What Causes a Brownout?

Photo by Rodion Kutsaev on Unsplash

As temperatures soar there’s nothing like cool air from an air conditioner. As temperatures drop you’re likely to crank the heat to stay warm. What’s the common thread? Extreme temperatures drives the need for appliances that use a lot of electricity, which in turn, creates a spike in demand for electricity. That’s why many people, including myself, like places where the weather is 70 degrees. Not too hot —  not too cold. Well, as luck would have it, our electric grid is no different. It would prefer to operate in the middle where there aren’t demand spikes that cause problems. What further exacerbates the problem is the aging infrastructure of utility grids that struggle to keep up with the increased demand.

What causes a brownout? A brownout can be intentional when the utility company regulates power to prevent a blackout or unintentional when caused by weather, falling trees, car accidents, and animals.

There are a few things you should know about preventing brownout damage to your home electronics. This quick read will open your eyes to the world of brownouts, why they happen, and what you can do to protect your home.

What Is a Brownout?

A brownout is a drop of voltage in the power supply, which reduces the load on the supply system. The dimming of your lights is where the name originated. 

What Does a Brownout Look Like?

When the voltage in the electric grid drops you’ll notice lights flickering or going dim, but potentially not going out. Some appliances may have minimum voltage requirements, which may make them turn off thus giving the appearance of a power outage. Other appliances may work fine and show no signs of problems as they can operate with a minimal decrease in voltage. Light bulbs tend to be the best measurements as they dim an emit a brownish color. Remember, with a power outage nothing would be on. A brownout will show some signs of life in your home.

Is a Brownout Intentional or Unintentional?

Well, both. A brownout can be intentional as the utility company detects a possible emergency and steps in to control how much electricity is being supplied. This preventative measure is necessary to prevent a blackout, which is a complete loss of power. The electric company forces a reduction in the load on the system at various points in the electric grid, which could be your neighborhood or city. The reductions can last a very short period of time up to many hours.

A brownout can be unintentional when any number of natural events or human elements take down part of the power supply and create a larger demand on the rest of the power grid. Things like: weather, falling trees, car accidents, utility companies accidentally breaking a line while working, and even animals can be contributors to the problem.

Another unintentional culprit is solar. You might be scratching your head thinking “I thought solar would help”. Solar panels can help offload demand when they’re producing energy for your home, thus reducing the load on the grid. During bad weather, like winter, for example, you’d have less production of electricity because of overcast skies. With little to no production, you’re now reliant on the grid again for your supply. Damaged or faulty solar systems cause a similar problem. When these panels aren’t producing, there’s an increased demand for electricity that wasn’t expected.

Events like this aren’t intentional, but without good forecasting tools, the utility company is blind to the scale of these demand spikes and has little time to plan for the increased utilization.

Can I Do Anything to Prevent a Brownout?

The general rule would be to reduce your overall electricity consumption. We all have power-hungry appliances in our homes such as stoves, washing machines, dryers, and air conditioners. When a brownout is suspected you should shut down power-hungry appliances provided there isn’t a health risk in doing so. I’ve lived in the heat of Texas and the bitter cold of Alaska and understand how tough the extreme temperatures can be.

Though comfort may be on your mind, as well as,  general safety — consider dealing with small variations in temperature in an effort to reduce demand. If everyone in an impacted area changed their air conditioner from 70 to 75 there would be a reduction in demand. Also, there has been a number of sources indicating the continued use of electronic devices under low voltage can harm or permanently damage them — so, turning things off helps with the problem and potentially eliminates damage to your appliances..

How Can I Prevent Damage to My Appliances During a Brownout?

  • The quickest and easiest way to protect your appliances is to unplug them. Keep in mind any medical equipment should remain on, but turn off and unplug TV’s, stoves, and air conditioners. 
  • Invest in an Uninterruptable Power Supply (UPS). This is the best way to protect your home and appliances safe. This is also a good option to keep ‘critical’ systems online. You’ll need to be the judge on what is ‘critical’ to maintain in your own home, but many choose a UPS to protect and maintain computers and/or health-related equipment.

In my research, I found a Harris Poll conducted by a company called Intermatic, who wanted to better understand their customer’s awareness of brownout impacts. They had some surprising findings:

“We were alarmed to find that 86 percent of homeowners are at risk of incurring significant replacement costs because their air conditioning units are not protected from power surges.”

“Most people don’t think twice about plugging a $200 television or $800 computer into a surge protector to ensure they are protected from transients and surges. However, expensive systems like central air conditioning units, which would cost thousands of dollars to replace, sit completely unprotected from surges, brownouts and blackouts”

Intermatic representative

For large major appliances like an HVAC system, reach out to a local professional to talk to them about surge protection via products like:

There are many options, so reach out to a local HVAC contact and have them walk you through your options.

For smaller appliances, there are brownout voltage protectors available for: refrigerators, freezers, water coolers or any appliance with specific amp specifications. We’ll cover those devices in an upcoming review.

Is There Anything Being Done by the Utility Companies?

The aging infrastructure is one of many things the utility companies are trying to address via a Smart Grid approach, which aims to modernize our electric grid. Advanced sensors would monitor loads for a potential problem and load forecasting technology to see these potential problems before they actually happen. Such improvements come at a steep cost, and unfortunately, you and I would carry the responsibility in the form of increased fees.

It’s somewhat of a catch-22 because, without action, we’re likely to see these brownouts become blackouts more often. With each brownout or blackout, it places more stress on the aging system.  In addition to increased frequency, the scale of the outages run the risk of becoming larger. We’d cringe at calling an electrician on the weekend to fix a problem because we’d pay a premium. Imagine our national grid failing and paying a premium to fix the problem once it has failed beyond a quick repair.

Other than upgrading the grid the utility company can do its best to prepare for an outage. In some cases the outages are intentional, but not by the power company trying to control the voltage. Another intentional culprit is cyberterrorism. This is one area that makes everyone nervous — even the government, which is why they perform GridEx exercises.

GridEx is a biannual exercise that involves utility companies, federal, state, and local agencies.GridEx is designed to simulate a cyber attack or a direct physical attack on the grid. The participating groups meet every few years and conduct a complex simulation, though the exact details aren’t made public until after the simulation. Here is a copy of the GridEx fact sheet.


A brownout is the warning of all warnings and you need to take them seriously. Knowing what to look for and how to react can mean the difference between a short-term brownout and a long-term blackout. The difficult component is getting this message out to everyone. So, be a good neighbor and make sure they know what to do as well.

Until we’re all dependent on ourselves for power — awareness and preparation are your best bet. As newer technology becomes available and renewable sources become more prevalent our new Smart Grid may be the answer we’re looking for, but could still be many years away before we can rest easy.

For now, protect the investments you’ve made in your home by being mindful of backup power, and safety equipment that can protect your appliances no only from voltage drops, but surges when the power comes back online. Remember that Harris Poll I discussed earlier?

In the poll, Intermatic found 84% of the homeowners mentioned protecting their home electronics from power quality issues, only 17% protected their air conditioners, heating systems and furnaces. Additionally, of those reporting brownouts — 12% reporting having to replace major appliances.

2014 Harris Poll

One final thought is to check with your federal, state, and local government agencies. Many states have an emergency notification system in place and have an app that provides critical alerts for your area. I’ve collected a list on my blog called Ultimate Guide: Best Apps in a Power Outage. Find those resources and get them into your smartphone. Having knowledge of a potential problem is half the battle. So, if you get an energy emergency alert you’ll know what’s coming and what to do.

Good luck. Be safe.

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