Power surges happen dozens of times per day inside your home. 80% of them are very short intense bursts of electricity, lasting for only a few millionths of a second. Power surges can even travel through phone, internet and cable lines. These surges can be caused by simple things like turning on and off your hair dryer or air conditioner, issues with a utility line or your electric provider, or lightning. Lighting is the most dangerous but also the least likely, as it would usually have to strike within a mile of your home to do any damage. Next is most dangerous would be caused by problems with utility lines and your electric provider. Fluctuations can be cause by downed trees, malfunctioning equipment or come from other properties using the same electrical system.
It is rare that one large power surge will take out all your electronics and appliances at one time, the most common damage that is cause by power surges will most likely go unnoticed. Power surges will slowly cause damage circuit boards and shorten the lifespan of electronics throughout your home, so instead of your fridge lasting for 15 years, it may only last for 10. This slow damage process can take an extreme toll over the years, costing you thousands of dollars as circuit boards fail. Today's modern homes have a lot more electronics in them than you might think, even LED light bulbs have small circuit boards inside of them.
A whole home surge protector can be connected directly to your fuse box. Once the device is connected it will act like a pressure relief valve and block dangerous power spikes originating from power lines and your utility company from entering your home. Some of the best whole home surge protectors react to surges in less than a nanosecond.
Outlets with built in surge protection are also still recommended for all your electronics. Small surges can still naturally occur in your home, however these are much less dangerous and damaging.
Although it is rare, a major electrical surge could potentially fry circuit boards throughout your home including computers, tvs, appliances, dimmer switches, LED lights, GFCI plugs, timers, and more. This kind of damage can cost well over $10,000 to repair.
Even without a major power surges, they can still cost you thousands of dollars as electronics in your home fail quicker than they would have with adequate surge protection. In the long run surge protection basically pays for itself.