All news

Damage from thunderstorms can be prevented

19.07.2012
Every year thunderstorms cause thousands of breakdowns that can damage sensitive electronic equipment. To protect your equipment from damage, unplug it before lightning strikes if there is a thunderstorm or use specially designed protection devices.

This year 470 breakdowns have been caused in Elektrilevi’s network by thunderstorms, and most of them happened in June and July. The breakdowns caused by thunderstorms have resulted in power outages in over 26,000 households so far this year.

"Thunderstorms are the second worst enemy of the electricity network after strong winds. Last year lightning caused 15% of all breakdowns," says Jaanus Tiisvend, head of Elektrilevi’s Asset Management. In 2011 thunderstorms resulted in a total of 2,150 breakdowns, and over half of them happened in July. The largest number of power outages caused by thunderstorms occurred in Pärnu, Rapla, Harju, Viljandi and Lääne-Viru counties. In 2010 thunderstorms led to as many as 4,130 breakdowns.

"Traditional bare cables on overhead lines are the most vulnerable to thunderstorms. The more overhead lines we manage to replace with underground cables as we upgrade the network, the better protected from lightning it will become," explains Tiisvend. He says that Elektrilevi is installing overvoltage limiters in the network, which will reduce the number of breakdowns in the network but will not prevent damage caused by thunderstorms from occurring in customers’ homes. A thunderstorm creates a very powerful electric field that causes overvoltage in power lines even if lightning does not strike the line directly.

"As July and August are the months when thunderstorms are most likely, we would like to remind people that electronic equipment must be protected from lightning damage," adds Tiisvend. The damage incurred because of thunderstorms will not be compensated by the manufacturer of the equipment, and as a network operator we consider lighting to be a force majeure beyond our control, so the user must cover the costs if equipment is damaged because of a thunderstorm.

The power units of computers, televisions and set-top boxes are typically the most sensitive to voltage surges, so it is sensible to unplug sensitive electronic equipment during a thunderstorm or if you are leaving home for a long period of time. If you have valuable household appliances, you could use overvoltage limiters or sockets equipped with such limiters, which are sold in electronics stores. You should also make sure that the mains network of the building is properly grounded and as protected from the effects of thunderstorms as possible. You can see our website for more information about preventing damage to electrical equipment.

Gusts of wind during a thunderstorm can break trees and branches and make them fall onto power lines. Elektrilevi would like to remind you that you should not approach broken power lines because the lines and the ground around them could be live and you could get a fatal electric shock. Please notify us about broken power lines or trees that have fallen on lines as soon as you can by calling Elektrilevi’s fault notification line 1343.


Elektrilevi (formerly known as Eesti Energia Jaotusvõrk) is a network operator that supplies electricity to households and companies and maintains and repairs the power network. The company manages the maintenance of almost 61,000 kilometres of power lines and more than 22,000 substations. In 2011 Elektrilevi invested 73 million euros in the power network, and it is planning to invest another 97 million euros this year. The company invests all of its operating profit in improving the quality of the power network every year.

Kaarel Kutti
Communications Specialist
Elektrilevi OÜ
Tel: 55 54 1989