When will 3-phase smart meters be available?
I wanted to start this thread to ask the question and capture any useful information in one place as it seems to be rare in the UK to have a domestic 3-phase supply. I realise that not many people are in the same situation as me.I've been asking for many many years - six or seven at least - over four different suppliers about getting a smart meter installed for the 3-phase supply to my larger house, but it's still nowhere in sight even though it's been promised since at least 2018.
This tantalising story and video from August 2020 shows that it is possible in the UK, but the person in the story was an employee of the power supplier which obviously helps.
The current answer is that a 3-phase smart meter is not available.
What is 3-phase?
In case you're wondering what 3-phase is and why is it needed, please let me explain briefly. The usual single-phase 240V supply in most people's houses is good to supply up to 60amps, allowing about 14kW of power (240 x 60 = 14400) to be supplied at one time. In practice this means an electric shower and some electric heating. But if you add another electric shower or you want to charge an electric car then your peak demand for electricity might be higher than 14kW.
That's where a 3-phase supply helps. Each of the three phases can supply up to 100amps, though it's unlikely you'll ever need as much as that. It's a big change because you need the local electricity network company (not the same as your electricity supplier) to run a new 3-phase cable to your house from the cable in the street (which is already 3-phase) and install the new main fuses (3 of them, one for each phase) and a new 3-phase meter. You will also need an electrician to install a 3-phase distribution board (that holds the circuit breakers) and balance the demands in your house across each phase so, for example, putting the two electric showers on different phases and your double oven on the third phase. At the same time, they might also install the high-power charging point for your new electric car which will use all three phases. In future, we may also replace a gas boiler with an electric boiler or a heat pump which also need a lot of power.
3-phase smart meters in other countries
Let's be clear, 3-phase smart meters do actually exist in the world. In Australia, the heavy electric demands of air-conditioning require 3-phase supplies and the sunny weather makes large solar electric installations a no-brainer, and in Germany I've read that most new houses are built with 3-phase supplies to allow for the demands of electric car charging.
3-phase and smart meters in the UK
A large solar panel system also needs the power that it generates to be distributed evenly across the 3 phases. In the UK, you can only attach up to 4kWp of solar panels per phase, so the 12kWp system in the story I linked above requires a 3-phase supply and smart meter. The smart meter has to measure the balance of generation and consumption across each phase and add it together intelligently to give a reading of how much power you've consumed or generated. This will vary across the day because, for example, some panels start to become shaded as the sun moves across the sky so they don't generate as much power, and someone has an electric shower or starts the washing machine. It's a complex picture.
As I understand it, there are three parts necessary before 3-phase smart meters can be installed:
- the meter itself
- a connection from the meter to the DCC, the national UK organisation that receives the data from each smart meter
- the billing system at each electricity supplier
All these aspects have to be working together before any smart meter can actually be smart.
Almost done...
If you're still reading this far, let me add in some more aspects:
Smart meters can enable time-of-day charging by the suppliers, where your electricity price changes depending on the time of day. The highest charges are at peak time in the morning and most of the evening when most people are active, a "middle" charge during the day between the morning and evening peaks, then a lower charge late evening and overnight. This makes us change our usage habits to reduce what we pay.
A battery storage system in your house might also help where you can charge it overnight at a cheaper night rate then use it during the morning peak time, for example, to avoid using peak-rate electricity. This is not as simple as it sounds because each time you convert the energy, putting it in to the battery or taking it out, you lose some power in the conversion, so the peak rate cost would have to be a lot higher to make this behaviour worthwhile.
A house battery system can store the output from roof solar panels when you're out during the day, but if more people are working from home then your panels will power your working day instead of charging the battery.
Eventually the large battery in your electric car will be integrated into the electricity system of your house. This means that when and how much you use your car has to be added in to the mix as well.
So, yes, this is going to cost money. And much of it won't be worth doing for many people, but suppliers and the power network companies need to be trying this out now with real customers to find out what works and what doesn't so we can all benefit.
Well done - you've reached the end!
As you can see, there's a huge potential that 3-phase smart meters can unlock. It's well past time that they're available to install.
But what can I do?
I'd be interested in any experience, answers, further information or anything you think might be useful to add here. I'm not expecting any immediate answers from Eon through Forum Admins - companies are busy trying to stay in business and manage all the changes in price cap and government help - but some idea of any internal progress or external industry plans would be really useful. There's not much information that appears in a search.
Thanks in advance,
James
PS. You're right - I was an engineer in the past 😊
[Edited to correct numbers]
Last edited by DeLory; 05-04-22 at 18:23.
