Steve Broderick Update
By Paul Homewood
This is a follow up to yesterday’s post on Steve Broderick’s work on the impact on the grid of EV charging.
Perhaps the first thing to note is that he is not the young student doing his PhD, which I think we all imagined. To put it kindly (!) he looks nearly as old as me!
In fact he has oodles of experience in engineering, and I gather he undertook the research for a PhD largely because he wanted to devote more of his time on the topic, not just for the qualification.
Since 2017 he has continued researching the issue, and had this paper published in 2020:
His latest work backs up his original conclusions, that the LV network simply will not be able to handle large scale rollout of EVs.
His comment about heavier cars is relevant. I cannot comment on the harmonics issue, but I am sure plenty of readers will!
His latest figures reckon that EV charging could add 1820 kW for a 200 house system designed to supply 300 kW:
And he quotes 2012 costings of £62 bn for network reinforcement. You can double that for current prices, totting up to over £4000 per household.
One interesting conclusion is that Vehicle to Grid (V2G), that is draining power from EV batteries to power the grid, could make matters worse, as it would increase the charging time needed at night.
Heat Pumps
Finally, let’s take a broad look at the load requirements for heat pumps.
A few very simple assumptions:
- Average annual household gas consumption – 15000 KWh
- Average annual household electricity consumption replacing gas for heat pumps, hot water and cooking – 6000 KWh – most of this, say 5000 KWh will be used between October and March
- 5000 KWh over 6 months equals 28 KWh a day
- But during periods of extreme cold, this could peak at maybe 40 KWh, which = 1.66 kW
The above assumes that heat pumps are running on a continual basis through the day. It is quite likely, however, that DSR will lead to heat pumps being switched off at certain times of the day, thus increasing their consumption during other times, notably at night when EVs will also be charged.
As Broderick notes, most typical networks are rated at around 1.5 kW per house, so heat pumps will immediately lead to overload, even if there are no other appliances running. This obviously won’t be the case during day time and evening, and matters will be even worse at night when EVs are charging, even if there is a control system to share the load around.
It is important to point out of course that heat pumps are designed to work for long periods, as they only provide low heat. To expect them to adequately heat homes throughout the day on the basis of a few hours operation is pie in the sky.
For most houses therefore, estimated at 80% by Broderick, the LV network will not be able to support either EVs or heat pumps, never mind both together.
Timescales
Finally let’s deal with the problem of timescales. Broderick thinks that smart control could delay major spend for long periods.
I think this is not feasible. Since 2020, when the paper was published, the government’s plan to roll out EVs has become clear, with not only all new car sales to be electric by 2030, but also mandates for the vast majority to be so in years leading up to 2030.
Back in 2020, the plan was to ban ICEs only after 2040. What Broderick rightly saw as a problem for the distant future will soon be upon us.
Maybe smart control will be able to manage the problem for the next few years, but it certainly won’t when the majority of cars are electric, which won’t be long coming.
And therein lies the rub. To rip up roads, replace cables and upgrade substations will take years, probably decades. The job will have to start now, smart controls or not.
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NOT A LOT OF PEOPLE KNOW THAT 
There is one very significant issue which Steve Broderick has omitted from his analysis which will dramatically affect the roll-out of domestic heat pump installation on the scale which the Government plans and alone will ensure that their idiocyisexposed.
That issue is the number of engineers which will need to be trained in order to undertake the millions of installations necessary.
To install heat pumps an engineer needs to be F-gas registered becauseit involves refrigeratedgases under high pressure. Current numbers of F-gass trained engineers are not even sufficient to instal the levels of air to air systems each summer to satisfy air conditioning installations in the UK.
So where are all the hundreds of thousands of engineers going to come from? and how long will it take to get them through college? And how long will it take to encourage enough young people to want a lifetime of hard and demanding physical work?
Going by the fiasco with “Smart” meters which involve changing the connections of four wires and two pipes, there is no chance whatsoever.
Hmmm, Why do we have to wait so long: we / I already know most of that and have being saying for such a long time. Wearisome reading all this so often: And yes He is correct …. but we still have to grow through the machinations of the stupid. Pity they didn’t pay attention at school about real world Physics amongst other things, in stead of aspiring to rule the world. i could go on, but to use my recent phraseology, It triggers me!
And you can be sure that there aren’t any amongst the hoards of single males of fighting age crossing The Channel every week.
I believe skilled labour was mentioned in the last post on the subject.
Michael Kelly published a number of reports for the GWPF which highlighted the problem, stating we probably have one third of the skilled labour required for all the government requires.
His estimation on a national basis to convert an average UK home to NetZero compliance was between £75k – £100k. That was pre covid following which materials costs jumped.
I costed to have my 3 bedroom, EOT, Victorian cottage converted with GSHP, insulation, mechanical ventilation etc and strangely enough, it came to nearly £100k (pre covid).
The heat pump engineer told me that, despite the rest of the alterations, they wouldn’t instal one for us because it wouldn’t work and they are wary of being sued.
Robert Burns
But Mousie, thou art no thy-lane,
In proving foresight may be vain:
The best laid schemes o’ Mice an’ Men
Gang aft agley,
An’ lea’e us nought but grief an’ pain,
For promis’d joy!
For me the last verse is equally appropriate
Still thou are blest, compared wi’ me!
The present only toucheth thee:
But Och! I backward cast my e’e,
On prospects drear!
An’ forward, tho’ I cannot see,
I guess an’ fear!
Especially the last line.
“As Broderick notes, most typical networks are rated at around 1.5 kW per house” – this isn’t actually correct most domestic premises were given 60A (14kW) rated supplies and usually 100A (23kW). The issue as Steve says is the assumption, that has stood the test of time, that all households never want to draw maximum power simultaneously so the local network has managed so far. Those assumptions get well and truly busted with EVs and heat pumps but we know full well that they won’t be digging up every street to reinforce the network it will have to be managed by controlling how much power you can have and when you can have it.
The network is rated at ~1.5kW per house, the house itself isn’t. That is the gist of the ‘assumption’ as you say. My average electricity consumption is less than 300W, my peak consumption is probably north of 15kW if everything lined up.
Well as I’ve said before: when you live up the end of the Glen and have to power up your machinery to feed the indoor cattle, milk the few cows, Wife busy cooking etc, and the neighbours lower down and before us at the end of the power line, single phase, they all know when I start ( try to) run the Feed mix machinery around 5-6 pm and maybe have to do some welding ….. Darkness in the Glen and the Bright light of the Arc tells them what’s up …. and it’s NOT Tea being served for a while.
I think the 1.5 kW per house is the maximum power the local network can typically support (it depends as some networks were built with electric storage heating in mind) simultaneously without any short term overloading.
There come a point when even rationing won’t get you out of a hole forget rationing to power heat pumps without people shivering.
If it was just EVs they could probably set it up to allow lower power charging (3 KW) on a rationed basis (to the highest bidder) but don’t forget the simultaneous load includes exported electricity too i.e. Solar PV. So it would be more practical to just ban home charging unless the household pay to have the supply upgraded. We will probably do what mainland Europe e.g. France does and restrict the simultaneous load.
https://forum.buildhub.org.uk/topic/30807-how-many-kva/
We already do. It’s the Company Fuse, rated typically at 60A for a small modern home. That’s a limit of ~15kW. On Fair Isle, the fuse is for just 5kW and the cost of having it replaced is substantial – and the whole island gets to know too. But I think we can guess that standing charges will leap in future if you need a larger fuse. In some countries the size of your fuse plays a much bigger element in your bill, though it will get that way here soon enough. In northern Norway most of the bill is “poles and wires” standing charge related to your maximum offtake. There can be big standing charges in Iberia too, IIRC.
Just wanted to ensure there is clarity that you can plug a 7kW EV charger into your home system without any need to upgrade the network feeding it generally. The issue is when every property has a 7kW EV charger and turn them all on at once. Even then the supply to your house wont be the problem it will the ability of the distribution transformer to support the aggregated load although the line fuses in the feeder pillar will blow before teh transformer cooks itself.
The fuse rating is just for the maximum household supply. But the street cabling and the size of the local transformer supplying 240/440V relies on the fact that not everyone is taking an electric shower or boiling their kettle at the same time. Say everyone boils a kettle at breakfast for 5 minutes at a random time over the course of an hour. If there are 120 houses on the local transformer, then on average 2 will start their boil every minute, and the average number of kettles in use will be 10 because they are on for 5 mins each. With a relatively small number of households there is a good chance that the peak might be say 15 on simultaneously. So the transformer only has to handle 45kW for that, not 360kW.
Local distribution companies have rules of thumb, reckoning on house size by bedrooms, whether there are electric heavy loads such as showers (up to 10kW each) and cookers (maybe 15kW/60A) and now EVs, in working out the number of homes that can be fed on each phase of the supply and on the transformer as a whole. There is a degree of safety margin built into the calculation.
Incidentally, the main cause of “TV pickup” is not kettles, but toilet flushing that leads to extra pumping of water and sewage. Most people watching an exciting football match have a beer or two, not wait until it is over for a mug of tea.
The 1.5kW per house is the DNO diversity factor for the total secondary substation transformer loading – as you say, adding chargers & heat pumps will overload the transformer and the LV distribution cables between the substation LV pillar switch and each home
And I’m sure that the sainted Millipede and all his SPADS will have the answers to all these issues post the general election. Ho, bloody ho ho.
does anyone know how many of our esteemed leaders in Parliament, especially front bench ministers/shadow ministers have committed to installing heat pumps in all of their homes, and have committed to only driving EVs?
or is once again do as I say, not as I do.
I am being nagged (amounting to coersion) to agree to have a “smart” meter installed. I think we all know why they want it. It is not to save me money but to give them the ability to control my consumption at times of overload caused by low wind and dull skies.
Can anyone tell me what happens if I continue to refuse a smart meter.
So far it is not a legal requirement to have one. If your current meter fails you will be assimilated, but you can apparently insist that it be switched to ‘dumb’ mode.
You may miss out on some cheaper tariffs by not having one and the joy of watching the nagging little green and red lights and the flashing display warning you have spent 5p boiling your kettle.
As long as your meter is in date (should be an sticker on it stating its calibration expiry date) they can’t impose a change on you. My supplier has tried every trick but they’ve given up now in part though they are responding to being forced to install a certain amount per annum or they get fined by OFGEM.
They cannot force you to have a smart meter – if your present meters are out of date, you can request new ‘dumb’ meters with the TXRX hub removed so it functions exactly as your old analogue meters did (you read them and send in the readings)
They can and do force business users to install them. I helped an old codger on a farm who was being forced to switch to smart gas meters; some of his supply was business and he was going to be put on a punitive rate if he disobeyed. When the installer (a lightly qualified subcontractor) came, he asked which of the various meters measured which of the various boilers. “Dunno” I said and he went away. A few weeks later another one came. As he started, I said casually, “You do know the electricity here is 3-phase?” “Not trained to work with that “he said and went away. But not before I made him sign a document saying we had cooperated. There is always a get out if it is not technically feasible to safely change a meter.
Theoretically speaking how difficult would it be to challenge the governments net zero plans with work like Steve Broderick’s like the green lawfare groups do as I can’t see how replacing ICE with EV or direct natural gas with heat pumps (probably from gas fired electricity is the demand is even served) is lawful without a technically feasible plan – I’m sure I recall someone in CCC suggesting we digging up as much of our roads as possible at the same time oblivious to how impractical that would be and even if it was possible where would the staff come from when the government has not to my knowledge created a plan to train all these engineers to upgrade the LV distribution network or build sufficient dispatchable generating capacity (200 GW+ )
We have a government policies (electrification of space heating & electric vehicles) that no rational person can believable claim won’t increase electricity demand and the law (Electricity Act 1989 Section 3A) explicitly requires the relevant secretary of state to secure that all reasonable demands for electricity are met and to consider future consumers.
There is no corresponding plan to adequately increase electricity generation to meet our equivalent instantaneous natural gas & heating oil demand https://www.birmingham.ac.uk/news-archive/2018/gas-consumption-during-the-beast-from-the-east-how-the-local-gas-system-kept-us-warm
Then God know what will happen during an unusually cold winter e.g 1947 or 1963.
The Climate Change Act may ironically be the way to put a stop to this madness as I would argue it is being used in a way not intended by parliament and the government’s plan for net zero is unlawful. You don’t have to become a so called climate sceptic as even people who belief in AGW (for context I was in the green party for a time) see the whole climate political apparatus as farcical and full of grifters who have no real interest in solving (seem to oppose anything that is actually feasible) or even acknowledging potential problems.
No one honestly believes parliament intended to reduce peoples living standards include making air travel & car use the preserve of the rich & connected), ignore the duties in the electricity act – “the need to secure that all reasonable demands for electricity are met” or as we saw in Sri Lanka changes to food production that could affect yields as well as a front to impose pseudoreligion on to people dietary restrictions like veganism.
Using the common law understand of negligence I would argue the government’s plan for meeting targets under the Climate Change Act have to be technically feasible at scale and they can’t also contain legal fictions like pretending all the imported electricity is zero carbon & Renewable Energy Certificates.
This isn’t the case from intermittent renewables in 2024 as TW/h scale storage does not yet exist or for that matter carbon capture and storage.
But there were things that were technically feasible in 2008 at scale as far as I’m aware have not even being look at:
1 – a large scale (40GW+) replacement of coal and natural gas generating capacity with nuclear fission using existing reactor designs which France clearly demonstrated was possible
Personally I would worked with the Canadians to build 50hz replica of a multi unit CANDU site e.g Darlington Nuclear Generating Station but with 8 units like Bruce Nuclear Generating Station as we don’t seem to have the heavy forging capacity for pressure vessels for PWR or BWR in the UK (sorting that may slow things). Its an established design where the bugs have being worked out and the skills need in refurbishments in Canada are similar to what a new build project would need so of the options the UK has its likely to be built on time and budget.
2 – I would have prohibited the demolition of all the old coal, oil and gas power station as they could clearly be repowered like many old coal power station in the post war period were to oil with small modular heat reactors based on what we use for nuclear submarines in the short term (as we have clear operating experience with them) but with an long term aim to make liquid fluoride thorium reactors work.
3 – Taking what climate scientist have told us ALL Co2 MATTERS equally it shouldn’t matter if it is from biomass burning or fossil fuel (which is essentially older biomass) if you can claim biomass burning is ok because supposedly the trees are replaced (even if it took decades to grow and absorb it Co2) then there is no reason you can’t do the same with fossil fuels especially if we look at the potential emissions e.g. methane from decaying vegetation in clear cut forrest. You could grow fast growing biomass somewhere semi arid with irrigation or in the sea that would remove Co2 a lot quicker than trees. – I’m sure we could look into a genetically modified crop to specifically do this. Although personally I have more faith in defensive engineering (floor defences, adequate unblocked drainage, desalination/water recycling, heating and air conditioning, not build unsuitable building on floodplains) protecting me from extreme weather than pseudotheology. We have an epidemic of inadequate infrastructure and even negligence being blamed on climate change. Don’t even get me started on wild fires .
4 – looking at ways for new building to affordably meet the passivhaus standard
5 – natural gas heat pumps
6 – quadricycles
7 – reintroducing trolleybuses
8 – nuclear marine propulsion
Why do we have 28+ GWe wind capacity & are the direct and indirect subsidies for renewables value for money or unnecessarily regressive to people on low incomes compared to the alternatives? Why are subsidise linked to generation when helping with the capital cost would be a more rational approach for the tax payer (if we must build them) a franchise mode would also make more sense if there running was to be in the private sector. Also if the computer models on climate change are accurate in future there would likely be less wind at speeds suitable for wind turbines and our winters may get colder.
We already know about the Renewable Heat Incentive or Cash for Ash scandal in Northern Ireland – I want to know if the people who set up net metering & the solar PV feed in tariff personally benefited from it especially as we have people who have done well from subsidy payments who are now donating to probably all the main political parties which feels like Racketeering – we have organisations getting public funds (I include subsidies) then making donations to political parties to influence them to pay the, not saying charities should not be allowed to lobby e.g a charity that provides a service like a hospice or citizens advice to keep or increase its funding but it should not feel like politicians scratching their mates back especially if it increases the donor’s personal wealth & the donor’s personal wealth matches the total paid in subsidies to business they are linked to.
We also need to find a way to stop hostile takeover of charities by allowing long time members of charities who are pushed out to require a review of any state funding & access to vulnerable groups like children as if they were a new charity.
A bigger question is where the hell have all the investigative journalists gone?
A new frontier. The concern has been at the grid level. Perhaps the local network is the biggest issue. Who will manage it? The local power company? They really, really don’t want to have to do that.
His latest figures reckon that EV charging could add 1820 kW for a 200 house system designed to supply 300 kW
I read a while ago that charging more than 6 EVs at once on a UK residential network could/would potentially overload the system. This seems to say the same?
Could the capacity of the LV underground cables be increased by increasing the voltage and using step down transformers at each meter/ unmetered supply point (thinking of street lights)? Does anyone know the maximum voltage the typical supply cables could typical handle?
Cables (at least modern ones) designed for 240/415v supplies are usually marked as suitable for up to 660volts, if memory serves me correctly. So you’d only gain about 50%, but transformers have their own losses, and are big, heavy & noisy if working hard! No way would I allow one in my house…
Indeed modern cabling is nominally 600/1000V rated but majority of cabling will be 60-70 year old paper insulated lead covered which wont be suitable. As an aside historically there were until relevantly recently rural supplies in the South that were fed at 2kV and you had a transformer at each house only 4kVA mind you!!
Those pole transformers for remote loads are still used, usually fed via overhead 415V or 11kv
Indeed most rural areas have that arrangement and relatively easy to upgrade actually as you don’t have to dig up the road! Also the HV system overhead lines generally have plenty of capacity as well as the lines are sized for mechanical strength not electrical load. Ultimately though if the eco loons daft plans come to fruition (can’t see it anytime soon) then the area distribution substations will need to upgraded. At least at the moment this isn’t being done until there is genuine load driving need unlike the national grid where we are flipping from load responding to now enabling the grid to deliver vast amounts of power which may never materialise from either the windmills or load demand. This repeats the cock ups made in the 60’s where the power station build got way ahead of demand.
Nice idea. It’s quite common in the USA to have pole transformers feeding just a handful of homes, allowing the distribution voltage to be a little higher until the final few yards where it drops to 120V single phase. Living rurally, I actually have a dedicated one that taps into what is I think 3.3kV distribution across the fields. However, the problem isn’t just at the local 240V level – it aggregates into the next tiers up. The entire distribution grid (i.e. everything below 132kV) will need uprating with bigger transformers, bigger cables and load optimising hardware that tries to keep power factors close to unity to maximise power transmission and suppress those nasty harmonics. Such devices are now “smart” but they are costly and of course themselves consumer power.
No, distribution cables also have voltage ratings plus a step down transformer at each meter would add uneconomic costs to the entire network (some properties have 3 phase supplies – LV cables are rated at 415V 3 phase, or 240V single phase
Apologies, modern LV power cables are rated at 600/1000V, but carry 415/230V
It all gets more farcical by the day. Not only can’t existing homes meet new enforced changes in demand BUT new homes can’t be built to meet them either!
https://www.theguardian.com/business/article/2024/may/04/capacity-crunch-why-the-uk-doesnt-have-the-power-to-solve-housing-crisis
It’s a sorry pass when even the Grauniad can see the problems – then again they will probably blame it on Brexit or Margaret Thatcher or whatever is suitably irrelevant
As Steve notes, non linear load harmonic pollution will kill the local DNO distribution transformer before the additional load current does – the semi conductor loading in EV chargers will introduce significant harmonic loading (particularly triplens h = 3, 9, 15, 21, . . ) – these parasitic harmonic currents cause voltage distortions (which adversely affect everything on that network) and they also add in the LV star connected winding neutral, causing severe heating – the transformer HV (delta connected winding) protections will not see the triplens causing the heating / overload characteristics, therefore cannot protect the transformer, leading to flash overs / burnout
As Steve notes, non linear load harmonic pollution will kill the local DNO distribution transformer before the additional load current does
That’s a bit of a showstopper ! My guess is that replacement transformers will resolve this … at a few more £££££.
The level of expertise demonstrated by other posters on this messageboard is notable.
As Paul suggested, only a few would understand the issues surrounding power harmonics, however, that does not mean they can be conveniently overlooked!
As you rightly point out, it is these lower level harmonics that are very difficult to filter out and are so potentially damaging. The problems are well known, here is a recent study.
https://www.intechopen.com/online-first/1162280
The conclusions are rather concerning and the suggested mitigation likely prohibitively expensive.
My understanding of electrical matters is very limited but I thought there were standards for equipment which defined the standard to be met with regard to harmonics, power factor, etc? I used to work in the ozone business supplying the water industry: the big ozone generators were driven by power supply units which required considerable design and engineering work to mitigate harmonics etc..
You are correct Mike, there are standards, unfortunately harmonics, particularly triplens are additive in transformer LV star connected windings, so even when items meet standard harmonic emission limits, a lot of them together, add a significant amount of pollution – most domestic items comprise non linear loads (smps phone chargers etc) and if you extrapolate that over millions of items, it presents a real issue for distribution networks – wind & solar farms also generate vast amounts of non linear loading from the electronic controllers, regulators and compensators
Click to access ENA_EREC_G5_Issue_5__2020_.pdf
Energywise: thanks for that – I sort of understand!
What’s the solution? Could some sort of “filter” be fitted to the transformer to protect it?
Or is it the case that the domestic supply systems were just not designed for large numbers of relatively large loads?
All non linear electrical equipment is supposed to be designed and installed to comply with ena standard G5/5 harmonic limits when in use – there are many forms of harmonic mitigation & reduction, however, they cannot be eradicated completely, thus, millions of kit operating within defined limits, are still polluting distribution networks via a cumulative effect – its akin to having a dam with lots of little holes, each contributing to the flood below!
“Average household gas consumption – 15000 KWh”
(i) It’s kWh not KWh
(ii) 15000 per what? Year, month, decade, … You gotta say.
Annual!
Don’t forget, guys, CO2 increase will not affect the climate and there’s not the slightest hope of checking the rise in the Keeling curve.
Slightly off thread but the Times had a piece triumphing the day in April last year that had no fossil fuel electricity generation. As we live through so far three and at least two to come days of Euro wide wind drought with our darling windmills at less than 2 GW. Wrote a letter!!
Paul, I do feel you are being very optimistic with this comment
“But during periods of extreme cold, this could peak at maybe 40 KWh, which = 1.66 kW”
Areas of housing served by the last transformer are often very similar. This data shows the remarkably large variation in heat loss between different property styles. An estate of early 20th century semis is very different to its early 21st century version.
https://tools.bregroup.com/heatpumpefficiency/dwelling-heat-loss
The table is based on typical heating period internal/external temperatures difference in Leeds of 24.2°C. so roughly assumes an external temperature of about minus 3°C. At that temperature an ASHP CoP of 3 is unlikely due to regular defrost cycles in typically high UK humidity. With the temperature gauge dropping seriously low the losses increase as quickly as the CoP decreases. In many areas the daily ASHP electrical load could easily exceed 60kWh in very cold weather.
It is a lot worse, with natural gas demonised, it will not be long before gas cookers are banned (As USA), and at some point the natural gas network will be shut down (Sir John Armitt, infrastructure Czar)
So add in the load from all the new electric cookers to the mix, and I suppose those who cannot afford a heat pump, have to resort to resistive heating, the old 3 bar electric fire we had in the 50s, I well remember my young sister touching the element to see if it was getting hot, not only burnt but a jolt of electricity as well. That’s the future?
Just how do these unelected busy bodies get to control our net zero crap, Lord Callanan was project/maintenance engineer at Newcastle Brewery, but he has a degree in Electronic and Electrical engineering, so probably no power distribution knowledge or he has forgotten.
The drivelling eco-nuts as they rapturously await Net-Zero recall to mind a religious hysteria that swept Europe just before 1000 AD. Many people gave away their property and wandered around expecting the end of the world. I wish there were some way I could persuade an eco-nut to give me, say, his house in Islington, but these people seem more intent on taking us down with them than giving up their possessions.
The overview concentrates on residential electric use, but added in must be all the commercial premises which will change their heating, which will provide BEV chargers for staff and customers, as well as dedicated public charge points.
Plus industrial processes will be required to swap from natural gas to electricity.
The calcs assume all cars to be EVs. It’s going to take a very long time to get to that point. Even if the ZEV targets are met, EVs will account for about half the fleet by 2035 when no form of ICE will be on sale. Unless, of course, some form of coercion is introduced to force existing ICEs off the road – wouldn’t be surprising.