted in extensive outage for several hours.
Overloads are handled by selectively shedding loads thus resulting in “rolling blackouts” up to several hours at a time. These will become much more common as the demand for electricity is increasing rapidly due to the use of electric vehicles and data centers. Artificial Intelligence is expected to make the situation much worse as the chips used are very energy intensive.
Instability due to the use of renewable energy sources is probably the most likely problem. The power consumed by the grid consists of two parts. About half is constant throughout the day, and this power is provided by “base load” generators (nuclear, coal or hydroelectric) that are very efficient but are relatively slow at responding to changes in the load. The portion of the power that is variable during the day is handled by faster responding gas turbine generators. Matching the changing power requirements by controlling these generators is a challenge because they must be matched for voltage, frequency and power factor (VARS). Grid level solar panels and wind turbines provide highly erratic source power due to the variability of cloud cover and wind. So additional fast responding generators need to be used to compensate for the variable output of these renewable energy sources. In practice, this means for every kilowatt (kW) of renewable power that is added to the grid, 1.25 kW of fast responding power generation must also be added to compensate for the variations. Wind and solar have their places in areas where commercial power is not available, but in my opinion, they should not ever be connected to the grid. But unfortunately they are, and they are making the grid less stable.
The Good News
Utility reliability was for many years spotty at best in Mexico. It is much better now, but houses are still built with a cistern and/or tinaco for water storage and a propane tank for cooking and heating. This is the case even in suburban and urban areas, whereas in the United States, only rural areas maintain on site storage of water and gas. Mexico also has a lower latitude than the US so sunlight is available for about 5 hours per day throughout the year. This makes planning for survival in the event of a grid failure much more practical in Mexico.
Backing Up
This website describes several alternative solutions for providing backup electricity. But having unlimited electricity does you no good if you run out of water, food, etc. So pages have been added that discuss backing up these essential items as well. These are the pages called Backup Electricity, Backup Water, etc.
The engineer in me motivated the inclusion of several other web pages that describe in detail the measurements and calculations that were used to prepare the “Backup xxx” pages.