BEC suspects lightning strike behind island-wide power outage

BEC Chairman Leslie Miller

As of Thursday, September 3, 2015

Traffic backed up after the power outage affected traffic lights on Thursday afternoon.

By RICARDO WELLS

Tribune Staff Reporter

rwells@tribunemedia.net

THE Bahamas Electricity Corporation (BEC) says it suspects that a lightning strike is the cause of Thursday afternoon's island-wide power outage.

BEC representatives have confirmed that crews are in the process of returning its generator units to service and have already restored power supply to a small group of customers.

According to outgoing BEC Executive Chairman Leslie Miller, a high-rise tension wire running power from the corporation's Clifton Station to its Blue Hill Station was hit by lightning around 2.30 pm.

He said: “That strike knocked out our operation and we are working to get that back up by at least 5.30pm. I am heading up to Clifton now to see exactly what is going on. But for now the power looks like it will be out for some time.”

Meanwhile, Bahamas Electrical Workers Union (BEWU) President Paul Maynard also said that employees suspected bad weather was behind the outage.

However, he refused to comment further until the matter could be properly investigated.

For more on this story, see Friday’s Tribune.

banker 8 years, 7 months ago

So nobody at BEC has ever heard of zener diodes for lightning protection in electrical grids? I'm a banker and I know about protecting power sources.

http://dkc1.digikey.com/ca/en/tod/Pan...">http://dkc1.digikey.com/ca/en/tod/Pan...

Have we no one who knows about modern concepts of electricity?

paul_vincent_zecchino 8 years, 7 months ago

Good point. Wondering what might knock out power islandwide.

Redundant main feeders might help, but if one substation feeds the island, then when that does down, so does the power.

Was this a direct hit? Any lasting damage?

No doubt utility poles are all grounded; do they also have lightning arresters on them?

As you ask, are zener diodes in use? If not, is it because they're not applicable, inadequate to the high voltages on the lines? Or is it due to economic reasons? Something else?

Are other lightining protection devices available?

One thing about lightning, the more one learns about it, the more questions one has.

And nothing survives a direct hit, rare though they are. Most lightning hits are in the woods or on the water.

Most lightning damage to electrical devices is caused by induced voltages rather than direct hits.

A bolt within a mile, even though it falls harmlessly to earth, can nonetheless induce a potential of several hundred thousand volts on power lines. This voltage and resulting current wants to get to ground by the path of least resistance. Sometimes that path runs thru power lines, into one's home and thru one's appliances.

Other times, though home wiring systems and substations alike are all grounded, ground potential due to a strike can rise 'above ground potential' to flow thru the ground wire back up into the home's appliances and electrical devices.

Lightning's funny stuff, a mind of its own. One can take steps to minimize its disruptive effects but there is sometimes no eliminating them.

The_Oracle 8 years, 7 months ago

Research SWER grid, Single Wire Earth Return. While individual poles may be grounded, ask BEC how many poles have had the copper ground wire stolen. The top wire pole to pole throughout Florida (for example) is a ground wire which usually takes a strike (which is what lightning wants, ground) and other than localized damage (immediate customers) the grid stays up. Without that ground wire the hot lines get hit, and go to ground through the customers and substations! Our grid is antiquated and not properly balanced, nor properly corrected for phase angle.

The Tribune