
Letters to the editor: volume 16, issue 11
Image credit: Patrick Tomasso/Unsplash
In the December 2021 issue of E&T, readers discuss right-to-repair legislation, standards for electric vehicle charging devices, domestic solar power and more.
Who will have the right to repair?
I fully support the principle of the government’s ‘right to repair’ proposals, mentioned by Antony Bourne in his Comment column in the November 2021 issue of E&T. I have repaired many supposedly unrepairable electrical and electronic items, particularly so-called ‘white goods’, both for myself and for my family and friends/colleagues.
However, there is a significant weakness in that only ‘qualified technicians’ will be able to purchase spares for ‘more specialist repairs’. The definition of who will be included in this class is crucial to both the success and safety of the proposed legislation.
If, as a chartered electrical engineer and holder of C&G 2392 certification, I am not to be included in this class (in the same way I am not included as a competent person for the purposes of Part P of the Building Regulations) then I will not be able carry out these repairs myself.
Over the last 40 years I have purchased and safely fitted many items that could be classed as falling outside the ‘simple and safe’ definition, such as heating elements, drive motors and pumps for washing machines, dishwashers, kettles etc. I am sure there are many IET members who have safely carried out these types of repairs and it would be completely wrong, in my opinion, that we should be excluded from doing repairs that we have safely carried out for many years.
I feel it is important that the IET make representations to the UK government that (at least) all chartered electrical engineers should be automatically included in the definition of ‘qualified technician’ for the purposes of right to repair legislation.
David Perry CEng MIET
Trowbridge
Standards for EV charging
The government has published legal requirements for smart electric vehicle chargers. They are required to do a number of ‘smart’ things, but compliance with legal metrology legislation doesn’t seem to be one of them.
Compliance with the Measuring Instruments Directive (now the UK Measuring Instruments Regulations) is a requirement when financial transactions arise from a measured value. The electricity meter in the home must comply with the regulations, but it appears the meter in the EV charger doesn’t have to.
The government wants to use smart EV charging to control demand through incentives and payments will be based on both the amount of charge supplied to an EV and when it was provided. The amount of energy supplied, and hence the amount paid, will be of the same order of magnitude as the whole house, so it is odd that there are no requirements for the metering to comply with the MID/MIR.
There are also no requirements for EV charger metering to be periodically checked for accuracy, unlike fiscal meters that must be sample-tested, so a customer will have no assurance that the device is generating an accurate bill. This would be like filling a car with petrol without any assurance the pump is accurate.
In the push to roll out ‘smart’ EV chargers it seems the government has overlooked basic legal requirements.
John Cowburn CEng FIET
By email
Keeping the lights on
Having had a new inverter and battery installed in 2017, I can assure Peter Finch (Letters, November 2021) that one can indeed buy systems that will supply a house, or some of it anyway, in the event of a mains power outage.
I am also sure that more recent systems may well incorporate automatic controls that mine did not have. The solar inverter had an output separate from the normal mains connection, which was connected to the house consumer unit via a changeover switch housed in a box together with the solar import/export meter. There was also a 100A isolator installed in the mains meter tails between the meter and the consumer unit.
In the event of a power outage, the procedure was to turn the latter isolator off, thus disconnecting the house from the normal mains supply, then turn the changeover switch from the normal to the battery position. This allowed the inverter to supply the consumer unit in battery/inverter mode. However, because the output was limited to just over 2kW, it was also essential to make sure no high-consumption appliances were on, or likely to come on.
The reason for this elaborate, and in my view over-the-top, installation was, the installer told me, because 2017 UK regulations prohibit the use of automatic generator switching in domestic premises.
Solar battery inverter systems with outputs of the order of 3.5kW and higher are now available, and it would be well worth checking whether auto switching is permitted. Then contact some reputable installers to see what they can offer.
So you can protect yourself from power outages. I did.
Chris Poole CEng MIET
By email
Good reasons for solar shutdown
Peter Finch highlights the inconsistencies that arise when a relatively new technology, in this case domestic solar panels and batteries, comes to market with a multitude of suppliers and installers. They don’t all read the (same) manual.
Strictly speaking, a smart meter is not necessary. There can be a separate generation meter installed that measures only the power you generate. This is the system I have, and twice a year I report the figure to my supplier. This was a fix which recognised that smart meter communication pathways in my rural location are unreliable. The supplier then credits me with the appropriate generation and feed-in credits.
A political decision means that both these tariffs are gradually being whittled away, which serves only to lengthen the payback period. My experience since 2017 is that even here in less-than-sunny north Yorkshire at latitude 54.2011 I have generated 32 per cent of my electricity from 16 panels.
I live in a rural area where power outages are relatively frequent. I was given two reasons why power cuts cause shutdown of the generation and battery output. First, the inverter has to have an incoming 50Hz AC signal that it can synchronise to – both frequency and waveform. Complete opposition of the wave form would result in at the very least a series of breaker switch actions.
The second reason came from Northern Powergrid workers undergrounding our local supply, and is quite basic. They often have to switch power off in order to work on lines downstream of the switch-off point. They need to be sure that there will be no power in the lines. As one put it: “We don’t want your solar panels chucking power back up the line to my hands now, do we?”
David Nelson
North Yorkshire

Image credit: E&T
Rural dropouts
I do not recall recent letters on domestic heat pumps and hot water discussing the effect of loss of electricity supply. My own supply suffers from frequent dropouts of tens of milliseconds up to a few seconds, sufficient to make our DVR/Freesat boxes restart and lose any recording in progress. I have a UPS to look after the PCs and lab equipment. Annoying but tolerable.
Worse, though, there are recurring interruptions lasting up to many hours. Every box loses its non-volatile settings, even the central heating controller, which is the latest generation from a major supplier. In work hours, my business is disrupted as UPS loads must be turned off. Fortunately, I am able to run our oil central heating manually from an inverter.
Those of us in rural locations must expect a few supply problems, but the situation is very unsatisfactory – it is not as if extreme weather is the cause, nor my location (a village close to a large town and at the end of a few miles of overhead line that was recently refurbished). These problems occur throughout the year and enquiries to suppliers have generated only mealy-mouthed responses.
If we are experiencing these problems now, then given the ever increasing use of renewables and a seeming lack of action by network owners, how can we expect future reliability from electricity-driven heat pumps and instant-on hot water? How are people living more remotely expected to live? Perhaps those of us living outside the major cities will need to consider planting our own solar arrays, turbines and battery packs.
I, for one, will be keeping the chimney cleaned and a good supply of wood to hand!
Martin Litherland MIET
By email
Reverse charges
I decided to help out on climate change by purchasing a 2.6kW set of solar panels. It works fine and surplus power goes into a battery bank.
I did not want a smart meter fitting as I have an ‘efergy’ unit that tells me what is being used electrically. As my electricity meter is one with the rotating disc, when we have surplus power it goes backwards into the grid. I don’t get feed-in tariff, but I am quite happy as the meter going in reverse does that for me. My supplier seems to accept this as it is getting a small supply of kilowatts and doesn’t have to pay me. I just get a reduced electricity bill.
With respect to power outage, as far as I know my system will just use its batteries until exhausted and not feed back into the grid. After all, the aim of a solar and battery system is to make you independent when possible from an external supply.
Roger Todd CEng FIET
By email
Satisfied customer
I was pleased to read John Adams’s response (Letters, November 2021) to my letter about the problems I had experienced with my Kia e-Niro and am delighted that he is happy with the performance of his new e-Soul.
Since getting my e-Niro back after its ten-week stay with Kia, it has performed superbly, hitting 280 miles from a full charge. It is a delight to drive and, should it continue to operate problem-free, I will revert to being the enthusiastic owner I was. It was certainly very reassuring to know that while others were waiting in line for several hours for fuel during the recent distribution problems, I could drive home and plug the e-Niro into the charger.
Andy Leslie CEng MIET
Horsham
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