Ask a Scholar: What Will be the Effects of a Local Power Line Upgrade?

Charles G. Beaudette

Dear Ask a Scholar:  We are concerned about a potential power line 'upgrade' in the neighborhood, one which will increase the voltage from  69 kVto 115kV.  With all the talk about health risks from  EMF's (let's ignore the debate on that for the moment), wouldn’t a voltage increase from 69kV to 115kV cause an increase in EMFs?  I realize that EMFs, or electromagnetic fields, are comprised of two separate things: an electric field and a magnetic field.  Intuitively, I would think that the increase in voltage (I believe that the current lines are also being replaced with heavier ones) would cause an increase in EMF readings.  What do you think?

Answered by NAS member Charles G. Beaudette, retired electrical engineer, and author of Excess Heat: Why Cold Fusion Research Prevailed.

Yes, the electromagnetic field will be larger --- approximately twice as great.  But this assumes that the reading is taken at the same distance from the source as was the original reading.  The two components of the field are not properly thought of as separate from one another.  Although electric and magnetic are different kinds of fields, they are intertwined with one another.  Also, we are talking here (in your question) about the "far field" from the wire.  Close to the wire, there are strong and separate electric and magnetic fields. 

With regard to the public debate: The effect on the questioner of raising the voltage will be that he may enjoy a more reliable source of electric power for his household and his hospital. 

* * *

Have a question Wikipedia can’t answer? We’ll match your question to a scholar with an answer.  Questions submitted to “Ask a Scholar” should call for educated judgment rather than facts that can be found easily with an internet search. We especially welcome questions that provide professors the occasion to draw erudite distinctions and incorporate mention of matters you had no idea were connected to the topic at hand. Simply email NAS or submit questions via Intellectual Takeout's Ask the Professor feature. We'll field your question to a scholar and get back to you with an answer as soon as possible.

  • Share

Most Commented

September 16, 2019

Slavery Did Not Make America Rich

'King Cotton' isn't King

September 18, 2019

Most Read

September 21, 2010

January 03, 2011