Discussion > EVs - Charging / Solar Panels
Another spontaneously combusting EV at a charger this time
tomo
DIY / Open Energy Accounting - targeted at "Nigerian" Generator in your back yard stuff.....
Sniffing substations will solve 'leccy car charging woes, reckons upstart
It's rather easy to assume that given the constipated and overly bureaucratic methodology for "making the grid more resilient" that backyard generators are going to become a thing....
tomo
tomo; thanks for those links.
The second one refers to a National Grid report saying:
"“Pilot projects, such as My Electric Avenue, were reporting potential issues at the distribution level. In one more extreme example they were identifying voltage issues when five 3.5kW chargers were connected to a network cluster (with 134 dwellings) and were charging at the same time. The project concluded that across Britain 32 per cent of low voltage circuits (312,000) will require reinforcing when 40 per cent –70 per cent of customers have EVs based on 3.5kW chargers.”
It gave a link to the report which failed. When I did a search on the NG website, it did not come up. However I did find the Electric Avenue project which confirmed the comment about the need to reinforce LV circuits.
This is all quite old - the project finished in 2015. So it is based on 3.5 kW chargers (mainly) and smallish EV batteries. The game has moved on: batteries are bigger and a lot of owners use 7 kW chargers.
The obvious conclusion is that more circuits will need "reinforcing" and, probably, to a greater extent.
On home generators, I wonder whether they might even be economic if run on gas from the grid?
While I don't plan to go that far, I would like to find a simple battery back-up to power my heating system pump and controls. Something using a trickle charger, truck battery and inverter (?) would do the trick but I've not found anything yet.
MikeHig
MikeHig
I feel that home generators are definitely economic and it's a small mystery why care homes, larger shops, schools, council offices and the like aren't sprouting them.... There are integration issues but I feel they aren't insurmountable - there are people doing it but the present market seems littered with severe early adopter price gouging and overly specified units.
One of the major hurdles is managing the grid connection and the lobbying / entrenched providers aggressively and ruthlessly defending their monopoly positions. The rates at the moment for "grid support temporary supply" have touched £3 per 3.8p gas kWh ... - so say (v.v. crudely) a 10kW generator supplying the grid in an "emergency" would be billing £30 per hour on 38p of fuel - nice work if you can get it.... I feel my sums are in the ballpark but capex / opportunity / maintenance etc. will dilute that considerably. The rates presently paid to "normal", everyday people who want to feed power to the grid are surprisingly low....
As far as powering your house is concerned - you can get away with a computer UPS and some wiring adjustments. The easiest way to protect your heating is to run it with something like this - which would likely also (just) cope with the lighting circuits. Extra external batteries can be added to extend run time and from my experience the APC software doesn't check that you've a larger battery and beep.... The standard batteries are usually sized to give ca. 10 mins run time at full rated output ...
So, separate the lighting and heating circuits get a UPS and some extra batteries - and optionally a generator to run heat and light from UPS for extended runs... Most UPSs produced in the last 10 years are at least as efficient as a standalone inverter. There are some considerations for UPSs which give more features... - more here.
Big Clive looks at a generator transfer switch - if you're more ambitious
tomo
Not difficult to imagine an EV trailer with a with a gas cooker connector, gas compressor, tanks and a generator :-)
tomo
tomo; many thanks for that UPS info. It's very much the sort of thing I'm looking for. My own research had led me to kit intended to work with solar panels, etc which was dramatically more expensive.
Based on recent experience of local outages, and expected problems in future, I'd want enough juice to tide me over for at least 6 hours. So one of those with an extra battery or just a gutsier version should do the job.
I'll need to talk to a sparky but there's a single feed to my boiler and controls so, hopefully, it should be fairly simple to wire in a UPS. I'm not worried about lighting.
MikeHig
MikeHig
UPSs are generally rated in kVA so multiply the offered output by .75 (rough) - a circulation pump generally is around 250W and a fan assisted boiler ca. 200W (again roughly)
- so say 500W or in UPS terms 750VA (rough again) which roughly translates to 20 Amps at 24V (UPS efficiency is usually >80% and often in the high 90% region) - so 6 hours @ 20A = 120Ah which is a standard battery size
I'd plan on not using the rated capacity of the battery so a pair of 130 amp-hour leisure batteries externally wired to the UPS would suffice and likely give a bit of margin....
I'd swerve all the solar systems unless they are Victron or Mastervolt - the rest are mostly rubbish. Both brands are £££££££ - but do what they claim without fuss.
tomo
800kW charging ? - that'll be 1200A per phase on LV (415VAC) 3 phase - there's no plain "push" terminals presently available that I know of that will handle that - and if the presently highest rated plug contacts are ganged up with appropriate housing I suspect that the connector alone would weigh in at 15kg plus and if copper cables are used - the 'elf 'n safertree wombles will ban human handling on the grounds of safe handling weight alone - lifting the connector and cable would be over 25kg.
One feature of high current contacts that few appreciate is how sensitive they are to contact resistance - the normal highest rated plugs are 250A and they are very sensitive to contact oxidation in repeated mating and burn out quite often .... Single conductor Powerlock are better - but these are presently the domain of certified "competent persons" / licensed electricians for the most part...
1200A @ 400V protection / circuitry suitable for public use seems a long way off - and if the batteries can charge that fast, they can discharge faster .... = fireworks.
The holy grail of "as fast to charge as it is to fill up with petrol / diesel " seems likely to be a bumpy and magic smoke filled path ...
Then... as we've covered up thread - what bits of the normal grid will be able to support these beasts?
Turn up the volts to reduce the copper? - there be more issues....
tomo
tomo; I don't have much grasp of electrics but it looked challenging before I read your comments.
You mention turning up the volts. The 350 kW chargers I mentioned run at 800V. For the moment the only cars which use that voltage are the Porsche Taycan and one from Kia/Hyundai. Some Teslas can charge at 250 kW using 400V but they are the exception. Most EVs max out at 150 kW.
I do suspect that this will all turn out to be much less critical than is presently believed. Say 250 kW becomes the norm over the next year or two. Not many, if any customers will be charging from 0 to 100%. EV fans say it is good practise to charge between around 20% and 80% as it is better for batteries and charging slows down above 80%. So even the biggest-battery cars will typically draw 60 kWh and then only when they need to be "full". Most will be in the 30 - 50 kWh range which will take 7 - 12 minutes at 250 kW.
So, in terms of (in)convenience, it will become a non-issue.
As for the main supply....Big charging stations already use chunky batteries to buffer demand. Even so I think a lot of "historic" cabling, transformers, etc are going to be challenged!
MikeHig
MikeHig - you are correct that 150 to 200kW will likely suffice.
Even that will usually require special provision - and I have a client who hires out generators who makes a fair living out of renting them to people waiting for the electricity utility to hook them up - sometimes months pass.... I know of several sites where they've installed permanent generators after being quoted high 5 figure sums to provision 3phase 400V 250A.
I hadn't realised how many rural places aren't supplied with 3 phase power and have had to install v.expensive special motors and switchgear. I've had several discussions with farmers about electric tractors, looked at the power provision they've got and wondered if they had thought it through.... a diesel generator to charge the tractor or an £80k bill to bring in 3ph.
As we've covered - the LV distribution network is creaking ....
An EV for noodling around locally is attractive (I've had my share of test drives) - "they" have yet to make a sane case for small vans / sub 3,5T commercials that do 150 miles + a shift and the longer distance random route business drivers.
I'm keeping an eye on the charging provision around my area and it's rubbish on reliability and the nearest fast charger is 20 miles away...
tomo
Autocar have just done an exercise to try out a variety of chargers to see how well/badly they work. They tried them out as if they were one-off users, looking for a quick, simple top-up. The results are mixed, to say the least.
https://www.autocar.co.uk/car-news/industry-news/analysis-electric-car-charging-still-hit-and-miss
MikeHig
MikeHig
thanks for the Autocar link (and the chuckles)
It would seem that the marketers are intent on dragging people into walled gardens - which works if you keep your prisoners content ....
69p per kWh @3.5mi/kWh = 19.7p a mile ... Surprised it wasn't covered in stickers for taxis and towing services.
- and I was pffff-ing in the local Tesco car park over their 37p/kWh large screen TV topped VW ad hoarding! (which is regularly u/s!)
tomo
Tractor stats on EVs from the usual suspects
tomo
Bluidy Bloomberg at it again...
You'll be able to charge your EV while driving along the road
tomo
MikeHig
saw you over at pistonheads in the "I can't get my Hydrogen car refilled" thread.... :-)
Bit of a TL/DR for me ... where's it at at the moment?
- looks like some retail remorse for Mirai owners ....
tomo
Hi tomo,
Yes, I do visit those EV threads on PH regularly. Amongst all the advocacy there are a lot of candid comments about the EV experience which are informative and give the view from the "other side of the hill", so to speak.
Not sure what you mean by "TL/DR"?
There are now two hydrogen threads. Both have bogged down completely in pointless and repetitive stuff. Early on the original thread was interesting, partly because I worked in industrial gases for some years and partly because it triggered me to learn a bit about the technology.
Afaik, the original poster has not been back to update the thread so his car is presumably still gathering crap somewhere. It's my impression that the only folk running FCEVs in this country either have professional reasons or are doing it out of curiosity (there was speculation that the poster might be James May).
Think I may have seen you posting on Paul Homewood's site?
MikeHig
TL/DR = "Too Long/Didn't Read" - I sensed the ennui that was setting in in those threads.... :-)
I do visit NALOPKT quite regularly. It's got quite a lot of lurkers I reckon - the late Chistopher Booker's patronage did a lot to drive traffic there.
I make it 157 Mirais registered and none on SORN (as if that'd matter I suppose at £0 tax)
I suspect there's a mechanism (paid for ...) to contact them via DVLA as an intermediary to quiz the owners - although Toyota will know where nearly every last one of them is on a minute to minute basis as they all have SIM cards and GPS.
tomo
157 Mirais? And it's been on the market for 4 - 5 years. Not exactly flying out of the showrooms then!
There's another thread I look at occasionally on PH called The Future of Power Generation in GB:
https://www.pistonheads.com/gassing/topic.asp?h=0&f=205&t=1673400&i=7380
There are some interesting comments from folk working in various bits of the power industries.
MikeHig
MikeHig
if there's no bottled protons to be had - maybe Rich Benoit can do something?
There'd be 44 Mirais that would be MOT candidates.... - unless they get a waiver like commercial EVs (yes... they don't need an MOT!)
tomo
O/T
EASA page on aviation biofuels
It rather looks on a skim read that there ain't a 100% airliner biofuel as all 6 presently certified products look to define a blend level with JET A1. Most are 50% but there's a 10% and a 5% ......
tomo
tomo: that EASA page shows that there are quite a few bumps in the road....
> Fuel produced from waste cooking oil, etc is 50+% more expensive than standard jet fuel and that feedstock is already oversubscribed for biodiesel production. I would guess that using virgin oil feedstock would just add to the price. And....
> The fuel vs food argument impedes the use of oils like rape, palm, etc.. Indeed, aiui, the EU is moving away from supporting the use of rape oil, etc; they have already dropped the plans for further increases in the mandated bio content of road fuels.
> There is no international agreed standard for bio jet fuel which must complicate international flights because a plane could fly to, say, the US with fuel which does not comply with local standards which has liability implications.
In a final irony, there is probably more coal-based fuel being used. South Africa still runs a big coal-to-liquids industry and one of its products is jet fuel: iirc 50% of the fuel used there is coal-based. China has a number of very big CTL plants built and in construction so they probably have quite a lot of "coal-powered" planes in the air.
MikeHig
MikeHig
I had assumed (which came back as usual and bit me) that Beardy Branson's Virgin PR op a couple of years ago was contrived - but - I hadn't appreciated how profoundly dishonest it actually was.
I had also assumed that the chemistry / physical properties of JET A1 had been emulated fully by the chefs brewing up the Green go-juice. The test fridges will required for a while yet - more funding needed.
tomo
Interesting article by Autocar on towing with EVs and towing EVs when broken-down:
https://www.autocar.co.uk/car-news/industry-news/can-you-tow-electric-car-or-hybrid
MikeHig
Covid impacting road diesel ...
Apparently all that unused aviation kerosene has to go somewhere
I hope they get the additive mix right - otherwise that's a lot of knackered engines.....
tomo
ah yes - regulatory compliance....
Brussels will mandate all sorts of paper work and employed thousands of bureaucrats busybodying away with a few academics to put raisins in the recipe for a fee.... - China will as per usual allow those making the batteries to just busk through with faked up paperwork.