On 4/17/2025 2:07 AM, Martin Brown wrote:
Time of use tariffs are still uncommon in the UK. It is possible with a smart meter (which I now have) but supplier offers are pretty poor. Previously I had a counter rotating dials mechanism dating from the 1950's (which had clocked - overflowing the counter back to all zeros).
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I believe all of the meters, locally, have now been switched over to solid
state devices. Remote monitoring being a desirable asset (*reading* a
meter is only "worth" ~25p so it, in itself, is not enough to justify
the cost of the swap).
The "smart" meter program in the UK has been hilarious. They rolled out model 1 systems that are almost trivial for a state actor to hack. I waited for a gen 2 "smart" meter which so far has behaved pretty well.
I had my own monitoring clipped onto the incoming live line so it doesn't really give me anything new except fewer meter reader visits.
There are different models (and manufacturers) in use, here. All share
the same power monitoring capability. Some include options to track
peak, peak-over-time, total-over-time, etc. And, some include "local"
comms to allow them to talk to local load management "options".
I've heard rumors that some can also be used to disconnect power
(for non-payment) but think that would be hard in the volume
typically set aside for the meter (?)
There are two different comms systems in use one which works and one which doesn't. The north of England where I live has the latter. My meter actually works OK but the one in our Village Hall nearby failed within days of being installed and they have now given up on it.
A bit more info here.
https://www.ovoenergy.com/guides/energy-guides/smets-1-and-2-new-smart-meter-generation
Only the SMETS2 meters are properly cryptosecure.
Security is almost always an afterthought in product design. To
do it *right*, it needs to be one of the FIRST things that you
address; not something that you "bolt on" afterwards. Especially
when folks can talk to the device without having a physical
presence.
It is possible to have local domestic battery storage and exploit the overnight low rates - though to get the best deals you need to own an electric car (or at least convince your electricity supplier you do).
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Here, the issue is the high PEAK demands that the ACbrrs place on individual
subscribers. We could probably get by on a 3-5KW plant -- but, only if
we could store and deliver for large loads (I think the ACbrr is ~14KW).
That is huge. I sometimes have a small fan on from time to time but the house temperature seldom exceeds 25C in summer. Night time almost always drops below 16C (56F) so tropical nights are rare here.
The load is the peak load when the compressor kicks in. If we wanted
to NOT connect it to the grid, a PV inverter would have to handle
that surge. (I think that any load connected to the grid triggers
special "solar treatment". OTOH, connecting the panels to something
freestanding shouldn't require the consent or participation of the
utility, at all -- just local building/electric codes)
Without refrigeration, it is quite easy for a house *interior* to
rise to over 100F during the summer months. Worse, Monsoon brings
moisture with it (the main reason to want refrigeration).
In summer, our nighttime lows will exceed 80F. It is often 90F
at midnight.
Amusingly, folks will often be seen wearing SWEATERS at night; the
air is so dry that you can feel chilled despite the heat!
Aircon isn't really a thing in domestic UK buildings. The number of days a year when it would be needed can be counted on the fingers of one hand. My house manages it with Victoria technology - very thick walls and windows to open at night. Centres of major cities do get rather warm due to office buildings with air conditioning pumping out heat!
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Most construction, here, is masonary -- 8" block. But, when the outside
temperatures rise so early in the year and persist for so long THROUGH the
year, that actually works against you -- the house STAYS hot because of the
thermal storage in its walls.
Aren't you in desert country?
I thought the overnight temperatures could drop quite low there...
We are in the *low* desert. The HIGH desert is known for cooler nights.
But, technically, the Sonoran Desert which is more distinctively "low"
despite having an elevation that one might consider as "high".
Even in winter, night lows seldom fall below freezing. It will be ~65F
tonight. It may drop to 60 in the last hour around sunrise -- but only
for a very short while.
E.g., when I took my evening walk at ~7P, it was just down to 90F.
[We've already had our first 100F day and it's been above 80F since February]
It is spring here. Has been as high as 20C (64F) but yesterday was cold 5C (40F?). Working towards Bank Holiday (bad) weather after a prolonged warm spell that has seen all cherry, plum and pear blossom out.
I suspect we saw "high 30s" a handful of times -- this WINTER.
A personal favorite, here, would be to capture the waste heat from the
ACbrrr condenser and use it to heat swimming pool water; the liquid medium
would likely be a more efficient coolant than air sourced in a typical
condenser. And, 100F pool water is delightful!
Outdoor swimming pools are not common in the UK. It is too cold - although wild swimming in open water is on the increase since Covid.
I think a casual survey of satellite imagery led me to conclude that
about 1 in 4 or 5 properties, here, have pools. But, they are
"toys" -- maybe 25 ft across and 15 ft wide. (at least they aren't
SPOOLS -- spa-pools barely large enough to fart!)
The utility has been complaining that they have "too much" residential
solar capacity (the utility has a say in whether or not YOU can use solar
and how large your installation can be)
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UK allows up to 4kW solar generation on any domestic premises. More than that
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I don't think the *city* places limits on size of plant. But, requires it
to reside on rooftops to avoid permitting, architects, etc. (of course).
That is a double win in a low latitude country because the double skin on the roof creates shade and delays ingress of heat. Clever backing on the panels (thin insualtion and Alu foil) can improve it further at the expense of losing efficiency of the solar panels due to increased heating.
The downside is that servicing the roof becomes considerably more expensive.
A neighbor with solar just had her roof replaced. The panels were OFF the
roof for almost two weeks -- leaving her paying the higher ToU rate.
and you have to apply for a license. It confused the load shedding algorithms last time there was a serious power outage since it was about 6pm in mid summer and so when they shed a nominal 1GW of load they also dropped off about 100MW of small solar PV systems. It was enough to lose control of the frequency again and a cascade failure ensued.
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Too funny. C'mon, this isn't rocket science!
The network stability is actually quite a tough problem. And getting tougher with the rapid removal of so much spinning generator kit which has serious angular momentum stored energy in the rotating equipment.
Of course! But, KNOWING where the cogeneration is sited shouldn't be
that hard to track. It's notlike it gets up and MOVES of its own accord!
The problem with locally electronic phase matched output is that it will quite happily track whatever frequency is sees on the mains.
Yes.
[OTOH, I am always amazed at how out-of-date the (network) "maps" are
that the utility uses. Didn't anyone write this stuff down? Do
you even KNOW where your equipment is? Or, does a crew have to go
out and visually identify it??]
They typically have no idea and fewer skilled engineers than are needed to reconnect people in more remote areas when there is big storm damage.
Our utility has actually been pretty responsive to equipment failures
(though I suspect the neighborhood in which you live plays an
important role). Our utilities are all below grade. And, all reaching
(or exceeding) their design life.
Each time a cable segment (about two property lengths long) has failed,
they've had us back on-line within 3-4 hours. Of course, they do this
by just changing the feed for the isolated segment. At some later
date, they will pull a new cable through.
We also have a ridiculous amount of solar PV for such a high latitude. This is governed by the fact that in a good year a farmer can make around £200/acre by actively growing crops and £2k/acre by stuffing their land full of solar panels. Many are choosing the latter.
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I suspect we will see a similar pattern (perhaps wind) with large
swatches of farmland, here -- esp as climate change renders particular
crops harder to grow, increased pestilence, etc.
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"This farm has been in my family for 5 generations! (but, now it's
a WIND/PV farm cuz I can't grow shit!)"
Wind power you can still graze animals or grow crops underneath as it doesn't shade the ground. UK has rather more offshore windfarms than most. The blades for the bigger ones are amazing things of beauty.
Here, they have been using goats to "trim" the weeds under PV farms.
I sometimes pass them on the motorway. Definitely "abnormal load" !
It is ultimately all about very clever financial engineering to load the balance sheet with debt and pay handsome dividends to foreign owners.
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Penny wise and pound foolish for the the UK.
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It seems like a change to the tax code could quickly change their fortunes?
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Not really - a lot of them have been sold off to foreign companies.
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Don't they still have to pay local taxes? Even if they ship the
profits off to foreign investors?
No. That is how the loading up with massive debt trick works. They are allowed to offset interest payments on loans against taxable profits.
(and pay themselves big dividends into tax havens)
Ah. Leave it to a bean counter to figure how to screw the system!