Would be nice if you added a bit of detail.
Probably just as well I didn't!
I left this all behind years ago...
but at that time the BIG ONE was called 'Green Deal'...
Now that I look at their Web site I see all kinds of:
> insulation
> heating
> draught-proofing
> double glazing
> renewable energy generation
but not Smart Meters!
Actually, it sort of makes sense for them to be part of a separate scheme - the supply companies are a bit sensitive about people fiddling with their meters. (It is not a difficult job, and they will let subcontractors do it after a bit of vetting and training...)
And things have obviously changed slightly...
However, the point I was trying to make is that the 'solution' depends on several players, who were playing different games, which is why I am not surprised the roll-out has taken much longer than expected. (Nor am I surprised you can list 4~5 schemes which might apply, might overlap, might...)
To put it another way - the problem of getting one 'box' to talk to another 'box' is much compounded when those boxes are sitting in different systems in different organisations, whose goals and objectives don't align terribly well (and mostly competitors who are not in the habit of collaborating with each other).
I'm sure you have more accurate and up-to-date information than me, but you are right... there are a lot of things the public are not aware of...
For starters - the meter and the isolation switch/fuse are the only parts of the system the 'supply' companies have responsibility for, the wires into your house belong to you, the wires into the meter belong to the 'distribution' companies - who are strictly kept separate to the supply companies.
The supply companies, ie. those companies which we as customers interact with (if you can call it that!) are simply billing companies - they need to track how much electricity you consume and bill you accordingly. That is all. Simple (you would think!).
Some people may not like the big supermarkets, like Tesco and Sainburys, but in terms of getting food from their suppliers and onto their shelves, they are incredibly efficient. In a similar way, the supply companies are also incredibly efficient - with millions of customers they cannot afford to screw it up. (They have done in the past when updating their systems, and it was not pretty!)
To be efficient they need efficient systems - ones which are not very flexible... (But equally you won't get far asking a supermarket for a pint of milk instead of a litre... if you see what I mean.)
The total number of supply companies around show the 'barriers to entry' have been removed. As many are going out of business, that shows the market is efficient. It also shows, as you say, there is not a lot of easy profits around in the business.
Yes, Centrica share price has declined from over 400p in 2012 to under 40p today - that would destroy most companies, yet they are largely the same company doing the same thing! It is their perceived ability to make profits in the future which has declined.
Consumers have complained - that has been picked up by the press who have kicked the government into doing something, they have kicked Ofgen who have kicked the supply companies.
What is not obvious is the amount of red tape involved - the companies have very little freedom of movement. For eg. if you compare the bills from two different companies I'll guarantee they are very similar in layout and format, often using identical words or phrases - that is because it is nearly all mandated by Ofgen. (Whether or not you find the information useful I'll leave to you to decide.)
Regarding the smart meters themselves - they have a memory sufficiently large to hold several days of readings, which they squirt out at night as a data stream when the network is idle anyway - so it does not cost much. (And seems there are other options now.)
But to work, there must be an agreement with a network carrier and bulk purchase SIM cards, so the installer is unlikely to have a selection of networks s/he can try out for signal strength at the time of installation.
For the internal comms, I am not sure zigbee would be chosen again if starting today, but obviously there is a certain amount of momentum given the 16 million systems already installed.
To be fair - all those low power rf systems have strengths and weaknesses. It is not just operating distances (and remember there can be big differences between optimum and non-optimum conditions), but also security, AND interference - in the 2.4 GHz band also sits wi-fi, bluetooth and your microwave oven for eg!
You are also totally right - the smart meters are part of a bigger picture - for suppliers to "offer cleverer tariffs and improve their balancing." That is because smart meters are more of less constantly monitoring the supply (please don't quote me, but it is something like each one minute reading is an average over that time span - which is very different from monthly (give or take!) readings!)
That is hugely important because the ability to charge different tariffs at different times of the day is a way of lowering peak demand by shifting when people charge their electric cars, for example.
The alternative is upgrading the electric supply network to meet the perceived rise in demand, which is mega expensive.
It is an industry wide problem, which no one wants to tackle, least of all the suppliers who, as you point out are already well screwed and don't have the resources to even think about it.
A lot of people will be happy to see the supply companies killed off, but that is not a solution. And a lot of people don't realise that a company need to make a profit in order to breathe - to make improvements. And very few people realise an efficient electricity supply is a core part of the low-carbon, green future they all want.
Apologies for waffling on and on!