What would a clean-sheet set of wiring regulations look like today?

Standardisation of wiring colours would be a useful step. Green/Yellow for ground/earth is almost there but the rest of the colours are scattered in function between the different countries. If I remove a light fitting in my Swiss apartment I may find a black wire and a yellow wire. The black is phase, the yellow is neutral. 

Redefining any of the current colours would merely increase the already huge legacy problem 

EIreland said:

We do have an example of a highly electrified society, in Quebec. Now obviously their heating loads are way more extreme than in the UK, especially in a heat pump future, but they also don't have huge penetration of electric cars there. 

Typical electrical installs there are 240/120V split phase systems with 200A on each side. That's something equivalent to a 200A supply in the UK.

The economics are very different though, Quebec has what are to British eyes, almost unbelievably cheap domestic electricity rates of around 7 CAD cents per kWh, that's about 3.5p/kWh. After the first 40kWh per day, that rate rises to the giddy heights of 11 cents, so 5.5p/kWh !

At those kind of prices, simple resistive heaters and storage heaters are a competitive form of heating.

With British domestic electricity unit rates around 5X that, the cost aspect will act to constrain demand in Britain.

Well yes, Quebec electricity rates are so low as to almost justify the old claim of electricity "too cheap to meter".

There is actually a cheaper tariff than the one you suggest if you have an auxiliary heat source to use in deep winter (defined as when the thermostat in your meter cabinet reads less than -12C!). That gives you 5.3 canadian cents per unit the rest of the time,  albeit with the cost of 30 canadian cents below -12C.
There is a reason  that Quebec has as many private pools per capita as California.

Whilst rates are in Ontario are much greater, they too have a time of use tariff with an overnight rate of only 3.9 canadian cents, or 2.1 pence per unit. That is a heavily nuclear dominated system, with their regular rates about 12 cents canadian per unit.

Off peak electricity will be extremely cheap in a renewable dominated system,although the times when it is used may be unpredictable.

If significant nuclear capacity is built it will be almost free. I believe before electricity market liberalisation, the "Option TEMPO" six-rate time of use tariff provided by EDF varied from 50 eurocents per unit to only 3.

We won't reach canadian levels, but the average electric car charging load will be something like 10GW, based on existing car mileage. If car mileage goes up due to low marginal costs, it will be more. We should expect radically more use than before, and this will probably drive down unit costs by amortising fixed costs.

EDIT: The cost delta per unit between my energy providers 'Economy 5' EV tariff and gas is getting much smaller than it has been in the past....

EIreland said:

After all, decarbonisation will require people to use a great deal more electricity than they have before, even if the heat pump rollout delivers everything that is promised.

Indeed. Average gas consumption in UK seems to be about 4 times as much as electricity. In our household, it is about 10 times as much, but we use gas for heating (including water) and cooking.

EIreland said:

I would think that any future supplies should be based on 2 or 3x100amp supplies.

Future houses should have a very much reduced heating burden as well as solar, so that may not be necessary. I'd certainly specify 3-phase for a self-build.

After all, decarbonisation will require people to use a great deal more electricity than they have before, even if the heat pump rollout delivers everything that is promised. 

That might  be far harder then you imagine. If you envisage the ADMD rising to anything above about about 8 amps per house, then every substation, every HV main and all the kit that supplies it will have to be re-done or at least re-configured. Just because all houses in the street have a 60/80/100A fuse next to the CU does not mean the street can supply that to each of them without catastrophic failure.  60-80 houses per phase on a half megwatt unit, fused at 400A /phase is a typical set-up on a modern-ish housing estate, older ones are less generous. An "all-electric" estates may increase that  half up to a one megawatt transformer, and then two branches of 400A each doing half the houses.
Given the speed with which we are still removing pre-war fused neutrals and looped supplies from terraces wired up in the early 1900s, I'm not sure we'll have the capacity to get your desired 3 phase to the house in time for the gas running out completely, let alone just getting rather expensive, as it is now.
The cheapski method is to up the voltage and transform at both ends, but that is not as easy as it sounds either. (though uplifting 11kV routes to 33 has some appeal, it is still a lot of substations to change).
So in the short term while we do that, probably only the first couple of decades, we either need heat pumps to be pretty efficient,  or to go back to a pre- central heating mentality, and learn to knit our own jumpers.

Mike

mapj1 said:

If you envisage the ADMD rising to anything above about about 8 amps per house

I put in a heatpump to replace the ageing gas boiler about a year ago, so we're "all electric" now (other than not having an EV yet) - cooking is all electric and the gas has been disconnected. Even on the worst day I can find data for (Jan 26th) we used less than 20kWh with the highest half-hour reading of 1.3kWh - so less than 12A over that half hour- and that level only lasted a couple of hours - the average over the day is still below 4A.


The place is pretty well insulated & airtight though - which probably makes a significant difference - but that's the sort of thing that can be replicated elsewhere if people have a mind to.

Adding in say another 7kWh a day for an EV - if it could be spread sensibly between other loads - could still work. After all 27kWh over 24 hours is still below 5A average.

  - Andy.

Indeed, it does appear we've made a rod for our own back.

Perhaps it would have been better if the first chief engineer at MANWEB, Peter d'Eyncourt Stowell, had been put in charge of the entire system. The Merseyside way of doing things, with a fully interconnected system and no tapered feeders would probably put us in a better position.

The problem, as it I see it, is to get the required performance out of heat pumps we'd have to do major retrofit on the bulk of the housing stock, the majority of which is in truly awful condition. The labour for that level of construction work almost certainly does not exist. It seems to be one of the main reasons that the heat pump rollout is still not going particularly well.

It may be that breaking feeders and fitting big 500kVA pole mount or pad mount transformers wherever we can, fed with 11/22kV aerial bundled conductor feeders is more tenable than tearing half the housing stock to pieces, but right now it appears to be a real mess.

Suppose you need a way to churn out high voltage electricians to do that.

Certainly makes me wonder if planning to reduce the supply voltage to a true 230V is a sane decision! I'd suggest changing the voltage tolerance to something like 230V-0%+10%

Perhaps we should just pay everyone to have a battery bank behind the meter.

Even if there is no further increase in car use, we're looking at something like 1.6A of ADMD per house just for electric cars. At some point we are going to have to tear the bulk of the system to pieces anyway, I think.

mapj1 said:

or to go back to a pre- central heating mentality, and learn to knit our own jumpers

I fear that the genie is out of the bottle.

EV or ICE, there were no heaters in cars until the 1950s. Anybody fancy a hot water bottle and a blanket? :-)

mapj1 said:

60-80 houses per phase on a half megwatt unit, fused at 400A /phase is a typical set-up on a modern-ish housing estate, older ones are less generous.

Maybe fewer than that in our road

The transformer a couple of doors down was replaced last year. The old one was 500 kW, built in 1959. Unfortunately, the plate on the new one is too far away to read with the naked eye, and too close for binoculars.

No need to train an army, it will train itself, but only at the last possible moment.

All you need to do is to convince people that they are competent to put in their own insulation, heat pump, battery storage ,etc ., and when it gets cold enough, they will. It would require general shift in the level of education  but its probably faster that trying to create a load of extra disinterested technicians in advance from kids who don't really want to learn how to do it.

Folk on here often disparage the work of the misguided enthusiast (but not as much as they do on the screwfix forum), vs some time served tradesman, and I agree there is some awful DIY out there, as well as some very good stuff,  but that is partly down to a culture of secrecy. It is worse for gas  ' you can't install a boiler without belonging to this club' is assured by keeping the info about  how to do it well under wraps, as if an educated customer might be a threat.

Well, a well educated customer should be a threat, to those who are on the inside but only doing a mediocre job. And there are a lot of those doing electricity too, not just drive by EICRs.

I therefore view things like the recent  plug-in solar developments with some amusement, as a sign of things to come, first on batteries and maybe heat pumps as well. Initially we all gather round and decide how best to regulate for an ideal super safe situation, but that prices too many folk out of the market, so we have to lighten up a bit, and accept some things that are not that great will happen, and eventually, when it gets tight enough, the rule makers eventually get out of the way again..
Mike.

Mike.

mapj1 said:

All you need to do is to convince people that they are competent to put in their own insulation, heat pump, battery storage ,etc ., and when it gets cold enough, they will. It would require general shift in the level of education  but its probably faster that trying to create a load of extra disinterested technicians in advance from kids who don't really want to learn how to do it.

Perhaps we should discuss means to write domestic wiring regulations (and associated regs) that allow even DIYers to easily do a competent job?

To eliminate the traps and pitfalls that get them into trouble.

mapj1 said:

All you need to do is to convince people that they are competent to put in their own insulation, heat pump, battery storage ,etc ., and when it gets cold enough, they will. It would require general shift in the level of education  but its probably faster that trying to create a load of extra disinterested technicians in advance from kids who don't really want to learn how to do it.

Perhaps we should discuss means to write domestic wiring regulations (and associated regs) that allow even DIYers to easily do a competent job?

To eliminate the traps and pitfalls that get them into trouble.