[RFI] [External] Re: Wireless Power Transfer with electric vehicles

Tue Apr 20 08:11:19 EDT 2021

We can speculate, but the solar system on a given house is probably no more than 1% of the total mass and electronics present in that house over the decades the solar system will be in place, and its components are far more likely to be recycled than the seven TVs that people will own over the lifetime of the system.   You and I don't know where that balance is, so we are just speculating that it might cost more energy to make than it produces.

I don't think that to be the case. Let's conservatively estimate that a home solar system generates 3 kW for 8 hours a day.  If that system has a lifetime of 20 years, can we really think that it would take the energy of running a 1.5 horsepower motor continuously, 24 hours a day, for 20 years to create that solar system from obtaining raw materials until disposal?  That alone seems to be way more energy than I can imagine it taking.

Then, if we don't do things with solar, what are the energy costs of creating and replacing the huge electric generators that will be needed to power all those unsolared homes? What of the additional costs of upgrading transmission lines to bring power in from outside rather than pushing it around on neighborhood distribution lines. Then factor in the fact that most of the energy created by those generators is derived from carbon-producing fuels and in my mind, I think that actual math has to come out on the side of solar power being quite energy positive. If it took more energy to produce the panels than they produced, none of the solar farms would be economically viable, yet they are springing up all the time.

Now, as global citizens, we can be interested in these questions, but as amateurs, and especially wiht ARRL, we have to be very careful not to step past the bounds of our standing, because if we are to raise this point based on speculation, we will lose the big EMC battle, and be sidetracked by people who HAVE done the math.

Solar will happen, and right now, working with the manufacturers to sensitize them to the importance of avoiding interference is the right step.  I must got ready with a a mobile van with a loop antenna located on a trailer behind it, 99% noise free except for what I believe to be a bit of tire static, ready to go visit local solar farms to really assess their interference potential.  I can calibrate that antenna against my calibrated loop and get a really good estimate of antenna factor, so, using a spectrum analyzer with RMS detection capability, I can get some good measurements to compare solar-farm noise to existing noise levels.

Well, this will keep me busy for a few more years, so no need to retire yet. all the rumors notwithstanding!

Ed Hare, W1RFI
ARRL Lab

Ed, W1RFI

________________________________
From: RFI <rfi-bounces+w1rfi=arrl.org at contesting.com> on behalf of Leonard Halvorsen via RFI <rfi at contesting.com>
Sent: Monday, April 12, 2021 2:43 PM
To: rfi at contesting.com <rfi at contesting.com>
Subject: Re: [RFI] [External] Re: Wireless Power Transfer with electric vehicles

One issue I have never seen addressed is the consideration of how much
energy is used to BUILD the components of the systems (solar arrays,
wireless chargers, etc.), and the associated pollution (read that: global
warming) resulting from that construction/production. Resources/Minerals
must be mined; then processed; then used in the production of the devices
in question. All of this takes energy. Probably more energy (including
fossil fuel energy) than would have been used if we spent that energy
(joules) directly on the work (watts, ft-lbs, calories, BTUs, etc.) to be
done (driving a car, heating/cooling your home, et-al). You are
saving/buying nothing if that EXTRA energy you use OVER the direct use of
the original expenditure EXCEEDS what you save at the end with the new
devices/systems/etc. Remember: Some of that extra expended (wasted) energy
is coming down your antenna feedline as noise.

73

Leo
WA2AMW

-----Original Message-----
> From: RFI <rfi-bounces+w1rfi=arrl.org at contesting.com> On Behalf Of Rob
> Atkinson
> Sent: Sunday, April 11, 2021 6:48 PM
> To: rfi <rfi at contesting.com>
> Subject: Re: [RFI] Wireless Power Transfer with electric vehicles
>
> The people who buy electric cars to Save The World are blissfully ignorant
> of all the pollution associated with making and recycling batteries.  They
> will also be blissfully ignorant of the fact that wireless charging energy
> transfer is about 50% efficient compared to a direct cable connection.
> Some won't care--they only want to virtue signal with their cars and have
> plenty of money to waste.  But maybe enough will avoid this idiocy IF they
> find out how expensive it will be.
>
> 73
>
> Rob
> K5UJ
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>
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