Agreed, those numbers are way overoptimistic.

My experience is somewhere in between. I got my leaf 7 years ago. We drive it about 5-6K miles per year, which is somewhere around half the normal, I think. So multiply the effect by two to get a better average per car. Going from memory, our electricity usage went up by about 10%. (We have gas heat.) About a year ago, we installed LEDs for almost all of our primary light sources. (I was putting that off partly for cost but mainly because most of our lighting is on dimmers and dimmable LEDs are only recently available.) Our electric bill went down about 10%.

Another aside, I read recently that, in spite of enormously rapid population growth, Seattle's overall electricity usage has gone down over the last decade. (As a consequence, they are raising our rates :( This is due to a number of factors, not just usage of LEDs. I think a big source is improvements in commercial space heating and cooling, which has lagged far behind that for domestic. Also think of display lighting which has typically been halogens. Now LEDs.

So, my conclusion, LEDs help significantly, but by themselves will not supplant EV charging consumption.

Peri

------ Original Message ------
From: "Matt Awesome via EV" <ev@lists.evdl.org>
To: "Electric Vehicle Discussion List" <ev@lists.evdl.org>
Cc: "Matt Awesome" <mattsawesomest...@gmail.com>
Sent: 25-Jul-18 11:08:21 AM
Subject: Re: [EVDL] Charging load on the grid (NOT)

Remember this factoid.

I'm all for saving energy and obviously I'm here so I'm passionate
about EV use, but, it's also important to me to not treat this like
some kind of religion.

Swapping out the average American home from Incandescent bulbs to LEDs saves the same amount of power needed to charge an EV the American 40 mile average
per day forever.

Plainly, no, it won't.

50 bulbs saving an average 60 watts each for 5 hours a day is 15 kWh.

Who the hell leaves 50 lightbulbs on in their house for 5 hours a day?

I don't even think I have 50 lightbulbs in my house, let alone leave
them all on 5 hours a day.

Anyone with that many fixtures is putting 40w bulbs into them. And
LEDs aren't free, so, there's not 60watts savings from a 60w bulb.

Let's try to get some more realistic numbers.

How many Kwh does an average US household consume in a day?:
Source 1: https://www.eia.gov/tools/faqs/faq.php?id=97&t=3 -
Independent US Energy & Information Statistics says ~10,000kwh/year.
That's 27kwh/day.
Source 2: http://www.nationmaster.com/country-info/stats/Energy/Electricity/Consumption-by-households-per-capita#2005
- Around half that.

What percentage of an electrical bill is comprised of lighting?:
Source 3: https://www.eia.gov/tools/faqs/faq.php?id=96&t=3 - 9%.
Source 4: https://www.quora.com/What-percentage-of-energy-consumption-is-from-lighting-in-a-typical-American-house
- 6%.

The split seems to vary depending on whether heat is made through gas
or electricity. Meaning the lower percentage use numbers for lighting
are from houses that use 2x as much electricity (for heat). If they're
not making heat electrically, their lighting percentage is higher (but
the same net total).

So, we could say 27kwh/day of which lighting is 6% or 15kwh/day of
which lighting is 9% to at least be in the right ballpark (this
argument is about general scale, not really precision).

What is the average lighting demand for a US household?:
- 27kwh*6% = 1.62kwh/day.
- 15kwh*9% = 1.35kwh/day.

Somewhere around 1500 watt-hours a day.

You're claiming 10x that amount in *savings* from switching to LED,
let alone total lighting use.

Charging an EV at 1.5kw for 10 hours a day is 15 kWh.

Since it's not the 1970s, the average household has at least 2
vehicles, more when there's teenagers/college kids.

So... your "factoid" for a household is now off by a factor of 20x.

Add in that LEDs aren't free, you're off by a factor of 25x.

It would be more accurate to say that by switching from incandescents
to LEDs, you could expect to save enough energy to cover 4% of your
electric vehicle use. A pretty banal, unsensational, non-headlight
grabbing rhetoric for sure, but at least an accurate one.

You can nitpick those numbers a bit, they might be off by, oh, perhaps
double, but they're not off by an order of magnitude.
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