The amount of burned insulation on the wire depends upon the size of the power surge on the electric line. The size of the power surge is typically dependent upon how far away the lightning hit the power line and how much power the lightning strike had when it hit the power line.
http://www.mechanicalconsultinggroup.com/pages/adjguide.htm
Facts about Lightning. 1  Lightning’s unpredictability increases the risk to individuals and property. 2  Lightning often strikes outside of heavy rain and may occur as far as 10 miles away from any rainfall. “ 3 Heat lightning” is actually lightning from a thunderstorm too far away from thunder to be heard.
https://www.ready.gov/thunderstorms-lightning
For most thunderstorms, 70-90% of lightning strikes are intracloud or from cloud to cloud. From 10-30% of lightning can be cloud to ground (CG), depending on the storm. Lightning strikes the earth more than 100 times each second and 8 million times per day.
http://emedicine.medscape.com/article/770642-overview
Lightning may injure an individual in 6 ways. 1  Direct strike (approximately 3-5% of injuries) 2  Side splash from another object (approximately 30% of injuries) 3  Contact voltage from an object that is struck and conducts electricity to the site of touch, such as plumbing or wiring (approximately 1-2% of injuries)
http://emedicine.medscape.com/article/770642-overview
The flash of a lightning strike and resulting thunder occur at roughly the same time. But light travels 300,000 kilometers in a second, almost a million times the speed of sound. Sound travels at the slower speed of 344 m/s, so the flash of lightning is seen before thunder is heard.
https://en.wikipedia.org/wiki/Lightning_strike
Lightning strike. A lightning strike is an electric discharge between the atmosphere and an earth-bound object. They mostly originate in a cumulonimbus cloud and terminate on the ground, called cloud to ground (CG) lightning.
https://en.wikipedia.org/wiki/Lightning_strike
So a lightning strike can cause a power surge (large amounts of energy flowing into the system in a small amount of time), which can blow transformers and cut your power. It can also damage sensitive components connected directly to the 'grid' (so without a surge protector).
https://www.reddit.com/r/askscience/comments/3n98qa/does_lightning_cause_a_power_surge_or_does/
Electronic equipment is far more susceptible to power surges or lightning damage than compressors or well pump motors. The possible exception would be if the insured has purchased a good surge protector for electronic equipment. 2. Find out if the neighbors have had damage due to lightning or a power surge. If lightning or a power surge came in on the power line, then all people off of the same utility transformer should have been affected. 3. Burned insulation on electric wiring is not necessarily an indication of a power surge due to lightning.
http://www.mechanicalconsultinggroup.com/pages/adjguide.htm
Lightning is evident in all thunderstorms. The danger of lightning may not be apparent to an individual because lightning can strike 10 miles or more away from the rain of a thunderstorm.(See Epidemiology.) Lightning starts with short (30-50 m) spurts of static energy in a cloud.
http://emedicine.medscape.com/article/770642-overview
Lightning is only one example of a surge. Most lightning strikes (and other surge sources) do not cause power outages because the surge (a microsecond event) connects to earth quickly and then terminates - without damaging anything. That means maybe 20,000 amps goes harmlessly to earth.
https://www.reddit.com/r/askscience/comments/3n98qa/does_lightning_cause_a_power_surge_or_does/
lightning strikes how far away can cause damage?
Lightning can strike 10 miles or more away from the rain of a thunderstorm can cause damage.