Posts by John Robson 5210 publicly visible posts • joined 19 May 2008
Tell me you don't understand physics...
Adding a trailer to any vehicle will impact it's range - and that impact is basically down to increased rolling resistance and increased aerodynamic resistance.
Typically you don't get as much benefit from regen braking with a larger trailer since they throw energy away as heat through friction before they push the vehicle hard enough.
Yes - we probably need to increase the local capacity... but it's also possible to have devices respond to local voltage, rather than just to grid scale DFS. And that could be very easy way to improve the distribution of demand... as we move to more and more "delayed usage" type loads (hot water tanks, storage heaters, EV charging, home battery charging) then those devices can actually drop their usage when local conditions require it.
Indeed some of them (specifically home batteries and EVs) can feed the local network, actively lowering the strain, and then recharge at a time when the local grid isn't as strained.
That's clearly not going to "solve" all the local network issues, but our current domestic usage is really peaky, e.g. cooking dinner tends to be at about the same time for most households.
We can shape much of that usage by time of day tariffs - Obviously E7 and E10 did that decades ago, and many ToD tariffs still follow the same process. But what you then end up with is everyone putting all their high load devices on at exactly the same time, to take advantage of that cheaper rate.
For something like an EV - they spend ~23 hours a day parked. You don't really care when it gets charged, just that you keep it topped up enough to account for typical daily usage - or that it can be filled for a special journey. Similarly you don't really care when your water tank is heated, just that you have hot water in the tank when you want it.
So local conditions based "avoided this time because of local conditions" credits (of some sort) would allow for the demand spikes at half time in sportsball to be much less of a drain on the grid, because all the kettles get put on, and high power devices can simply go "you know what, voltage is dropping a bit, I'll pause for a few minutes". Some of them could even export for a higher credits.
The result is actually beneficial to the grid, and no significant effect on users.
My peak half hour power draw from the grid last year was 14.5kW, but my average was well under a kW.
Smoothing out that curve is entirely possible, but at the moment it's very beneficial to be fully lumpy - only 5% of my electricity for the year was used at "peak" rate... I actually don't care when peak/off peak is, I just schedule things to use the off peak whenever possible.
If I assume I can replace gas with a heat pump at a SCOP of 3 (very conservative) then my electricity average usage would still be under 1.5kW, but again it would be lumpy, and more seasonally lumpy than it is at the moment - January would have been at about 2.2kW for instance.
There is no way you're telling me that the grid can't cope with a third of the country boiling a kettle at the same time.
UK electricity consumption is actually falling, despite increasing electrification:
"Electricity demand reached a record low in 2022 of 320.7 TWh, down by 3.8 per cent from 2021. Electricity demand has declined year-on-year since 2015"
If you look a bit further back, that decline has actually been ongoing since 2005 (where we used 406 TWh) Table 5.1
So we know the grid can handle more than it currently does - by more than 25% - because it's already done it.
(Note that the effect of additional substations for new developments and towns isn't being taken account of here - those will spread the load even further, but I'm ignoring that).
"Second, I doubt if BTC miners pay spot price for their electricity. (Indeed, the story some months ago about them selling back power to the grid in Texas implies that those miners, at least, pay a precontracted rate.) So they will not respond to wholesale prices in the way you suggest."
That implies that they are paying market rates - they are just buying the energy a long way in advance, since they have very well known static load, and can power things down (or just idle them) to get a different, well known, static load.
That means they can buy (making up numbers) 1MWh for each settlement period months, or even years, in advance - and come the time when those are due for "delivery" they can choose to either use the energy they bought (potentially *months* ago) to do whatever it is they do to make a profit, or sell it on to another user at a higher price than they bought it - again for profit?
THe EU didn't limit the "suckage", they limited the power draw, resulting in significantly more efficient hoovers being put together.
I'd like to have a 2kW element in my kettle - since then I'd be within my battery inverter, which means I only draw from the grid when there is plenty of capacity.
Lowering the amount of water you boil is still something most people don't do... we have a water dispenser for other reasons, but it does mean that we only boil the water we need.
Replacing a gas hob with an induction hob is a significant benefit in terms of both energy use and, more importantly, home safety. Noone is going to take your existing hob off you, but when you upgrade, you'll have to upgrade. No doubt you complained when they banned DDT or formaldehyde...
My shower is still mains pressure, and plenty strong, not quite as strong as my direct mains shower from twenty years ago, but then I've moved 100 miles and the water pressure here is slightly lower.
"Cryptomining is an interesting challenge" No it's not - it's a complete waste of time...
"(I suspect that if I asked that of the men and women working on this system, exactly zero of them would respond by slapping their forehead and exclaiming "holy crap Mr. AC, we never thought of that!")"
I suspect you're right.
Laser ablation is vapourising the surface of the material, so what's left in orbit is probably mostly individual atoms - which aren't that much of a concern.
Additionally that ablated material is exiting the target satellite at some significant velocity (since it appreciably changes the orbit of the much more massive target) and will therefore end up in an interesting elliptical orbit which keeps it out of trouble most of the time (assuming it isn't simply accelerated to escape velocity)
"Naturally, not perfect, but lets cross our fingers and hope it gets charged and good to go for the next sun cycle."
Lunar night will absolutely kill it... there is next to no chance it will survive (and it wasn't designed to).
We might (and it would be great if we did) get several days of operation as the lunar evening draws in.
"I understand the criticisms about focusing on embedded/industrial clients to the detriment of the thinker community"
Well what we don't see is the complaints from people who wouldn't have been able to purchase whatever devices were built with those industrial pis (or things they then produced)
"I find it useful to take handwritten notes"
As do many people - others need other methods.
For instance in a meeting with a deaf participant... hand outs are useless - "Do you want me to look at the handout or listen to you?", and writing almost impossible.
A d/Deaf touch typist could take some notes during the meeting, despite having to have eyes up to listen to the meeting.
One could easily argue that there is also movement when typing... my fingers certainly aren't still.
36 is a pretty small sample, and they therefore won't have looked at the effects of things like dyslexia, or left handedness (given that the written world is RH focussed)
I wonder if it's different in arabic (or other right to left written languages)?
To be honest I wonder if it's a real effect, or whether the digital pen was not familiar and therefore required more concentration to write with.
Not only would this help data centres, but it could put a substantial distributed base load to the grid, a couple at each motorway service area... waste heat can be used by the services, and the electricity can supply the grid, or local storage, or local chargers... that fat grid connection can work both ways.
I think you might have misinterpreted my (not particularly clear) comment about there being no market... the manufacturers have decided that there is no market.
I think it's pretty obvious that there is demand for smaller devices, which don't attempt to be all things at all times, but the decision has presumably been made that they're not worth selling - therefore there is no product to make a market.
I spent some time with a nice thin, small bar phone (nokia something I can't remember) which provided a bluetooth PAN for my Nexus 7 tablet.
That gave me a week or of standby on the phone, with a decent connection for the tablet which gave me a decent screen for anything else I needed to do (which included having a BT keyboard and a USB OTG connected mouse to run games in dosbox)
I know you initiated the joke alert... but one thing about smaller reactors... is that they can shed heat enough rapidly enough to make a thermal runaway much more controllable.
One of the big issues in places like Fukushima was that the secondary reactions generated more heat than the core could reasonably reject for many days after the earthquake and tsunami wiped out most the surrounding infrastructure. A smaller core has a lower power input from secondary reactions and a (relatively) high surface area from which heat can be dissipated.
Of course the bigger thing that we've done since those were designed in the late 1960s is to design reactors with passive cooling systems, rather than relying on active systems.
"Yeah, it is ridiculous that you need an App."
You don't - a tesla driver pulls up to the charging station, plugs in, and then walks off to relieve themselves.
Then they come back, unplug and drive off again.
That's the entire process, the billing is automatic - the car talks to the charger, the relevant account is billed.
Far easier than any liquid fuel station.
If only CCS had that built in as part of the standard (and it clearly has enough, since various chargers/cars now do the same).
"Lithium-ion batteries have to be pretty warm to fast-charge, over 100F."
Nope - mine fast charges (100kW+) at anything over ~15-18 degrees, which is in the 60s for those using arcane units.
Could it charge faster if it was over 40? Maybe a little, but not much - and the battery temperature does increase noticeably as the charge continues, so it's fairly easy to watch the temperature/soc/charge rate.
Regularly used to cycle past all the cars stuck on the icy roads...
Particularly remember overtaking a gritter stuck behind a queue of cars unable to crest the hill, I got about 30 yards further than any of them, then popped a foot down and pushed for about 10 yards before cycling again.
Whilst I've come home to find snow "aero rims", I've never had any sprockets or mudguards clogged with snow.
Negative 50 is sufficiently cold that it doesn't matter which temperature scale you use.
The lowest "minimum typical winter low" is Minessota according to https://wisevoter.com/state-rankings/coldest-states/#minnesota
And that's -19C...
https://www.visitnorway.com/plan-your-trip/seasons-climate/winter/#
"The climate varies greatly from region to region in this long country. Along the coast, temperatures usually stay around zero degrees Celsius. Inland, the temperatures are mostly lower and might sink down to 10-20 degrees below zero Celsius. Some places can even experience an bone chilling minus 40 degrees Celsius!"
So whilst Minnesota does have a record low of negative 50, so does Norway (it's 51.4).
By the time you need block heaters... you plug in the EV when you stop, and you probably want a software change to keep the battery conditioned.
You know, do the same "special treatment" for both vehicle types - because at that temperature anything designed for "normal" operating conditions isn't going to fare well.
"As for waiting a couple of days that's makes zero difference because the thing will still need to be delivered"
But it doesn't have to be a dedicated vehicle... so it can be delivered more efficiently if it's delivered where there is other demand as well...
If they'd talked about medical supplies (as with the rather good drone system in <can't remember the african country>) then they'd get alot more sympathy.
There are occasions when a rapid delivery is needed, but pasta?
"For the small percentage of people who need that (asthmatics and the like) if they wanted one they can probably one on eBay. IIRC the patents in question expire "
I just read that as patients expiring... which isn't the same thing *at all*.
I thought you'd gone really dark, really quickly.
"It allegedly 'saves' £20k a year, and that number has remained strangely constant."
Two possibilities:
- The model is the only thing they can possibly quote, and they don't remodel each time the costs change.
- The contract is "cost -£20k"
Since I actually know something about that system... the issue is that they couldn't drill nearly as far as they wanted, so they are scavenging from a far smaller loop, at lower temperature than was expected.
Aiming to keep an open air pool at 30-35 degrees is also just crazy hot.
Electricity is fairly expensive, mostly because the market is set up to make sure that burning gas remains the determination of cost - we'll get away from it soon - but it doesn't matter what the cost is if your visitor numbers drop substantially...
"These are council services, and councils are busy dropping like flies, thanks to their 'investments'" chronic underfunding from central government. FTFY
"LED Community Leisure Ltd (LED) is a not-for-profit charitable trust" - i.e. not the council directly.
District heating can use low grade heat, though it's better with slightly higher grade... but again - if you can run your heat pump using the output of a data centre then that's easily scavengable heat to convert into medium grade heat - i.e. a substantial cost saving operationally.
The Register 
Biting the hand that feeds IT
Copyright. All rights reserved © 1998–2024
