[SystemSafety] Smart heating [was: Comment on Risks note on "Smart Power Outlets" ....]

Mike Ellims michael.ellims at tesco.net
Fri Aug 26 13:11:13 CEST 2016

> I use 110 kW a day at the moment for heating needs (air+water), and could
use a bit more.
> That's at least 17 Powerwalls.

Peter 110 kw seems a) excessive and b) the wrong units.

Average usage here at home is 8.4 kWh drawn from the grid (a LOT less in
summer) and in Oz the average house uses around 15.4 kWh per day in 2014.

Another web site gives the average per year for Germany as 9.7 kWh per day,
the peak usage seems to be Canada at 32.5 kWh per day...

Did you mean 11.0 kWh?

-----Original Message-----
From: systemsafety
[mailto:systemsafety-bounces at lists.techfak.uni-bielefeld.de] On Behalf Of
Peter Bernard Ladkin
Sent: 26 August 2016 10:57
To: systemsafety at lists.techfak.uni-bielefeld.de
Subject: [SystemSafety] Smart heating [was: Comment on Risks note on "Smart
Power Outlets" ....]

On 2016-08-25 17:05 , Martyn Thomas wrote:
>> [PBL] Burning your house down by firing up appliances?....
> It's not impossible (though culpably stupid) that someone would leave 
> a radiant heater plugged in somewhere that could cause a fire if it 
> was left on for a while. The electrical protection might cut in when the
fire finally caused the cable to melt, but it would be too late ...

I am guessing this happens regularly but not frequently: Section 3 of
arch/statistics/ says that, of the 46 people who died in Britain in "fires
of electrical origin" in the time-frame 2011/12 (which I am guessing is an
annual figure not aligned with year boundaries), 11 died in a fire derived
from "articles too close to heat". That's just under a quarter.

A phenomenon here worth remarking is the vast differences in national
attitudes towards home infrastructure.

First, Germany. I bought a Dyson AM09 heater/cooler last year. I use it for
spot heating, of course.
I have a large building with two "units" (no throughway between them) and
more spaces used for diverse tasks which are logically "units" but currently
connected. Rather than spend to heat the whole building to living
temperature constantly, it makes sense to me to maintain causally-used parts
at a lower temperature (14°-16°C) and use spot heat to raise one to 20° when
in use. Figures seem provisionally to bear this strategy out.

In Germany, heating from the electrical supply is regarded as inappropriate.
I told my heating engineer's lady that I'd bought a Dyson. She lectured me
for five minutes. Her husband called me the next week and lectured me. Then
his senior techie called up to discuss my heating and I received another

I have not seen a radiant heater in nearly twenty-two years of living here,
except industrial ones on pedestals used by restaurants to heat their
outdoor areas when it's cool or cold.

Second, the US. In response to my note, AlMac told some hair-raising stories
about US building electrical circuitry. He thinks much of it in the US is
nowhere near being what I would call electrically safe, because standards
aren't enforced (or, indeed, required in some smaller towns, he suggested).
That reinforces my point, I think, that the smart money is spent on
electrical safety before it is spent on "smart power outlets".

Third, sustainable electric heating. I don't know whether sustainability is
really a safety topic (I have some sympathy with those who argue it is THE
safety topic). But safety+sustainability does come together in debates about
power, notably the viability of nuclear power.

I wonder about PV roof panels feeding a decent battery in the basement which
could support my spot-heating paradigm. Short version: it needs batteries.
High-capacity lithium-ion batteries such as the Tesla Powerwall installed in
a building are a potential fire-safety issue. Further, it is impractical as
a sole heating technology. I use 110 kW a day at the moment for heating
needs (air+water), and could use a bit more. That's at least 17 Powerwalls.
I might have enough spare roof space for PV panels to charge 2 or 3, and I
certainly don't have the wall space to install 17 of the things. Enough said
here for now; more at



Prof. Peter Bernard Ladkin, Bielefeld, Germany MoreInCommon Je suis Charlie
Tel+msg +49 (0)521 880 7319  www.rvs-bi.de

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